Follow the preparations and launch of the Orbital Sciences Pegasus XL rocket with NASA's Galaxy Evolution Explorer spacecraft. Reload this page for the very latest on the mission.

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TUESDAY, MAY 6, 2003

The protective cover on the Galaxy Evolution Explorer's telescope was successfully opened at 4:32 a.m. EDT (0832 GMT) Tuesday morning as ground controllers guide the craft through its early life in space.

Here is the project status report:

The cover deployment sequence involved the heating of a thermal actuator, which melted a wax pellet. When the wax melted, it pushed a mechanical pin, which in turn released the cover. This release enabled a spring-loaded hinge to swing open the cover. The cover is now safely stowed against the side of the spacecraft, where it will remain for the duration of the mission. Confirmation of successful cover deployment was received in real time at the Mission Operations Center at Orbital Sciences Corporation in Dulles, Virginia.

On Saturday, May 3, engineers began the process of turning on the science instrument. So far, they have powered up both the digital processing unit, which houses the main computer, and the detector front-end electronics box, which contains the photon discrimination and processing logic. The procedure went very smoothly. The spacecraft computer, mechanisms and heaters are operating properly, and telemetry and data have been routinely transmitted to Earth.

The rest of this week ground controllers will put the spacecraft through its paces by sending it simulated sequence commands. Next week, the high voltage power supply will be gradually brought up to operational voltage. High voltage is essential for the telescope to gather the ultraviolet photons that will help scientists piece together the story of how and when stars form inside galaxies.

The two weeks after launch serve as a decontamination period, when moisture and other materials absorbed by the spacecraft's paint and thermal blankets bleed away, or "outgas."

Once the optic wheel is rotated into position, the telescope will begin gathering photons -- a milestone known as first light. This will occur on or about May 19.

MONDAY, APRIL 28, 2003

A diminutive satellite with a monumental goal of mapping the history of star formation in a million galaxies streaked into space today atop an air-launched rocket booster. Read our full launch story.

1320 GMT (9:20 a.m. EDT)

GALEX is operating well, NASA says. The power-generating solar panels on the spacecraft have been deployed. Also, the orbit achieved is right on target.

1218 GMT (8:18 a.m. EDT)

NASA Launch Manager Chuck Dovale confirms a successful deployment of GALEX today.

So with that, we will pause our coverage for now. Check back a little later this morning for an update on deployment of the GALEX solar arrays and the spacecraft's health.

1215 GMT (8:15 a.m. EDT)

Ground controllers have seen indication that GALEX is alive and active following its launch this morning.

1212 GMT (8:12 a.m. EDT)

The launch team is reporting that the orbit achieved today has a high point of 702.12 km, low point of 689.5 km and inclination of 28.996 degrees to the equator.

1211 GMT (8:11 a.m. EDT)

T+plus 11 minutes, 20 seconds. The third stage is performing a maneuver to move away from the GALEX spacecraft.

1211 GMT (8:11 a.m. EDT)

T+plus 11 minutes, 2 seconds. SPACECRAFT SEPARATION! NASA's Galaxy Evolution Explorer spacecraft has been deployed from the Orbital Sciences Pegasus XL rocket's third stage to complete today's launch!

1210 GMT (8:10 a.m. EDT)

T+plus 10 minutes. The vehicle has slewed around to the proper attitude for GALEX release.

1209 GMT (8:09 a.m. EDT)

T+plus 9 minutes, 30 seconds. The rocket is now maneuvering itself to the proper orientation for spacecraft deployment.

1209 GMT (8:09 a.m. EDT)

T+plus 9 minutes, 10 seconds. The third stage has burned out, completing the powered phase of GALEX's launch.

1208 GMT (8:08 a.m. EDT)

T+plus 8 minutes, 45 seconds. Third stage is firing. Attitude is still normal.

1208 GMT (8:08 a.m. EDT)

T+plus 8 minutes. Confirmation has been received of ignition by the solid-fueled third stage motor, accelerating the GALEX spacecraft to its orbit.

1207 GMT (8:07 a.m. EDT)

T+plus 7 minutes, 44 seconds. The spent second stage has separated. Standing by for ignition of the upper stage.

1207 GMT (8:07 a.m. EDT)

T+plus 7 minutes, 30 seconds. Altitude is now 400 miles.

1207 GMT (8:07 a.m. EDT)

T+plus 7 minutes. The vehicle is now reorienting in preparation for stage separation and third stage burn.

1206 GMT (8:06 a.m. EDT)

T+plus 6 minutes, 15 seconds. Vehicle system performance being verified healthy.

1205 GMT (8:05 a.m. EDT)

T+plus 5 minutes, 30 seconds. Attitude still nominal as the rocket passes 300 miles.

