The above was based on several livestreams from the ISS as well as mission control. The public streams are down now.
It seems like there were several alarms and issues, including a fire alarm, but seems like they were (mostly) false alarms. Crew going through appropriate checklists.
Not following NASA and the ISS and well as I used to, I know there were plans to build a 'lifeboat' for the crew. Is that a thing now? If something catastrophic happens, what does the crew do?
There's usually two three-person crews on the station at any given time, so two capsules are kept docked and ready to serve as lifeboats.
Since the Soyuz is the sole means of transportation to and from the station, they simply put the capsules into a rotation. When a new crew arrives, they leave their capsule docked and the departing crew rides the oldest capsule back to Earth.
The docked capsules are rated for about six months, due to chemicals aboard that can degrade or escape. So if a replace vehicle doesnt arrive in time, then the astronauts may be forced to return. I recall a complete evacuation of the ISS almost happened after the Columbia accident because there werent enough Soyuz in the pipeline on Earth. The 20-some modules of the ISS are finicky enough that you dont want to leave the ISS empty for too long or it may catastrophically fail.
A lesser concern is that seats have mould inserts specific to the shape of each cosmonaut. I am not sure how they handle swaps. Maybe store the moulds on the ISS.
The seat liners can be installed in Soyuz on-orbit. When the Shuttle was delivering someone who would return on a Soyuz, they'd bring the liner up as cargo on the Shuttle and swap it in. I imagine they routinely do the same for crew who arrive and depart on different Sayuz (which happens fairly regularly.)
If there are six onboard two Soyuz will be docked. Always. There will never not be lifeboat for everyone, nor was there ever not one for everyone. Currently two are docked and those are the two lifeboats.
Those aren’t only lifeboats, though. They are also just the normal crew return vehicles. Here is how crew rotation currently works: Three depart in the oldest Soyuz docked to the station, leaving the station with a crew of three and only one remaining Soyuz. A couple days later a new Soyuz arrives at the station, meaning there’s now a crew of six and two Soyuz docked to the station. Then everyone stays up there for a couple months longer before the now veteran crew departs on the oldest Soyuz and everything repeats.
One advantage of doing it this way is that you are constantly renewing the lifeboats, so a Soyuz doesn’t have to survive years in space, only six or so months before it is replaced. Basically, it has to work for its main purpose (returning the crew to Earth as planned) anyway, insuring that it also works as a lifeboat. (Though I would assume that many changes were made to make the Soyuz work as a lifeboat. I would imagine that rapidly departing from the station, potentially with injured crew, is quite a different task compared to a planned departure.)
This makes me wonder, I assume they have procedures to dock a deserted ISS, right? What would happen in case of an emergency where both teams (3+3) have to return back to Earth, leaving ISS without a crew? Will they be able to "get back in"?
Continuous habitation of a space station is a bit historically unusual. Skylab had three visiting manned missions, none of which overlapped. Early Russian stations operated similarly. Mir was operated more like ISS, but left unoccupied several times. (See http://en.wikipedia.org/wiki/Soyuz_TM-30 for a commercial mission to revive and try to restore the previously-abandoned MIR.)
And the ISS (or early parts thereof) went about two years before its first long-term crew.
So, yes, you can get back into the ISS if it's empty. That capability has been designed into both halves of the space station from the beginning.
Soyuz can dock to deserted stations, or at least could in the past. They had to do it all the time with the Salyut stations, and I suspect it is how the first docking with the ISS went down as well.
Technically there is berthing and there is docking. Berthing requires that both sides cooperate, but docking doesn't necessarily require this. However while docking both sides are very nearly always under control (with the deserted side under robotic control).
Non-cooperative docking has only been done exactly once in the history of human spaceflight on the Soyuz T-13 mission to the Salyut 7 space station [0]. In addition, Wikipedia mentions a few unmanned tests.
In practice, all spacecraft docking and berthing operations are fully automated and no human intervention is required apart from emergency conditions (which have never occured). The last intentional attempt (1997) at manual docking ended up in a bad collision between the Mir space station and a Progress spacecraft [1]. The last Mir mission (Soyuz TM-30) did the last few meters under manual control. ISS crews are trained for manual docking but I don't think has ever been necessary.
