BY JUSTIN RAY

January 30, 2001 -- Follow the countdown and launch of a Boeing Delta 2 rocket with the U.S. Air Force's GPS 2R-7 navigation satellite. Reload this page for the very latest on the mission.

TUESDAY, JANUARY 30, 2001

Exactly ten years after the U.S. military troops reaped the benefits from the Global Positioning System while fighting the Gulf War in featureless deserts, a new satellite was launched into orbit today to keep the constellation going. The GPS 2R-7 satellite rode to space aboard a Boeing Delta 2 rocket. Read our launch story.

We have also posted a video clip of today's liftoff.

0820 GMT (3:20 a.m. EST)

T+plus 25 minutes, 38 seconds. SPACECRAFT SEPARATION! The $50 million NAVSTAR Global Positioning System 2R-7 military navigation satellite has been released from the Delta rocket's third stage following a successful launch today.

Over the coming month, activities to prepare the satellite for service will include deploying its solar arrays in order to generate power and recharge onboard batteries, manuevers to circularize the orbital altitude and testing of the spacecraft bus and payload.

Check back later this morning for a full report on the launch, a movie clip and some pictures.

0819 GMT (3:19 a.m. EST)

T+plus 24 minutes. Now there is confirmation of burn out of the solid-fueled third stage following its planned firing. Coming up on spacecraft separation to complete this launch in less than 90 seconds.

0818 GMT (3:18 a.m. EST)

T+plus 23 minutes. Engineers at Cape Canaveral report they are not seeing all the data coming back the Delta 2 rocket's third stage, which is making it difficult to determine exactly what is happening.

0817 GMT (3:17 a.m. EST)

T+plus 22 minutes. The data is too noisy to show whether the stages have separated and third stage ignition.

0816 GMT (3:16 a.m. EST)

T+plus 21 minutes, 35 seconds. The spin rockets on the third stage have fired to spin-up the vehicle.

0815 GMT (3:15 a.m. EST)

T+plus 20 minutes, 40 seconds. The Delta rocket's second stage has completed its second burn today to deliver the third stage and attached GPS spacecraft into the proper orbit. Coming up on second and third stage separation in one minute.

0815 GMT (3:15 a.m. EST)

T+plus 20 minutes. Still awaiting second stage data from the Ascension Island tracking station.

0814 GMT (3:14 a.m. EST)

T+plus 19 minutes. Less than a minute until the second stage engine is restarted for a 35-second firing as the GPS 2R-7 satellite continues its journey to space.

0810 GMT (3:10 a.m. EST)

T+plus 15 minutes, 30 seconds. Nothing much to report at this point in the flight because the rocket has passed out of range from the downrange tracking station network. The next data will come in a few minutes via the Ascension Island station near the equator.

0809 GMT (3:09 a.m. EST)

T+plus 14 minutes. Boeing reports this initial orbit achieved by the Delta 2 rocket is right as planned with an apogee of 211.6 miles, perigee of 94.4 miles and inclination of 36.9 degrees.

0807 GMT (3:07 a.m. EST)

T+plus 12 minutes. The Delta rocket is now in a coast period that will last another 8 minutes before the second stage restarts. Vehicle rates reported normal.

0806 GMT (3:06 a.m. EST)

T+plus 11 minutes, 5 seconds. SECO 1. Confirmation that the second stage engine has cut off as planned and the Delta 2 rocket with the GPS 2R-7 spacecraft have arrive in a preliminary orbit around Earth.

0805 GMT (3:05 a.m. EST)

T+plus 10 minutes, 40 seconds. The rocket is nearing orbital velocity. Speed is currently 16,600 mph.

0804 GMT (3:04 a.m. EST)

T+plus 9 minutes, 40 seconds. Altitude 97.4 miles, downrange distance 1280 miles, velocity is 15,700 miles per hour.

0804 GMT (3:04 a.m. EST)

T+plus 9 minutes. Just under two minutes left in the first firing of the second stage engine.

0802 GMT (3:02 a.m. EST)

T+plus 7 minutes, 50 seconds. Altitude 95 miles, downrange distance 910 miles, velocity is 14,300 miles per hour.

0802 GMT (3:02 a.m. EST)

T+plus 7 minutes. The official launch time was 2:55:00.512 a.m. EST.

