Atlas 2A rocket launches NASA data relay satellite

Posted: March 8, 2002

The Atlas 2A rocket roars to life. Photo: NASA
An advanced communications satellite built to keep NASA's orbiting data relay network working for years to come was successfully hauled into space Friday aboard a Lockheed Martin Atlas 2A rocket.

The $220 million mission began at 5:59 p.m. EST when the rocket fired off launch pad 36A at Cape Canaveral Air Force Station in Florida. The launch was pushed back 20 minutes so engineers could work through a data glitch between the pad and control center.

The Atlas rocket arced over the Atlantic Ocean on an easterly track, soaring into crystal clear skies. With perfect lightning conditions from the setting sun to the west, powerful tracking cameras were able to follow the rocket much longer than usual, even showing the spent first stage falling away nearly five minutes after liftoff.

The Centaur upper stage performed two firings, the first to achieve a low-altitude parking orbit around Earth and later to reach a highly elliptical subsynchronous transfer orbit.

The Lockheed Martin-built rocket lifts off from on pad 36A. Photo: NASA TV/Spaceflight Now
The Centaur was programmed to fire until it ran out of propellant, ensuring its cargo would be placed into the highest orbit possible in a bid to extend the useful life of the satellite by conserving its fuel supply.

Thirty minutes into the flight, the Tracking and Data Relay Satellite-I, or TDRS-I, was successfully deployed from the rocket into an orbit about 2,000 miles higher than required.

"This was another flawless flight for Atlas," said Mark Albrecht, president of International Launch Services, the U.S./Russian endeavor that globally markets the Atlas and Proton family of rockets.

The orbit achieved has a high point of 18,105 miles. The minimum requirement for success was 15,767 miles. The low point of the orbit is 138 miles for a predicted 139 miles and inclination right on the money at 27.0 degrees to the equator.

It was the 60th straight time an Atlas rocket has launched successfully, a string that dates back to 1993.

The booster and sustainer engines propel the Atlas 2A rocket into the sky. Photo: NASA TV/Spaceflight Now
"We're proud of our record, which is 100 percent for the Atlas 2 and 3 families. We also have provided 100 percent success for NASA missions on Atlas. This demonstrates the dedication of the Atlas team to Mission Success," Albrecht said.

Ground controllers quickly picked up the signal from TDRS-I through the Air Force's Diego Garcia tracking station in the Indian Ocean, confirming the Boeing Satellite Systems-built craft was alive following launch.

"The entire TDRS team did an outstanding job preparing for and conducting today's launch," said TDRS Project Manager Bob Jenkens. "I'm very happy to report that we have received telemetry indicating that we have a healthy spacecraft."

Over the next 10 days, the satellite is slated to perform eight maneuvers to climb into a circular geostationary orbit 22,300 miles over the equator. The craft will match the Earth's rotation at such an altitude, appearing fixed over one spot of the globe.

Controllers will position TDRS-I at 150 degrees West longitude above the equator so a two-month series of tests can be conducted.

Once the checkout is completed, NASA will take complete ownership of the spacecraft from Boeing, renaming it TDRS-9 for its entry into the TDRS constellation. Tentative plans call for the new satellite to be serve in the network's "East" slot over the Atlantic Ocean.

Illustration of TDRS system and its various users. Photo: NASA
Working like switchboards 22,300 miles above the planet, the NASA Tracking and Data Relay satellites receive voice, television and data transmissions from orbiting space shuttles, the International Space Station and various other satellites and relay the information to Earth. The satellites work in reverse, too, allowing ground teams to send signals to their spacecraft via TDRS.

"This becomes an essential link in the exploration of space, the ability to get the data back and provide the ability to process it and exploit it and carry on the task of exploring the Universe," said Jack Wormington, senior vice president of Programs for Boeing Satellite Systems.

The TDRS system was conceived in the 1970s as a means to close costly ground stations scattered around the globe. The first TDRS satellite was launched by space shuttle Challenger on STS-6 in April 1983.

Today, NASA operates a constellation of seven TDRS satellites. One other satellite, TDRS-B, was destroyed in the 1986 Challenger accident.

