BY JUSTIN RAY

Follow the countdown and launch of the Boeing Delta 2 rocket with NASA's ICESat and CHIPSat spacecraft. Reload this page for the very latest on the mission.

Video coverage for subscribers only:
   VIDEO: FIVE-MINUTE CLIP OF THE DELTA 2 ROCKET LAUNCH QT or RV
   VIDEO: AERIAL VIEW OF DELTA SOARING AT SUNSET QT or RV
   VIDEO: REPLAY FROM CAMERA BEHIND THE PAD QT or RV
   VIDEO: LAUNCH ANGLE FROM IN FRONT OF PAD QT or RV
   VIDEO: VIEW OF UMBILICALS PULLING AWAY AT LIFTOFF QT or RV
   VIDEO: NASA LAUNCH MANAGER'S POST-FLIGHT COMMENTS QT or RV
   VIDEO: WATCH FRIDAY'S PRE-LAUNCH NEWS CONFERENCE QT or RV
   VIDEO: NARRATED OVERVIEW OF THE ICESAT MISSION QT or RV
   VIDEO: COMMENTS FROM ICESAT PROJECT SCIENTIST QT or RV
   VIDEO: ANIMATION OF CHIPSAT ORBITING EARTH QT or RV
   VIDEO: COMMENTS FROM CHIPSAT PRINCIPAL INVESTIGATOR QT or RV
   SUBSCRIBE NOW

MONDAY, JANUARY 13, 2003

Two NASA spacecraft -- one that will bounce laser beams off Earth to gauge environmental changes, the other to study relics of a supernova explosion in our galactic neighborhood -- rode a Boeing Delta 2 rocket into orbit Sunday from California. Read our full story.

0233 GMT (9:33 p.m. EST Sun.)

T+plus 108 minutes. The Delta's upper stage has just performed its third engine firing of the day. The brief firing was an evasive maneuver to change its orbit from that of the ICESat and CHIPSat spacecraft. The new orbit has a high point of 316.5 nautical miles, low point of 267.4 nautical miles and inclination of 94.83 degrees.

A final burn is scheduled for a little later tonight to deplete the remaining propellant in the stage for protecting against orbital debris. The engine firing should put the stage in an orbit of around 295 miles at apogee, 107 at perigee and inclination of 97.3 degrees.

We will conclude our coverage at this point. Watch for movies to be posted above for our Spaceflight Now Plus subscribers. And we will have a full wrap-up story later tonight.

0229 GMT (9:29 p.m. EST Sun.)

T+plus 104 minutes. "I'd like to thank the Delta team for another mission success. The excellent cooperation between the many industry and government participants involved in this mission made this achievement possible. I look forward to the opportunities in 2003 to add to our string of 49 consecutive successful Delta 2 missions as we continue to provide reliable launch services for our customers," said Boeing's vice president and Delta deputy program manager Jay Witzling.

The next Delta 2 launch is scheduled for January 29 from Cape Canaveral Air Force Station in Florida carrying the GPS 2R-8 military navigation satellite for the U.S. Air Force. The next Delta 2 mission for NASA will launch the Space Infrared Telescope Facility (SIRTF) aboard the new Delta 2-Heavy in mid-April from Cape Canaveral.

0226 GMT (9:26 p.m. EST Sun.)

T+plus 101 minutes. Officials at Vandenberg are celebrating a successful launch of the Boeing Delta 2 rocket, lofting NASA's ICESat and CHIPSat spacecraft.

0224 GMT (9:24 p.m. EST Sun.)

T+plus 99 minutes. Controllers have picked up communications from the CHIPSat, confirming the craft is alive following its launch. Earlier, contact was established with ICESat and verified its solar arrays had been deployed.

0218 GMT (9:18 p.m. EST Sun.)

T+plus 93 minutes. The initial contact with CHIPSat is expected in a few minutes.

0214 GMT (9:14 p.m. EST Sun.)

T+plus 89 minutes. The upper stage has performed a maneuver designed to move the rocket away from the ICESat and CHIPSat spacecraft.

0208 GMT (9:08 p.m. EST Sun.)

T+plus 83 minutes, 25 seconds. NASA's Cosmic Hot Interstellar Plasma Spectrometer Satellite has been commanded to separate into orbit from the upper stage, completing this double payload deployment mission by Boeing's Delta 2 rocket. For more on the CHIPSat mission, click here.

0207 GMT (9:07 p.m. EST Sun.)

T+plus 82 minutes. The Thule tracking station in Greenland has locked on to the rocket, Boeing says.

