BY SPACEFLIGHT NOW

Follow the progress of the Expedition Two crew's stay aboard the international space station as well as the STS-100 flight of space shuttle Endeavour. Reload this page for the very latest.

FRIDAY, APRIL 20, 2001
2225 GMT (6:25 p.m. EDT)

Flight controllers report the Russian Vozdukh carbon dioxide removal system aboard the international space station is not working properly. The Vozdukh's flow rate has been reduced by half, according to NASA officials.

It is possible that a clogged filter is to blame. Expedition Two astronaut Jim Voss will perform some troubleshooting early Saturday prior to Endeavour's docking. He will also look at a pump associated with system, which could be replaced with an onboard spare.

If it is just a filter, that can be corrected. However, should the problem persist the shuttle can handle carbon dioxide scrubbing during its stay through April 28.

The shuttle is also delivering to the station 10 lithium hydroxide canisters that are an alternative way to remove carbon dioxide.

The trouble was discovered when controllers were testing the Vozdukh in preparation for arrival of the Soyuz taxi crew on April 30. The three-man crew including millionaire tourist Dennis Tito will double the number of people on the station, and the air purification system needs to be working to ensure the health of the outpost's occupants.

Meanwhile, the Carbon Dioxide Removal Assembly in the U.S. Destiny remains down. The crew recently replaced a suspect pump in the system, but that didn't fix the problem. Endeavour is carrying a replacement check valve to replace one that might be stuck in the open position. But the astronauts won't attempt to install it until after the shuttle departs.

If the check valve doesn't work, the next shuttle mission in June will ferry a replacement catalyst bed for the system.

1545 GMT (11:45 a.m. EDT)

The astronauts aboard shuttle Endeavour are spending their first full day in space today checking out the tools and equipment they will use during the upcoming visit to the international space station.

Commander Kent Rominger, Pilot Jeff Ashby and Mission Specialists Chris Hadfield of the Canadian Space Agency, John Phillips, Scott Parazynski, Umberto Guidoni of the European Space Agency and Yuri Lonchakov of Rosaviakosmos were awakened at 3:41 a.m. EDT by "Then the Morning Comes" by the musical group Smashmouth. It was chosen for Phillips, making his first spaceflight.

The crew has been testing the rendezvous tools needed for Saturday's docking with the station, which is slated to occur at 9:32 a.m. EDT. (See our docking timeline.) This afternoon the centerline camera will be installed in Endeavour's docking port and the Orbital Docking System ring will be extended in preparation to couple with the station.

Earlier today the astronauts checked out of the spacesuits Hadfield and Parazynski will wear during a pair of spacewalks during the mission. And Endeavour's 50-foot robot arm was powered up and put their its paces to ensure the crane will be ready for mounting the new Canadarm2 robotic arm and Raffaello cargo module to the space station.

And as all that work have been ongoing, Endeavour has been performing calculated rocket firings to fine-tune its approach to reach the station.

0350 GMT (11:50 p.m. EDT Thurs.)

The shuttle astronauts are asleep at this hour. Mission Control is due to wake up the crew at 3:41 a.m. EDT to begin Flight Day 2 of the STS-100 mission. See our detailed flight plan for a summary of the astronauts' work schedule.

Endeavour is reported in good shape as the shuttle embarks on its 16th voyage. The shuttle is about 7,000 miles behind and below the international space station, closing at a rate of about 500 miles with every 90-minute orbit of Earth. That rate will be slowed as the shuttle nears the station for docking at 9:36 a.m. EDT Saturday.

Back on Earth officials at Kennedy Space Center say launch pad 39A suffered no significant damage from Thursday's thunderous liftoff. And the twin solid rocket boosters are being picked up by the Liberty Star and Freedom Star retrieval ships in the Atlantic Ocean off the coast of Jacksonville. The ships are due to return to Port Canaveral with the boosters in tow around mid-morning Saturday.

THURSDAY, APRIL 19, 2001
2030 GMT (4:30 p.m. EDT)

The space shuttle Endeavour rocketed into orbit today on a tricky, make-or-break flight to install a $900 million Canadian robot arm on the international space station, a high-tech space crane able to creep about the outpost like a mechanical inchworm. Read our full launch story.

2019 GMT (4:19 p.m. EDT)

T+plus 1 hour, 39 minutes. Endeavour's two 60-foot long payload bay doors have been swung open and Mission Control has given the astronauts the "go" for on-orbit operations following a safe and successful journey into space today. Next up will be deployment of the Ku-band radar and TV antenna shortly.

The astronauts -- awake since 4 a.m. EDT -- are due to begin an 8-hour sleep period at 7:41 p.m. EDT.

2006 GMT (4:06 p.m. EDT)

T+plus 1 hour, 26 minutes. Mission Control has given Endeavour's astronauts a "go" to open the payload bay doors as the crew marches through steps to turn the shuttle into an orbiting platform.

1925 GMT (3:25 p.m. EDT)

T+plus 45 minutes. The orbital maneuvering system firing has been successfully completed to raise Endeavour's orbit to 205 by 120 statute miles. The shuttle is now well on its way to reach the international space station on Saturday morning.

1914 GMT (3:14 p.m. EDT)

T+plus 34 minutes. Less than 10 minutes away from the OMS-2 burn to boost the shuttle from its highly elliptical suborbital trajectory of 197 by 50 miles achieved at main engine cutoff to a safe orbit of 205 by 120 miles. The 54-second firing of the twin orbital maneuvering system engines on the tail of Endeavour is slated to begin at T+plus 43 minutes 38 seconds to increase the shuttle's velocity by 56 miles per hour.

1908 GMT (3:08 p.m. EDT)

T+plus 24 minutes. Today's official launch time was 2:40:42.044 p.m. EDT.

1904 GMT (3:04 p.m. EDT)

T+plus 24 minutes. The umbilical flapper doors on Endeavour's belly are now being closed. These doors are opened for the external tank umbilicals. They need to be closed and sealed for heat protection during the shuttle's reentry at the end of the mission.

1900 GMT (3:00 p.m. EDT)

T+plus 20 minutes. Endeavour now approaching Europe following its successful blastoff today from Kennedy Space Center in Florida.

1854 GMT (2:54 p.m. EDT)

T+plus 14 minutes, 30 seconds. Main engine valves are being opened to dump any remaining propellant. And the shuttle will soon be maneuvered so the astronauts can take pictures of the discarded external tank.

1851 GMT (2:51 p.m. EDT)

T+plus 10 minutes, 30 seconds. Endeavour has achieved an orbit of 197 miles at the high point and low point of 50 miles. An upcoming orbital maneuvering system engine firing in about a half-hour will raise that low-point to a safe altitude.

1849 GMT (2:49 p.m. EDT)

T+plus 8 minutes, 40 seconds. MECO! Endeavour's main engines have cutoff as planned, completing the powered phase of the launch. Space shuttle Endeavour has safely embarked on its two-day chase to rendezvous and dock with the international space station on Saturday at 9:36 a.m. EDT.

1848 GMT (2:48 p.m. EDT)

T+plus 8 minutes. Speed 16,500 miles per hour, 800 miles downrange, altitude 63 miles.

1848 GMT (2:48 p.m. EDT)

T+plus 7 minutes, 30 seconds. The main engines beginning to throttle back to ease the force of gravity on the shuttle and astronauts.

1847 GMT (2:47 p.m. EDT)

T+plus 7 minutes. Endeavour can now reach orbit on the power of just one of the three main engines. However, this has been a smooth ascent so far with no problems reported.

1847 GMT (2:47 p.m. EDT)

T+plus 6 minutes, 30 seconds. Speed 10,000 as its altitude levels off at 67 miles in an effort to gain velocity.

1845 GMT (2:45 p.m. EDT)

T+plus 5 minutes. Endeavour can now reach orbit on the power of two main engines should one fail. But all three continue to fire properly.

1845 GMT (2:45 p.m. EDT)

T+plus 4 minutes, 30 seconds. Altitude 64 miles, speed over 6,000 miles per hour.

1844 GMT (2:44 p.m. EDT)

T+plus 4 minutes. Negative return. The shuttle is traveling too fast and is too far downrange so it can no longer return to the launch site in the event of a main engine problem.

1843 GMT (2:43 p.m. EDT)

T+plus 2 minutes, 40 seconds. Endeavour's twin orbital maneuvering system engines now firing to give an added assist in thrust to orbit.