0801 GMT (3:01 a.m. EST)

T+plus 6 minutes, 40 seconds. Second stage systems continue to look good. The downrange Antiqua tracking station has acquired the rocket's signal as it heads away from Florida on the way to orbit.

0800 GMT (3:00 a.m. EST)

T+plus 5 minutes, 40 seconds. Altitude 77 miles, downrange distance 495 miles, velocity is 12,900 miles per hour.

0800 GMT (3:00 a.m. EST)

T+plus 5 minutes, 10 seconds. The protective payload fairing enclosing the GPS satellite atop the rocket has separated with no recontact detected.

0800 GMT (3:00 a.m. EST)

T+plus 5 minutes. Good chamber pressure reported from the second stage main engine as it begins the first of two burns in today's launch.

0759 GMT (2:59 a.m. EST)

T+plus 4 minutes, 44 seconds. MECO. The first stage main engine cutoff confirmed, the stage has been jettisoned and second stage engine ignition has occurred.

0759 GMT (2:59 a.m. EST)

T+plus 4 minutes. The Delta 2 rocket continues climbing into the upper atmosphere. Chamber pressure looks good on the first stage main engine. No problems have been reported so far in today's flight.

0758 GMT (2:58 a.m. EST)

T+plus 3 minutes. The Delta 2 rocket continues on the proper trajectory. Altitude is 36 miles, velocity is 6600 mph.

0757 GMT (2:57 a.m. EST)

T+plus 2 minutes, 20 seconds. The three air-start solid rocket boosters have burned out and separated. The rocket continues its trek to orbit on the power of the first stage liquid-fueled main engine.

0756 GMT (2:56 a.m. EST)

T+plus 1 minute, 15 seconds. All six ground-start solid rocket boosters have burned out and separated. The three air-lit solids have ignited.

0755 GMT (2:55 a.m. EST)

T+plus 45 seconds. Solid rocket boosters and first stage main engine continue to fire well as the vehicle passes through maximum dynamic pressure.

0755 GMT (2:55 a.m. EST)

T+plus 35 seconds. Vehicle has passed Mach 1. A smooth flight reported so far.

0755 GMT (2:55 a.m. EST)

LIFTOFF! Liftoff of the Boeing Delta 2 rocket to reinforce the Global Positioning System with a fresh new satellite. And the vehicle has cleared the tower.

0754 GMT (2:54 a.m. EST)

T-minus 30 seconds. Hydraulics and electronics reported go.

The launch ignition sequence will begin at T-minus 2 seconds when a Boeing engineer triggers the engine start switch. The process begins with ignition of the two vernier engines and first stage main engine start. The six ground-start solid rocket motors then light at T-0 for liftoff. At launch, the rocket will produce over 750,000 pounds of thrust.

0754 GMT (2:54 a.m. EST)

T-minus 1 minute. The Range has given its final clear-to-launch. The Delta 2 rocket's second stage hydraulic pump has gone to internal power after its pressures were verified acceptable. At the telemetry receiving areas where data from the rocket will be transmitted, the data recording charts have gone to high speed as the liftoff nears.

0753 GMT (2:53 a.m. EST)

T-minus 90 seconds. The launch pad water system is activated.

0753 GMT (2:53 a.m. EST)

T-minus 2 minutes. The first stage liquid oxygen vents are now being closed so the LOX tank can be pressurized for launch. Puffs of vapor from a relief valve on the rocket will be seen in the remainder of the countdown as the tank pressure stabilizes.

The U.S. Air Force has declared the NAVSTAR Global Positioning System 2R-7 spacecraft officially "go" for launch today. The spacecraft will join 28 other operational GPS satellites in space to provide precision navigation and timing information to military forces and civilians on land, in the air and at sea around the globe. Officials are launching the craft to expand the existing constellation and have it already in space when older GPS satellite should each the end of life.

0752 GMT (2:52 a.m. EST)

T-minus 3 minutes. The safety destruct safe and arm devices are being armed.

This will be a 25-minute flight of three-stage Delta 2 rocket. See the timeline for a summary of launch events.

0751 GMT (2:51 a.m. EST)

T-minus 4 minutes and counting. Now in the final phase of the countdown as Delta launch vehicle systems begin transferring to internal power. All systems are now ready for launch today at 2:55 a.m. EST from pad 17A at Cape Canaveral Air Force Station in Florida.