0206 GMT (9:06 p.m. EST Sun.)

T+plus 81 minutes. Confirmation has been received that the Reduced Height-Dual Payload Attach Fitting, or RH-DPAF, has separated from the Delta 2 rocket's second stage.

The Astrium-built structure of this size is flying for the first time on this launch. It allows two distinctly different satellites to be flown aboard one Delta 2 rocket, a feature NASA paid Boeing to develop. The larger-sized DPAF has flown on two previous Delta 2 missions for NASA.

DPAF is basically a cylinder with cone on its top where ICESat was mounted and inside resides the CHIPSat payload.

0205 GMT (9:05 p.m. EST Sun.)

T+plus 80 minutes, 20 seconds. The payload adapter should have separated by now. However, officials at Vandenberg do not have live data to verify this event occurred.

0203 GMT (9:03 p.m. EST Sun.)

T+plus 78 minutes. Ground controllers report that the power-generating solar arrays on the ICESat spacecraft have been deployed.

0152 GMT (8:52 p.m. EST Sun.)

T+plus 67 minutes. The second stage has moved out of contact with Malindi. Contact with the rocket should be reestablished via the station in Svalbard, Norway to confirm jettison of the dual payload structure's top portion, revealing CHIPSat packed inside. That separation is expected at T+plus 80 minutes. The deployment of CHIPSat will follow about two-and-a-half minutes later.

0149 GMT (8:49 p.m. EST Sun.)

T+plus 64 minutes. NASA's Ice, Cloud and Land Elevation Satellite has been deployed into orbit from the Boeing Delta 2 rocket! For more on the ICESat mission, click here.

The Delta 2 second stage now will be maneuvering to the proper orientation for separation of the upper portion of the dual payload adapter. CHIPSat release is just under 20 minutes away.

0148 GMT (8:48 p.m. EST Sun.)

T+plus 63 minutes. Now one minute away from deployment of ICESat.

0147 GMT (8:47 p.m. EST Sun.)

T+plus 62 minutes. The Delta 2 rocket has achieved the proper orbit for the ICESat and CHIPSat spacecraft. The high point is 319.388 nautical miles, perigee of 318.744 nautical miles and inclination of 94.0 degrees.

0146 GMT (8:46 p.m. EST Sun.)

T+plus 61 minutes. The vehicle is back in a coast mode again.

0145 GMT (8:45 p.m. EST Sun.)

T+plus 60 minutes. SECO 2 -- the second stage engine has cut off for the second time of this launch.

0144 GMT (8:44 p.m. EST Sun.)

T+plus 59 minutes, 50 seconds. Engine ignition!

0144 GMT (8:44 p.m. EST Sun.)

T+plus 59 minutes. Less than a minute from ignition. This burn will last about eight seconds, raising the orbit's low point to circularize the altitude.

0141 GMT (8:41 p.m. EST Sun.)

T+plus 56 minutes, 40 seconds. The Delta 2 is maneuvering to the engine restart attitude. Ignition is about three minutes away.

0140 GMT (8:40 p.m. EST Sun.)

T+plus 55 minutes, 30 seconds. Malindi has acquired the rocket's signal.

0135 GMT (8:35 p.m. EST Sun.)

T+plus 50 minutes. About 10 minutes remain until the second stage engine is refired to circularize the orbit. The rocket is approaching the southeastern coast of Africa. A tracking station in Malindi, Kenya will be acquiring the rocket's signal and relaying the data back to Vandenberg so engineers can determine the success of the upcoming burn. Deployment of ICESat from the Delta 2 also will be in view of the Malindi site.

0125 GMT (8:25 p.m. EST Sun.)

T+plus 40 minutes. During the coast, the vehicle enters a programmed "BBQ" roll, allowing the second stage and spacecraft to be thermally heated evenly. This roll should conclude at T+plus 50 minutes, 50 seconds. At which time, the stage will maneuver itself into the proper orientation for engine restart.

0115 GMT (8:15 p.m. EST Sun.)

T+plus 30 minutes. The coast phase continues for the Delta 2 rocket. You can see what is left to come, including restart of the second stage and deployment of the spacecraft, on our launch timeline page.

0105 GMT (8:05 p.m. EST Sun.)

T+plus 20 minutes. To see the track this launch is following today, click here.

0100 GMT (8:00 p.m. EST Sun.)

T+plus 15 minutes. This preliminary orbit achieved is right on the mark with a high point of 322.17 nautical miles, low point of 99.95 nautical miles and inclination of 93.96 degrees.