1843 GMT (2:43 p.m. EDT)

T+plus 2 minutes, 20 seconds. The twin solid rocket boosters have done their job and separated from the space shuttle Endeavour. The shuttle continues its climb to orbit on the power of the three liquid-fueled main engines.

1842 GMT (2:42 p.m. EDT)

T+plus 90 seconds. All systems of Endeavour are performing well as the shuttle accelerates to orbit. Burning propellant at remarkable rates, the shuttle weighs half of what it did at liftoff.

1841 GMT (2:41 p.m. EDT)

T+plus 75 seconds. Endeavour's engines have throttled back up. Smooth flight so far.

1841:17 GMT (2:41:17 p.m. EDT)

T+plus 35 seconds. Endeavour one and a half-miles in altitude. Speed 500 miles per hour.

1840:42 GMT (2:40:42 p.m. EDT)

LIFTOFF! Liftoff of shuttle Endeavour on a mission to extend the reach of the international space station with Canadarm2. And the shuttle has cleared the tower!

1840:11 GMT (2:40:11 p.m. EDT)

T-minus 31 seconds. Auto sequence start. Endeavour's onboard computers are now controlling the countdown.

In the next few seconds the solid rocket booster hydraulic power units will be started and the orbiter's body flap and speed brake will be moved to their launch positions. The main engine ignition will begin at T-minus 6.6 seconds.

1839:42 GMT (2:39:42 p.m. EDT)

T-minus 1 minute. Computers verifying that the main engines are ready. Sound suppression water system is armed. System will activate at T-minus 16 seconds to suppress the sound produced at launch. Residual hydrogen burn ignitors have been armed. They will be fired at T-minus 10 seconds to burn off any hydrogen gas from beneath the main engine nozzles. And the solid rocket booster joint heaters have been deactivated.

Shortly the external tank strut heaters will be turned off; Endeavour will transition to internal power; the liquid oxygen and liquid hydrogen outboard fill and drain valves will be closed; the payload bay vent doors will be positioned for the launch; and the gaseous oxygen vent arm will be verified fully retracted.

1838:12 GMT (2:38:12 p.m. EDT)

T-minus 2 minutes, 30 seconds. Orbiter steering check now complete -- the main engine nozzles in their start positions. The external tank liquid oxygen vent valve has been closed and pressurization of the LOX tank has started. Standing by to transfer Endeavour's power-producing fuel cells to internal reactants. The units will begin providing all electricity for the mission beginning at T-50 seconds. And pilot Jeff Ashby has been asked to clear the caution and warning memory system aboard Endeavour.

In the next few seconds the gaseous oxygen vent hood will be removed from the top of the external tank. Verification that the swing arm is fully retracted will be made by the ground launch sequencer at the T-37 second mark.

Coming up on T-minus 2 minutes. The astronauts will be instructed to close and lock the visors on their launch and entry helmets. At T-minus 1 minute, 57 seconds the replenishment of the flight load of liquid hydrogen in the external tank will be terminated and tank pressurization will begin.

1837:12 GMT (2:37:12 p.m. EDT)

T-minus 3 minutes, 30 seconds. The main engine nozzles now being moved through a computer controlled test pattern to demonstrate their readiness to support guidance control during launch today.

1836:42 GMT (2:36:42 p.m. EDT)

T-minus 4 minutes. Activation of the APUs complete. The three units are up and running. The final helium purge sequence is under way in the main propulsion system. This procedure readies fuel system valves for engine start. In the next few seconds the aerosurfaces of Endeavour will be run through a pre-planned mobility test to ensure readiness for launch. This is also a dress rehearsal for flight of the orbiter's hydraulic systems.

1835:42 GMT (2:35:42 p.m. EDT)

T-minus 5 minutes. Go for Auxiliary Power Unit start. Pilot Jeff Ashby is now flipping three switches in Endeavour's cockpit to start each of the three APU's. The units, located in the aft compartment of Endeavour, provide the pressure needed to power the hydraulic systems of the shuttle. The units will be used during the launch and landing phases of the mission for such events are moving the orbiter's aerosurfaces, gimbaling the main engine nozzles and deploying the landing gear.

Over the course of the next minute, the orbiter's heaters will be configured for launch by commander Kent Rominger, the fuel valve heaters on the main engines will be turned off in preparation for engine ignition at T-6.6 seconds and the external tank and solid rocket booster safe and arm devices will be armed.

1835:17 GMT (2:35:17 p.m. EDT)

T-minus 5 minutes, 25 seconds. APU pre-start is complete and the units are ready for activation. The orbiters flight data recorders now in the record mode to collect measurements of shuttle systems performance during flight.

1834:42 GMT (2:34:42 p.m. EDT)

T-minus 6 minutes. Pilot Jeff Ashby has been asked by Orbiter Test Conductor Ray Propst to pre-start the orbiter Auxiliary Power Units. This procedure readies the three APU's for their activation at T-minus 5 minutes.

1833:12 GMT (2:33:12 p.m. EDT)

T-minus 7 minutes, 30 seconds. The ground launch sequencer is now pulling the orbiter access arm away from the crew hatch on the port side of the vehicle. The arm was the passage way for the astronauts to board Endeavour a few hours ago. The arm can be re-extended in about a quarter of a minute should the need arise later in the countdown.

1832:42 GMT (2:32:42 p.m. EDT)

T-minus 8 minutes and counting. Pilot Jeff Ashby has flipped the switches in the cockpit of Endeavour to directly connect the three onboard fuel cells with the essential power buses. Also, the stored program commands have been issued to the orbiter for the final antenna alignment and management for today's launch.

1831:42 GMT (2:31:42 p.m. EDT)

T-minus 9 minutes and counting. The ground launch sequencer is now controlling the final phase of today's countdown to launch of space shuttle Endeavour at 2:40:42 p.m. EDT.

The launch of STS-100 will mark the 104th flight in the space shuttle program since 1981, the 79th since return-to-flight after Challenger, the 16th for Endeavour and the third shuttle flight of 2001.

1830:42 GMT (2:30:42 p.m. EDT)

One minute remaining in this built-in hold.

Once the countdown picks up, the Ground Launch Sequencer will be initiated. The master computer program is located in a console in Firing Room 3 of the Complex 39 Launch Control Center. The GLS is the master of events through liftoff. During the last 9 minutes of the countdown, the computer will monitor as many as a thousand different systems and measurements to ensure that they do not fall out of any pre-determine red-line limits. At T-minus 31 seconds, the GLS will hand off to the onboard computers of Endeavour to complete their own automatic sequence of events through the final half minute of the countdown.

1828 GMT (2:28 p.m. EDT)

So with no problems today and perfect weather, the launch of Endeavour is set to occur right on schedule. Countdown clock will resume from T-minus 9 minutes at 2:31:42 p.m.

1827 GMT (2:27 p.m. EDT)

NASA Launch Director Mike Leinbach has polled senior officials and no problems were announced. He then gave the clear to proceed to resume the countdown for an on-time launch at 2:40:42 p.m. EDT today.

1826 GMT (2:26 p.m. EDT)

The final readiness poll by NASA Test Director Steve Altemus has been completed with all launch team members reporting "go". Mission Control also has given its "go" which indictates weather at the abort landing sites will not be a factor against launch today.

1821:42 GMT (2:21:42 p.m. EDT)

Now 10 minutes remaining in this built-in hold at T-minus 9 minutes. Liftoff still on track for 2:40:42 p.m. EDT.

1819 GMT (2:19 p.m. EDT)

Mission Management Team Chairman Jim Halsell has completed the pre-launch poll of his senior-level officials. All parties reported a "go" for launch.

1816 GMT (2:16 p.m. EDT)

Two solid rocket booster recovery ships -- the Freedom Star and Liberty Star -- are on station in the Atlantic Ocean about 140 miles northeast of Kennedy Space Center, off the coast of Jacksonville, Florida. The ships will retrieve and return the spent boosters to the Cape for disassembly and shipment back to Utah for refurbishment and reuse on a future shuttle launch.

Following the boosters' parachuted descent and splashdown in the Atlantic, the recovery teams will configure the SRBs for tow back to Port Canaveral, with arrival expected in a couple of days.

The ships sailed from Port Canaveral yesterday afternoon.