0749 GMT (2:49 a.m. EST)

Standing by to resume the countdown in two minutes. The earlier commanding problem involved the rocket's destruct system, Boeing says, but it is now resolved.

0747 GMT (2:47 a.m. EST)

NEW LAUNCH TIME! Boeing has set a new liftoff time of 2:55 a.m. EST. Countdown clocks will pick up from the T-minus 4 minute mark at 2:51 a.m. EST.

0745 GMT (2:45 a.m. EST)

It appears the launch team needs a few minutes to get everything synched up again before being ready to resume the countdown for liftoff today. The available launch window extends until 3:11 a.m. EST.

For these NAVSTAR GPS launches, Boeing uses a model 7925-9.5 Delta 2 rocket. The expendable launch vehicle consists of three stages, nine strap-on solid rocket boosters and a 9.5-foot diameter payload fairing. The rocket stands 126 feet tall. See our rocket fact sheet for more.

0741 GMT (2:41 a.m. EST)

The launch team has been polled by Boeing's launch conductor. All parties reported "go". The team is now receiving a final briefing of procedures. Still awaiting officials to confirm the new launch time once the earlier commanding glitch is put to rest.

0739 GMT (2:39 a.m. EST)

Countdown clocks remain holding at T-minus 4 minutes. A new liftoff time has not been annouced by Boeing yet.

0736 GMT (2:36 a.m. EST)

Weather in the Cape Canaveral area have been verified "go" for launch.

0733 GMT (2:33 a.m. EST)

The Boeing launch conductor just told the sequencer to NOT resume the countdown from the T-minus 4 minute as scheduled at 2:39 a.m. EST. This means the Delta 2 will not launch on time at 2:43 a.m. EST. A new liftoff time has not been established.

0731 GMT (2:31 a.m. EST)

To recap, there is a commanding problem being experienced by the launch team. Also, Boeing has already announced that an on-time 2:43 a.m. EST liftoff was unlikely this morning because of delays that pushed back countdown events including the loading of the rocket's first stage liquid oxygen tank. The launch team has until 3:11 a.m. EST (0811 GMT) to get the Delta 2 rocket airborne today or else scrub until tomorrow.

0730 GMT (2:30 a.m. EST)

The latest computer program based upon upper level winds have been uploaded to the Delta 2 rocket's guidance computer. The information tells the computer what wind conditions to expect during the climb to orbit today.

0729 GMT (2:29 a.m. EST)

T-minus 4 minutes and holding. The countdown has stopped at the final planned built-in hold point for today's launch attempt. This hold was slated to last 10 minutes, however that can be extended if necessary.

0727 GMT (2:27 a.m. EST)

Launch Conductor George Stout reports a commanding problem has been encountered.

0727 GMT (2:27 a.m. EST)

The first stage fuel tank vent is being closed and the tank is being pressurized for launch.

0723 GMT (2:23 a.m. EST)

The GPS 2R-7 spacecraft is now running on internal power. Meanwhile, we are still awaiting the new launch time. The countdown activities have been late throughout the morning following delays in getting the launch pad cleared of workers.

0721 GMT (2:21 a.m. EST)

Checks are now under way of the Range Safety command destruct receivers that would be used to destroy the Delta rocket should a problem arise during the launch. A little earlier, the Range completed RF link checks with the rocket.

0720 GMT (2:20 a.m. EST)

The trickle charge is being stopped to the Global Positioning System 2R-7 spacecraft atop the Delta rocket, and the satellite is switching to internal power for launch.

0719 GMT (2:19 a.m. EST)

Boeing engineers assessing the upper level winds from data gathered by weather balloons say conditions are acceptable for launch throughout today's 28-minute window.

0715 GMT (2:15 a.m. EST)

The Delta rocket is now fully fueled for launch today to deliver the NAVSTAR Global Positioning System 2R-7 satellite into orbit.

The vehicle's first stage was successfully loaded with RP-1 kerosene fuel and liquid oxygen this morning. The second stage was loaded with its storable nitrogen tetroxide and Aerozine 50 fuels a couple of days ago; and the third stage and strap-on booster rockets are solid-propellant.

0711 GMT (2:11 a.m. EST)

Boeing reports liftoff likely will be delayed a few minutes beyond the planned 2:43 a.m. EST opening of today's window. The reason is the need to let the rocket's liquid oxygen tank to settle for at least 30 minutes from the time it is loaded until launch.