In the hypothetical situation that the ISS would be left unmanned, it's extremely unlikely that they would decide to (or have time to) power down the attitude control systems (control moment gyroscopes and thrusters). So even if the station ended up unmanned, it's not likely that it would be non-cooperative (ie. out of control). If all the attitude control systems would disabled because of damage (e.g. fire), the station would probably not be salvageable.
So it's possible but very unlikely to have a scenario where a manned mission would need to manually dock an out of control space station. But it has happened once before, so it's not impossible either.
Well, the ISS was actually built as a constant iterative process, it wasn't just sent on space as is and then assumed operative. Also I'd assume the first module that was sent to space might have contained humans already right on departure from the Earth.
But yeah, obviously they have procedures to retrieve and re-enter an empty ISS, I was mostly curious how or if there's any material around.
Zarya (the first module, launched in 1998) was pressurized and could support a crew short-term-- the crew of STS-88 (which launched Unity, the second module added to the ISS) entered the station and began unstowing gear and stuff. The ISS couldn't support its permanent crew until Zvezda (the station's service module) launched in 2000, though-- Zvezda contains the station's primary life support equipment and contained crew facilities like toilets and bunks.
My guess of a likely reason to completely evac the station is one astronaut gets hurt, two healthy astronauts land with the sick one, then in a stroke of incredibly bad luck another astronaut gets hurt. For hurt, substitute in appendicitis, broken arm, heart attack, severe burn, poisoning from some kind of leak (ammonia?). If you're looking for a hard sci fi plot line, maybe major system malfunction hurts one astronaut, then after the medivac, while making duct tape repairs, another gets hurt, then the space pirates arrive and take charge of a derelict abandoned vessel, or whatever.
I would guess that docking with a completely dead powered down archeological relic of a station would be much more exciting than docking with a powered up and running station that merely happens to not have any humans onboard.
Station without power would start to tumble. Makes docking much harder. This actually happened with Salyut 7: the station died on orbit, no electrical or anything. The pilot of the rescue Soyuz matched its spin to dock manually. Effected emergency repairs while wearing fur-lined winter clothing.
It must not have been tumbling too badly. Seems like once you have significant motion in more than one axis it'd be pretty hard to match up. At that point, you probably have to grab and despin, or something. Or dock really really fast and hope your docking mechanism holds up to the stress.
Trying to fix/salvage it? I'm sure the russians reactivated a "dead" station at least once, sending a better prepared crew to repair quite a while after it was abandoned.
No, it isn't. SpaceX's human-rated Dragons haven't flown yet (and probably aren't finished, nor are they human-rated by NASA yet). The cargo version currently docked has no seats and you definitely can't just hang onto the walls and hope it works.
Of course it is, rating has nothing to do with reality. Dragon has brought supplies safely back to earth every time so far, and the g-forces were on the same level( edit:actually less ) as soyuz. And Dragon is of course pressurized in case it isn't obvious.
As I have pointed out, in a crisis, where there are no other options, it is capable of returning humans. This would involve makeshift seats/beds and landing in the ocean.
There's two Soyuz spacecraft in case things go bad.
If you are aware of a plan to use a Dragon as a lifeboat, please bring out some sources for that.
That's a pretty far fetched possibility and surviving re-entry in an unmanned capsule is unlikely. There aren't any life support capabilities (ie. oxygen for breathing) and surviving the 5-10 G accelerations of re-entry would be rather unlikely without being strapped to a seat.
Can the Dragon spacecraft even undock from the space station and robotic arm without a human operator on the Canadarm controls?
Astronauts will enter Dragon to remove cargo.
Dragon’s cabin is habitable, with air circulation, lighting, fire detection and suppression, air temperature control,
pressure and humidity monitoring.
Transporting Crew
While it initially is transporting cargo, Dragon was designed from the beginning to transport crew and is currently
undergoing modifications to make this possible. Crew configuration will include life support systems, a crew escape
system, and onboard controls that allow the crew to take control from the flight computer when needed. This focus on
commonality between cargo and crew configurations minimizes the design effort and simplifies the human-rating
process, allowing systems critical to Dragon crew safety and ISS safety to be fully tested on unmanned flights.
