BY JUSTIN RAY
June 7, 2000 -- Follow the countdown and launch of Orbital Sciences' Pegasus rocket with the TSX-5 experimental satellite for the U.S. Air Force. Reload this page for the very latest on the mission.
1424 GMT (10:24 a.m. EDT)
Today's successful launch marks the 15th straight for an Orbital Sciences Pegasus rocket and 26th out of the 29 flights made in the vehicle's 10-year history. The next Pegasus is scheduled for July to place NASA's HETE-2 satellite into orbit.
1353 GMT (9:53 a.m. EDT)
1337 GMT (9:37 a.m. EDT)
TSX-5 mission manager Capt. Kevin Benedict gives this overview of what should be happening with the satellite:
"After separation of the spacecraft from the rocket, we go through a sequence that deploys the solar arrays immediately. Unfortunately, we're not able to see that exactly because we do not have ground stations that is capable of picking that up. Our first look at it will be approximately 55 minutes after launch we will go over Diego Garcia tracking station, which is part of the Air Force Satellite Control Network. At that time, we should be able to see the satellite, the solar arrays should be deployed, the satellite goes through its boot-up sequence and it is basically waiting there for commands.
"Our Launch and Early Orbit period is approximately four days long -- about 65 hours. With that we take a methodical step of bringing the satellite up, checking out all the systems, making sure everything is operating correctly. Once that is done, we go into our what we call our experiment checkout and that is when we turning on all the major experiments and checking those out, which takes approximately between 15 and 30 days. So at Launch+35 to 45 days, we will actually start operating the experiments."
Meanwhile, the L-1011 carrier aircraft is now heading back to Vandenberg Air Force Base. Also, the first stage has impacted the Pacific Ocean and a boat will be dispatched in a few hours to recover the pieces, the launch team reports.
We will next update once ground controllers establish contact with TSX-5.
1334:06 GMT (9:34:06 a.m. EDT)
1333:04 GMT (9:33:04 a.m. EDT)
1332 GMT (9:32 a.m. EDT)
1330:30 GMT (9:30:30 a.m. EDT)
1329 GMT (9:29 a.m. EDT)
1328 GMT (9:28 a.m. EDT)
1327 GMT (9:27 a.m. EDT)
1326 GMT (9:26 a.m. EDT)
1324:20 GMT (9:24:20 a.m. EDT)
1322:15 GMT (9:22:15 a.m. EDT)
1321:15 GMT (9:21:15 a.m. EDT)
1320:53 GMT (9:20:53 a.m. EDT)
1320:10 GMT (9:20:10 a.m. EDT)
1319:35 GMT (9:19:35 a.m. EDT)
1319:30 GMT (9:19:30 a.m. EDT)
1318:48 GMT (9:18:48 a.m. EDT)
1318:18 GMT (9:18:18 a.m. EDT)
1317:48 GMT (9:17:48 a.m. EDT)
1317:18 GMT (9:17:18 a.m. EDT)
1316:18 GMT (9:16:18 a.m. EDT)
1315:18 GMT (9:15:18 a.m. EDT)
1314 GMT (9:14 a.m. EDT)
1313 GMT (9:13 a.m. EDT)
1310 GMT (9:10 a.m. EDT)
1309 GMT (9:09 a.m. EDT)
1308 GMT (9:08 a.m. EDT)
1305 GMT (9:05 a.m. EDT)
1303 GMT (9:03 a.m. EDT)
1257 GMT (8:57 a.m. EDT)
1250 GMT (8:50 a.m. EDT)
Capt. Bill Weaver earlier described what is like to fly the Stargazer jet during the launch of a Pegasus booster.
"When we drop the Pegasus, there is a pronounced jolt in the airplane. We can all feel it and hear this. The nose will pitch up...because of the 52,000 pound weight loss."
The actual release of Pegasus will be in the hands of co-pilot Don Moore. He will flip a switch on the center console of the cockpit to drop the rocket.
