Mumbai: NASA is presently working on its first Space Lifeboat , which will be able to help people travel into low-Earth orbit in the International Space Station for up to seven months.
Currently, the lifeboat function on the space station is served by requiring a pair of Russian Soyuz spacecraft to be docked at all times. Official reports stated, ‘Each Soyuz holds three people. So with two docked, there can be six people working on the station at any one time. The crew drops to three when one Soyuz leaves and before another arrives during a procedure called an indirect handover.’
There are fundamentally two capabilities a spacecraft must perform to be called a lifeboat, said NASA engineers who are working with companies developing spacecraft in the agency's Commercial Crew Program (CCP).
First, the spacecraft should be able to provide a shelter for astronauts in case of a problem on the station. Second, the ship has to be able to quickly get all its systems operating and detach from the station for a potential return to Earth. "We’ll make sure it provides the same capability on day 210 as it does on day 1," adds Justin Kerr, manager of CCP's Spacecraft Office.
Designers will also have to face the challenge of building a spacecraft strong enough to withstand impacts from micrometeoroids, but cannot carry a lot of armor because it would be too heavy to launch. Although numerous impacts are not expected, designers are still expected to show their craft can survive an occasional hit.
The amount of power dedicated for a docked crew spacecraft is similar to the amount of electricity a refrigerator uses. ‘Spacecraft power and protection from things outside the spacecraft like micrometeoroids is the biggest challenge in the making process of this space lifeboat,’ as per the official report of NASA. The vast amount of electricity generated by the space station's acre of solar arrays is reserved for the station's systems and science experiments.
"There's very little power available for these spacecraft so what we're really driving the partners to do is develop this quiescent mode that draws very little power," highlighted Kerr.
NASA also further specified, ‘Ideally, designers want to have the spacecraft powered off when it is attached to the station. That might not be possible, though, because air doesn't automatically circulate in microgravity the way it does on Earth. So a spacecraft, even with its hatch open inside of the station, can develop dead spots, or sections of the cabin without air for breathing, unless there is something to move the air around.’
CCP gave aerospace companies a list of requirements their spacecraft need to meet during NASA’s certification process for use as in-orbit lifeboats, said Thurston. Boeing, Sierra Nevada Corporation and SpaceX are working in partnership with NASA on spacecraft designs that meet these criteria under their Commercial Crew Integrated Capability agreements.
