The I.S.S. was the setting for a refueling test conducted by a robot this week. The Robotic Refueling Mission, or RRM is a testbed to learn how to correctly repair and refuel satellites in orbit. Satellites have a useful life that is usually determined by the amount of fuel that is carried on board. This fuel is used to keep the satellite in a proper orbit, as there is trace atmosphere in low Earth orbits that eventually drags satellites back to Earth. It is like having an incredibly expensive car with a big, full gas tank that you can never refuel. Making it even more difficult to refuel, most satellites are not set up to be refueled and thus have a triple sealed gas tank that is covered over with protective blankets. While refueling satellites may be difficult, we definitely have the tools to make it possible.
To accomplish the re-fueling testing, the Canadian made DEXTRE robot that is mounted on the outside of the I.S.S. is being used. This robotic arm is remotely controlled from inside the space station by astronauts and will use four unique RRM tools to cut through and peel away protective blankets, unscrew refueling caps, turn valves, and transfer ethanol. The RRM module itself will hold the simulated caps, valves and fuel tanks and is mounted on the outside of the space station. The arm has cameras mounted on it with LED lights, so that the astronauts will be able to see exactly what they are doing.
We can only hope that these tests are completely successful. While it's not likely that we will see the I.S.S. repairing or refueling actual satellites anytime soon, we may see refuel and repair satellites being launched in the near future. This will ultimately benefit everyone who uses anything that interacts with satellites at some point. Services like GPS will become cheaper because less satellites will have to be launched when they can simply be refueled. Weather satellites may become better when more money can be spent on precision instruments instead of multiple launches to replace old or damaged satellites. Even the amount of space junk may be reduced as less satellites are launched into orbit. The ability to repair satellites would also reduce the number of satellites killed by space junk and extend longevity. With the amount of satellites in orbit and the cost of launching satellites, being able to refuel and repair satellites in orbit would have a great number of benefits to all mankind.