0709 GMT (2:09 a.m. EST)

The Delta 2 rocket's first stage liquid oxygen tank has been topped off at 100 percent. The tank will be replenished through the remainder of the countdown to replace the liquid oxygen that naturally boils away. It took 24 minutes, 35 seconds to load the LOX tank today, an operation completed at 2:09:15 a.m. EST.

0704 GMT (2:04 a.m. EST)

The first stage liquid oxygen tank is nearly full. The "rapid load" phase of filling the tank will continue to the 95-percent level before the slower "fine load" takes over to reach the 99-percent mark, which is then followed by topping off the tank to 100 percent.

0701 GMT (2:01 a.m. EST)

Work to pressurize the Delta 2 rocket's second stage propellant, helium and nitrogen tanks has been completed.

0654 GMT (1:54 a.m. EST)

Loading of liquid oxygen continues. Now 10 minutes into this approximate 25-minute process.

0650 GMT (1:50 a.m. EST)

Over the next few minutes, the "slew" or steering checks of the first and second stage engines will be performed and RF link tests between the Range and rocket are scheduled.

0644 GMT (1:44 a.m. EST)

Cryogenic liquid oxygen, chilled to Minus-298 degrees F, is now flowing from a storage tank at pad 17A, through plumbing and into the bottom of the Boeing Delta 2 rocket. The LOX will be consumed by the first stage main engine along with RP-1 kerosene loaded aboard the vehicle over the past hour.

0642 GMT (1:42 a.m. EST)

The launch team has been given a "go" to begin loading liquid oxygen into the Delta 2's first stage, the final step in fueling the three-stage rocket for flight.

0638 GMT (1:38 a.m. EST)

Boeing is reworking the countdown timeline this morning following an earlier delay that held up routine pre-flight activities.

0630 GMT (1:30 a.m. EST)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded for today's planned 2:43 a.m. EST liftoff from Cape Canaveral Air Force Station in Florida. The tank was loaded with 9,961 gallons of a highly refined kerosene, called RP-1, during a 18-minute, 52-second process today that concluded at 1:29:57 a.m. EST.

The next major task in the countdown will be loading super-cold cryogenic liquid oxygen into the first stage.

0626 GMT (1:26 a.m. EST)

The first stage fuel tank has been loaded with 9,000 gallons so far. Once the tank is filled with 9,760 gallons, or 98 percent, the "rapid load" valve will be closed and the slower "fine load" phase will top off the tank to 9,961 gallons for launch.

0623 GMT (1:23 a.m. EST)

The Delta 2 rocket's first stage helium and nitrogen systems have been pressurized for flight. Similar work on the second stage is still to be completed.

The countdown activities are running about an hour behind schedule today because the launch pad not cleared of workers until just a short time ago. The count does have 30 minutes worth of built-in holds to make up for the earlier lost time. There has not been any announcement of delaying the 2:43 a.m. EST liftoff time.

0621 GMT (1:21 a.m. EST)

Fueling of the rocket's first stage has now been underway for 10 minutes. Over 6,000 gallons have already been pumped aboard at this point.

0616 GMT (1:16 a.m. EST)

Now five minutes into this approximate 20-minute process to load the rocket's first stage with nearly 10,000 gallons of refined kerosene. The flow rate is several hundred gallons per minute as the "rapid load" phase of fueling continues. The rate will be decreased once the tank is 98 percent full.

0611 GMT (1:11 a.m. EST)

Valves have been configured and about 10,000 gallons of propellant is now flowing from a storage tank into the Boeing Delta 2 rocket's first stage. Called RP-1, the highly refined kerosene will be guzzled along with liquid oxygen (to be pumped into the rocket a little later this morning) by the first stage Rocketdyne RS-27A main engine and twin vernier steering thrusters during the initial four-and-a-half-minutes of flight.

0603 GMT (1:03 a.m. EST)

A warning horn has been sounded three times at the pad 17A seaside complex to alert any remaining personnel to clear the area. Meanwhile, the Delta 2 rocket's guidance computer -- known as the Redundant Inertial Flight Control Assembly or RIFCA -- has been turned on as the countdown continues.