1806 GMT (2:06 p.m. EDT)

Now less than 35 minutes away from Endeavour's launch from Kennedy Space Center in Florida to begin the 9th U.S. voyage to the international space station. This smooth countdown remains on schedule for liftoff at 2:40:42 p.m. EDT. There are no problems being reported.

After an 8 1/2-minute climb to orbit, Endeavour should achieve an elliptical orbit with a high point of 137 miles and low point of 36 miles. A later firing of the twin orbital maneuvering system engines on the tail of Endeavour more than 40 minutes into flight will raise the orbit to about 143 by 98 miles as the shuttle chases to catch the space station. Docking is planned on Saturday at 9:36 a.m. EDT.

1751 GMT (1:51 p.m. EDT)

As with all shuttle-station rendezvous missions, Endeavour's launch is timed to coincide with the moment Earth's rotation carries the launch pad into the plane of the space station's orbit. At the moment of launch, the space station will be over the Indian Ocean south of the southern coast of India near the Maldive Islands.

The lab's crew - commander Yuri Usachev, Jim Voss and Susan Helms - may be able to see Endeavour's launch via a live video uplink to the station from Mission Control. Endeavour is due to reach the station on Saturday morning.

1746 GMT (1:46 p.m. EDT)

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute, 42-second built-in hold. Today's launch remains set for 2:40:42 p.m. EDT. There are no significant technical problems being reported and weather conditions are well within limits for an on-time liftoff.

1744 GMT (1:44 p.m. EDT)

The flow rate of conditioned air into the payload has been adjusted.

1743 GMT (1:43 p.m. EDT)

The Air Force-controlled Eastern Range has verified the Kennedy Space Center area is clear for launch.

1740 GMT (1:40 p.m. EDT)

The Orbital Maneuver System/Reaction Control System crossfeed valves are configured for launch. The Main Propulsion System helium system has been reconfigured. And the gaseous nitrogen purge to the aft skirts of the solid rocket boosters is starting.

1739 GMT (1:39 p.m. EDT)

Pilot Jeff Ashby is configuring the displays inside Endeavour' cockpit for launch while commander Kent Rominger enables the abort steering instrumentation. Also, Mission Control in Houston is loading Endeavour's onboard computers with the proper guidance parameters based on the projected launch time.

1735 GMT (1:35 p.m. EDT)

T-minus 20 minutes and counting. The countdown has resumed after a 10-minute hold. Clocks will tick down for the next 11 minutes to T-minus 9 minutes where the final planned hold is scheduled to occur. The hold length will be adjust to synch up with today's preferred launch time of 2:40:42 p.m. EDT.

Endeavour's onboard computers are now transitioning to the Major Mode-101 program, the primary ascent software. Also, engineers are dumping the Primary Avionics Software System (PASS) onboard computers. The data that is dumped from each of PASS computers is compared to verify that the proper software is loaded aboard for launch.

In about one minute, the astronauts will configure the backup computer to MM-101 and the test team will verify backup flight control system (BFS) computer is tracking the PASS computer systems.

1730 GMT (1:30 p.m. EDT)

NASA flight controllers have announced the official launch window for today's attempt to get Endeavour off the ground. The launch window opens at 2:40:42 p.m. and extends to 2:45:31 p.m. EDT. The update is based upon the latest radar tracking of the international space station.

1725 GMT (1:25 p.m. EDT)

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch remains scheduled for 1841 GMT (2:41 p.m. EDT). There are no technical problems and weather conditions are looking promising at this time.

During this built-in hold, all computer programs in Firing Room 3 of the Complex 39 Launch Control Center will be verified to ensure that the proper programs are available for the countdown; the landing convoy status will be verified and the landing sites will be checked to support an abort landing during launch today; the Inertial Measurement Unit preflight alignment will be verified completed; and preparations are made to transition the orbiter onboard computers to Major Mode 101 upon coming out of the hold. This configures the computer memory to a terminal countdown configuration.

1723 GMT (1:23 p.m. EDT)

The primary avionics software system (PASS) is transferring to Endeavour's BFS computer so both systems can be synched with the same data. In case of a PASS computer system failure, the BFS computer will take over control of the shuttle vehicle during flight.

1719 GMT (1:19 p.m. EDT)

At this time, the ground pyro initiator controllers (PICs) are scheduled to be powered up. They are used to fire the solid rocket hold-down posts, liquid oxygen and liquid hydrogen tail service mast and external tank vent arm system pyros at liftoff and the space shuttle main engine hydrogen gas burn system prior to engine ignition.

Endeavour's two Master Events Controllers have been tested. They relay the commands from the shuttle's computers to ignite, and then separate the boosters and external tank during launch.

Also, the shuttle's backup flight control system (BFS) computer has configured. It would be used today in the event of emergency landing.

1716 GMT (1:16 p.m. EDT)

The ground launch sequencer main line activation is being completed. Also, commander Kent Rominger is pressurizing the gaseous nitrogen system for Endeavour's Orbital Maneuvering System engines, and pilot Jeff Ashby has activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water boilers.

1714 GMT (1:14 p.m. EDT)

The Orbiter Closeout Crew has completed its job today with the hatch of Endeavour sealed for flight. The crew is now preparing to depart launch pad 39A and head back to the safety roadblocks.

1705 GMT (1:05 p.m. EDT)

The latest update on weather indicates conditions are currently acceptable and forecast to be "go" for launch today. It is a beautiful spring day here in Central Florida.

1700 GMT (1:00 p.m. EDT)

At this point in the countdown the Ground Launch Sequencer mainline activation is performed. Also, the Air Force Eastern Range shuttle safety system terminal count closed-loop test will be performed to verify the countdown can be stopped in the final seconds before liftoff should a safety issue arise.

1645 GMT (12:45 p.m. EDT)

T-minus 1 hour and counting. The countdown is ticking along to today's scheduled launch at 2:41 p.m. EDT. The pre-flight alignment of Endeavour's Inertial Measurement Units is now beginning, and will be completed by the T-minus 20 minute mark. The IMUs were calibrated over the past few hours of the countdown. The three units are used by the onboard navigation systems to determine the position of the orbiter in flight.

Meanwhile, the S-band antennas at the MILA tracking station here at the Cape are shifting from low power to high power. The site will provide voice, data and telemetry relay between Endeavour and Mission Control during the first few minutes of flight. Coverage then is handed to a NASA Tracking and Data Relay Satellite in space.

1628 GMT (12:28 p.m. EDT)

Endeavour's crew module hatch has been closed for flight as countdown activities run a bit ahead of schedule. Pressure and leak checks will be performed shortly to ensure a good seal on the hatch for today's launch.

1623 GMT (12:23 p.m. EDT)

The Orbiter Closeout Crew has removed platforms used by the astronauts to board the shuttle today in advance of swinging shut Endeavour's hatch.

Also in the countdown, the booster test conductor will soon verify the chamber pressure in the twin solid rocket motors. Sensors measure pressure in the thrust chambers at nozzles of the boosters. The data tells onboard computers when the boosters have consumed their solid-fuel propellant and should be separated in-flight.

1605 GMT (12:05 p.m. EDT)

The ground launch sequencer software that will control the final nine minutes of the countdown is initialized as the clock continues to today's planned launch at 2:41 p.m. EDT (1841 GMT).

Also, the solid rocket boosters' gas generator heaters in the hydraulic power units are turned on, the aft skirt gaseous nitrogen purge is starting and the rate gyro assemblies (RGAs) are being activated. The RGAs are used by the orbiter's navigation system to determine rates of motion of the boosters during the first-stage flight.

1554 GMT (11:54 a.m. EDT)

The final Endeavour astronaut has boarded the shuttle today. Rookie John Phillips, mission specialist No. 2 and flight engineer, has now entered the hatch. He will sit in the flight deck center seat, giving an extra set of eyes to aid the command and pilot watch displays and switches during launch and landing.

You can read Phillips' biography in our Crew Report.

1545 GMT (11:45 a.m. EDT)

T-minus 2 hours and counting. The countdown continues smoothly for launch of Endeavour at 2:41 p.m. EDT (1842 GMT) today from Kennedy Space Center. There are no technical problems being reported by the launch team.

1542 GMT (11:42 a.m. EDT)

Endeavour's mission specialist No. 4, Umberto Guidoni, has boarded the shuttle. He will sit in the middeck center seat seat.

You can read Guidoni's biography in our Crew Report.

