The current deadline for their return is the on-orbit lifespan of their return capsule. It's possible that grounding "crewed" flights doesn't mean grounding all flights. An uncrewed capsule could be sent up (they dock autonomously), and the missions of the on-station crews could be extended. Something similar has been done in the past due to a suspected fault in the on-orbit capsule.
One of the ways you can land a Soyuz is basically an uncontrolled crash land. It is so dependable compared to any other spaceship that I wouldn't be surprised if it becomes an emergency return capsule, after it stops being the main spaceship used to reach the ISS.
It's like the space equivalent of fielding a fleet of shitboxes as your daily driver(s).
One Soyoz has a hole. The other Soyuzes won't run because safety. You scrapped the shuttle a few years ago. You haven't finished assembling your SpaceX project car yet. Little Jimmy is going to have to hold the flashlight for daddy while he fixes a shitbox so mommy can get to work in the morning (metaphorically speaking of course, because space).
This seems deeply unfair and dismissive of the accomplishments of the people who built Soyuz. Soyuz is a proven reliable spacecraft, it’s not a shitbox.
Who is little jimmy or daddy in this analogy? Why can’t mommy fix her own car? I don’t see the connection to human spaceflight.
> Soyuz is a proven reliable spacecraft, it’s not a shitbox.
I was going to say... It might not be flashy and shiny and new but what else is really important when you are doing space travel? Personally I'd rather have the indestructable, boxy, non-aerodynamic 1995 Jeep Cherokee and its inline V6 engine than some brand new "2.4L Tigershark® MultiAir® 2 I4 Engine with Electronic Stop/Start (ESS) Technology".
All of those adjectives / descriptors after the "2.4L" look and sound nice but beside looking fancy is there any merit to them being added? Most people in and around the Jeep car scene / motor heads / people with decent car knowledge KNOW that Jeep's Inline V6 was nearly indestructible. They lasted forever when properly maintained (regular oil changes, fluid changes, and tune ups) and could take loads of abuse. Most other things in and on the car would wear out and/or burn out (things like electronics) before the engine and transmission would even become an issue at all.
That said, in 2018, there are lots of reasons a 1995 Jeep Cherokee isn't the ideal car. Namely gas mileage, lack of aerodynamics, weight and weight distribution (materials and generally being overweight), and so on. Even knowing all of that I'm sure if paying for gas wasn't a major issue lots of people who had Jeep Cherokees in the past would love to have a properly running one again for one simple reason:
Reliability and dependability. What else really matters? I'd definitely trade in the offset in cost at purchase time for a gas guzzler if the cost winds up the same or the scale even tilts toward the Jeep if you consider all of the upkeep and maintenance costs included, after purchase, for another vehicle.
The Soyuz, if nothing else, is extremely reliable. If I were an astronaut that's the main thing I'd be worried about and if I had any say it'd be the one thing I absolutely required -- for obvious reasons.
It might; at least part of them. I presume they have contingency plans for exactly this situation. Probably leave a skeleton crew up there until either a new crew can be launched or the station has to be abandoned (supply missions are probably not a problem, but the Soyuz return capsules have a limited ”shelf life”).
They have a single return capsule there. They can't leave anyone without a return/rescue boat, so they all have to return together and leave the station empty. And as you said they can't extend stay for a year because Soyuz has limited life.
ISS scheduling is responsible for at most one month of that slip - DM-1's capsule will be ready in December, and was set to launch NET January because of station availability.
Given that it's currently mid-October, moving up a month from January to December represents a pretty substantial chunk of the remaining time (I'm not suggesting NASA or SpaceX are willing, able, or interested in doing this, but it's not impossible)
Assuming that an investigation takes a year, that means a lot of missed flights and no way to reach the ISS until Boeing/SpaceX are ready.