And the second pdf:
Crew Capability
•Both Dragon & Falcon 9 were designed from
inception to readily accommodate crew
•Immediate focus is on cargo for COTS
& CRS commitments, BUT…
•In every design decision, the ability to attain
human rating rapidly & at low additional cost is
paramount
Note: Many human-rating requirements are
mandated on the cargo vehicle because it must be
safe for ISS crew
Space Exploration Technologies Corp
June 16, 2009
This is why SpaceX was founded
21
Dragon Already Designed to
Accommodate ISS Crew
•For COTS Capabilities A-C, astronauts will enter (and temporarily
inhabit) the Dragon spacecraft for loading and unloading of cargo to
and from the International Space Station
•Therefore, Dragon already meets the manned requirements to allow
this activity, as called out in SSP 50808
•Air sampling and circulation
•ISS crew sample Dragon’s air supply through the Air Revitalization
System (ARS) port before entering the spacecraft, breathing in the
air as provided by the Dragon Environmental Control System.
• Air circulation is provided to ensure safe breathability throughout the
spacecraft
•Temperature and humidity requirements
•Touch temperature limits: between 39 F and 113 F
•Human Factors
•Protection from shock
•Restrictions on sharp corners, sharp edges, exposed screw threads, burrs, and pinch points.
• All fonts, colors, and labels are consistent with SSP 50005.
Dragon is capable of docking and undocking, but for reasons, it is rather berthed via the Canadaarm.
But the question is: is there a planned procedure / contingency plan involving the Dragon as a lifeboat? If not, then it's not going to be used. They have rehearsed procedures for these situations. Including the worst of crises.
The 5 year old link you provided mentions the possibility of modifying the Dragon capsule to provide life boat capabilities. That's not what is up there today. The other one talks about "air circulation" systems, but that's not the same as life support.
> But the question is: is there a planned procedure / contingency plan involving the Dragon as a lifeboat?
Wouldn't it be safe to assume there is such a backup plan? You've got a vehicle that should be able to return humans to earth. If an emergency arose with other vehicle(s) damaged, why wouldn't the Dragon be in the mix? I would assume that in a worst case scenario, all sorts of unusual measures could be taken.
Well no and and yes. The Dragon that is currently attached to the space station is unable to return humans to Earth. As far as I know, it is unable to undock from the space station without human assistance, it doesn't have any kind of seats in it and it's really not capable of transporting humans to or from the orbit. So practically it would mean that someone is left behind, sacrificing their own life to give someone else a marginal chance of survival. This will not happen unless it is known ahead of time that the Soyuz capsules are fatally damaged.
In contrast, the option of using the Lunar Module as a life boat in the Apollo 13 flight was planned and rehearsed ahead of time. Not all the details were worked out because it was thought that the crew would be dead before this would turn into reality (and the whole Apollo program was a bit rushed).
But yes, they must have thought long and hard about the option of using the Dragon. The whole Dragon program is built upon the idea of possibly using it as a life boat in the future but that is not the role of the Dragon up there at the moment. But the lessons learned have been translated into the next-gen human rated Dragon program.
But we don't really have to think about that. The last I heard, the CAPCOM and the crew were discussing about feeding the fruit flies onboard the ISS so the scientific objectives do not suffer more than they have to.
These are references to Dragon the program, the design, not to individual dragon capsules. Given the rate of development in space programs, no two Soyuz are identical, I imagine the answer as to whether a particular dragon would/could carry people back to earth changes with every mission.
For detachment, nearly every large connection in space has explosive bolts for cutting things loose. The docking ports have emergency modes.
Correct. The links in GP describe the option of adding a "quick detach" mechanism, but that was a hypothetical development direction of the Dragon program, not something that currently flies.
Dragon is "berthed" to the ISS, unlike Soyuz which is "docked".