"When the rocket motor ignites, it should be about 500 feet below the airplane, as that lights and accelerates beneath us, it sounds kind of like a freight train going by," Weaver said.
The plane will make a turn to the left to avoid flying through the exhaust plume from the solid-fueled rocket.
"As soon as we rollout from the turn, the Pegasus should be plainly visible in front of us and below us and then it goes up very steeply. Quite impressive and spectacular," Weaver said.
1237 GMT (8:37 a.m. EDT)
1230 GMT (8:30 a.m. EDT)
1221 GMT (8:21 a.m. EDT)
1220:33 GMT (8:20:33 a.m. EDT)
1218 GMT (8:18 a.m. EDT)
1200 GMT (8:00 a.m. EDT)
1150 GMT (7:50 a.m. EDT)
1120 GMT (7:20 a.m. EDT)
Currently senior members of the launch team are conducting voice checks on the various communications channels to be used today.
0830 GMT (4:30 a.m. EDT)
With about 3 1/2 hours until the "Stargazer" aircraft departs Vandenberg, bound for the launch zone over the Pacific Ocean, the Launch Panel Operator will now board the jet at the Hot Pad staging area. The LPO will power up the Pegasus rocket under direction from the Launch Conductor.
While that chore is underway, efforts to close out the Pegasus' access compartments will be finished and Range Safety engineers are scheduled to verify that the Flight Termination System is functioning by sending arm and fire commands to the FTS antennas.
Later this morning other tests will be conducted to ensure the readiness of Pegasus systems. The checks will include verifying the rocket can switch from aircraft-supplied power to its own internal batteries, the Inertial Measurement Unit guidance computer, the Pegasus' flight computer and telemetry system are working normally and testing the control link from the LPO to the payload.
Activities will culminate with the team members opening their launch checklist and starting the carrier jet's engines in the final hour prior to takeoff. Also, the FTS will be powered on and all safety inhibits checked, the Safe and Arm safing pins removed and the rocket placed in a ready state. Shortly before departure, the L-1011 will taxi from the Hot Pad to the runway.
Weather forecasters are calling for a 70 percent chance of acceptable conditions for the launch today. The concerns to watch will be low ceiling/visibility problems, turbulence and layered clouds. Air Force Launch Weather Officer Capt. Joseph Kurtz gave this overview on Tuesday afternoon:
A broad upper-level trough continues to deepen off the west coast of the U.S. The trough will move to the east into the drop box over the next 24 to 48 hours. As this system moves east, the drop box will see increasing layered clouds. Precipitation associated with the system will move into the box about 12 hours after launch. Locally, the marine layer continues to be a thorn in our side, as Vandenberg was about the only area along the central coast that saw low clouds and fog. Expect the marine layer to remain in place on Wednesday morning, although we may see some improvement in ceiling and visibility. Above the marine layer in the Vandenberg area we will have scattered clouds. Flight level winds will increase to between 75 and 85 knots from the southwest, which could cause some turbulence in the drop area.The airfield forecast is calling for stratus clouds with complete sky coverage at 200 feet and cirrus clouds covering 3/8ths of the sky at 25,000 feet, north-northwesterly winds 5 to 10 knots, a temperature between 50 and 54 degrees F and fog.
In the drop box, at an altitude of 39,000 feet over the Pacific some 60 miles west of Monterey, conditions are forecast to include stratus clouds at 1,000 feet, altocumulus clouds at 10,000 feet and cirrus clouds at 24,000 feet, unrestricted visibility, flight level winds of 75 to 85 knots from the southwest and light turbulence.
TUESDAY, JUNE 6, 2000
Just after 5 a.m. local time (8 a.m. EDT; 1200 GMT), the L-1011 carrier aircraft will take off from Vandenberg bound for the predetermined launch zone 60 miles west of Monterey over the Pacific Ocean. Release of the rocket from the belly of the "Stargazer" jet is expected at 6:07 a.m. local time (9:07 a.m. EDT; 1307 GMT).