1539 GMT (11:39 a.m. EDT)

Endeavour's mission specialist No. 1, Chris Hadfield, has boarded the shuttle. He will sit in the flight deck aft right seat.

You can read Hadfield's biography in our Crew Report.

1529 GMT (11:29 a.m. EDT)

Mission Specialist No. 3, Scott Parazynski, has boarded Endeavour. Parazynski will sit in the middeck left seat.

You can read Parazynski's biography in our Crew Report.

1528 GMT (11:28 a.m. EDT)

Pilot Jeff Ashby has entered the shuttle's hatch. He will sit in the flight deck forward right seat.

You can read Ashby's biography in our Crew Report.

1520 GMT (11:20 a.m. EDT)

Mission specialist No. 5 Yuri Lonchakov has boarded Endeavour. He will sit in the middeck right seat.

You can read Lonchakov's biography in our Crew Report.

1516 GMT (11:16 a.m. EDT)

Endeavour commander Kent Rominger has become the first astronaut to enter the shuttle today. He will sit in the flight deck forward left seat.

You can read Rominger's biography in our Crew Report.

1511 GMT (11:11 a.m. EDT)

The crew has taken the elevator to the 195-foot level of the pad structure where the Orbiter Access Arm is located with the White Room. In the White Room the crew will be outfitted with the rest of their gear and communications hat before entering Endeavour's crew module hatch.

1508 GMT (11:08 a.m. EDT)

The shuttle astronauts have arrived at launch pad 39A. They will take the elevator up to the 195-foot level of the fixed service structure to enter Endeavour's crew cabin.

1452 GMT (10:52 a.m. EDT)

Endeavour's astronauts have embarked on the 20-minute ride in the "AstroVan" from their quarters to launch pad 39A on the edge of the Atlantic Ocean. They departed the Operations & Checkout Building in Kennedy Space Center's Industrial Area at 2:56 a.m. EDT.

The AstroVan convoy will stop at the Launch Control Center for the NASA management and NASA astronaut Jim Wetherbee to exit the Astrovan. The managers will take their positions in the Firing Room while Wetherbee heads over to the Shuttle Landing Facility to begin weather reconnaissance flights in a T-38 jet. He will later switch to the modified Gulfstream jet, which is known as the Shuttle Training Aircraft because its flying characteristics are very similar to the space shuttle.

1445 GMT (10:45 a.m. EDT)

T-minus 3 hours and counting. The countdown has resumed from the planned two-hour built-in hold as scheduled. The count will continue to T-minus 20 minutes where the next built-in hold will occur. A final hold is planned at T-minus 9 minutes.

1430 GMT (10:30 a.m. EDT)

Endeavour's astronauts are continuing with work to don their day-glow orange partial pressure suits in their quarters at the Operations & Checkout Building. The crew is scheduled to depart for the launch pad at 10:55 a.m. EDT.

Activities are going well in the final hours of today's countdown. There are no problems to report, the weather looks good and Endeavour remains on track for liftoff at 2:41 p.m. EDT (1841 GMT.

1414 GMT (10:14 a.m. EDT)

The astronauts have received an upated weather forecast for the abort landing sites here at Kennedy Space Center, the Western U.S., Spain and Morocco. And the word is the weather should not be a problem today with acceptable conditions expected in Florida and at least one TransOceanic Abort Landing site within limits to permit Endeavour to be cleared for liftoff.

1345 GMT (9:45 a.m. EDT)

Now half-way through this planned two-hour built-in hold at T-minus 3 hours. The launch team is not working any significant technical problems, NASA says, and forecasters are still calling for a 90 percent chance of acceptable weather conditions.

1326 GMT (9:26 a.m. EDT)

The seven Endeavour astronauts have been seated in the dining room of the Operations & Checkout Building for lunch and the traditional photo in front of the cake designed with the mission patch.

In the countdown, the Eastern Range and Mission Control are scheduled to perform hold-fire checks to ensure they have to ability to stop the countdown in the final seconds if necessary. Also, communications link tests will be conducted with the Ponce Inlet tracking station 35 miles north of Kennedy Space Center. The site will be used to provide voice communications and telemetry with Endeavour during the second minute of flight.

1245 GMT (8:45 a.m. EDT)

T-minus 3 hours and holding. Countdown clocks have entered the planned two-hour hold. Launch is still scheduled for 1841 GMT (2:41 p.m. EDT).

Endeavour stands fully fueled and ready for launch from pad 39A at Kennedy Space Center, Florida. The loading of 528,000 gallons of liquid oxygen and liquid hydrogen into the external tank began at 5:19 a.m. EDT. The operation went smoothly and was completed at 8:06 a.m. EDT. A stable replenishment mode then started to continuously top-off the respective tanks within the external tank through the final minutes of the countdown.

Following tanking procedures, a team called the Final Inspection Team was dispatched to the pad to check the vehicle one last time prior to liftoff. Currently, the six-person team, comprised of five engineers and one safety official, is performing the inspections at pad 39A. At the conclusion of their two-hour tour-of-duty, they will have walked up and down the entire 380-foot fixed service structure and mobile launcher platform.

The team is on the lookout for any abnormal ice or frost build-up on the vehicle that could break-off during ignition and damage the spacecraft. The team, which is headed by Greg Katnik of the Kennedy Space Center, is also looking for any loose debris that could possibly fly up and strike the launch vehicle. And the third item of interest to the team is the thermal integrity of the external tank foam insulation.

The team uses a portable infrared scanner that gathers temperature measurements on the surface area of the vehicle and can spot leaks. The scanner will be used to obtain temperature data on the external tank, solid rocket boosters, space shuttle orbiter, main engines and launch pad structures. The scanner can also spot leaks of the cryogenic propellants, and due to its ability to detect distinct temperature differences, can spot any dangerous hydrogen fuel that is burning. One teammember is also responsible for photo documentation.

Each member of the Final Inspection Team is in constant contact with NASA Test Director Steve Atlemus in the Firing Room.

The team wears the highly visible day-glow orange coveralls that are anti-static and flame resistant. Each member also has a self-contained emergency breathing unit that holds about 10 minutes of air.

Following the Final Inspection Team's activities, Greg Katnik will meet with NASA Launch Director Mike Leinbach, the Mission Management Team, and engineering directors in the launch control center. Katnik will give the managers a full and detailed report on the team's inspections and findings at the pad 39A.

A full inspection of the vehicle and pad was performed yesterday and the external tank received a thorough check prior to fueling.

An inspection of the launch pad and beach will be made following launch. That inspection will be to look for anything unusual, particularly anything that could have fallen off of the vehicle during the first few seconds of flight. Later there will be a meeting to review high-speed videotape and film of the launch and early ascent to determine if there was any damage to the vehicle.

1235 GMT (8:35 a.m. EDT)

FUELING COMPLETED. Loading of shuttle Endeavour's external tank was completed at 1206 GMT (8:06 a.m. EDT). A stable replenishment is now underway to continuously top-off the liquid hydrogen and liquid oxygen supplies to replace the cryogenics that naturally boil away during the remainder of the countdown.

With fueling wrapped up, the Orbiter Closeout Crew and Final Inspection Team will be dispatched to the pad to perform their jobs. The closeout crew will ready Endeavour's cockpit for the astronauts' boarding later this morning; and the inspection team will give the entire vehicle a check for any ice formation from fueling.

1049 GMT (6:49 a.m. EDT)

The fueling of space shuttle Endeavour is nearing the half-way point with no problems reported. The weather forecast remains favorable for launch today both at Kennedy Space Center and the emergency landing sites overseas. And for the latest update to Endeavour's available launch windows, we have updated our chart.

0930 GMT (5:30 a.m. EDT)

FUELING BEGINS. The loading of space shuttle Endeavour's external fuel tank with 528,000 gallons of super-cold liquid hydrogen and liquid oxygen has commenced at Kennedy Space Center's launch pad 39A this morning. Tanking began at 5:19 a.m. EDT (0919 GMT) and will take about three hours to complete.

The fueling process is being orchestrated by engineers in the safe confines of the Launch Control Center some 3.5 miles from pad 39A.

The bullet-shaped external tank is being filled with 385,000 gallons of liquid hydrogen chilled to minus 423 degrees Fahrenheit (minus 253 degrees Celsius) and 143,000 gallons of liquid oxygen chilled to minus 298 degrees Fahrenheit (minus 183 degrees Celsius).

