I don't know the circumstances under which this could occur, but if someone got detached from their craft during a spacewalk (for example) and started drifting off into space at a significant velocity, is there any way his/her fellow astronauts could do anything?
Hypothetically: Is there any to recover a "lost" astronaut in space?
- Thread starter TheMadCloner
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Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
Pardon my ignorance, but what is a MMU?
So there is no way to adjust the orbit or movement of the craft to "target" the lost astronaut? Or is it just not feasible?
I imagine it'd be very tough for the family. Would radio contact be possible?
Pardon my ignorance, but what is a MMU?
So there is no way to adjust the orbit or movement of the craft to "target" the lost astronaut? Or is it just not feasible?
I imagine it'd be very tough for the family. Would radio contact be possible?
A
Amaris
Guest
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
A Manned Maneuvering Unit. That little jet pack type thingy they wear on their backs if not attached to a lifeline.
The reason they couldn't adjust orbit would be fuel based I imagine. The shuttle carries very little fuel, and it's to adjust for re-entry into the atmosophere, so yes, the astronaut would be as good as gone.
(Hope I didn't step on your toes, msbae ).
J.
A Manned Maneuvering Unit. That little jet pack type thingy they wear on their backs if not attached to a lifeline.
The reason they couldn't adjust orbit would be fuel based I imagine. The shuttle carries very little fuel, and it's to adjust for re-entry into the atmosophere, so yes, the astronaut would be as good as gone.
(Hope I didn't step on your toes, msbae ).
J.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
As mentioned, another astronaut can use a MMU to retrieve a free-floating astronaut. But MMUs aren't really available much anymore.
Astronauts on EVAs can wear SAFERs (Simplified Aid for EVA Rescue) which is kind of like a smaller maneuvering unit than the MMU. If they get detached, they can maneuver themselves to safety.
As mentioned, another astronaut can use a MMU to retrieve a free-floating astronaut. But MMUs aren't really available much anymore.
Astronauts on EVAs can wear SAFERs (Simplified Aid for EVA Rescue) which is kind of like a smaller maneuvering unit than the MMU. If they get detached, they can maneuver themselves to safety.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
There are actually several ways in which a lost astronaut could be recovered but they are all contigent on velocity, time and fuel. For instance, if an astronaut simply "fell off" the space craft, he would not be moving at a fast speed at all. All it would take then, is another astronaut in a space suit tethered to the ship in some way. This second astronaut would simply launch himself at the first astronaut, catch him and then they could both pull themselves back to the ship. There is not even any fuel expended in this maneuver. Other methods have been mentioned above.
There are actually several ways in which a lost astronaut could be recovered but they are all contigent on velocity, time and fuel. For instance, if an astronaut simply "fell off" the space craft, he would not be moving at a fast speed at all. All it would take then, is another astronaut in a space suit tethered to the ship in some way. This second astronaut would simply launch himself at the first astronaut, catch him and then they could both pull themselves back to the ship. There is not even any fuel expended in this maneuver. Other methods have been mentioned above.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
Since the earliest days of spaceflight, there have also been plans to provide astronauts operating on low Earth orbit with their own reentry devices. Usually, these have been projected as a personal means of ejecting from a doomed spacecraft, but some versions could plausibly be carried along on spacewalks.
Essentially, what the package would consist of would be a solid or otherwise surefire rocket engine, an orientation aid, a large unfolding surface (probably a balloon of some sort) and a high altitude parachute. A stranded astronaut would already be in the upper reaches of the atmosphere anyway; he would fire the rocket to dip down further (a complete deorbit delta-vee would not be required), would unfold the balloon, and would let air resistance slow him to a downward spiral where eventually he would be falling like a rock. At no time would the deceleration reach the levels at which one would need a heat shield, though. At a suitable point, the balloon would be deflated and the parachute deployed.
No such device has ever actually been constructed AFAIK. For use as a backup in spacewalks, the limiting factor would be the great mass and bulk of the rocket engine. As a sports device, the setup would have great potential, though...