0553 GMT (12:53 a.m. EST)

At T-minus 80 minutes and counting, the chief launch conductor reports the launch pad deck plate has just been removed and the Complex 17 area will soon be cleared of personnel. Due to the earlier audio distribution problem it is not yet known why activities have been delayed at the pad tonight. The pad was scheduled to be cleared over an hour ago.

Once the pad is evacuated, launch team members in the Delta Operations Building, or "soft blockhouse", located about eight miles west of the pad will oversee the pressurization of helium and nitrogen storage tanks inside the rocket's first and second stages; and the second stage fuel and oxidizer tanks will be pressurized for launch. In addition, the loading of 10,000 gallons of RP-1 fuel into the first stage will commence.

Today's launch window extends from 2:43 to 3:11 a.m. EST.

0543 GMT (12:43 a.m. EST)

Now two hours away from the scheduled launch time. There has been an audio distribution problem at the Cape, which has caused the countdown audio to be lost for a good portion of our Webcast tonight. We are waiting for the problem to be resolved.

0523 GMT (12:23 a.m. EST)

Sitting atop the Delta rocket is the Lockheed Martin-built GPS 2R-7 spacecraft, which will be the 35th operational satellite to be launched since 1989.

The Navigation Signal Timing and Ranging Global Positioning System (NAVSTAR GPS) was established in the 1970s to provide the military with navigation data for ground, sea and air forces. The first 11 satellites, known as Block 1, were launched from 1978 through 1985 and served to test the fundamentals behind the GPS concept. Beginning in 1989, the Block 2 and 2A series satellites began flying to form the current constellation that provides precise navigation data not only to the military but civilians as well.

In 1997 a newer, more advanced series of GPS satellites, the Block 2R, debuted. However, the first was lost in a launch failure. The second was successfully launched in July of that year. Today, the seventh of 21 is scheduled to leave the Earth aboard the Delta 2 rocket. The craft are considered to be operational replenishment satellites and are developed by Lockheed Martin. They will carry GPS into the next century. Block 2R satellites are designed to provide at least 14 days of operation without contact from controllers and up to 180 days of operation when operating in the autonomous navigation (AUTONAV) mode. The spacecraft maintain their accuracy by communicating with other Block 2R satellites in orbit. This so-called cross-link ranging will be used to estimate and update the parameters in the navigation message of each Block 2R satellite without contact from ground control. Other enhancements include reprogrammable micro-processors for upgrading in-flight, additional radiation protection, greater fuel capacity, the ability to determine their own position and two atomic clocks working at all times, providing a "hot backup."

The GPS constellation is comprised of 24 primary satellites divided into six orbital planes with four spacecraft in each. They circle in formation about 10,900 nautical miles above Earth every 12 hours in orbits inclined 55 degrees to the equator. The GPS 2R-7 satellite being launched today will join the 28 spacecraft currently in operation. Controllers plan to place the new craft in Plane E, Slot 4 of the constellation. The craft currently in that position -- GPS 2A-10 -- will be moved to the backup slot E5 for the rest of its useful life.

The continuous navigation signals sent from the satellites allow users to find their position in latitude, longitude and altitude and measure time. A GPS user receiver measures the time delay for the signal to reach the receiver, which is the direct measure of the apparent range to the satellite. Measurements collected simultaneously from four satellites are processed to solve for the three dimensions of position, velocity and time. Users can determine their location to within feet, speed within a fraction of a mile per hour and time to within a millionth of a second.

Countless uses have been found for the revolutionary GPS system. Everyday, GPS guides U.S. military troops, aircraft, submarines and ships around the globe. Troops also relied on the system extensively in the featureless desert battlefield of the Gulf War. Weapons can use GPS data for guidance. GPS also found its way into the civilian commercial market -- assisting planes, automobiles, boats, hikers and map makers.

0443 GMT (11:43 p.m. EST Mon.)

T-minus 150 minutes and counting. The terminal countdown has begun for the launch of the Boeing Delta 2 rocket carrying the NAVSTAR Global Positioning System 2R-7 military navigation satellite. Over the next three hours, the launch team will ready the three-stage rocket, payload and ground support systems for the planned 2:43 a.m. EST (0743 GMT) blastoff from pad 17A at Cape Canaveral Air Force Station in Florida.