The cryogenics are pumped from storage spheres at the pad, through feed lines to the mobile launcher platform, into Endeavour's aft compartment and finally into the external fuel tank.

NASA officials are not reporting any technical problems and the countdown continues to the planned 2:41 p.m. EDT (1841 GMT) liftoff.

0300 GMT (11:00 p.m. EDT Wed.)

The metal cocoon shrouding space shuttle Endeavour atop launch pad 39A was wheeled back Wednesday evening as NASA gears up for Thursday afternoon's liftoff. Launch time is still set for 2:40:40 p.m. EDT (1840:40 GMT), and there are no technical problems or major weather concerns being reported.

Chores underway this evening include configuring all the switches in Endeavour's cockpit to the proper positions for launch; activating the orbiter's power-generating fuel cells; and changing the shuttle's purge air to gaseous nitrogen.

The countdown resumed from its planned hold at the T-minus 11 hour mark at 10:45 p.m. EDT as scheduled. And tonight workers are making final preparations for fueling Endeavour's external fuel tank with 500,000 gallons of super-cold liquid hydrogen and liquid oxygen.

The pad's "blast danger area" will be cleared of all non-essential personnel shortly after midnight EDT. All workers will be ordered out of the area after 4 a.m. in advance of the hazardous fueling operation.

The Mission Management Team will convene their traditional pre-tanking meeting at 4:45 a.m. EDT to review the status of countdown work, the weather forecast and any outstanding issues or concerns. If there are no significant problems, officials will give the launch team approval to begin fueling Endeavour at about 5:15 a.m. EDT, beginning the three-hour tanking process.

The seven astronauts, meanwhile, are scheduled to be awakened at 4 a.m. inside Kennedy Space Center's Operations & Checkout Building crew quarters. They will have some medical checks then eat breakfast at 5 a.m. After some free time, the crew will be seated for lunch and the traditional pre-flight photo opportunity with the Mission Cake at 9:25 a.m. A briefing on the weather conditions at KSC and abort landing sites around the world will follow at 10:15 a.m. Donning the day-glow orange launch and entry suits is the next event on the crew's timeline before departing for the pad at 10:55 a.m. Entry into Endeavour should begin around 11:25 a.m. with the shuttle's hatch scheduled to be closed for flight at 12:40 p.m.

Spaceflight Now will be here to provide the most comprehensive live coverage of the countdown and 11-day flight of Endeavour!

WEDNESDAY, APRIL 18, 2001
1750 GMT (1:50 p.m. EDT)

The countdown is entering the final day for the launch of space shuttle Endeavour on the ninth American mission to the international space station. Liftoff remains on track for Thursday at precisely 2:40:40 p.m. EDT (1840:40 GMT).

NASA Test Director Steve Altemus said this morning that activities were running about two hours behind schedule. However, that time is expected to be "made up" later today.

The delay is a result of unplanned work to replace a suspect electronics box in Endeavour's cockpit overnight. As we reported Tuesday afternoon, technicians smelled an electrical odor on the shuttle's flight deck. That odor was traced to a dimmer switch package that controls the lights on an overhead cockpit panel.

The troublesome box is being examined to determine what caused the apparent overheating. The new box on Endeavour has been checked out without incident, Altemus said.

Otherwise, the countdown has progressed to ready Endeavour for its 16th trip to space. The three power-generating fuel cells located beneath the shuttle's payload bay were loaded with cryogenic liquid hydrogen and liquid oxygen on Tuesday. The Orbiter Mid-Body Umbilical Unit used in the loading was then retracted into the pad structure. The overnight hours this morning were spent making final checks of Endeavour's three main engines.

The countdown entered the planned 12-hour, 45-minute hold at the T-minus 11 hour mark at 10 a.m. EDT today. During this hold the shuttle's star trackers are checked and the Inertial Measurement Units and orbiter's communications systems are activated.

The gantry-like Rotating Service Structure enclosing Endeavour at launch pad 39A is scheduled to be rolled into the park position at 6:30 p.m. tonight.

The weather forecast remains favorable with a 90 percent chance of acceptable conditions.

1305 GMT (9:05 a.m. EDT)

Expedition Two commander Yuri Usachev showed off his piloting skills today and successfully flew the Soyuz capsule from the nadir docking port on the Zarya module around to the aft port on Zvezda.

This relocation maneuver was performed to clear the Zarya module's port for the arrival of a fresh Soyuz capsule on April 30. Zarya's nadir port is the preferred parking spot for the Soyuz lifeboats at the station. The aging Soyuz will be brought back to Earth in early May.

Over the next few minutes the hooks and latches will be closed to firmly hold the Soyuz and station together and pressure and leak checks will occur. The astronauts are due to open hatches leading back into the station at around 1530 GMT (11:30 a.m. EDT).

1301 GMT (9:01 a.m. EDT)

Contact and capture! Redocking of the Soyuz capsule confirmed.

1300 GMT (9:00 a.m. EDT)

Russian flight controllers have given Usachev the final "go" to dock the Soyuz capsule to the Zvezda module.

The Soyuz is now properly aligned, closing at a rate of about two-tenths of a meter per second.

1259 GMT (8:59 a.m. EDT)

Range now 80 meters.

1256 GMT (8:56 a.m. EDT)

Usachev has completed the manual flyaround from the Earth-facing docking port of the Zarya module to the rear of the Zvezda module. The Soyuz is now holding its position about 150 meters from Zvezda allow alignment errors to be corrected before the push in to docking begins.

1251 GMT (8:51 a.m. EDT)

Mission Control reports the space station is in the correct orientation for the upcoming redocking of the Soyuz spacecraft. The Soyuz flyaround to the rear of the station continues without any problems reported.

1250 GMT (8:50 a.m. EDT)

The international space station is now unoccupied for the first time since February when the Expedition One crew performed a Soyuz relocation maneuver.

1247 GMT (8:47 a.m. EDT)

Under the manual control of commander Yuri Usachev, the Soyuz is now beginning its trek from a point below the Zarya module around to the aft end of the Zvezda module.

Over the past few minutes the Soyuz backed away from Zarya and then performed a roll maneuver.

1240 GMT (8:40 a.m. EDT)

Physical separation confirmed as the Soyuz with the Expedition Two onboard has departed the space station. Once the hooks and latches were opened, springs pushed the Soyuz away from the Earth-facing, or nadir, docking port of the Russian Zarya module.

The Soyuz will move about 150 meters away from the station before commander Usachev begins the flyaround.

1237 GMT (8:37 a.m. EDT)

The hooks and latches are now opening in preparation for the Soyuz spacecraft to undock from the international space station. And Mission Control reports the station's attitude control systems have been inhibited to ensure their are no thruster firings or anything of the sort during the undocking and later redocking.

1217 GMT (8:17 a.m. EDT)

Now 20 minutes from the scheduled start of the undocking process for the Soyuz capsule as the Expedition Two crew temporarily leaves the international space station to relocate their lifeboat from the Zarya to the Zvezda module.

The undocking will begin at 1237 GMT with Russian mission control sending a command to open the hooks and latches holding the Soyuz and station together. It will take about three minutes for those mechanisms to open, leading to physical separation of the two spacecraft at 1240 GMT.

The Soyuz then backs about 150 meters away from the station. Expedition Two commander Yuri Usachev will take manual control of the capsule to fly it from a position beneath the station around to the back-end of the complex for docking to the aft port on Zvezda. Redocking is expected at 1303 GMT.

1200 GMT (8:00 a.m. EDT)

The Expedition Two crew has suited up in their Sokol spacesuits, entered the Soyuz capsule and closed hatches leading to the international space station for today's relocation maneuver.

In preparation for today's departure from the station, although just a short trip, the astronauts have shut down many of the outpost's onboard systems -- including the environmental and air purification systems -- and configured others to run without the control by an onboard crew. This work is done to ensure the station can continue to operate in the unlikely event the Soyuz can't redock and the Expedition Two crew has to return to Earth.

0100 GMT (9:00 p.m. EDT Tues.)

The three-person Expedition Two crew aboard the international space station have been awakened for what won't be just another day working inside their orbiting outpost. Commander Yuri Usachev and American astronauts Jim Voss and Susan Helms will actually leave the station for a short time Wednesday to move their escape capsule to a different docking port.

