Dec. 21 (UPI) -- An unmanned Boeing Starliner spacecraft will return to Earth on Sunday after failing to reach the International Space Station during a launch two days earlier, NASA and Boeing officials said Saturday afternoon.
The capsule is scheduled to land softly, with the aid of three parachutes, at the White Sands Missile Range in New Mexico at 7:57 a.m. EST, mission officials said at a teleconference.
If any problems arise on the spacecraft or the landing site, a backup landing opportunity for White Sands comes 8 hours later, officials said.
"Entry, descent and landing are not for the faint of heart. Make no mistake, we still have a lot of things to prove" on the return, said Jim Chilton, senior vice president of Boeing's Space and Launch Division.
After it leaves orbit, Starliner is to descend as fast as 25 times the speed of sound, but then slow to below the speed of sound when it reaches 30,000 feet above Earth and the parachutes deploy.
Starliner's orbital flight test is in day two, and NASA said flight controllers and engineering teams worked through the night and into Saturday morning, "accomplishing many of the flight test objectives planned for the mission."
The spacecraft is in a circular orbit roughly 155 miles above sea level. Despite not reaching the International Space Station, which is 220 miles high, Boeing officials said they were pleased that all systems crucial for human spaceflight had functioned well.
They said that included avionics, life support, thermal management, power, attitude control and instrumentation.
"What's really crucial," Chilton said, "is that we established a link with the International Space Station."
He said the guidance system needed to dock with the space station performed properly and that mission controllers extended and retracted the docking station to ensure it worked.
The Starliner failed to reach the space station, officials said, because of a software glitch that that resulted in improper timing, causing the capsule to act as it it were in orbit and approaching the space station when it wasn't.
NASA has not decided whether to require a second unmanned Starliner test flight before sending astronauts to the space station.
"What is important is that we have a healthy spacecraft," NASA Administrator Jim Bridenstine said. "NASA and Boeing have been working hand in glove, but we still have a lot to learn and a lot of data to collect."
