Indian origin scientist creates temp regulating film for “micro-spacecraft”

August 20th, 2008 - 2:39 pm ICT by ANI  

Washington, August 20 (ANI): A scientist of Indian origin and his team have constructed a thermo-regulating technology, which could be applied on the surface of a “micro-spacecraft” like a skin, to control the temperature of the spaceship.
The scientist in question is Prasanna Chandrasekhar, who has described the new, razor thin temperature-regulating film that brings the sci-fi vision of “micro-spacecraft”, weighing barely 50 pounds and 10-pound “nano-spacecraft” closer to reality.
“We don”t have the processes in space to remove excess heat or keep the spacecraft warm in excess cold,” said Chandrasekhar. “It may sound very trivial, but controlling the temperature of a spacecraft is absolutely crucial,” he added.
Micro-spacecraft are expected to be the thrust of future aerospace development, which would enable NASA, military and private firms to launch more probes and satellites at lower cost, opening the doors to profound new applications for communications and defense.
But, before the first micro-spacecraft can blast off, scientists need to shrink the titanic thermal regulation systems used to help prevent today’’s ships from frying in the harsh sunlight of space - or freezing in the pitch black absence of it.
Chandrasekhar began tackling the problem in 2003 as an offshoot of a military technology.
His solution was to design a so-called “thin-film variable emittance electrochromic device” that feels like plastic and can change color when given an electrical charge.
The thin-film could be applied to micro-spacecraft like a skin, switching color from light to dark based on its exposure to harsh sunlight or extreme darkness.
Chandrasekhar added that the “color change” is in the infrared as well as in the visible color spectrum.
The film moves from a high “emittance” state - or one that emits lots of heat - in hot temperatures and a low emittance, or insulating, state in freezing temperatures.
The thermo-film also has a protective layer consisting of germanium silicon oxides to protect it from atomic oxygen, which can corrode ships and shorten their lifespan - a serious problem for space stations and vital communications satellites.
The silicon oxide topcoat also imparts a lower “solar absorptance” to the skin.
Even in its light-color state, the skin is still highly absorptive of solar radiation and can get very hot as a result. The topcoat ensures that the solar absorptance stays below a value that prevents heating of the skin under direct solar radiation.
Although the film is under one hundredth of an inch thick, it is tough enough to withstand the micrometeoroids hurtling through space.
NASA aims to get the first micro-spacecraft prototypes operational by 2013, so Chandrasekhar and his team are working to get their thermo-film tested in space as soon as possible.
Once deployed, micro-spacecraft would fly in constellation, making them nearly impossible to detect or blast out of the sky. (ANI)

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