0059 GMT (7:59 p.m. EST Sun.)

T+plus 14 minutes. The vehicle has now passed out of range from the instrumented aircraft positioned over Pacific. The next live data is expected in about 40 minutes when the rocket passes over the next ground station.

0057 GMT (7:57 p.m. EST Sun.)

T+plus 12 minutes. The second stage and the attached ICESat and CHIPSat spacecraft have arrived into a preliminary orbit around Earth. The vehicle will coast until T+plus 59 minutes, 50 seconds when the stage reignites.

0056 GMT (7:56 p.m. EST Sun.)

T+plus 11 minutes, 12 seconds. The second stage engine has shut down as planned. The Delta 2 rocket and the attached ICESat and CHIPSat spacecraft are now in coast period.

0055 GMT (7:55 p.m. EST Sun.)

T+plus 10 minutes, 15 seconds. The Delta 2 rocket is now passing out of range from the Vandenberg tracking station. An instrumented aircraft flying over the Pacific Ocean is relaying data from the rocket back to engineers at Vandenberg.

0053 GMT (7:53 p.m. EST Sun.)

T+plus 8 minutes, 15 seconds. The second stage engine pressures reported normal.

0052 GMT (7:52 p.m. EST Sun.)

T+plus 7 minutes. The official Range liftoff time was 4:45:00.102 p.m. local time.

0051 GMT (7:51 p.m. EST Sun.)

T+plus 6 minutes, 20 seconds. Second stage engine continues to fire. Altitude is 96 miles, downrange distance 410 miles, velocity 10,900 miles per hour.

0050 GMT (7:50 p.m. EST Sun.)

T+plus 5 minutes, 5 seconds. The protective payload fairing enclosing the ICESat and CHIPSat spacecraft atop the rocket has separated.

0049 GMT (7:49 p.m. EST Sun.)

T+plus 4 minutes, 43 seconds. Stage separation confirmed. And the second stage engine has ignited!

0049 GMT (7:49 p.m. EST Sun.)

T+plus 4 minutes, 25 seconds. MECO. The first stage main engine cutoff confirmed.

0049 GMT (7:49 p.m. EST Sun.)

T+plus 4 minutes. Altitude is 47 miles, downrange distance 96 miles, velocity 7,700 mph.

0048 GMT (7:48 p.m. EST Sun.)

T+plus 3 minutes, 5 seconds. A smooth flight reported so far. First stage main engine and twin vernier thrusters are performing normally.

0046 GMT (7:46 p.m. EST Sun.)

T+plus 1 minute, 40 seconds. The spent ground-start solid rocket motors have been jettisoned now that the rocket has cleared the offshore oil drilling platform. The rocket continues to power toward space on the first stage liquid fueled main engine. Altitude 14 miles, downrange distance 12 miles, speed 1,073 mph.

0046 GMT (7:46 p.m. EST Sun.)

T+plus 1 minute, 10 seconds. All three ground-start solid rocket boosters have burned out. Separation will occur once the vehicle passes into a safe drop zone.

0046 GMT (7:46 p.m. EST Sun.)

T+plus 1 minute. Vehicle is stable as it climbs into the dense lower atmosphere.

0045 GMT (7:45 p.m. EST Sun.)

T+plus 20 seconds. Vehicle has rolled to the proper trajectory to head southward to a polar orbit with the ICESat and CHIPSat spacecraft.

0045 GMT (7:45 p.m. EST Sun.)

LIFTOFF! Liftoff of the Boeing Delta 2 rocket -- launching a pair of NASA satellites that seek knowledge of the planet's changing environment and the relics of a cosmic explosion in our galactic neighborhood millions of years ago. And the vehicle has cleared the tower.

0044 GMT (7:44 p.m. EST Sun.)

T-minus 30 seconds. Hydraulics and electronics reported go. Launch pad water system has been activated. Ignitors will be armed at T-minus 11 seconds.

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 three solid rocket motors then light at T-0 for liftoff.

0044 GMT (7:44 p.m. EST Sun.)

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. Also, the first stage liquid oxygen tank is being topped off at 100 percent.

0043 GMT (7:43 p.m. EST Sun.)

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.

0042 GMT (7:42 p.m. EST Sun.)

T-minus 2 minutes, 30 seconds and counting. The final "go for launch" for ICESat and CHIPSat atop the Delta 2 rocket has been given from the spacecraft management team.

