Is the ISS itself causing the Soyuz entry failures?
…the Soyuz used to fly long duration missions to the space station flawlessly for years. So what changed in the last two flights? Some bad parts out of the same lot?
A unique confluence of circumstances being investigated appears to be at fault. The space station has grown in size considerably since those first early long duration flights that the Soyuz so flawlessly serviced. It is a bit larger now with all the new modules the Emperor has sent aloft for our friends. As such it makes quite a target for training gangly military officers on ground based radars around the world. It has also become quite a source of electromagnetic energy itself, with all the radios and such from all the international partners blasting their messages back to the homelands.
Did you hear the recent news about cell phones in your pocket causing your little reproductive agents to slow down or become ineffective? The same thing may be at work when the cacophony of EMI on the space station envelops the Soyuz separation pyros and causes them to become inert.
If true, it raises some interesting issues. Is there something intrinsic in the Soyuz design, or pyro design, that causes this effect? Or is it a problem for pyros on any lifeboat that we put up there? Do they need to make it possible to change them out on orbit (if this capability isn’t already there), and keep them in a shielded box until they have to go home? Of course, this would slow things down in an emergency, if they had to get away immediately.
The problem of a space station lifeboat is a much tougher one than people realize (which is why I’ve always opposed it, at least if such a thing is defined as a device that gets you all the way to earth if there’s a problem on the station). You simply can’t trust hardware that has been sitting dormant for months in the space environment to work reliably when you need it to (at least not at our current level of experience with space operations).
This is also the reason that we couldn’t use an Orbiter for a lifeboat, even if we had enough of them that taking one out of the processing flow wouldn’t have a severe impact on turnaround times. We can’t know for sure if it can survive six months on orbit, even with power and support from the ISS, and have the reliability needed to safely come home.
That’s why I’ve always advocated a robust space transportation infrastructure that is always being exercised (e.g., multiple co-orbiting facilities with different purposes, and space tugs/crew modules for transit from one to the other). It provides redundancy, and reliability, and obviates the need to abandon a single space station to take people all the way back to earth in the event of a problem.