Over the next several hours the crew will prepare the station to be abandoned then suit up and float into their Soyuz lifeboat. At 1237 GMT (8:37 a.m. EDT) the Soyuz will undock from its current parking slot on the Earth-facing side of the Zarya module for a half-hour flight to the aft docking port of the Zvezda service module. Redocking is expected at 1303 GMT (9:03 a.m. EDT).

The relocation maneuver is being done to free up the preferred Soyuz docking port on Zarya for the arrival of a fresh escape capsule at the end of the month. The Zvezda port is where Progress cargo craft are intended to dock, but the most recent freighter to the station departed on Monday, setting the stage for the Soyuz relocation.

The replacement Soyuz is due for blastoff on April 28 with Russian cosmonauts Talgat Musabaev and Yuri Baturin and American tycoon Dennis Tito. After a two-day chase to reach the station, the three men will spend nearly a week aboard the station before riding the old Soyuz back to Earth.

The capsule swap out is necessary because the Soyuz's hydrazine is only certified for 180 days in space. The Soyuz currently at the station was launched on October 31 carrying the Expedition One crew.

Watch this page for updates on the Soyuz flyaround beginning at 1300 GMT (8 a.m. EDT).

TUESDAY, APRIL 17, 2001
2015 GMT (4:15 p.m. EDT)

Technicians plan to replace a suspect electrical box aboard space shuttle Endeavour later tonight after workers smelled an odor emanating from the box inside the crew cabin today.

At a Kennedy Space Center news conference underway at this hour NASA's director of shuttle processing, Dave King, says the extra work shouldn't delay the overall countdown and Endeavour remains on track for liftoff at 2:41 p.m. EDT on Thursday.

Described as an electrical odor that you might smell from hot electronics, the workers made their report earlier today just prior to loading Endeavour's three fuel cells with liquid oxygen and liquid hydrogen. The troubleshooting to find the source of the odor delayed the fuel cell loading by about an hour, King said.

The smell was traced to a specific box that is associated with powering the lights in the cockpit. The box will be removed and replaced with a spare after work concludes to fill the fuel cells sometime after 10 p.m. EDT tonight.

King said there was no smoke in Endeavour's cockpit and engineers don't know what caused the problem. The suspect box will be studied tomorrow and early results of the investigation are expected on Thursday.

1430 GMT (10:30 a.m. EDT)

Endeavour's countdown continued smoothly overnight and NASA officials report there are no technical problems standing in the way of liftoff on Thursday. The weather forecast remains favorable with a 90 percent of acceptable conditions.

The countdown clock has entered the first in a series of planned holds. This four-hour pause at T-27 hours began at 10 a.m. EDT. During the hold launch pad 39A will be cleared of all non-essential personnel and a check of the shuttle's pyrotechnic initiator controllers will be performed. On launch day the PICs fire the explosive bolts holding the shuttle to the pad.

Once the count resumes at 2 p.m. today work will begin to load Endeavour's three fuel cells with cryogenic liquid hydrogen and liquid oxygen. The reactants are combined to generate electricity for the shuttle's systems and drinking water for the astronauts. The loading should take about seven hours to complete.

MONDAY, APRIL 16, 2001

The shuttle Endeavour stands poised for blastoff Thursday on the most complex space station assembly flight yet attempted, a two-spacewalk mission to install a $900 million Canadian robot arm able to move around the station's exterior like a 58-foot-long mechanical inchworm. Read our multi-part mission preview!

2200 GMT (6:00 p.m. EDT)

COUNTDOWN BEGINS! Inside Firing Room 3 of the Complex 39 Launch Control Center the countdown has been started for Thursday's planned liftoff of space shuttle Endeavour on a mission to deliver the Candarm2 robotic arm to the international space station.

NASA officials report there are no technical problems being addressed and the weather forecast calls for a 90 percent chance of acceptable weather conditions on Thursday.

The countdown began at the T-minus 43 hour mark. There are 25 hours and 35 minutes of planned holds built into the count leading to the preferred 2:41 p.m. EDT launch time.

The first chores to be accomplished as part of the three-day countdown include starting the final close-outs of the space shuttle and launch pad 39A facilities, reviewing the flight software loaded into Endeavour's mass memory units and display systems and loading the backup flight system software into the General Purpose Computers.

Overnight the platform on Endeavour's flight and mid decks will be removed, and later the shuttle's navigational systems will be activated and tested.

1504 GMT (11:04 a.m. EDT)

NASA flight controllers in Houston report the Progress 3P cargo ship that undocked from the international space station earlier today has reentered Earth's atmosphere as planned. The spent vessel performed its deorbital burn and plunged to a fiery destruction.

The Progress' departure opens up the station's Zvezda module aft docking for the Soyuz lifeboat. The capsule is currently docked to the Earth-facing port on Zarya. But that is where officials want the fresh Soyuz to attach when it arrives no sooner than April 30. So the three Expedition Two crew members will get inside the Soyuz and fly it over to Zvezda module on Wednesday, leaving the station for about 30 minutes.

1437 GMT (10:37 a.m. EDT)

Astronauts representing four countries -- the most diverse for any one crew -- flew to Kennedy Space Center today in preparation for blastoff aboard space shuttle Endeavour on Thursday bound of the international space station.

The seven astronauts -- commander Kent Rominger, pilot Jeff Ashby and mission specialists John Phillips, Scott Parazynski, Chris Hadfield of Canada, Italian Umberto Guidoni and Russian cosmonaut Yuri Lonchakov -- traveled in T-38 jet trainers their home base in Houston to Florida just a few hours before the launch countdown begins for Thursday's planned 2:41 p.m. EDT liftoff.

"We are all very excited to be here," Rominger told reporters gathered at the runway.

Over the three days prior to launch, the astronauts will undergo their final medical examinations, review flight plans, receive periodic countdown, vehicle and weather status briefings, double-check the fit of the day-glow orange partial pressure suits to be worn during launch and landing and have some free time to relax with family members.

Endeavour's mission will deliver the Canadian-made Space Station Remote Manipulator System robot arm. The 58-foot long arm is critical in the continued assembly of the international space station. The pallet containing the arm will be mounted to the station's Destiny lab module. Two spacewalking astronauts -- Hadfield and Parazynski -- will bolt the sections of the arm together and perform the re-wiring necessary to bring the Canadarm2 to life.

Endeavour is also carrying the Italian-built Raffaello module filled with supplies, hardware and equipment to be transferred into the station's newly installed Destiny laboratory. Raffaello will be lifted out of Endeavour's payload bay and docked to the station for unloading, then stowed back in the shuttle for its return to Earth for later reuse.

The countdown remains scheduled to begin at 6 p.m. EST (2200 GMT). There are no significant technical problems being reported by NASA and the early weather forecast shows a 90 percent chance of favorable conditions for Thursday's launch attempt. The only slight concern is crosswinds at Kennedy Space Center's emergency landing strip.

1422 GMT (10:22 a.m. EDT)

Endeavour's seven astronauts just touched down at Kennedy Space Center in their T-38 jets following a flight from Houston.

1335 GMT (9:35 a.m. EDT)

A busy period of comings and goings at Space Station Alpha began this morning with the departure of the Progress M-244 cargo craft from the aft docking port of the Zvezda service module. The craft undocked at 0848 GMT (4:48 a.m. EDT) today and was due to fire its engines to deorbit at 1323 GMT (9:23 a.m. EDT). The Progress, which was packed with trash and discarded equipment, was to burn up in the atmosphere.

Meanwhile, at the Kennedy Space Center all looks set for the start of the countdown for shuttle Endeavour's launch to the space station. Weather forecasters are predicting only a 10 percent chance of a weather violation during the shuttle's launch window which opens at 1840 GMT (2:40 p.m. EDT) on Thursday.

Subscribers to our Mission Theater service can see an animation describing space station activities over the next few weeks.

SUNDAY, APRIL 15, 2001

The Russian Progress cargo freighter attached to the aft end of the international space station's Zvezda service module will undock from the outpost on Monday for reentry into Earth's atmosphere. The departure -- set for just after 4:30 a.m. EDT (0830 GMT) -- kicks off the busiest time for the infant outpost with the upcoming space shuttle visit and swap out of the Soyuz lifeboat capsule.

Packed with trash and unneeded equipment, the Progress' hatch was closed by the Expedition Two crew on Friday. The astronauts stowed the hardware and garbage in a way to ensure the freighter's load distribution and center-of-gravity don't adversely affect the separation engine firings.