Berthing is what they do to ISS modules. It's basically bolted on--which requires a fair bit of work from the crew on the station side, both mechanically and in getting the spacecraft in place (which they do by robotic arm capture). They do this for the cargo stuff because the berthing mechanism is wider, lighter, and cheaper.
Docking is what you do for a manned spacecraft. They have fancy mechanisms to attach and detach quickly and mostly-automatically. It's complex and the opening is enough to get people through, but it's fast and easy. A docked spacecraft can leave on its own; a berthed one would require crew still on to help.
While cargo Dragon could take a person down to Earth, and they'd probably survive (probably nestled among bags of trash), it's not going to do so in a hurry, and since you have a seat on a Soyuz already, and it's designed for it, you might as well use that. Especially if you're in a hurry. I think the only time cargo Dragon would be involved would be something catastrophic happening to one of the Soyuz--but not to anything else.
The space station would stay in orbit quite a long time without being boosted, that only happens once in several months.
Based on past experiences, it's possible to salvage even badly damaged space stations. This has been done before in the US Skylab program and the Soviet Salyut and Mir programs, although never in the same scale as the ISS.
Skylab had problems with solar panels and heat shielding which was fixed by spreading a huge blanket of reflective material.
In one of the Salyut programs, there was a loss of power which caused the station to freeze over. It was eventually recovered by cosmonauts who entered the dead space station wearing gas masks, and slowly melted the water reservoirs and eventually recovered the station.
The Mir station suffered a bunch of problems, including an onboard fire and a collision with an incoming supply vessel. The station persisted despite all these issues as well as the fall of the Soviet union.
In the case of a serious accident on the ISS, some kind of contingency plan would certainly be improvised. The exact details would depend on the damage, but it would most certainly not be abandoned without serious attempts at fixing the issues.
As far as I know the station is too close to earth and is thus slowed by the atmoshpere -> It will crash and burn on earth if no one keeps it on track.
That process takes years. Even if the station ws uninhabitable we would be able to dock a propulsion unit to it and increase it's altitude if we needed to keep it available.
Does it have thrusters that burn now and then to maintain its orbit?
AIUI, the Soyuzes (is that the right plural) that are attached as lifeboats/return craft, also are used to adjust ISS orbit. They've got engines, etc., so it's relatively easy to use them in this capacity.
You are correct, but the station also has two main engines on Zvezda that are rarely used. It's easier and cheaper to keep these main engines ready for emergencies and let the docked craft perform altitude boosts.
As to the parent comment, burns are required because the ISS is at a very low altitude. It is still technically within our atmosphere and experiences significant drag from it. In addition, as the stations rotation changes, it's corrected using gyroscopes on the station. Once these gyroscopes have stored their maximum momentum in the flywheels they need to be released, and thrusters are used at that point to cancel out the momentum.
Something a lot of people don't seem to realize is that the station is moving all the time. Anything you do on the inside, such as exerting force on a wall or running on the treadmill (which had to be specially designed to minimize vibration transfer to the station) affects the station and must be cancelled out over time. The station moves as part of it's daily operation as well, such as when it enters [night glider mode](http://en.wikipedia.org/wiki/Night_Glider_mode) to reduce atmospheric drag.
Anything you do on the inside, such as exerting force on a wall ... affects the station and must be cancelled out over time.
Won't this cancel itself out over time anyway? If the astronaut kicks off one wall (acquiring momentum by applying a force), won't he just float over to the opposite wall and negate that momentum by applying a complementary but opposite force?
This actually makes me wonder: what if there's a false bomb report in the ISS? Akin to when some 12 year old prankster says in twitter that there's a bomb in flight XYZ123, will chaos happen up in the ISS?
There is an odd-man-out problem. Nobody has ever tried to don a spacesuit without some help from people not in spacesuits. So even if they had enough, which they probably do not, it might not be possible. Getting into a modern suit also requires hours of decompression to adjust to their lower pressure. You can't just hop in and step outside.
(Mercury/Gemini and early soviet pilots were suited/dressed before takeoff. And Apollo suits were different than modern systems.)