0042 GMT (7:42 p.m. EST Sun.)

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

0041 GMT (7:41 p.m. EST Sun.)

T-minus 4 minutes and counting. Now in the final phase of the countdown as the Delta 2 rocket's systems begin transferring to internal power for launch. Liftoff of NASA's Ice, Cloud and Land Elevation Satellite (ICESat) and Cosmic Hot Interstellar Plasma Spectrometer Satellite (CHIPSat) is set to occur at 4:45 p.m. PST from Vandenberg Air Force Base in California.

0040 GMT (7:40 p.m. EST Sun.)

Now five minutes from launch! Standing by for release of the hold in one minute. All the polling has been completed with the decision made to resume the countdown for an on-time launch today.

0037 GMT (7:37 p.m. EST Sun.)

The launch team has been polled with no issues reported.

0036 GMT (7:36 p.m. EST Sun.)

Now half-way through this 10-minute built-in hold. Standing by for the final pre-launch poll of the Boeing launch team to confirm all systems are "go" to resume the countdown for liftoff.

0035 GMT (7:35 p.m. EST Sun.)

NASA Launch Manager Chuck Dovale has performed his clear-to-proceed poll with no problems from the space agency.

0032 GMT (7:32 p.m. EST Sun.)

The ICESat spacecraft is switching to internal power. CHIPSat has been confirmed configured for flight.

0031 GMT (7:31 p.m. EST Sun.)

T-minus 4 minutes and holding. The countdown has entered the final planned built-in hold. This is a scheduled 10-minute pause leading to today's liftoff time of 4:45 p.m. PST (7:45 p.m. EST) for the Boeing Delta 2 rocket with two NASA spacecraft.

During the hold, officials will poll the various team members in the "soft blockhouse," Range Operations Control Center and Mission Directors Center.

At this point, all appears set for an on-time launch today. There have been no technical problems reported and the weather is observed and forecast "go" for launch.

0025 GMT (7:25 p.m. EST Sun.)

T-minus 10 minutes and counting. The countdown is heading to T-minus 4 minutes for a 10-minute hold. Liftoff the Boeing Delta 2 rocket from Vandenberg Air Force Base is still slated to occur at 4:45 p.m. PST.

0022 GMT (7:22 p.m. EST Sun.)

Inhibited checks are beginning for the Range Safety command destruct receivers that would be used in destroying the Delta rocket should the vehicle veer off course and malfunction during the launch.

0015 GMT (7:15 p.m. EST Sun.)

T-minus 20 minutes and counting. Countdown clocks are running again following the planned 20-minute hold. The count will continue to the T-minus 4 minute mark where another hold is scheduled. Launch remains set for 4:45 p.m. PST (7:45 p.m. EST).

0011 GMT (7:11 p.m. EST Sun.)

The Boeing Launch Conductor has polled the launch team to pick up the countdown as planned. No issues were announced. Clocks are set to resume in four minutes.

0008 GMT (7:08 p.m. EST Sun.)

NASA Launch Manager Chuck Dovale has polled his agency team with all reporting "ready" status.

0005 GMT (7:05 p.m. EST Sun.)

Now half-way through this 20-minute built-in hold in the countdown.

0000 GMT (7:00 p.m. EST Sun.)

The launch weather officer just completed briefing to managers. Conditions are currently acceptable and forecast to remain within limits today's liftoff. There are clouds moving onshore and expected to produce broken cloud conditions from 700 to 900 feet at launch time. That's only a problem for viewing, not a problem for actually launching.

Meanwhile, Range Safety's checks of the computer models, based on today's wind conditions and other factors, show the toxics and debris from an explosion early in the Delta rocket's flight would remain away from populated areas. So that constraint to launch is "go" today.

Should liftoff be scrubbed for some reason, the next launch opportunity is Tuesday. The weather is predicted to be 80 percent favorable then.

SUNDAY, JANUARY 12, 2003
2355 GMT (6:55 p.m. EST)

T-minus 20 minutes and holding. Clocks have entered the first of two planned hold periods during the last 20 minutes of the Terminal Countdown for today's 4:45 p.m. PST (7:45 p.m. EST) launch. This pause will last 20 minutes in duration.

These holds are designed to give the launch team a chance to deal with any problems and catch up on work that could be running behind schedule. But at this point, there are no significant issues being addressed on the Delta or spacecraft.

Engineers have just completed gimbal checks of the nozzles on the first stage main engine and twin vernier engines and second stage engine. This test is performed to ensure the engines will be able to steer the rocket during launch.