At the Kennedy Space Center, meanwhile, NASA is preparing to start the countdown for Thursday's planned launch of space shuttle Endeavour. The shuttle and its seven-member crew will deliver the Canadian-made robotic arm to the international space station. The countdown is slated to begin at 6 p.m. EDT (2230 GMT) on Monday.

THURSDAY, APRIL 12, 2001

This is the latest Expedition Two status report:

The International Space Station's Expedition Two Crew spent this week loading the Progress supply craft with trash and unneeded items in preparation for its undocking next week to clear the aft port on the Zvezda module for the relocation of the Soyuz capsule. This air traffic control activity clears the way for the arrival next week of Space Shuttle Endeavour and the STS-100 crew delivering the Canadian built station robot arm and another high tech moving van full of supplies.

Remaining fuel and oxidizer from the Progress vehicle was transferred into tanks on the Russian Zvezda module Tuesday and Wednesday, and plans call for final fuel and oxidizer transfer to the Zarya module Thursday and Friday. The Progress engines were fired earlier this week in a small reboost maneuver that verified for the first time a command link of the thrusters through the Zvezda module's computer.

The Progress is scheduled to be remotely undocked from Zvezda's aft docking port about 3:30 a.m. CDT Monday after which it will be deorbited to burn up harmlessly in the Earth's atmosphere. The relocation of the Soyuz spacecraft that delivered the first expedition crew to the station is planned for 7:30 a.m. April 18. The 35 minute procedure calls for the three crewmembers to climb aboard the Soyuz, undock from a docking port on Zarya and fly-around to the aft docking location on Zvezda. This will provide the necessary clearance for the Raffaello Multi Purpose Logistics Module's (MPLM) attachment to the Unity module's nadir port during STS-100.

The resident crew of the International Space Station -- Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms -- is nearing the end of its first month aboard the complex, having begun its increment work on March 18.

The activation of the station's Ku-Band communication system is essentially complete and several television downlinks this week have shown the crew in its daily routine of experimenting, housekeeping and maintenance aboard the station. One of the major tasks accomplished is a complete checkout of two Robotic Work Stations, which will serve as the command and control locations for the station Remote Manipulator System, known as Canadarm2.

The high-tech robot arm and the second Italian Space Agency-built MPLM are the major cargo aboard Endeavour. The seven-person crew will fly to Florida Monday morning for the final three days of the countdown to launch. The countdown is set to begin at 5 p.m. CDT Monday leading toward liftoff at 1:41 p.m. CDT April 19. An on time launch will see Endeavour dock to the station at about 8:36 a.m. CDT April 21.

In and around preparations for the Progress departure, the Soyuz fly-around and upcoming shuttle arrival, the Expedition crew continues to conduct science investigations aboard the ISS. With the station's Ku-band television system working, experimenters are working to activate the Human Research Facility (HRF) rack in the Destiny Laboratory and are preparing for the arrival of new racks of experiments on the upcoming shuttle visit. The HRF is managed and operated by a team in the Telescience Support Center at the Johnson Space Center. All station payloads are overseen from NASA's Payloads Operations Center in Huntsville, Alabama.

The International Space Station continues to orbit the Earth in good shape at an altitude of 240 statute miles (386 km).

WEDNESDAY, APRIL 11, 2001

Here is some insight inito the scientific work underway aboard the international space station by the Expedition Two crew as provided by the payload ground control team:

The Expedition Two Space Station crew transmitted the first science data to the scientists on the ground Wednesday night using the Station's Ku-band antenna.

A massive 610 megabytes of data, representing 61 files of tests with the Middeck Active Control Experiment -- MACE -- were transmitted from the Station to NASA ground controllers, who distributed it to experimenters.

Earlier Station science data on the Hoffman Reflex neurological experiment was downlinked using the Space Shuttle communications system. Station science data is transmitted using the KU band antenna because it can transmit data faster than the S band antenna used for voice communications.

MACE studies the effects of vibrations on moving structures in space. The results are expected to help engineers design and build lighter, stronger, space structures.

The experiment platform is 60 inches (152 cm) long, including four struts and five nodes. Astronauts use a hand control unit to make gimbals and reaction wheels on one side to vibrate while gimbals and wheels on the other side try to damp the vibration.

MACE involves science teams from the Air Force Research Laboratory at Kirtland Air Force Base in New Mexico and the Massachusetts Institute of Technology at Cambridge.

Flight Engineer Susan Helms conducted several tests using the MACE equipment during the past week. In addition, the Expedition Two crew also monitored the operation of automated radiation-measuring experiments and participated in a study of crew relationships.

The Bonner Ball Neutron Detector and the Dosimetric Mapping radiation experiments continued to collect radiation data that will be used to more accurately predict human radiation exposure during long-duration missions and develop counter-measures to safely prolong human exposure to radiation during space travel. Flight Engineer Jim Voss kept the experiment hard drives changed out with fresh units with additional memory storage.

Dr. Tateo Goka, of the National Space Development Agency of Japan, is the principal investigator for Bonner Ball. Dr. Guenter Reitz of the German Space Agency, is the principal investigator for DOSMAP.

Using a laptop computer, the crew continued to fill out questionnaires as part of the Interactions experiment. After the mission, their answers to questions about living and working with their colleagues will help experimenters identify and characterize interpersonal and cultural factors that may affect crew performance in space.

Dr. Nick Kanas, of the Veterans Administration Medical Center in San Francisco, is the principal investigator for Interactions.

A pair of Earth photography experiments -- Crew Earth Observations and EarthKAM -- are on the crew's task list for the week as time permits during the early phase of setting up the orbiting laboratory.

The Payload Operations Center is also busy planning for the next Space Shuttle mission, which will carry two additional payload racks and many new experiments to the Space Station. These experiments include the first commercial experiments, developed by private companies through NASA's Commercial Space Centers across the United States.

The Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, Ala., manages all science research experiments aboard the International Space Station. The center is also home for coordination of the mission-planning work of a variety of international sources, all science payload deliveries and retrieval, and payload training and payload safety programs for the Station crew and all ground personnel.

THURSDAY, APRIL 5, 2001

NASA officials on Thursday decided to keep Endeavour on track for blastoff April 19 as originally planned after the Russians agreed to delay the launch of a new Soyuz space station escape capsule to give the space shuttle more liftoff opportunities.

Endeavour and a crew of seven astronauts are due to launch from Kennedy Space Center's pad 39A at 2:41 p.m. EDT (1841 GMT) on a mission to attach the Canadian-made robotic arm to the international space station.

NASA had contemplated moving up Endeavour's launch day to April 18 to provide three opportunities to get the shuttle airborne before the mandatory Russian launch to swap out the Soyuz lifeboat docked to the station. But an agreement to slip the Soyuz launch if needed, coupled with concerns about compressing the space station resident's workload, forced NASA to abandon the option of getting Endeavour off the ground early.

Based on an April 19 launch scenario, Endeavour will reach the station on April 21 and spend a week delivering the 58-foot long Canadarm2 and tons of fresh supplies and equipment. The shuttle would then depart on April 28, the same day the Soyuz is launched from Central Asia with two Russian cosmonauts and, presumably, millionaire tourist Dennis Tito.

Since the Soyuz spacecraft currently attached to the station is reaching the end of its certified life of 180 days in space, the Russians are eager to launch the new one.

But under the agreement reached between NASA and Russia, the Soyuz launch could be delayed by several days to give Endeavour "multiple" attempts at liftoff should weather or technical problems thwart the April 19 opportunity.

It is unclear, however, at what point the Russians would want NASA to ground the shuttle to allow the Soyuz launch to proceed should Endeavour be delayed significantly. There isn't enough room for the shuttle and both Soyuz capsules to be docked to the station at one time.

The Soyuz would be launched the same day the shuttle undocks from the station, beginning a two-day orbital chase to catch the space station. The so-called "taxi crew" would spend about a week at the station before riding the aging Soyuz back to Earth.

Earlier this week NASA was seriously considering moving Endeavour's launch a day sooner than scheduled, but officials had grown concerned the early arrival of the shuttle at the station would compress the Expedition Two crew's workload aboard the orbiting complex too much.