1204 GMT (8:04 a.m. EDT)

T+plus 4 minutes, 15 seconds. Orbital Sciences reports the performance thus far looks normal. The rocket is currently in a good attitude in this coast period.

1204 GMT (8:04 a.m. EDT)

T+plus 4 minutes. Third stage ignition is now calculated to occur at T+plus 7 minutes, 55.2 seconds. The start time based upon the performance of the vehicle's first two stages.

1202 GMT (8:02 a.m. EDT)

T+plus 2 minutes, 55 seconds. The solid-fueled second stage has burned out. The Pegasus rocket is now in a coast period for the next four and a half minutes or so. During this time the rocket will compute the performance of the flight thus far and adjust the third stage ignition time if necessary.

1202 GMT (8:02 a.m. EDT)

T+plus 2 minute, 38 seconds. Altitude 100 miles. Standing by for burnout of second stage.

1202 GMT (8:02 a.m. EDT)

T+plus 2 minute, 12 seconds. The two halves of the payload fairing enclosing the GALEX satellite on the end of the Pegasus rocket has been jettisoned. Second stage continues to burn.

1202 GMT (8:02 a.m. EDT)

T+plus 2 minutes. Velocity passing 7,000 mph as the second stage continues to fire.

1201 GMT (8:01 a.m. EDT)

T+plus 1 minute, 40 seconds. The first stage has separated and ignition of the Pegasus' second stage has occurred.

1201 GMT (8:01 a.m. EDT)

T+plus 1 minute, 20 seconds. The solid-fueled first stage has burned out. The vehicle is now in a ballistic coast for a few seconds before the spent stage is jettisoned and the second stage ignites.

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

T+plus 40 seconds. The Pegasus rocket is passing through maximum dynamic pressure. Attitude of the vehicle is reported normal.

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

T+plus 30 seconds. Vehicle is pitched up at 30 degrees as it climbs into the morning sky.

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

IGNITION. NASA's GALEX spacecraft is on its way to survey the history of star formation in the Universe!

1159:54 GMT (7:59:54 a.m. EDT)

DROP. The Orbital Sciences Pegasus XL rocket has been released from the L-1011 aircraft.

1159 GMT (7:59 a.m. EDT)

T-minus 30 seconds. The batteries for the first stage flight control fins have been activated, allowing the fins to undergo a sweep test prior to launch. The fins are used to steer the rocket during its initial climb to space.

With the batteries activated there is just 90 seconds to launch today or else an abort will be called. That is due to the limited life of the batteries.

In the final moments prior to release of Pegasus, the L-1011 carrier aircraft crew will oversee the last seconds of the countdown and flip the switch that will drop the three-stage vehicle, with the GALEX spacecraft aboard, from the belly of the jet.

1159 GMT (7:59 a.m. EDT)

T-minus 1 minute and counting.

1158 GMT (7:58 a.m. EDT)

T-minus 90 seconds. The carrier aircraft now achieving the proper launch heading.

1158 GMT (7:58 a.m. EDT)

T-minus 2 minutes. Data recorders in the telemetry receiving lab have been started.

1156 GMT (7:56 a.m. EDT)

T-minus 3 minutes, 30 seconds. The transient power bus has switched to internal and the rocket's guidance computer is going to free inertial mode.

1156 GMT (7:56 a.m. EDT)

T-minus 4 minutes and counting. The launch team now entering the final checklist for today's flight of the Pegasus rocket with NASA's GALEX spacecraft. Drop time is set for approximately 8:00 a.m. EDT.

1154 GMT (7:54 a.m. EDT)

Launch Weather Officer Jim Sardonia confirms weather conditions are "go."

1154 GMT (7:54 a.m. EDT)

The Pegasus rocket's avionics are now switching from power provided by the L-1011 to internal battery power with no problems reported. Also, the Range reports the FTS checks were nominal.

1153 GMT (7:53 a.m. EDT)

The final launch readiness poll by NASA Launch Manager Chuck Dovale has been performed and all systems remain "go" for drop the Pegasus rocket.

1153 GMT (7:53 a.m. EDT)

Based on the flight time of the carrier jet, the planned drop time has been adjusted to 7:59:52 a.m. EDT.

1152 GMT (7:52 a.m. EDT)

Checks of the flight termination system are being performed. The FTS would be used to destroy the Pegasus rocket should a problem arise during the launch.

1151 GMT (7:51 a.m. EDT)

The rocket's flight termination system is transferring to internal power.

1150 GMT (7:50 a.m. EDT)

The L-1011 has completed its loop and is now heading back to the east for launch.

1148 GMT (7:48 a.m. EDT)

NASA's GALEX spacecraft aboard the Pegasus rocket is now switching to internal power for launch.

