https://twitter.com/NASA/status/555353082209767424

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.

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.

edit: There's also the now cancelled http://en.wikipedia.org/wiki/Crew_Return_Vehicle, which is probably what you were thinking of.

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.

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.)

Last time it happened was Nov 2013, and apparently previously in 2009:

http://www.space.com/23542-space-crew-olympic-torch-landing-...

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.

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).

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.

[0] http://en.wikipedia.org/wiki/Docking_and_berthing_of_spacecr... [1] http://en.wikipedia.org/wiki/Progress_M-34#Collision

But reading http://er.jsc.nasa.gov/seh/docking_with_ISS.pdf, at least the Space shuttle could dock with MIR all on its own.

Also, reading http://en.m.wikipedia.org/wiki/Docking_and_berthing_of_space..., there are almost more standards for docking mechanisms than different types of spacecraft.

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.

http://en.wikipedia.org/wiki/Assembly_of_the_International_S...

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.

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.

They've got a Soyuz for that.

In an extreme emergency, a crew could put on emergency breathing equipment, and use makeshift seating, then ride the capsule home.

One of the major reasons the Dragon v1 can't launch with human crew inside is that it has no launch abort system.

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.

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?

Your third paragraph is not correct at all. Dragon has life support and reentry acceleration of 3.5g.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/2011001...

http://www.nasa.gov/pdf/361838main_11%20-%20SpaceX%20Augusti...

Quoting from the first pdf:

Environmental Control System

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.

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.

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.

For detachment, nearly every large connection in space has explosive bolts for cutting things loose. The docking ports have emergency modes.

Please correct me if I'm wrong.

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.

For example: http://www.space.com/15031-space-junk-station-astronaut-thre...

I wonder how we would go about recovering the station, without a space shuttle to go around and live on while doing repairs.

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.

Apparently they just screw around while it's going on: https://www.youtube.com/watch?v=u4ggQdkTcLo

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.

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.

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?

(Mercury/Gemini and early soviet pilots were suited/dressed before takeoff. And Apollo suits were different than modern systems.)

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.

http://arstechnica.com/science/2014/02/the-audacious-rescue-...

"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."