2345 GMT (6:45 p.m. EST)

Now one hour away from the scheduled liftoff time for the Boeing Delta 2 rocket from Space Launch Complex-2 West at Vandenberg Air Force Base along the central coastline of California. The base is located about half-way between Los Angeles and San Francisco. The rocket will head southward and should be visible to Southern California, weather permitting.

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

2335 GMT (6:35 p.m. EST)

T-minus 40 minutes and counting. Countdown clocks are continuing to the T-minus 20 minute mark where a 20-minute built-in hold is planned. A final 10-minute hold at T-minus 4 minutes will lead to the target liftoff time of 4:45 p.m. PST (7:45 p.m. EST; 0045 GMT).

In the countdown, the launch team has finished the work to pressurize the first and second stage helium and nitrogen systems and the second stage fuel and oxidizer tanks.

2326 GMT (6:26 p.m. EST)

The launch team reports the loading of the Delta 2 rocket's first stage liquid oxygen tank was completed at 3:25:25 p.m. PST (6:25:25 p.m. EST). The operation took 24 minutes and 1-second today. The tank will be replenished through the remainder of the countdown to replace the liquid oxygen that naturally boils away.

The rocket is now fully fueled for launch. The vehicle's first stage was successfully loaded with RP-1 kerosene fuel along with the liquid oxygen over the past hour. The second stage was loaded with its storable nitrogen tetroxide and Aerozine 50 fuels last month; and the three strap-on booster rockets are solid-propellant.

There are no significant problems being reported with the rocket, payloads or ground systems that threaten an on-time launch. And the weather is within limits.

2324 GMT (6:24 p.m. EST)

The liquid oxygen tank has reached the 95 percent full level. The "rapid load" valve is now closed and the slower "fine load" phase is continuing fill the tank.

2311 GMT (6:11 p.m. EST)

Ten minutes into the LOX tanking. The bottom of the rocket is icing over as the super-cold liquid oxygen flows into the first stage.

2306 GMT (6:06 p.m. EST)

Now five minutes into this approximate 25-minute process to fill the first stage liquid oxygen tank.

Weather officials report there is a 100 percent chance of acceptable conditions for today's launch window extending from 4:45 to 5:30 p.m. PST (7:45 to 8:30 p.m. EST; 0045-0130 GMT).

2301 GMT (6:01 p.m. EST)

Cryogenic liquid oxygen, chilled to Minus-298 degrees F, has started flowing from a 28,000-gallon storage tank at Space Launch Complex-2 West, through plumbing and into the bottom of the Boeing Delta 2 rocket. The LOX will be consumed by the first stage main engine during the first four-and-a-half minutes of flight along with the 10,000 gallons of RP-1 kerosene loaded aboard the vehicle during the past hour.

2255 GMT (5:55 p.m. EST)

The Boeing Launch Conductor has given the launch team a "go" to begin preparations for loading the rocket's first stage liquid oxygen tank as planned. Countdown activities are basically back on schedule after the earlier hold up with the control center issue.

2235 GMT (5:35 p.m. EST)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded for today's planned 4:45 p.m. PST (7:45 p.m. EST) liftoff from Vandenberg Air Force Base in California. The tank was loaded with 9,973 gallons of a highly refined kerosene, called RP-1, during a 20-minute, 57-second process that concluded at 2:34:18 p.m. PST.

The next major task in the countdown will be loading super-cold cryogenic liquid oxygen into the first stage starting around the top of this coming hour.

2231 GMT (5:31 p.m. EST)

The first stage fuel tank has been loaded with 9,000 gallons so far. Once the tank is filled with 9,774 gallons, or 98 percent, the "rapid load" valve will be closed and the slower "fine load" phase will continue top off the tank.

2229 GMT (5:29 p.m. EST)

The launch team has computed that the full load for the first stage fuel tank is 9,973 gallons. Over 8,000 gallons are already aboard.

2227 GMT (5:27 p.m. EST)

Now passing the 7,000-gallon mark.

2221 GMT (5:21 p.m. EST)

Now eight minutes into this approximate 20-minute process to load the rocket's first stage with about 10,000 gallons of refined kerosene. Just over 4,000 gallons have been loaded to this point.

Called RP-1, the propellant will be guzzled along with liquid oxygen -- to be pumped into the rocket a little later this afternoon -- by the first stage Rocketdyne RS-27A main engine and twin vernier steering thrusters during the initial four-and-a-half minutes of flight.

