Atlas V rolls to pad as TDRS-M is prepared for launch
CAPE CANAVERAL, Fla. — A United Launch Alliance Atlas V rocket is undergoing final preparations in advance of a planned August 18, 2017, liftoff with NASA’s next communications relay satellite. Liftoff of the rocket is targeted for the beginning of a 40-minute window opening at 8:03 a.m. EDT (12:03 GMT).
NASA’s Tracking and Data Relay Satellite (TDRS) System is a communications system originally set up in the 1980s and 1990s by NASA’s now-retired fleet of Space Shuttle orbiters. It is designed to ensure that the U.S. space agency maintains constant communications with satellites, spacecraft, telescopes, and the International Space Station. TDRS-M will be the 13th satellite launched in support of the program.
There are currently seven active TDRS satellites positioned in geostationary orbit, with two in storage and two in “graveyard” orbits. One satellite never made it to orbit as it was lost along with the crew of STS-51L in the 1986 Challenger accident.
Once TDRS-M achieves orbit, it will be renamed TDRS-13. It is the third spacecraft in the third generation of relay satellites, the first of which was launched in 1983. It is also the last of six that Boeing has produced.
The satellite will augment the existing constellation and allow the system to remain functioning well into the 2020s. NASA officials have not yet decided what the future of the system will be.
Tipping the scales at 7,600 pounds (3,450 kilograms), TDRS-M can host 60 transponders with a power of up to 10 kilowatts. It is built on the Boeing 601 satellite platform and is made up of two segments: a primary structure with the propulsion system, electronics, and batteries; and a secondary structure that has the communication payload and its related avionics, and thermal control equipment.
“The Space Network is critical to numerous NASA missions that are fundamentally changing the way we think about science,” said Bill Marinelli, TDRS development manager with the Space Communications and Navigation (SCaN) program office at NASA Headquarters, which provides programmatic oversight to the TDRS mission. “By expanding the fleet of satellites that support communications from these missions, TDRS-M will enable NASA to continue scientific exploration and discovery for years to come.”
The road to the launch pad was not a smooth one, however. On July 14, it was reported that an “incident” occurred on one of the spacecraft’s Omni S-band antenna. The damage caused the launch, which was originally scheduled for August 3, to be postponed until the necessary repairs could be made.
Meanwhile, the Atlas V 401 rocket that will carry the relay satellite continued to be prepared for launch. As noted, the vehicle will fly in the 401 configuration, meaning it will have a four-meter fairing, zero solid rocket boosters, and a single-engine Centaur upper stage.
On August 16, 2017, the booster, with the satellite mated on top, was rolled from its Vertical Integration Facility to nearby Space Launch Complex 41 at Cape Canaveral Air Force Station. The rollout began at 9:08 a.m. EDT (13:08 GMT) and lasted for about an hour.
Some 25,000 U.S. gallons (94,640 liters) of highly refined kerosene, also known as RP-1, was expected to be pumped into the first stage by the end of the day. On launch day, the first stage’s liquid oxygen tank will be fueled, along with the Centaur upper stage’s liquid hydrogen and liquid oxygen tanks.
The 191-foot (58.2-meter) tall Atlas V rocket has flown 36 times in the 401 configuration. This flight will be the sixth Atlas V to launch a TDRS satellite. The 45th Weather Squadron at Cape Canaveral Air Force Station has predicted a 70 percent chance of acceptable conditions during the launch window. The primary concerns are thick and cumulus clouds.
When it is all totaled, the cost for NASA to place the TDRS-M satellite in orbit has been estimated at being approximately $132.4 million, which includes the launch service, spacecraft processing, payload integration, tracking, data and telemetry, and other mission elements.
If everything goes according to schedule, Friday’s flight will be the second to take place from Florida’s Space Coast in less than four days – highlighting the current tempo of launches to take place out of the Cape and Kennedy Space Center this year (2017).
Video courtesy of NASA Goddard
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.