London, May 7 : Experiments at the MIT Space Systems Laboratory in the US have shown that magnets can help spacecraft to stick together.
According to a report in New Scientist, the experiments have shown that by varying the current running through superconducting coils, mock spacecraft can be made to attract, repel, and move sideways relative to each other.
Many proposals for groundbreaking space missions require multiple spacecraft to fly in formation, with the method to keep them in right arrangement being the use of thrusters, which fire jets of gas to push a craft in the opposite direction.
Unfortunately, thrusters can limit the lifetime of a mission because they rely on limited supplies of fuel.
But two groups of researchers are developing a technology that replaces thrusters with electromagnets, which they say can keep spacecraft in formation without the need for fuel.
In this scenario, each spacecraft in the fleet would be outfitted with coils made of superconducting wire. Running electric currents through the coils turns each spacecraft into a magnet with a north and south pole.
By adjusting the current, the orientation of the poles can be changed to either attract multiple spacecraft towards each other or push them farther apart, keeping them at the desired distance.
A group headed by David Miller of MIT's Space Systems Laboratory in Cambridge, US, has been testing out the concept in the laboratory using mock spacecraft.
The test vehicles squirt jets of air down from their bases in order to hover nearly frictionless on a glass table to simulate floating in space. Using superconducting coils, the vehicles attract and repel each other, and even move sideways relative to one another.
"The biggest advantage is that you have no fuel that can run out," Miller told New Scientist. "The magnetic coils work purely on electrical energy, which you can generate through solar arrays that point at the Sun," he added.
The superconducting coils would need to be kept at low temperatures in order for them to work properly - a temperature of 196 °C is required for one commercially available superconducting material, for example.
"This temperature could be achieved with a combination of insulation and an electrically powered cooling system," said Miller.
The concept is promising enough that the US Defense Advanced Research Projects Agency (DARPA) is funding the MIT group to develop it for possible use in a project called F6, which aims to create clusters of little spacecraft that can collectively do everything a single, large satellite can.