In late 1996, when the issue of how to build up the ISS was being thrashed out, the Russians proposed that the FGB (the vehicle now more commonly referred to as the “control module”) at the front of the Mir complex, so that the early ISS crews could live aboard Mir. NASA rejected this, in part because assembling the ISS in Mir’s high (400 km) orbit would compromise the shuttle’s lift-capacity; the ISS is to be assembled in low orbit and then boosted higher once it is nearly complete.
If the Russians keep Mir going until the ISS is in a state to be boosted, the two stations could still be linked however. Mir couldn’t play the active role in this docking, but the shuttle could maneuver the ISS through the final phase.
Now why do this? Firstly, it would give the ISS an awful lot more habitable volume, and even if it was only used to store all the miscellaneous apparatus that will accumulate (and it will, because there will be stuff that’s there that’s needed, but not often), it will serve a useful function. Secondly, there are undoubtedly a lot of still-useful instruments on Mir (or rather, built into or onto Mir) that could be useful. Mir is a pressurised shell, surely that’s worthy? At the very least, it could be used as a site to mount new autonomous external payloads?
As to the problem of Mir’s reliability. As I see it, this issue becomes a non-issue because if Mir isn’t called upon to provide navigation, or attitude control, or any other critical functions, then it does not need to be in tip-top condition. It can supply its own power, so it need not be a drain either.
It is just a thought, but you fellows might kick this about a bit, instead of wondering what role it could serve as a standalone system. It simply cannot be left uncrewed. Experience has shown that the station cannot survive without a crew aboard (this was realised a decade ago), so all the proposals that it be placed in a storage orbit for some future use are non-starters. If it is to serve a role, it will have to be crewed continuously, from now right though to the day it is finally discarded. The crew needs it for life support, and it needs them for maintenance. It is a symbiotic relationship. This is not a failing of Mir; far down the line, the ISS will find itself in the same situation.
So, if it isn’t kept crewed, and it cannot be put into storage, what should be done with it? Dumping it in the ocean is one solution, but it delivers no worthwhile result. Sending it out to serve as a base in lunar orbit is impracticable, because it would still need a flow of logistics. It seems that we have only two choices: to keep it or to dump it, and if we keep it, it makes more sense to link it to the ISS so that there is a single station. After a few years, of course, it might be jettisoned, but by then it would have served its role.
In the Media, Mir is usually referred to as an aging station, the implication being that it is a clunker that should be scrapped. Mir’s great age is actually the most striking demonstration of its success. If there’s to be a way of retaining Mir without risking it being lost to an equipment failure, there has to be a human being somewhere handy, and if the thing is too old to support the crew, it should be docked with a new crewed facility, and the only one available is the ISS.
Now some will say that to dock the ISS with Mir will be more trouble than it is worth. That is a matter of opinion. The Russians are criticised for seeing Mir as a symbol to be retained, no matter what. The Americans, as always, having learnt what they could from Mir, are keen to operate independently. Both points of view are valid. Speaking as a Brit, I am frustrated by the fact that my State seems to have fallen into the habit of forever criticising others in their space activities, whilst not having the technology, the resources, nor the sense of purpose to achieve anything of its own. Personally, I reckon that Mir is a wonderful achievement, and Russia is to be congratulated.
For those of you who want to read about those achievements, I heartily recommend a book written by my good self, entitled The Mir Space Station, which was published by John Wiley in association with Praxis (ISBN 0-471-97587-7), pp440, priced at 48 dollars (U.S.).
– David Harland