ATV Re-entry – original image from DLR
One of the dangers of flying low orbit missions, like the GOCE mission and various Earth explorers, is the chance of being hit by a bit of debris. A fleck or paint, a bolt, or a 10 cm piece of an exploded rocket stage that has the potential to wipe out your satellite…and create more debris in the process.
And it’s not just low orbit that has this risk….This is also something that happens in the geostationary ring.
These days agencies are trying to get proactive and put in place mitigation measures so that they can remove material from orbit. There is also some hope that the Sun will decide to get a bit more active so that the upper atmosphere expands a bit and causes a bit more drag on particulates.
Here’s an interesting article on that very thing.
Whatever happens it seems the space community is really waking up to the increased risk of leaving disused material in space. It’s getting to the point where it doesn’t matter if your comm-sat has all fancy technology…if it is left in a high risk area then it’s going to be a danger to other satellites. You need to move it!
And this is where the real heart of the issue is: money and risk.
Or put another way, the cost of insuring the mission in the face of increasing populations of space debris. Of insuring against higher chances that you’ll have to move out of the way or worst-case, get hit.
With regards to ion propulsion, one of the areas that has become an interest out of this, is the ability to fly small simple devices that could de-orbit the satellite once the mission is over. The balance is then to find a decent-size thruster, one that can deliver enough punch and specific impulse, when there are limits on fuel.
Yet in problems there are opportunities!…
Here is the chance to piggy-back a basic thruster onto a commercial mission, or at least a demonstration mission, to get flight heritage. And as you may know, flight heritage is the currency that gets you in the door. The leverage to get more sophisticated types of ion propulsion onto satellites.
From the seemingly unsavoury idea of space junk floating above the Earth, comes the chance to test out new technologies. And possibly get enough flight time to justify using more ion propulsion devices on special missions to maybe clear up some of the debris?
It may be a long shot now…but the more technology that gets tried out to de-orbit satellites, the more the feasibility of such missions becomes clearer.