At higher orbits, the system would be useless, because use of air resistance as a deceleration aid is rather essential here. But I'd guess that at ISS orbital height, it would perhaps still be possible to reenter before life support ran out. Extending life support endurance would be a good goal in any case, and would facilitate other methods of rescue.
Perhaps one might also strive to install that badass rocket in the spacesuit in any case, even when a MOOSE-type atmospheric reentry rig isn't intended? But the task of using that firecracker to reenter would be much easier than the task of aiming it so that one can return to one's spacecraft.
Timo Saloniemi
Since the earliest days of spaceflight, there have also been plans to provide astronauts operating on low Earth orbit with their own reentry devices. Usually, these have been projected as a personal means of ejecting from a doomed spacecraft, but some versions could plausibly be carried along on spacewalks.
Essentially, what the package would consist of would be a solid or otherwise surefire rocket engine, an orientation aid, a large unfolding surface (probably a balloon of some sort) and a high altitude parachute. A stranded astronaut would already be in the upper reaches of the atmosphere anyway; he would fire the rocket to dip down further (a complete deorbit delta-vee would not be required), would unfold the balloon, and would let air resistance slow him to a downward spiral where eventually he would be falling like a rock. At no time would the deceleration reach the levels at which one would need a heat shield, though. At a suitable point, the balloon would be deflated and the parachute deployed.
No such device has ever actually been constructed AFAIK. For use as a backup in spacewalks, the limiting factor would be the great mass and bulk of the rocket engine. As a sports device, the setup would have great potential, though...
At higher orbits, the system would be useless, because use of air resistance as a deceleration aid is rather essential here. But I'd guess that at ISS orbital height, it would perhaps still be possible to reenter before life support ran out. Extending life support endurance would be a good goal in any case, and would facilitate other methods of rescue.
Perhaps one might also strive to install that badass rocket in the spacesuit in any case, even when a MOOSE-type atmospheric reentry rig isn't intended? But the task of using that firecracker to reenter would be much easier than the task of aiming it so that one can return to one's spacecraft.
Timo Saloniemi
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
Only if we invent a Sliding device to travelinto a parallel universe were that actually happened. The Russians lost four cosmonauts during re-entry and landing, and others in training on the ground, but lost in orbit, etc? Never happened.
Only if we invent a Sliding device to travelinto a parallel universe were that actually happened. The Russians lost four cosmonauts during re-entry and landing, and others in training on the ground, but lost in orbit, etc? Never happened.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
There are many legends about covered-up cosmonaut deaths that have at least some sort of "evidence" to back them up: snippets of radio communication overheard, curious incompletely censored records, etc.
However, such legends necessarily refer to suborbital or very low-orbit missions performed early on in the Soviet space program, and thus the chances of orbiting corpses remaining in the 21st century would be zero. By the time stuff was being shot to survivable orbits, the means of tracking it had also been evolving, and it appears highly unlikely that any manned craft could have slipped by the foreign observers at that point. There are certain obvious telltales to accompany a crewed launch that would have been progressively more difficult to hide.
Really, in order to get a mysterious cosmonaut death, the Soviets would have had to begin with flying a mysterious mission, one deliberately camouflaged as uncrewed from the start. The effort would probably have been prohibitive, no matter what the mystery motivation behind it.
I'm perfectly willing to believe in the possibility of early cosmonaut deaths in failed suborbital shots, many of which went ill documented and perhaps even unobserved. The myth about Ilyushin Junior is a particularly good and entertaining one...
Timo Saloniemi
There are many legends about covered-up cosmonaut deaths that have at least some sort of "evidence" to back them up: snippets of radio communication overheard, curious incompletely censored records, etc.
However, such legends necessarily refer to suborbital or very low-orbit missions performed early on in the Soviet space program, and thus the chances of orbiting corpses remaining in the 21st century would be zero. By the time stuff was being shot to survivable orbits, the means of tracking it had also been evolving, and it appears highly unlikely that any manned craft could have slipped by the foreign observers at that point. There are certain obvious telltales to accompany a crewed launch that would have been progressively more difficult to hide.