The available launch window extends from 6:02 to 6:57 a.m. local time (9:02 to 9:57 a.m. EDT; 1302-1357 GMT).
It will take the three-stage Pegasus some 14 minutes and 32 seconds to inject the Tri-Service Experiments Mission-5 satellite into a highly elliptical orbit inclined 69 degrees around Earth. The launch azimuth will be 154.2 degrees.
Spaceflight Now will provide extensive live reports throughout the final hour of the countdown and the launch on Wednesday. Return to this page for the coverage.
0401 GMT (12:01 a.m. EDT)
Officials will review the situation later today at Vandenberg Air Force Base in California where the launch will originate.
Wednesday's available launch window will extend from 6:02 to 6:57 a.m. local time (9:02 to 9:57 a.m. EDT; 1302-1357 GMT). Release of the Pegasus from the L-1011 carrier aircraft is targeted to occur within the window at 6:07:00 a.m. local (9:07:00 a.m. EDT; 1307:00 GMT).
Launch Weather Officer Capt. Joseph Kurtz says there will be a 70 percent chance of acceptable conditions. The weather threats will be layered clouds, turbulence and avoiding cumulus clouds.
A weather disturbance is forecast to move toward the drop box early this week and the area will see increasing layered clouds and a chance for isolated rainshowers, Kurtz said. The jet stream will also move into the box and winds at flight level will be 95 knots from the southwest, which could cause some turbulence.
MONDAY, JUNE 5, 2000
"We are taking more time to understand it and then we will be ready to go," Orbital Sciences spokesman Barry Beneski said.
0401 GMT (12:01 a.m. EDT)
Activities are reported to be on track for the launch, which will be staged from Vandenberg Air Force Base in California.
The L-1011 carrier aircraft -- called "Stargazer" -- arrived at Vandenberg on Thursday. A four-hour operations rehearsal was successfully completed on Friday night.
On Saturday morning, the three-stage solid-fueled Pegasus rocket was rolled atop a mobile transport trailer from its processing facility -- Vandenberg's Building 1555 -- to the "hotpad" a few miles away to join the L-1011. Mating between the two occurred at around 8:30 a.m. local time with no significant problems.
The Combined Systems Test to verify the electrical and mechanical connections between Pegasus and Stargazer was scheduled for Sunday; and the final launch readiness meeting is planned this morning.
Satellite technicians will begin arriving at the launch site just after midnight local time (3 a.m. EDT; 0700 GMT) on Tuesday morning to begin last-minute preparations. Their work will include transferring the spacecraft from ground power to a trickle-charge and unhooking the umbilical cord leading to the satellite in advance of the L-1011 heading to the runway for takeoff.
The launch team will begin reporting on station about an hour later and Launch Operations should start at 1:30 a.m. local (4:30 a.m. EDT; 0830 GMT).
If all remains in readiness, the L-1011 will depart Vandenberg at 5:07 a.m. local (8:07 a.m. EDT; 1207 GMT) bound for the "drop box" about 60 miles west of Monterey, Calif., over the Pacific Ocean.
Tuesday's available launch window extends from 5:57 to 6:55 a.m. local (8:57 to 9:55 a.m. EDT; 1257-1355 GMT). However, officials are targeting 6:07:00 a.m. local (9:07:00 a.m. EDT; 1307:00 GMT) for drop of Pegasus, said Capt. Kevin Benedict, the TSX-5 mission manager.
Read our launch preview story for more details on the TSX-5 satellite and its $85 million multi-nation research mission.
Flight data file
Vehicle: Pegasus XL
Launch date: June 7, 2000
Launch window: 1302-1357 GMT (9:02-9:57 a.m. EDT)
Launch site: Over Pacific Ocean
Launch preview - Our story describing the launch and TSX-5 satellite's mission.
Launch timeline - Chart with times and descriptions of events to occur during the launch.
Pegasus XL vehicle data - Overview of the rocket that will launch TSX-5 into space.
TSX-5 - Description of the U.S. Air Force satellite to be launched.