Helium Leaks, Thruster Problems Delay Astronaut Sunita Williams' Return. 5 Things to Know

New Delhi: Boeing's new space capsule which went to space with Indian-origin astronaut Sunita Williams and Butch Wilmore on board developed technical glitches which prompted the NASA to delay their return to Earth. Veteran NASA test pilots Williams and Wilmore who launched aboard Boeing's Starliner capsule for the orbiting laboratory on June 5 were scheduled to return in a week or so but their extension of their has entered its third week. 

What Delayed Sunita's Return?

• Soon after a glitch was reported in the capsule, their return was postponed by NASA saying it wanted more time to analyze problems in the spacecraft's propulsion system, which is used to maneuver in flight. The propulsion system is attached to the capsule, but it doesn’t come back to Earth for inspection. It is ditched during reentry and burns up.
• Five of the capsule’s 28 thrusters went down during docking, as the capsule closed in on the International Space Station. All but one thruster was restarted, and they worked during test firing later, NASA said. 
• It is suspected that heat from all the thruster action at docking caused the shutdown. The one faulty thruster has been turned off. 
• Global media outlet AP quoted Steve Stich, NASA’s commercial crew program manager, as saying that more thruster testing on the ground would be done before setting a return date. 
• The capsule had launched on June 5 with one small helium leak, but four more leaks sprung up by the time it entered the space station. 

Helium is used to pressurize fuel for the thrusters, and a faulty rubber seal was suspected in the initial leak. Officials say there's an ample supply of helium, and Boeing says the leaks are stable and not a concern. 

“We understand these issues for safe return,” Boeing program manager Mark Nappi to AP adding, “We don't understand these issues well enough to fix them permanently."