TDRS-I is the second of three next-generation satellites being launched. Photo: NASA
TDRS-I is the second of three next-generation satellites ordered by NASA to keep its preeminent space-based communications relay system functioning into the next decade, while also increasing its capabilities.

"This is a very capable switchboard in the sky with S-band, Ku-band and Ka-band capabilities," Wormington said of the advanced TDRS-H, I and J satellites.

With their new Ka-band relay package, an addition from earlier TRW-built TDRS satellites, the data rate capability has increased to 800 million bits per seconds rather than 300 million bits per seconds provided through other means, and is less susceptible to interference from the increasingly busy radio environment.

"This TDRS-I satellite, along with H and J, will replenish and augment the current TDRS fleet, which has served the space shuttle and other orbiting spacecraft for almost two decades," Jack Wormington said.

"The TDRS spacecraft are the lifeline of mankind in space, safeguarding astronauts by providing direct contact with Earth. The TDRS satellites relay large volumes of user satellite data -- including voice, video and scientific -- from manned missions or orbiting scientific spacecraft back to ground control centers."

An artist's concept of the TDRS-H, I, J. Photo: Boeing
The TDRS-H satellite was launched in June 2000, but soon after engineers discovered a design flaw with an onboard antenna that reduced the craft's performance. Five of the 18 communications services provided by TDRS-H were affected by the problem.

"In the build of the Multiple-Access Antenna for TDRS-H, we had one material that didn't perform as required," Wormington said. "It was a condition not detectable in ground tests. Unfortunately, when we discovered it, it was already on orbit.

"We investigated it, found what was wrong with it, changed the design to account for the material's property and fully expect both TDRS-I and J will perform as required."

The high data rate services using the satellite's 15-foot-diameter Single Access antennas were not impacted by the flaw.

NASA finally took possession of TDRS-H last fall, renaming it TDRS-8. Jenkens said the satellite is currently co-located with TDRS-7 at the constellation's "West" slot a 171 degrees West longitude. Following the completion of the ongoing space shuttle mission, NASA will press the new satellite into full service.

The TDRS-J satellite is being prepared for launch in November aboard the final flight of the Atlas 2A rocket, which is currently the smallest and least powerful version of the Lockheed Martin Atlas family currently in operation.

Now showing
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The 219-foot tall mobile service tower is wheeled away from the Lockheed Martin Atlas 2A rocket in the final three hours of the countdown to launch.
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The Atlas 2A rocket lifts off from Cape Canaveral at 5:59 p.m. EST carrying NASA's Tracking and Data Relay Satellite-I. This is a 2 1/2-minute clip of the launch.
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With lighting conditions just right, separation of the booster package, jettison of the nose cone and even the spent Atlas stage falling away is seen in this remarkable footage of launch.
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With the Atlantic Ocean as backdrop, this replay of launch is from a camera positioned southwest of launch pad 36A to provide a picturesque view.
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A launch pad camera proves this dramatic view of umbilicals pulling away from the Atlas 2A rocket has it lifts off.
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Watch the liftoff of the Lockheed Martin Atlas rocket as seen from the press viewing area at Cape Canaveral.
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A camera located in the Cape Canaveral Air Force Station's Industrial Area recorded this view of the Atlas rocket launching the TDRS-I spacecraft.
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A powerful tracking camera at Patrick Air Force Base follows the Atlas rocket has it blasts off and arcs over the Atlantic Ocean.
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See full listing of video clips.
Flight data file
Vehicle: Atlas 2A (AC-143)
Payload: TDRS-I
Launch date: March 8, 2002
Launch window: 5:39-6:19 p.m. EST (2239-2319 GMT
Launch site: SLC-36A, Cape Canaveral AFS, Fla.
Satellite broadcast: GE-2, Trans. 9, C-band

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

Ground track - See the trajectory the rocket will follow during its flight.

Launch windows - Available windows for possible future launch dates of TDRS-I.

Atlas 2A vehicle data - Overview of the rocket to be used in this launch.

TDRS-I - Description of this NASA tracking and data relay satellite.

Atlas index - A directory of our previous Atlas launch coverage.