CAPE CANAVERAL, Florida — The United Launch Alliance Atlas V rocket carrying NASA’s Tracking and Data Relay Satellite (TDRS-K) mission successfully lifted off tonight at 8:48 p.m. from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. Photo Credit: NASA.
“It has some higher bandwidth speeds,” said Diana Calero, mission manager for NASA’s Launch Services Program, or LSP, based at Kennedy Space Center in Florida. “We have some aging satellites, so we need some new spacecraft to go in there and carry some more of the bandwidth.”
“The antennas are furled and they have a margin, a certain amount of days that they can stay furled,” Calero said. “If they pass that margin, then the antennas, when they’re deployed, they can actually have a degradation in space and so we have to play close attention to how long that stays furled. So it was really challenging trying to schedule the shipping of the spacecraft with the launch date. We’re still watching it very closely.”
TDRS-K is the 11th TDRS launched by NASA since it began building the space-borne network in 1983. The most recent spacecraft launched in 2002.
“We haven’t launched a TDRS in about 10 years so it’s really good to have this,” Calero said.
The new TDRS will be able to transmit several times more information than its predecessors.
“In terms of bandwidth capability, it’s probably four or five times higher bandwidth improvement” said Paul Buchanan, deputy project manager for TDRS.
Orbiting about 22,300 miles above Earth, positioned roughly over Hawaii, TDRS-K will put a myriad of antennas to work to receive and transmit signals from a wide range of spacecraft to Earth and vice-versa.
The number of satellites required to serve NASA’s orbiting fleet of scientific spacecraft has grown to such an extent that the TDRS network already operating in orbit plus the TDRS-K and two identical TDRS spacecraft launching next year and in 2015 will have plenty of commands, telemetry and data to relay.
The communications constellation replaced the ground stations positioned on Earth so NASA could communicate with astronauts in orbit. That system allowed contact only when the spacecraft passed within range of the antennas, however. With TDRS satellites in place, controllers have near-constant contact with spacecraft.
“If you roll back in history maybe 30, 40 years, back in Mercury days and Apollo there were no TDRS satellites for communication so you had outages between the ground stations,” Buchanan said. “We didn’t want the outages, we wanted continuous (communications), so that’s what prompted the TDRS.”
Six TDRS spacecraft are operational in orbit, one new satellite is in orbital storage ready to take the place of an older TDRS and two older models have been retired. The oldest one still working is TDRS-3, launched in September 1988 aboard the space shuttle Discovery.
“We’ve had to decommission two legacy spacecraft in the last year or two due to the fact that electronics start to die after 20, 25 years,” Buchanan said. “We’re launching now for an immediate need and replenishment schedule. I think it’s a fine balance between the existing system and replenishment.”