…why I was asking about ISS crew capacity, this is why:
The new space station would have an initial design life of about 15 years, Orbital Technologies officials have said. Soyuz spacecraft would ferry crews to the station, while unmanned Progress vehicles would keep it stocked with supplies.
The station will also fly in an orbit about 62 miles (100 km) from the International Space Station and in a similar inclination, or tilt, to make any transfers of crew or cargo between to two stations easier, the company said.
…The Russian space agency’s chief, Alexey Krasnov, added that a commercial space station could serve as a backup for International Space Station crews.
“For example, if a required maintenance procedure or a real emergency were to occur, without the return of the ISS crew to Earth, habitants could use the CSS as a safe haven,” Krasnov said.
If NASA was smart, they’d be buying a Sundancer or two from Bob Bigelow for the same purpose. With these kinds of co-orbiting facilities, you can have a true lifeboat, that doesn’t need to be able to enter. It might be Dragon based, or something else, but it’s basically a pressurized tug with life support and hatches (and perhaps an airlock), but it lives in space. And the ridiculous requirement that the entire ISS be capable of evacuating all inhabitants all the way back to earth goes away.
Fits nicely with the Space Guard concept.
Sounds fine. But a permanent station at that kind of low orbit would need periodic reboosts. Even the consumables probably would not last very long without replacement.
If it is a commercial space station, at least the space is paying for itself.
Actually, once Shuttle retires, it frees up a constraint on ISS altitude — it can be much higher, with less reboost required, because the expendables are much less sensitive to altitude than the Shuttle is. The upper limit would be set by the Van Allen belts.
I don’t know how many on this list have read the NASA reports on Soyuz, as well as various histories available on the web. Some bill it as the safest, most reliable manned space vehicle ever. If “safe” means “doesn’t kill crews, only injures most of them,” that’s probably true.
It’s favorite failure mode on reentry is to lose it’s control system. It then automatically goes into a roll which averages out the lift vector, and puts 8 or more G’s on the crew. Its second favorite is to fail to jettison the service module after the deorbit burn. The vehicle is then aerodynamically stable with the nose pointed in the direction of travel. The (aluminum) hatch gets very toasty, and smoke fills the cabin until by luck the structure holding on the SM fails, and the craft reorients heat-shield first. This first happened on Soyuz 5, and has happened twice more recently.
The landings are nothing more than controlled crashes, sometimes without the control.
How NASA “got comfortable” flying U.S. crews on this dog is something I’m now learning. My first impression, though, is that they just held their nose and jumped.
BTW, I didn’t type “it’s” where “its” is clearly right. I don’t know what mechanism did this….
Isn’t one of the constraints on using the Soyuz those custom fitted seat liners? So that each “cosmonaut” has a permanently designated spot on each one. Or are those just for convenience? (I know they can be swapped out in orbit, but how time consuming is that, too?)
Here’s a really stupid question… if you can reasonably make plans to co-locate in the same (highly-inefficient) plane, why not simply dock? Why not buy a Sundancer modified to carry a light RCS capable of getting out of Dodge in the event of a debris-causing event, with enough supplies to serve as an in-orbit lifeboat? Why park the Sundancer 60 miles away and then need to cram everybody into a taxi to get there?
Is there too great an additional danger from debris-causing failure modes that a docked escape pod module would be trashed while a free-floating one would survive to be used? How does this compare to failure modes where no structural damage occurs to the escape pod, but the crew needs to get to it quickly?
If “safe” means “doesn’t kill crews, only injures most of them,” that’s probably true.
Its better than .. many other manned space vehicles flying, no ?
Not ridiculous at all, Rand. How else will they be able to justify a multibillion dollar program that delivers pork to twenty-seven states?
“Its better than .. many other manned space vehicles flying, no ?”
I should have written “doesn’t kill many crews.” Soyuz has killed as many crews as the Shuttle, they were just smaller crews. So, no, it isn’t better than Shuttle.
What’s the maximum altitude of Soyuz? Mir flew at the same altitude as ISS, so that may be a constraint.
AFAIK Soyuz only killed two crews. The very first flight (Soyuz 1) with just one person inside had numerous faults from being rushed into service. Allegedly the guy died cursing the people who designed the capsule. Then there was that Salyut flight (Soyuz 11) which depressurized with three people inside. That was when they modified the capsule to only take two people, instead of three, so they could fit with pressurized suits. Later on they enlarged the Soyuz capsule to fit three people again.
There have been many partial failures, which resulted on high-G reentries where people broke their teeth, or which landed in frozen lakes in the middle of nowhere. But hey, accidents happen. To me this is proof that the system has a large degree of resilience built into it. I cannot see the fragile Shuttle surviving through similar events.
Soyuz isn’t perfect but it’s reliable. Of course, now they’re building a new 6 seat vehicle that lands without a parachute. It’ll be interesting to see if it is as reliable.
Oh, and the new vehicle was designed by a commercial company and will be built by that company.
There is a huge reason for not being physically connected to ISS: NASA. Co-location outside whatever zone of exclusion the bureaucrats decide on will make it clear your cabin is not beholden to their cabin building standards. At the same time it makes you commercially viable as an emergency backup and lets you keep commercially viable because you are cheaper and you do not have to ask their permission, or even give them details, when you bring a honeymoon couple or a porn filming team on board.
Incorrect. The upper limit would be set by Soyuz (425 km), far below the Van Allen belts.
The shuttle could operate above that altitude, but the payload penalty to ISS is substantial.
The Soyuz payload is much less affected by higher altitude than Shuttle.
So has shuttle. The safety records of both spacecraft are roughly equal.
Up to a point, yes. 425 km is a hard limit.
The reality of orbital mechanics is that any such safe haven must maintain its orbital plane very close to ISS in order to remain within the delta-V capability of Soyuz (or whatever spacecraft will be used to reach the safe haven… the numbers will not be drastically different). This requires that the safe haven coordinate its reboosts with ISS. (Look up Soyuz T-15 and its Salyut-Mir transfer… this is not trivial). So this will not be a matter of “come on over”; the prospective safe haven will have had a working relationship with the ISS partners over the lifetime of the haven and likely there will be a contingency contract requiring the haven to remain within specified delta-V limits of ISS, in exchange for a retainer-type payment. And if NASA is paying for that contract, the haven will meet NASA human-rating standards. End of story.
Up to a point, yes. 425 km is a hard limit.
Only for their launcher, from Baikonur. If they start going out of Kourou, or on a different launch system, they could go higher. It’s an artificial constraint. I’d actually find it quite amusing if we developed commercial systems that allowed an ISS altitude out of the range of Soyuz…
We’ve had non-commercial systems that did that. On more than one shuttle flight (100/6A was one I know for sure, but there were others), a shuttle-performed ISS reboost was limited based on altitude limits for the next Soyuz.
“Allegedly the guy died cursing the people who designed the capsule. ”
I have a friend who was in Army Signal Intelligence in stationed in Berlin in 1967.
There is nothing ‘alleged’ about it. And he was cussing the leadership all the way to the top of the Soviet food chain.
likely there will be a contingency contract requiring the haven to remain within specified delta-V limits of ISS
Which would be another justification for orbital fuel depots.