Space is awesome. Most of us get excited to watch rocket launches, satellite imagery, and even the thought of manned missions to places like Mars get people’s hearts racing. As we become a space-faring civilization, there will be challenges in getting off of the only planet we’ve ever known. Namely getting off of the only planet we’ve ever known. Launching ships into orbit is still prohibitively expensive, and finding ways to avoid or at the very least improve that situation remains high on the list of priorities. We’ve seen designs for space elevators that would at least reduce the cost of getting cargo into orbit, but there would still be the issue of moving that cargo elsewhere via some type of spacecraft. That spacecraft would likely need to be both reusable, and be able to stay in orbit for extended periods of time. What happens when those ships need to be refueled, or repaired? Scientists at DARPA (Defense Advanced Research Projects Agency) have thought that through and feel that an automated spaceport run by robots is the solution.
To that end, DARPA is developing a highly sophisticated robot arm that they see as part of a future transportation hub in space. This automated station could be used to repair, refuel, and even in some cases rebuild spacecraft, reducing the need to launch quite as much mass into orbit, since as The Martian‘s Mark Watney says, “NASA isn’t in the habit of putting unnecessary mass into orbit.” This also allows for some larger ships to stay in orbit, similar to the Hermes spacecraft from The Martian (yeah, I just recently finished reading The Martian, great book, btw), where they will not so frequently incur the cost of launching to escape Earth’s gravitational pull. These theoretical ships will still need to be maintained though, and that’s where DARPA’s spaceport comes in.
At DARPA’s “Wait, What? A Future Technology Forum” in St. Louis on September 10th, former NASA Astronaut and current DARPA Deputy Director of Tactical Technology Pam Melroy likened the proposed space station to the seaports of the world:
Look at the great seafaring port cities in the world for inspiration, and imagine a port of call at 36,000 kilometers
A station at that height would place it in geosynchronous orbit (GEO), providing a much more stable location to keep the station in orbit. For reference, the International Space Station is in Low Earth Orbit (LEO) at a range of 300-600 kilometers. Any station in Low Earth Orbit – including the ISS – will have that orbit decay and get pulled back towards the Earth after around 25 years if course correcting adjustments aren’t made. Objects in geosynchronous orbit can stay in one spot for significantly longer – up to around one million years according to Melroy.
The issue with geosynchronous orbit is that the radiation that far out would be too high for a human crew to handle for any extended period of time. Plus, launching a crew out to the station when repairs are needed would again require a costly space launch each time. Robots wouldn’t have that issue since they can be built to withstand radiation and can stay on any proposed space station without having to come back to Earth. I’d imagine any station built would have redundancies in place or even abilities for the robots to repair themselves in case of a malfunction. Sending a crew out for repairs would have to be a last resort, though an undesirable one due to the necessary space launch.
The perfect station in this instance would obviously have a tremendously expensive cost up front, but by being able to stay in orbit and service spacecraft without requiring a space launch, it would ultimately drive down costs significantly. Robots really are the answer in this instance, and DARPA is working on the robotic arm that they believe will get us there.Source: Space.com