This is very complicated. I was researching this as kind of a logic puzzle or scheduling logistics kind of game. Not just evac the ISS, but general ISS ops. This is actually pretty boring compared to the engineering challenge of working around ECLSS issues and the mysteriously complicated electrical system. Elements of lemmings and DF and simcity and scheduling game on the ISS. On a map of modules that is not a full mesh connected network, etc. How long can you improvise in face of disaster kind of game mechanic. This game idea went nowhere, mostly.
First of all the Orlan suits are just tuned up moon suits, continuous evolutionary change since the 60s no revolutionary change like the USA suits, and it appears two dudes have no problem dressing each other while in suits. I couldn't find anything one way or another WRT one dude jumping in a suit by himself or much about Russian suit training. I get the feeling it wouldn't be a problem based on past mission profiles for two astronauts to dress each other aka it's been done but isn't talked about much, just kinda assumed. That doesn't mean a 3rd unsuited helper would have nothing to do.
Sokol suits are available but they are not really built for outdoor use (thermal, wear and tear, sun visors, maybe harnesses?), you'd be basically immobile and probably stiff and uncomfortable after awhile. Doing an EVA in a sokol would likely suck pretty bad but would beat breathing space. If there's a hole in the capsule during re-entry (or takeoff) the sokol will keep you alive for a couple hours, although uncomfortably.
The USA suits don't fit thru russian airlock holes (holy cow! but true!) so you can only put the (two?) USA suits thru the Quest airlock. The Russian suits can go out Pirs airlock, although many believe it'll never happen, Pirs is supposed to be re-entered when the new russian multipurpose lab module is launched to replace it. We'll see if that ever happens. Russian suits historically went thru the Zvezda but its ridiculous, you seal the hatches and open a door to the outside, its not a "real" airlock. I was never able to get stats on which modules could "zvezda style" evac if necessary.
Where the suits are stored is a mystery vs where the disaster is (meteor hole or whatever). I guess if you need to get to Quest and there's a de-pressurized segment in the way, one of the Russians has to go out and fix it.
I never saw any pictures or written description claiming more than 2 USA suits in stock and 2 Russian Orlan suits in stock at any given time. I believe they have a sokol for every crewmember, three sitting in each re-entry capsule. The onboard suits are rotated and thrown out every couple years. The Russians got new Orlan suits a couple years ago with semi-advanced onboard system debugging computers, kinda interesting.
Decompression sickness is crazy analog and non-binary thinking goes over VERY poorly on this site, lets just say its a game of statistics, and if half of DCS symptoms don't even kick in for 6 hours (or whatever it was exactly) then given the 100% possibility of death vs maybe 50% some symptoms in six hours and 10% death, then obviously you risk it. If you have the most expensive people on the planet the furthest of our species from medical help and you're in no hurry, then you spend the full 3 hours doing the pre-breathe and the ISLE exercise protocol. In the olden days they slept overnight in the airlock but ISLE works and only takes 3 hours... Just spending a half hour in utter panic breathing pure O2 during a disaster in healthy young athletic bodies "probably" lowers the odds of DCS to about zero, or at least lower than the odds of whatever would make you panic EVA, so in practice its probably not an issue. You wouldn't screw around with DCS unless you were in severe danger, but you wouldn't have an emergency EVA just for the heck of it either. My point being if you die of DCS thats probably just a dice roll that something else almost got you anyway. Its not the main threat or even the most important threat. There would be no need to risk DCS unless you were about to die, in which case the odds of DCS not killing you are pretty good. Or rephrased DCS is not a realistic game criteria in my planned game that went nowhere.
"Ars consulted a number of sources to gauge the difficulty of donning spacesuits without any assistance from unsuited crew. Though none would speak on record, the consensus is that it would involve what was universally categorized as an extremely high degree of difficulty."
I don't know where to find a current inventory, but I think they now keep four US EMUs on the ISS. They've been dealing with various failures, and at one point were down to 2 working ones, but I believe there are 4 functional at this time: 3003, 3011 (the one that tried to drown Luca), 3010, and 3005. Dragon I think took up 3003 and returned 3015 during CRS-3.
https://twitter.com/NASA/status/555353082209767424