0400 GMT (11:00 p.m. EST Mon.)

The Delta launch team are continuing with final activities in advance of picking up the Terminal Count later this hour. Chores being conducted have included restoring the team's workstations by rebooting the frontend computer network, configuring the GPS 2R-7 satellite's S-band and RF communications systems and performing Range Safety's hold-fire checks to verify its ability to stop the countdown if a problem arises.

Countdown clocks are currently holding at T-minus 150 minutes in a planned pause. The count is slated to resume at 11:43 p.m. EST.

As the action begins build, we have started our live streaming Webcast. Tune in now!

0120 GMT (8:20 p.m. EST Mon.)

The 12-story mobile service tower enclosing the Boeing Delta 2 rocket at Cape Canaveral's pad 17A was rolled back this evening as preparations continue for launch at 2:43 a.m. EST (0743 GMT) tonight.

Boeing officials have not reported any problems and the weather forecast continues to show generally acceptable conditions for blastoff. Skies are clear, the stars are shining brightly, the temperature is a comfortable 70 degrees F and there is a breeze.

Pre-launch activities are ongoing in advance of starting the terminal countdown at 11:43 p.m. EST at T-minus 150 minutes.

Once terminal count begins, the rocket's guidance computer will be activated and first stage fueled.

A pair of holds, lasting a half-hour in total duration, are built into the countdown. One hold for 20 minutes is planned at T-minus 20 minutes while a final hold at T-minus 4 minutes should last 10 minutes.

MONDAY, JANUARY 29, 2001
1943 GMT (2:43 p.m. EST)

Now 12 hours away from the scheduled launch time of the Boeing Delta 2 rocket and the $50 million Global Positioning System 2R-7 navigation satellite.

The Lockheed Martin-built GPS 2R-7 satellite, which the Air Force also refers to as Space Vehicle No. 54, will join the 28 spacecraft currently operating in the U.S. military's Global Positioning System constellation.

The orbiting network provides precision location, speed and timing information to guide U.S. military troops, aircraft, submarines, ships, weapons and civilians around the globe. The constellation relies on 24 primary satellites and several spares.

Controllers plan to place the new GPS 2R-7 satellite in Plane E, Slot 4 for the six-plane GPS constellation. The craft currently in that position -- GPS 2A-10 -- will be moved to the reserve slot E5 for the rest of its operational life, the Air Force told Spaceflight Now. That is an extra position being created in the constellation to keep the aging craft in service even though it has some technical problems. GPS 2A-10, also known as Space Vehicle No. 23, was launched on November 26, 1990 and has long since surpassed its originally-advertised life span of seven years.

1830 GMT (1:30 p.m. EST)

The latest weather forecast continues to indicate an 80 percent chance of acceptable condition for launch during Tuesday's window of 2:43 to 3:11 a.m. EST (0743-0811 GMT). Clouds and ground winds are the main concerns.

Launch Weather Officer Joel Tumbiolo issued this summary today:

"Cold front associated with strong storm system over the central U.S. will be located over the western Gulf of Mexico. Ground level winds will increase during the countdown as the front moves closer to Florida. Based on with the forecasted wind direction (170 deg), the wind constraint will be winds >28 KTS at 90 ft level. Core of the jet stream will be located well west and north of Florida, with expected max upper level winds to be in the order of 80 KTS. Concerns on launch day will be for ground level winds, and to a lesser extent thick layered clouds and cumulus clouds in the flight path. The concern for thick clouds and precipitation increase if a launch slip occurs."

The launch time conditions are predicted to include a few clouds at 3,000, 10,000 and 25,000 feet, visibility of 10 miles or better, southerly winds 12 gusting to 24 knots, a temperature of 64 to 66 degrees F and relative humidity of 90 percent.

Should the launch slip to Wednesday or Thursday, the forecast worsens to a 60 percent chance of favorable conditions. The concerns will be ground winds, thick layered clouds, cumulus clouds and rain in the flight path.

1420 GMT (9:20 a.m. EST)

It is a quiet morning at Cape Canaveral's Complex 17 today as most workers are at home resting up for this evening's countdown and middle-of-the-night launch of a Delta 2 rocket with an Air Force Global Positioning System satellite.

Launch pad crews will begin arriving this afternoon in advance of retracting the 12-story mobile service tower from around the rocket at about 6 p.m. EST (2300 GMT). The full launch team will be stationed at their consoles a few hours later to start Terminal Count at 11:43 p.m. EST (0443 GMT).