2217 GMT (5:17 p.m. EST)

Some 2,000 gallons are already aboard.

2213 GMT (5:13 p.m. EST)

Fueling of the Delta 2 rocket's first stage has begun for today's launch. About 10,000 gallons of a highly refined kerosene propellant, called RP-1, are being pumped into the rocket from a 15,000-gallon storage tank at the Space Launch Complex-2 West pad.

2209 GMT (5:09 p.m. EST)

The Boeing launch team is now beginning the steps to prepare for loading the Delta 2 rocket's first stage RP-1 fuel tank. After verifying valves, sensors, flow meters and equipment are ready, the highly refined kerosene fuel will start flowing into the vehicle.

2205 GMT (5:05 p.m. EST)

With the countdown activities now underway, the launch team is turning on the rocket's Redundant Inertial Flight Control Assembly guidance computer and pressurizing the first and second stage helium and nitrogen systems and second stage fuel tanks.

The first stage fueling that was supposed to start at this time will be temporarily delayed while crews catch up on the earlier work.

2203 GMT (5:03 p.m. EST)

The delayed polled by the Boeing Launch Conductor has been performed, verifying the team members are on console and that all systems are ready for continuing the countdown.

2200 GMT (5:00 p.m. EST)

The launch team members are configuring their consoles again after the earlier glitch. Countdown operations should be restarted shortly.

2145 GMT (4:45 p.m. EST)

T-minus 150 minutes and counting. The Terminal Countdown has started for today's launch of NASA's ICESat and CHIPSat spacecraft aboard a Boeing Delta 2 rocket. Liftoff is scheduled for 4:45 p.m. PST (7:45 p.m. EST) from Space Launch Complex-2 West at Vandenberg Air Force Base in California. The site is on the Pacific Coast, about 140 miles northwest of Los Angeles.

The available launch window extends for 45 minutes. Just like yesterday, officials say there are no COLAs -- Collision Avoidance blackout periods -- for the window. COLAs prohibit liftoff for a few minutes during a window to ensure a rocket isn't launched on a course that would take it too close to an object already orbiting Earth.

The weather is currently reported to be acceptable for launch.

2142 GMT (4:42 p.m. EST)

The plan is to resume the countdown as planned. Some initial activities scheduled after picking up the clock will be performed. Once the control center issue is resolved, a poll of the launch team will occur before pressing on with the rest of the countdown timeline.

2140 GMT (4:40 p.m. EST)

Now five minutes away from picking up the count. The glitch apparently deals with the front-end processor at the control center. The Boeing Launch Conductor has delayed his readiness poll of the launch team while engineers work the problem.

2130 GMT (4:30 p.m. EST)

"Man stations for Terminal Count." That was the message just announced to the launch team in preparation for starting the Terminal Countdown in 15 minutes. Over the last little while, engineers have been working through a control center glitch.

2115 GMT (4:15 p.m. EST)

Now half-way through this scheduled hour-long hold in the countdown. The communications loops are fairly quiet at this point. But the activity will be picking up as polls are conducted before resuming the count.

2100 GMT (4:00 p.m. EST)

The SLC-2W launch pad danger area has been cleared of all personnel.

2045 GMT (3:45 p.m. EST)

T-minus 150 minutes and holding. The countdown has just entered a planned 60-minute built-in hold at Vandenberg Air Force Base in California. The Terminal Countdown will begin once this hold is concluded. Launch is still set for 4:45 p.m. local time (7:45 p.m. EST; 0045 GMT).

2000 GMT (3:00 p.m. EST)

The countdown has entered the final five hours to the launch of Delta 294 with ICESat and CHIPSat for NASA. The launch remains targeted to occur at 4:45 p.m. PST (7:45 p.m. EST) today, the opening of an available 45-minute window.

Clocks at Vandenberg Air Force Base are counting down to the T-minus 150 minute mark where a one-hour hold is planned to begin at 12:45 p.m. PST (3:45 p.m. EST).

1620 GMT (11:20 a.m. EST)

With the faulty valve unit in the launch pad's helium system replaced overnight, Boeing is moving forward with the second countdown for the flight of its Delta 2 rocket with NASA's ICESat and CHIPSat spacecraft. Liftoff is scheduled for 4:45 p.m. PST (7:45 p.m. EST) today.

At the SLC-2W pad, the mobile service tower has been rolled into its launch position and securing work is underway this morning.

The Terminal Countdown is slated to commence at 1:45 p.m. PST (4:45 p.m. EST).

Read our earlier status center coverage.