NASA Wants To Drift Two Satellites For Awesome Space Pics
A "virtual telescope" which owes its precision not to complex, high-strength optics but to precisely flying a pair of satellites in tandem and combining the data from each could help the hunt for Earth-like planets in the galaxy and even picture the event horizon of a black hole, NASA scientists suggest. Although space telescopes like Hubble have been operating for several decades, the new virtual telescope project will take a distinctively different approach, initially using two CubeSats – tiny satellites far cheaper and easier to launch, thanks to their compact and standardized design – that would each contribute a part of the overall vision process.
In the first trial, one satellite would carry the communication crosslink, the thrusters, and the GN&C (guidance, navigation, and control) technology, as well as the occulter, which is the disk used to block the central, brightest portion of an object – such as the sun itself – so that the fainter outer light – such as the sun's corona – can be better seen.
The other satellite would carry a laser beacon, communications equipment, and the coronagraph, which is used to examine a star's outermost plasma layer.
The second satellite would follow approximately 20 meters behind the first, both aligned to the sun, and combine their strengths to investigate solar eruptions that can cause electromagnetic interference and weather pattern disruptions on Earth.
Flying two satellites together is not a new idea, but neither is it one that's been put into practice before. The issue has always been the scale of the GN&C work required to accurately pilot not one but two objects in such a precise way.
Until now, "the systems-level capability to align two spacecraft to an inertial source isn't mature enough for projects to take the risk," aerospace engineer Neerav Shah at NASA's Goddard Space Flight Sensor, and team leader, said of the scheme.
According to Shah, though, that could be about to change, as off-the-shelf navigation and relative-position sensors, actuators, and cross-communication links all reach the point where they're reliable and accurate enough to fit the bill. Paired with some in-house GN&C algorithms, the tech would first figure out the respective alignment of the two satellites themselves, and then each would independently adjust itself so that such a position could be maintained.
If it all works out, not only could it be more affordable than traditional, vast space telescopes, but more flexible too. The same approach could be taken to hunt down Earth-like exoplanets, for instance, or even to gain never-before-seen data on the event horizon around a black hole, where its gravitational pull is irresistible.
It's not the only unusual telescope project NASA is considering. One of the proposals for the space agency's Innovative Advanced Concepts (NIAC) Program for 2014 was a system which promised 1,000x the resolution of Hubble but at a fraction of the cost.
SOURCE NASA