The two astronauts who flew on the Boeing Starliner spacecraft were supposed to start the journey back to Earth on Wednesday (June 26) night, but instead, they will stay on the International Space Station (ISS). No return date has been officially announced as engineers on the ground try to fix the spacecraft’s problems.
The Starliner blasted into space from Florida’s Cape Canaveral Space Force Station with astronauts Sunita “Suni” Williams and Barry “Butch” Wilmore on board on June 5.
The mission was supposed to last eight days. But problems cropped up.
Helium gas leaks
The Boeing Starliner was launched despite a small leak of helium gas. Helium is used to push propellant to the thruster systems needed for manoeuvring in space and slowing down to re-enter the Earth’s atmosphere.
Engineers believed the small gas leak would not affect the mission.
But four more helium leaks developed during the mission, and five of the 28 manoeuvring thrusters cut out during the approach to the space station. Only four were restarted.
Nasa said in a blog post the leaks posed no danger to the astronauts because: “Only seven hours of free-flight time is needed to perform a normal end of mission, and Starliner currently has enough helium left in its tanks to support 70 hours of free flight activity following undocking.”
How long can Starliner be docked to space station?
Starliner can stay docked at the International Space Station for up to 45 days, according to a NASA official. But another official said, if absolutely necessary, the spacecraft could stay docked for up to 72 days, relying on various backup systems.
Nasa stated that flight engineers wanted to study the spacecraft before it re-entered the Earth’s atmosphere. That’s because while the crew capsule will parachute to the ground, Starliner’s faulty lower ‘service module’ will burn up upon re-entry. Therefore, some of the information on what went wrong will be lost.
Internally at NASA, Starliner‘s latest targeted return date is July 6.
This is Starliner‘s first mission to orbit carrying astronauts – the final test needed before NASA can certify it as the U.S. space agency’s second ride to the ISS. It would join SpaceX’s Crew Dragon, which has dominated the government and nascent private markets for human space flight.
If Starliner is considered unsafe for returning the astronauts to Earth, they could be brought home by Crew Dragon. The SpaceX spacecraft ferried four astronauts to the space station in March.
But that would be embarrassing for Boeing.
Sources: BBC, The Independent