1147 GMT (7:47 a.m. EDT)

The drop time for the air-launched Pegasus depends on when the L-1011 reaches the proper location to release the rocket. At this point, clocks in the control center are now counting down to an 8:01:11 a.m. drop.

1146 GMT (7:46 a.m. EDT)

The release mechanism that will drop the Pegasus rocket from the L-1011 carrier jet has been armed. This hydraulic system involves four main hooks holding the Pegasus to the aircraft as well as a nose hook.

1145 GMT (7:45 a.m. EDT)

Now 15 minutes from the targeted launch time.

1139 GMT (7:39 a.m. EDT)

The "P-turn" point is now occurring for the L-1011. The aircraft is banking to the right, heading northwesterly for the start of a loop to turn around and head back to the drop point.

1137 GMT (7:37 a.m. EDT)

The aircraft crew reports the current altitude is 38,000 feet and still climbing.

1134 GMT (7:34 a.m. EDT)

The Stargazer carrier aircraft has completed the U-turn and is now headed westerly through the drop box for today's launch. The plane will actually fly through the box before making another looping turn to head back and drop the Pegasus.

1125 GMT (7:25 a.m. EDT)

T-minus 35 minutes and counting. The L-1011 is nearing the U-turn, which is the furthest point east on the flight track.

1120 GMT (7:20 a.m. EDT)

T-minus 40 minutes and counting. Things are still progressing on schedule for launch at 8:00 a.m. EDT. The aircraft is on course. No problems are being reported.

1110 GMT (7:10 a.m. EDT)

T-minus 50 minutes and counting. The flight path of the L-1011 today takes the jet east away from the Cape. After reaching a point well off the coast, Stargazer then will make a U-turn to head west, back toward Florida, allowing the aircraft to fly through the pre-determined drop box where the Pegasus rocket will be released, albeit traveling in the wrong direction. The pass through the box, however, allows the aircraft crew to verify weather conditions in the area.

After flying through the box, the aircraft will make another looping turn to head back for the box. About 90 seconds before the drop the flight crew will turn the L-1011 to the proper heading for launch.

1103:05 GMT (7:03:05 a.m. EDT)

The "Stargazer" carrier aircraft with the Orbital Sciences Pegasus XL rocket attached to its belly has departed the Skid Strip at Cape Canaveral Air Force Station in Florida for today's launch to place NASA's GALEX spacecraft into orbit.

1102:31 GMT (7:02:31 a.m. EDT)

Stargazer is now rolling down the 10,000-foot long runway.

1101 GMT (7:01 a.m. EDT)

The tower has given the aircraft clearance for takeoff.

1100 GMT (7:00 a.m. EDT)

T-minus 1 hour and counting.

1058 GMT (6:58 a.m. EDT)

After polling the ground launch team, the Orbital Sciences launch conductor has given the aircraft crew a "go" for takeoff.

1056 GMT (6:56 a.m. EDT)

The weather reconnaissance aircraft reports the flight path for the Pegasus rocket's L-1011 carrier jet is currently clear. There have been two thunderstorms that officials were tracking. But at this point, the weather does not appear to be a problem.

1052 GMT (6:52 a.m. EDT)

NASA Launch Manager Chuck Dovale has given his approval for takeoff following a poll of the space agency team.

1048 GMT (6:48 a.m. EDT)

The takeoff time has been shifted a minute to 7:03 a.m. EDT.

1037 GMT (6:37 a.m. EDT)

A poll of the GALEX spacecraft team has been performed with officials reporting a "go" status for continuing with countdown operations.

1030 GMT (6:30 a.m. EDT)

Dawn is breaking at Cape Canaveral as activities continue for today's Pegasus rocket launch carrying NASA's GALEX observatory.

The L-1011 carrier jet has moved to the runway for takeoff. The "Stargazer" aircraft with a 5-person primary crew aboard is expected to be airborne by 7:02 a.m. EDT. Drop of Pegasus remains scheduled for 8:00 a.m. EDT about 100 miles off the coast.

The weather has prompted some discussion for launch officials this morning. There are some showers off the coast which might require some tweaking to the Stargazer's flight path to avoid that weather.

Otherwise, there are no technical problems being reported by NASA.

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

The countdown is underway at Cape Canaveral Air Force Station in Florida for this morning's launch of NASA's Galaxy Evolution Explorer spacecraft aboard an Orbital Sciences Pegasus XL rocket.

The Pegasus countdown lasts a little less than five hours. It features a series of ground-based events such as final preparations to the GALEX payload, performing power tests on the rocket and checking the Range Safety's Flight Termination System. In about an hour, the L-1011 carrier aircraft will taxi to the runway. Takeoff it expected around 7 a.m. EDT. The jet will fly a pre-determined "race track" pattern over the Atlantic to reach the proper launch point where Pegasus will be released to roar into orbit.