There are no significant technical problems being addressed by engineers and the weather forecast is generally favorable for Tuesday's 2:43 a.m. EST (0743 GMT) launch time.

"Everything is going well," Boeing Mission Director Rich Murphy said in an interview this morning.

The launch will be the first of 11 Delta 2 rockets slated to fly in 2001. The busy manifest includes a total of three Global Positioning System satellite launches, six flights carrying science probes for NASA, one launch for the National Reconnaissance Office to loft a technology demonstration craft and a commercial mission for Iridium.

In all, there are 7 launches scheduled from the Cape and four from Vandenberg Air Force Base in California.

SUNDAY, JANUARY 28, 2001

A Boeing Delta 2 rocket stands ready for an overnight liftoff from Cape Canaveral Air Force Station in Florida on Tuesday with a replacement NAVSTAR Global Positioning System military navigation spacecraft.

Check this page for updates throughout the day on Monday, then live coverage of the countdown and launch.

SATURDAY, JANUARY 27, 2001

Boeing and the U.S. Air Force completed launch readiness reviews today as the Delta 2 rocket and NAVSTAR Global Positioning System Block 2R-7 spacecraft remain set for liftoff Tuesday at 2:43 a.m. EST (0743 GMT).

No significant problems were reported from the meetings and pre-launch preparations continue as planned at Cape Canaveral Air Force Station's pad 17A.

Meanwhile, the latest weather forecast has been downgraded slightly from the prediction made on Friday. Air Force Launch Weather Officer Joel Tumbiolo is now giving an 80 percent chance of favorable conditions. Cumulus clouds and thick clouds are concerns during Tuesday's 28-minute launch window.

"On launch day high pressure will be centered well east of Florida bringing SE winds. Next significant weather system will be located over the center of the U.S. on launch day. Cold front associated with this system could affect central Florida by Tuesday and Wednesday of next week. Core of the jet stream will be located well west and north of Florida on launch day. Concerns on launch day will be the chance of thick layered clouds and cumulus clouds in the flight path. These concerns increase if a launch slip occurs."

The launch time conditions are predicted to include a few clouds at 3,000 feet with 1/8ths sky coverage, scattered clouds at 10,000 feet with 2/8ths sky coverage, scattered clouds at 25,000 feet with 2/8ths sky coverage, visibility of 10 miles or better, southeasterly winds 10 gusting to 15 knots, a temperature of 62 to 64 degrees F and relative humidity of 90 percent.

FRIDAY, JANUARY 26, 2001

The first Delta rocket launch of 2001 is scheduled for early Tuesday from Cape Canaveral with a replacement Global Positioning System military navigation satellite onboard.

The 126-foot tall rocket will carry the GPS 2R-7 satellite into an elliptical transfer orbit around Earth. Liftoff from pad 17A is set to occur at 2:43 a.m. EST (0743 GMT), the opening of a 28-minute window extending to 3:11 a.m. EST (0811 GMT).

Weather forecasters are calling for a 90 percent chance of acceptable conditions with only a slight concern of cumulus clouds presenting a problem. Launch Weather Officer Joel Tumbiolo issued this summary today:

"High pressure to dominate the area through the weekend. Dry cold front will pass through late Sat or early Sun but with little noticeable change. Warming trend will take place during this time. By launch day high pressure will be centered well east of Florida bringing light SE winds. Next significant weather system will be located over the center of the U.S. on launch day. Cold front associated with this system could affect central Florida by Tues and Wed of next week. Core of the jet stream will be located well west and north of Florida on launch day. Only concern on launch day will be slight chance of cumulus clouds, associated with the expected onshore flow, being near the flight path."

The launch time conditions are predicted to include a few clouds at 3,000 feet with 1/8ths sky coverage, visibility of 10 miles or better, southeasterly winds 8 gusting to 12 knots, a temperature of 62 to 64 degrees F and relative humidity of 90 percent.

Should the launch be delayed for some reason, the weather forecast does worsen for Wednesday and Thursday liftoff opportunities. There is a 60 percent chance of good weather on both days with concerns being cumulus clouds, thick layered clouds and rain in the flight path.

Spaceflight Now will have a complete launch preview later this weekend. We'll also have comprehensive live coverage of the countdown and launch with status reports on this page and a streaming Webcast starting at 0440 GMT (11:40 p.m. EST Monday).