Really, in order to get a mysterious cosmonaut death, the Soviets would have had to begin with flying a mysterious mission, one deliberately camouflaged as uncrewed from the start. The effort would probably have been prohibitive, no matter what the mystery motivation behind it.
I'm perfectly willing to believe in the possibility of early cosmonaut deaths in failed suborbital shots, many of which went ill documented and perhaps even unobserved. The myth about Ilyushin Junior is a particularly good and entertaining one...
Timo Saloniemi
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
If you're talking something like Frank "Bumper Pool" Pool in 2001, no. There isn't enough fuel or crossrange capacity built into the shuttle or previous manned craft to do anything but wave bye.
For less significant events, hardware already exists. The SAFER EMU addon provides up to 10 ft per second of delta v.
http://en.wikipedia.org/wiki/Simplified_Aid_for_EVA_Rescue
There were plans for more zippy rocket packs prior to Apollo. The AMU that was to be tested during Gemini 9 was to provide a total delta v of 250 feet per second, but was not tested due to Gene Cernan having trouble with visor fogging and overheating during his EVA. All systems that have been utilized on orbit used cold gas like nitrogen. The AMU was configured to use hydrogen peroxide and a silver catalyst screen... the same as the Bell jet pack popularized by Mr James Bond.
No WIKI entry exists for the AMU, but it is referenced on the MMU page:
http://en.wikipedia.org/wiki/Manned_maneuvering_unit
If you're talking something like Frank "Bumper Pool" Pool in 2001, no. There isn't enough fuel or crossrange capacity built into the shuttle or previous manned craft to do anything but wave bye.
For less significant events, hardware already exists. The SAFER EMU addon provides up to 10 ft per second of delta v.
http://en.wikipedia.org/wiki/Simplified_Aid_for_EVA_Rescue
There were plans for more zippy rocket packs prior to Apollo. The AMU that was to be tested during Gemini 9 was to provide a total delta v of 250 feet per second, but was not tested due to Gene Cernan having trouble with visor fogging and overheating during his EVA. All systems that have been utilized on orbit used cold gas like nitrogen. The AMU was configured to use hydrogen peroxide and a silver catalyst screen... the same as the Bell jet pack popularized by Mr James Bond.
No WIKI entry exists for the AMU, but it is referenced on the MMU page:
http://en.wikipedia.org/wiki/Manned_maneuvering_unit
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
No.
The suits are already under low (5psi) pressure. Any less an you'd pass out and die anyway.
EVA's are like deep-sea diving. You know and accept the risks when you step out the door.
No.
The suits are already under low (5psi) pressure. Any less an you'd pass out and die anyway.
EVA's are like deep-sea diving. You know and accept the risks when you step out the door.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
Well, yeah they have O2 tanks, But they're only big enough to allow breathing at that reduced pressure for the design duration of the suit.
I can breathe underwater for about an hour at 60 feet with my 80 cubic foot scuba tank. Air being about 20 percent O2, that means there's 16 cubic feet of O2 in there. That hour duration is at roughly 3 atmospheres of pressure (Divers, I know what you're gonna say but the air column above the water column counts in this case since we're comparing it to space instead of sea level.), let's say 45 psi so I don't have to do too much math.
If the suit is at 5 psi (and I think it's lower, but this is a good target figure), that same 16 cubic feet of O2 would keep me going for 9 hours if we ignore the fact that I'd be breathing way more than on a dive, cuz I'd be in freakin' outer space!
A 13 cubic foot "pony tank" is about 4.5 inches in diameter and a bit over a foot long.
If you're thinking "uncork the valve and play bottle rocket" It'd be nigh unto impossible to doff the PLSS, get into it, get access to the tank, and find a way to shear the valve off or otherwise control gas output while holding it at an angle that gives you a good return vector.