Today's launch window extends from 7:50 to 9:50 a.m. EDT.

SUNDAY, APRIL 27, 2003

The weather forecast has improved for tomorrow's launch of GALEX aboard the Pegasus rocket. Launch Weather Officer Jim Sardonia now says there is a 90 percent chance of acceptable conditions.

"Dry air behind the last front has produced ideal weather conditions today with clear to partly cloudy skies and light winds in the local area. These dry conditions are expected to continue locally and to the east of Cape Canaveral through the early AM hours of Monday, improving the chances of favorable weather for the launch operation. There will only be a slight chance of enhanced cumulus clouds developing in the Gulf Stream along the flight path of the L-1011 prior to Pegasus drop.

"The only concern for launch day will be the slight chance of enhanced cumulus clouds developing in the L-1011's flight path east of Cape Canaveral (Cumulus Cloud Rule)."

We will begin our live reports on this page beginning at 6:30 a.m. EDT as the L-1011 prepares to depart Cape Canaveral's Skid Strip for the pre-determined drop zone about 100 miles off the coast.

1600 GMT (12:00 p.m. EDT)

The launch readiness review was successfully conducted earlier today. The meeting concluded with senior managers giving final approval to continue with preparations for Monday's flight of the Pegasus rocket carrying NASA's GALEX spacecraft. The launch window extends from 7:50 to 9:50 a.m. EDT with drop of the air-launched rocket targeted for 10 minutes into the period.

No problems are being reported by NASA.

"It's certainly been a long road getting here. But I can tell you that the team is ready and determined for a good flight on Monday," NASA launch director Chuck Dovale said at the pre-launch news conference.

The weather forecast remains favorable for the launch opportunity. There is just a 20 percent chance that rainshowers along the L-1011 carrier aircraft's flight path from Cape Canaveral to the launch zone over the Atlantic Ocean would present a problem.

"The convective system responsible for all the rain and thunderstorms in the last 24 hours is slowly shifting to the south and east of Central Florida. Rainshowers will gradually diminish today as the system moves south, however skies will remain Overcast and surface winds will be gusty for most of the day. Improving conditions are expected on Sunday and early Monday as the remnants of the front remain south of Cape Canaveral," Launch Weather Officer Jim Sardonia reported today.

"During the launch countdown (Monday AM), there will be a slight chance of enhanced Cumulus Clouds developing into rainshowers along the Flight Path of the L-1011 prior to Pegasus Drop.

"The main concern for launch day will be the slight chance of rainshowers developing in the L-1011's flight path east of Cape Canaveral (Cumulus Cloud Rule)."


An observatory that will survey 10 billion years of the Universe's history like never before will be hurled into space Monday aboard an air-launched Pegasus XL rocket.

Dropped from the belly of the Stargazer carrier jet off the east coast of Florida at 8:00 a.m. EDT (1200 GMT), the 51,000-pound, three-stage Orbital Sciences launcher will deliver NASA's Galaxy Evolution Explorer into a 430-mile circular orbit inclined 29 degrees to the equator.

Read our launch preview.

The weather forecast for Monday's launch calls for an 80 percent chance of favorable conditions.

Launch Weather Officer Jim Sardonia says: "A weak frontal system will bring a chance of rainshowers and isolated thunderstorms to the area on Friday and early Saturday. This system is expected to clear the local area on Sunday moving into the waters of the Atlantic. As the system moves over the warmer waters of the Gulf Stream late Sunday and early Monday, there is a chance of enhanced Cumulus Clouds developing into rainshowers in that area (50-100 miles east of Cape Canaveral Air Force Station).

"The main concern for launch day will be the slight chance of rainshowers developing in the portion of the L-1011's flight path located over the Gulf Stream (Cumulus Cloud Rule)."

We will provide live play-by-play countdown and launch reports on this page starting at 6:30 a.m. EDT Monday as the L-1011 prepares for takeoff.

Flight data file
Vehicle: Pegasus XL
Payload: GALEX
Launch date: April 28, 2003
Launch window: 7:50-9:50 a.m. EDT (1150-1350 GMT)
Mission staging site: Cape Canaveral, Florida
Satellite broadcast: AMC 2, Transponder 9, C-band

Pre-launch briefing

Mission preview - Our story providing an overview of this launch.

Launch timeline - Chart with times and descriptions of events to occur during the launch.

GALEX spacecraft - A technical look at the Galaxy Evolution Explorer.

Telescope - Description of the telescope at the heart of GALEX.

Science goals - A look at the GALEX mission objectives.

Galaxies - Article on why study how galaxies form.

Pegasus XL rocket - Overview of this air-launched rocket.

Pegasus directory - See our coverage of previous Pegasus rocket flights.



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