Last Updated on 07/09/2024 by Arun jain
Boeing’s Starliner is finally coming home, but the two NASA astronauts who traveled to the International Space Station on the spacecraft are not.
The mission, which began in June, was the first time Starliner had carried people into orbit. The flight was intended to be the final push before NASA certifies the spacecraft for a once-a-year mission that carries astronauts to and from the space station.
The vehicle’s propulsion system experienced problems during its approach to the space station, including several balky thrusters and leaks of helium, the gas used to push propellant in the weightlessness of orbit. Although the Starliner was able to dock successfully, the cause of the problems was still not fully understood, and NASA officials decided that it would be safer for the Starliner to return without a crew aboard.
When will Starliner return and how can I see it?
Starliner is scheduled to undock from the space station at 6:04 p.m. ET on Friday. NASA will start Broadcast coverage at 5:45 p.m
Coverage of re-entry and landing Off Starliner is scheduled to start at 10:50 PM
What happens during undocking and landing?
A command sent from the ground would retract the hooks holding the Starliner to the outpost’s forward docking port and the springs would push the spacecraft away. After a minute and a half, the spacecraft will fire its thrusters in short bursts to move up and away from the space station.
At higher altitudes, it will move more slowly than the space station and the distance between them will increase rapidly.
After several orbits, at 11:17 a.m., Starliner will fire its large thrusters to lift it out of orbit and back into the atmosphere, aiming for White Sands Space Harbor, in New Mexico’s Chihuahuan Desert. Before re-entry, it will jettison its service module, the cylindrical part beneath the capsule that houses the troublesome thrusters.
Landing is expected after midnight Eastern time.
Why does the Starliner travel home without any astronauts?
The Starliner mission carried two NASA astronauts, Suni Williams and Butch Wilmore, to the space station.
Uncertainty about the cause of the vehicle’s propulsion problems led to unease about what might be a more serious underlying problem. A catastrophic failure of the Starliner’s propulsion system during the return trip could leave the spacecraft stranded in orbit or it could burn up on re-entry.
Boeing officials have said they believe weeks of analysis and ground tests show the Starliner could have safely returned Ms. Williams and Mr. Wilmore to Earth. But NASA officials decided it would be less dangerous for the two astronauts to stay on the space station than return to Earth in the Starliner.
Are there any risks during undocking?
Anytime a spacecraft approaches or leaves a space station, there is a risk of collision if something goes wrong. Spacecraft travel very slowly when approaching or leaving the ISS, and are designed with backup systems to avoid that possibility.
When the Starliner was docked at the station, all but one of the 28 small thrusters were briefly fired to test their performance. (One thruster appears to be completely nonfunctional, and that one will not be used. The Starliner was designed to maneuver even if one or more thrusters failed.)
The undocking trajectory was changed so that the Starliner could move away from the space station more quickly, and the thruster pulses that the Starliner would fire to propel itself away would not cause significant heat, which is believed to have caused the thruster problems. During the approach.
“We really don’t expect any problems with the thrusters near the station,” Steve Stich, manager of NASA’s Commercial Crew Program, said during a news conference Wednesday. “And then we drift away pretty quickly.”
Now what will happen to the astronauts?
Two Starliner astronauts will become full members of the space station crew. NASA calls each rotation of crew members an “expedition,” and Ms. Williams and Mr. Wilmore will now be part of Expedition 72.
Later this month, two other astronauts, Nick Hague of NASA and Alexander Gorbunov of Russia, are scheduled to launch to the space station in the SpaceX Crew Dragon capsule, which will also serve as part of Expedition 72. To secure seats for Ms. Williams and Mr. Wilmore on the return trip to Earth next year, two other NASA astronauts who were scheduled to serve on Expedition 72 — Zena Cardman and Stephanie Wilson — withdrew from the mission, known as Crew-9.
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