There's also the problem of breathing after doing this. Dunno what kind of check valves are built into the suit. There's gotta be some, NASA still thinks that way I hope.
Well, yeah they have O2 tanks, But they're only big enough to allow breathing at that reduced pressure for the design duration of the suit.
I can breathe underwater for about an hour at 60 feet with my 80 cubic foot scuba tank. Air being about 20 percent O2, that means there's 16 cubic feet of O2 in there. That hour duration is at roughly 3 atmospheres of pressure (Divers, I know what you're gonna say but the air column above the water column counts in this case since we're comparing it to space instead of sea level.), let's say 45 psi so I don't have to do too much math.
If the suit is at 5 psi (and I think it's lower, but this is a good target figure), that same 16 cubic feet of O2 would keep me going for 9 hours if we ignore the fact that I'd be breathing way more than on a dive, cuz I'd be in freakin' outer space!
A 13 cubic foot "pony tank" is about 4.5 inches in diameter and a bit over a foot long.
If you're thinking "uncork the valve and play bottle rocket" It'd be nigh unto impossible to doff the PLSS, get into it, get access to the tank, and find a way to shear the valve off or otherwise control gas output while holding it at an angle that gives you a good return vector.
There's also the problem of breathing after doing this. Dunno what kind of check valves are built into the suit. There's gotta be some, NASA still thinks that way I hope.
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Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
I suppose what we really need is a "life preserver"----an autonomous jetpack which is capable of maneuvering towards a stranded astronaut either automatically or via remote control. Minimal propellant would be needed to get it out there since it wouldn't have to accelerate another human, and you'd also save fuel on the way back since you'd only be accelerating one person rather than two.
Also, making the rescue device unmanned would enable the crew to take more risks with it than they otherwise would, possibly allowing rescues which would be too tenuous to risk another crewer on.
I suppose what we really need is a "life preserver"----an autonomous jetpack which is capable of maneuvering towards a stranded astronaut either automatically or via remote control. Minimal propellant would be needed to get it out there since it wouldn't have to accelerate another human, and you'd also save fuel on the way back since you'd only be accelerating one person rather than two.
Also, making the rescue device unmanned would enable the crew to take more risks with it than they otherwise would, possibly allowing rescues which would be too tenuous to risk another crewer on.
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
...or just make it deliver a new tether.
Maybe it could look something like this?
http://spaceflight.nasa.gov/station/assembly/sprint/index.html
...or just make it deliver a new tether.
Maybe it could look something like this?
http://spaceflight.nasa.gov/station/assembly/sprint/index.html
Re: Hypothetically: Is there any to recover a "lost" astronaut in spac
Yes, that is an older article, but Aerus/Sprint did fly and get some time outside while astronauts were on EVA.
Google is your friend. There's one really nice pic of the Aerus/Sprint loitering near the rudder of the shuttle, with Earth as a backdrop.
Anyway, this contraption has throttled back versions of the SAFER package thrusters. Scale it up a little and you've got an on-orbit ROV capable of delivering a rescue tether for some distance from the station or shuttle. Scale it up to peroxide/silver thrusters like the old Gemini AMU had and you've got something you have to make sure dosen't bump into the rescuee at full speed or it's the Frank Pool syndrome all over again, and no HAL to blame this time!
Yes, that is an older article, but Aerus/Sprint did fly and get some time outside while astronauts were on EVA.
Google is your friend. There's one really nice pic of the Aerus/Sprint loitering near the rudder of the shuttle, with Earth as a backdrop.
Anyway, this contraption has throttled back versions of the SAFER package thrusters. Scale it up a little and you've got an on-orbit ROV capable of delivering a rescue tether for some distance from the station or shuttle. Scale it up to peroxide/silver thrusters like the old Gemini AMU had and you've got something you have to make sure dosen't bump into the rescuee at full speed or it's the Frank Pool syndrome all over again, and no HAL to blame this time!
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