August 18th, 2017
CAPE CANAVERAL, Fla. — A United Launch Alliance (ULA) Atlas V rocket with NASA’s newest communications spacecraft, Tracking and Data Relay Satellite M (TDRS-M). Liftoff took place at 8:29 a.m. EDT (12:29 GMT) on August 18, 2017.
The launch occurred about 26 minutes into a 40-minute window due to an issue detected on the vehicle’s Centaur upper stage engine, the RL10C. Thermal conditioning took a bit longer than planned. The pre-chill eventually took place, clearing the way for a successful liftoff and eventual satellite deployment.
Weather for the launch was nearly perfect. In the hours before liftoff, the had predicted a 90 percent chance of favorable conditions. The only concern was the potential for thick clouds. However, those never materialized. Additionally, an offshore anvil cloud stayed just far enough away to not be a problem.
Once the finally reached zero, the 191-foot (58-meter) tall Atlas V (AV-074), which was in the 401 configuration (four-meter fairing, zero solid rocket boosters, and a single engine Centaur upper stage), rose into the Florida skies away from Space Launch Complex 41 atop a column of flame produced by the first stage’s RD-180 engine.
Just under 1.5 minutes into the flight, the vehicle passed Mach 1 – the speed of sound. Some three minutes later, the Common Core Booster first stage finished consuming its rocket grade kerosene and liquid oxygen propellant. At 4 minutes, 8 seconds after leaving Cape Canaveral, the booster separated with the upper stage and fell away.
About 10 seconds later, the Centaur upper stage’s RL10C engine ignited to continue powering toward orbit. Consuming liquid oxygen and liquid hydrogen, the engine burned for almost 14 minutes before shutting down as planned. During that time, at 4 minutes, 26 seconds into flight, the payload fairing jettisoned, revealing TDRS-M to the vacuum of space.
About 18 minutes after launch, the Centaur upper stage with TDRS-M on top was in a parking orbit. There, the duo coasted for about 90 minutes before the RL10C ignited again for about a minute to place the satellite into a geostationary transfer orbit of about 2,882 by 22,237 miles (4,638 by 35,787 kilometers) inclined 26.2 degrees from the equator.
TDRS-M separated from Centaur at about 1 hour, 53 minutes into the flight. It will use its onboard propellant to finish the job of circularizing its orbit into a geostationary orbit where it will reside with nine other TDRS satellites – seven of which are active and two are in storage orbits.
The is the set of geostationary orbiting satellites that NASA uses to communicate with its array of low-Earth orbiting spacecraft, and with U.S. scientific facilities in Antarctica. The satellites are used by the space agency to communicate with an array of orbiting assets.
TDRS is considered to be essential to maintaining continuous communications with important NASA spacecraft, including the International Space Station and the Hubble Space Telescope. TDRS-M is the latest addition to this constellation and completes the of TDRS satellites.
“ULA uses the TDRS system as a primary means of receiving and distributing launch vehicle telemetry data during every flight. In fact, the TDRS-K and TDRS-L spacecraft, launched by ULA in 2013 and 2014 tracked today’s launch” said Laura Maginnis, ULA vice president of Government Satellite Launch, in a news release. “We are absolutely honored to have delivered this core NASA capability and critical national resource for our country.”
The launch of TDRS-M was delayed from August 3, 2017, when a July during the satellite’s check-out damaged the spacecraft’s Omni S-band antenna. Boeing, the spacecraft’s manufacturer, replaced the antenna and resolved an unrelated damage incident caused by static electricity discharge.
After the repairs, NASA expected to launch on August 20 but managed to get an earlier launch date of August 18 with a 40-minute window opening at 8:03 a.m. EDT (12:03 GMT).
The TDRS-M satellite was encapsulated in its payload fairing and delivered to the Vertical Integration Facility on August 9. The Atlas V rocket was to its launch pad on its Mobile Launch Platform on August 16.
NASA has not yet begun acquiring the fourth generation of TDRS spacecraft, but the agency is planning a test bed satellite for laser communications for launch in 2019. The Laser Communication Relay Demonstration will launch alongside other payloads on a host satellite and will demonstrate the ability to relay a communications laser from a spacecraft to a ground station. The satellite is being developed at Goddard Space Flight Center, which also develops the TDRS constellation.
The satellite was manufactured by Boeing, the aerospace giant delivered the first of these spacecraft in 2000 and TDRS-M was the sixth TDRS satellite to be produced by Boeing.
“This TDRS-M milestone is another step forward in Boeing’s commitment to developing technologies to support future NASA near-Earth, moon, Mars and deep space missions – and to do so affordably, drawing on our 40-plus years of strong Boeing-NASA partnership,” said Enrico Attanasio, executive director, Department of Defense and Civil Programs, Boeing Satellite Systems via a release issued by the company.
Today’s flight was the 120th ULA mission and the 72nd Atlas V launch. In particular, it was the 37th flight of the 401 configuration. This was the third TRDS satellite launched by ULA.
The next Atlas V launch is currently targeting early September from Vandenberg Air Force Base. The mission, NROL-42, will send a classified payload into orbit for the National Reconnaissance Office. The rocket will fly in the 541 configuration, meaning it will have a five-meter fairing, four solid rocket motors, and a single engine Centaur upper stage.
“The TDRS fleet is a critical connection delivering science and human spaceflight data to those who can use it here on Earth,” said Dave Littmann, the TDRS project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland via a release issued by the space agency. “TDRS-M will expand the capabilities and extend the lifespan of the Space Network, allowing us to continue receiving and transmitting mission data well into the next decade.”
Video courtesy of NASA
Christopher Paul has had a lifelong interest in spaceflight. He began writing about his interest in the Florida Tech Crimson. His primary areas of interest are in historical space systems and present and past planetary exploration missions. He lives in Kissimmee, Florida, and also enjoys cooking and photography. Paul saw his first Space Shuttle launch in 2005 when he moved to central Florida to attend classes at the Florida Institute of Technology, studying space science, and has closely followed the space program since.
Paul is especially interested in the renewed effort to land crewed missions on the Moon and to establish a permanent human presence there. He has covered several launches from NASA’s Kennedy Space Center and Cape Canaveral for space blogs before joining SpaceFlight Insider in mid-2017.