The crew -- led by Russian commander Yuri Usachev with American astronauts Jim Voss and Susan Helms -- will oversee the undocking of a Progress cargo freighter from the Zvezda service module's aft port on April 15. The three crewmates will then climb into the Soyuz capsule attached to the Earth-facing docking port of the Zarya module and fly it to the freed-up Zvezda port on April 17.

The flyaround is necessary to ensure safe clearance for the shuttle astronauts to mount the Raffaello cargo module to the U.S. Unity node during Endeavour's upcoming mission.

"After we considered all the options and the impact to the on-orbit crew, we decided to stay on the 19th," NASA spokesman Bruce Buckingham said today.

"The launch of Endeavour marks a significant milestone for us in that it completes a quick, safe and successful full turnaround of the Space Shuttle fleet dedicated to assembly of the station in only a few months," Space Shuttle Program Manager Ron Dittemore said today in a statement announcing the launch date. "Once Endeavour arrives on this flight, all three shuttles capable of docking with the station will have done so twice in the past eight months. The international space station's assembly has relied on our ability to maintain a schedule of regular launches to complete uniquely complex missions, and the shuttle team has come through in safe, successful and spectacular fashion."

In addition to the Canadarm2, which is the centerpiece of Canada's contribution to the International Space Station, Endeavour's flight, designated STS-100, also will carry the second Italian Space Agency logistics carrier, a module named Raffaello. Endeavour's flight is planned to include the most complex and intricate robotics work ever conducted in space to install the arm, as well as to deliver more research equipment and experiments to the station than any previous mission.

Commanded by Kent Rominger, Endeavour's crew represents four space agencies and is the most diverse international crew to ever fly in space. The pilot is Jeff Ashby, with mission specialists John Phillips and Scott Parazynski, Chris Hadfield, a Canadian Space Agency astronaut, Umberto Guidoni, a European Space Agency astronaut and Yuri Lonchakov, a Russian Aviation and Space Agency cosmonaut.

Endeavour is scheduled to land April 30 at the Kennedy Space Center.

WEDNESDAY, APRIL 4, 2001

This is today's Expedition Two status report:

The resident crew of the International Space Station -- Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms -- spent the last week conducting experiments and performing routine housekeeping chores and some maintenance work.

The activation of the station's Ku-Band antenna remains on hold until a software update is uplinked to the station's computers Thursday. This command is designed to correct an apparent pointing error with the dish-shaped antenna. The Ku-Band system is used to transmit television, voice and high-speed data to the ground. Normal communication is being managed through the S-Band audio system. Any required TV images, in the meantime, can be accommodated through the use of the laptop computer-based digital video system.

Also, the crew changed out components of the carbon dioxide removal assembly system in the Destiny Laboratory in an effort to recover its use. Troubleshooting work continues as engineers evaluate what appears to be a sluggish vent valve on the unit. The Zvezda module's CO2 removal system is working fine and providing more than adequate capability to cleanse the cabin air in the meantime.

Oxygen for the crew currently is being provided by supply tanks in the Progress supply vehicle, which boosted the cabin air yesterday. Without the Progress, the Russian Elektron in Zvezda provides oxygen generation. Not presently needed, the Elektron is turned off.

Apart from maintenance tasks and routine housekeeping chores, the crew has been working with experiments on board. The Human Research Facility rack in Destiny is managed and operated by a science and operations team from the Telescience Support Center down the hall from the station's flight control room in Mission Control, Houston. All payloads on the station are overseen from NASA's Marshall Space Flight Center in Huntsville, Alabama where the Payloads Operations Center is located.

The Progress supply craft currently docked to the aft end of the Zvezda module is scheduled to be undocked around April 15 in preparation for the arrival of the next shuttle flight carrying the station's Canadian-built robot arm and a second Italian Space Agency supplied logistics module called Raffaello. The open port allows for the relocation of the Soyuz capsule around April 17, which will provide clearance for the placement of Raffaello during the docked phase of the shuttle mission. The Flight Readiness Review to evaluate the readiness of Endeavour, its crew and the station for the shuttle's launch on the STS-100 mission will be held Thursday to select a target launch date, which currently is around April 19.

Earlier today, a small test firing of the Progress supply ship's thrusters was performed to verify command capability of the steering jets via the Zvezda module's computers. The brief engine burn resulted in a change in the velocity of the Station of only one meter per second. It was the first time the Progress thrusters were commanded from the ground through the Zvezda module's computers.

The test sets the stage for another Progress engine firing early next week designed to refine the orbit of the station relative to the Baikonur Cosmodrome in Kazakhstan in preparation for the arrival of a new Soyuz capsule to replace the one presently docked to the station. Soyuz capsules routinely are changed about every 180 days. A taxi crew, as it's called, will deliver the new capsule and return to Earth in the one launched last October carrying the station's first Expedition Crew.

Late Tuesday, a handover of the station's attitude control from the electrically driven Control Moment Gyroscopes to the Zvezda module's thrusters was performed as a test to verify that the automatic switchover would occur in the event that the CMGs developed a problem. The test allowed the system to Īthink' that the gyros had failed down to one operational system and the computers automatically switched to the thrusters. The test verified the system is fully operational.

The International Space Station continues to orbit the Earth in good shape at an altitude of 238 statute miles (384 km).

WEDNESDAY, MARCH 28, 2001

Here is the latest NASA status report on Expedition Two issued today:

The International Space Station has become home to its new residents -- the Expedition Two crew of Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms -- who are settling in for a four-month stay after assuming command of the complex 10 days ago.

Minor issues being worked by the crew and flight control teams in Houston and Moscow are not impacting the operation and health of the complex, but are occupying time of engineers in preparing troubleshooting procedures for items on board.

The activation of the station's Ku-Band antenna is on standby until procedures are put in place for a possible software patch to account for an apparent pointing error with the dish-shaped antenna. The Ku Band system is used to transmit television, voice and high-speed data to the ground. Normal communication is being managed through the S-Band audio system. Any required TV images, in the meantime, can be accommodated through the use of the laptop computer-based digital video system. Until that problem is corrected, transmission of experiment data from the Human Research Facility experiment rack in the Destiny laboratory is on hold.

A Destiny condensate venting system is not working and while troubleshooting continues, the thermal loop temperatures have been increased so that no water currently is being condensed. As a point of verification, a contingency water container has proven to be useful in serving as a storage location for condensate, if required.

In and around maintenance tasks and routine housekeeping chores, the crew has been busy setting up additional equipment and conducting status checks on some of the payloads. A new bicycle exercise machine called CEVIS (for Cycle Ergometer with Vibration Isolation System) was setup this week, while engineers assess the work needed to repair the station's treadmill, which is showing wear in many of the slats that provide support to the unit designed to allow exercise with little or no vibration that could impact sensitive experiment work.

The Progress supply craft docked to the Zvezda module delivered 89 kilograms of oxidizer to the service module's storage tanks via remote commanding from the ground. The Progress will be undocked from the station in mid-April in preparation for the arrival of the next shuttle flight carrying the station's Canadian-built robot arm and another Italian Space Agency supplied logistics module called Raffaello.

The Progress undocking provides an open port for the relocation of the Soyuz capsule around April 16-18 which will provide clearance for the placement of Raffaello during the shuttle mission, which launches April 19.

Later this week the Expedition Two crew is scheduled to perform some maintenance work in an attempt to get the carbon-dioxide removal assembly in Destiny working. The plan calls for a test of a cable to ensure it is working before changing the pump with a spare brought up on the most recent shuttle flight. As of now, with only three people onboard, carbon dioxide removal from the cabin air is adequately conducted by Zvezda's Vozdukh system.

The crew plans to take part in its first interview opportunity on Friday with reporters from CBS and the Associated Press at 10 a.m. CST Friday. The interview will be broadcast on NASA TV, but will be audio only.

Meanwhile down at the Kennedy Space Center in Florida, the crew of shuttle mission STS-100 is conducting its traditional countdown dress rehearsal in preparation for launch to the ISS April 19. The international crew consists of Commander Kent Rominger, Pilot Jeff Ashby, Flight Engineer John Phillips, Mission Specialist Scott Parazynski, Canadian astronaut Chris Hadfield, European astronaut Umberto Guidoni and Russian Aviation and Space Agency cosmonaut Yuri Lonchakov.

The International Space Station continues to orbit the Earth in good shape at an altitude of 238 statute miles (384 km).

Read our earlier status center coverage.