Less than a week after its launch from the Cape Canaveral US
Space Force Base in Florida, the CST-100 Starliner was scheduled to
autonomously undock from the space station at 2:36 p.m. EDT (12:06am IST on
Thursday) to embark on a five-hour-plus return flight.
If all goes as planned, the mission finale will come with
the gumdrop-shaped craft making a fiery atmospheric re-entry followed by an
airbag-cushioned parachute landing on the desert floor near White Sands, New
Mexico at 6:49pm PDT (7:19am IST on Thursday).
Starliner was lofted to orbit last Thursday atop an Atlas V
rocket furnished by the Boeing-Lockheed Martin joint venture United Launch
Alliance and achieved its main objective, a rendezvous with the ISS, despite
four of its multiple onboard thrusters malfunctioning along the way.
Boeing engineers also had to improvise a workaround for a
thermal control defect during the final approach of the capsule to the space
station, orbiting some 270 miles (430 kilometres) above Earth.
But NASA and Boeing officials said none of the problems
encountered so far should preclude Starliner from safely returning, and they
chalked up such snafus to the learning process of developing a new spacecraft.
A successful mission would move the Starliner, beset by
repeated delays and costly engineering setbacks, a major step closer to
providing NASA with a second reliable avenue for ferrying astronauts to and
from the space station.
Since resuming crewed flights to orbit from American soil in
2020, nine years after the space shuttle program ended, the US space agency has
had to rely solely on Falcon 9 rockets and Crew Dragon capsules from
billionaire Elon Musk's private company SpaceX.
Previously the only other option for reaching the orbiting
laboratory was by hitching rides aboard Russia's Soyuz spacecraft, an
alternative currently less attractive in light of heightened US-Russian
tensions over the war in Ukraine.
Much is also on the line for Boeing, as the Chicago-based
company scrambles to climb out of successive crises in its jetliner business
and space-defense unit. The Starliner program alone has cost the company nearly
$600 million over the past two and a half years.
An ill-fated first orbital test flight of Starliner in late
2019 nearly ended with the vehicle's loss following a software glitch that
effectively foiled the spacecraft's ability to reach the space station.
Subsequent problems with Starliner's propulsion system,
supplied by Aerojet Rocketdyne, led Boeing to scrub a second attempt to launch
the capsule last summer.
Starliner remained grounded for nine more months while the
two companies sparred over what caused fuel valves to stick shut and which firm
was responsible for fixing them.
The do-over test mission winding up on Wednesday could pave
the way for Starliner to fly its first astronaut crew to the space station as
early as the fall, NASA has said.
The orbiting outpost is currently home to a crew of three US
NASA astronauts, an Italian astronaut from the European Space Agency and three
Russian cosmonauts. © Reuters