What would happen to an astronaut if they floated away in space? originally appeared on Quora - the place to gain and share knowledge, empowering people to learn from others and better understand the world.
Answer by Clayton C. Anderson, a NASA astronaut who lived and laughed in space for quite a while:
Having read a few of the other answers to this question, it's time for me to officially weigh in, as I have a tad bit of experience in this area.
For an astronaut to "float away in space," one must assume that our American hero astronaut:
1) Is outside of his/her space vehicle, performing a spacewalk (EVA in NASA acronym-ese, meaning Extra-Vehicular Activity) and
2) Has gooched up said spacewalk by failing to tether themselves appropriately to their space vehicle (we typically have both safety and local area tethers), AND
3) Enough force has been imparted to their spacesuit-clad body to send them tumbling away on any one of a million-plus possible trajectories.
Let us further assume --for the purpose of answering this question-- that our space vehicle is the International Space Station (ISS) since currently no other US astronaut-occupied space vehicles exist (that's a Q/A for another time!).
Given these things have all happened, our brave spaceflier must resort to their hours of spacewalk training, including those lessons that taught us how to use a jet pack called SAFER (Simplified Aid for EVA Rescue).
Performing one of my six career spacewalks, my SAFER backpack is clearly visible near my rear end, attached below/on the side of my PLSS (Primary Life Support System). On this walk, I am using SAFER number 6, as shown on the jetpack's extended "boom." Various dark circles on the backpack are thruster openings.
To save themselves in the event of a mea culpa such as this, astronauts --in the quiet confines of a small laboratory in Building 9 at NASA's Johnson Space Center (JSC)-- refine their skills at virtual reality (VR). They play a GAME... you ask? Not hardly. While it may seem like a game, it is training of a significant nature, and a skill set we must master if we ever hope to perform a spacewalk in the first place. Check out the following link to learn more:
Our SAFER is a jetpack straight out of a Buck Rogers comic book. A bit more modern, and slightly less capable, its purpose is nearly the same. Allow the astronaut to "fly" back to structure (on the ISS) where they can reattach and --more likely than continuing the spacewalk-- head back inside and clean up their now-full diaper!
SAFER gives astronauts basically one-shot to "come home." Limited in fuel, and governed by the laws of orbital mechanics, it is not simply a leisurely task to fly back to safety. That's why we practice using VR. Multiple scenarios, each harder than the last, toss us from the ISS with varying degrees of (separation) velocity and directional tumbling. In its simplest form, our training teaches us to:
- Realize one's predicament (not hard to do, but might involve internal verbalization of cuss words!).
- Deploy the SAFER handcontroller, power it on and stop the tumbling by initiating attitude hold (a button push). Note that you will still be moving away from the ISS.
- Reorient yourself to "find" the ISS using only directional yaw (imagine slowly rotating to your right or left). Try to stop so you are facing --as much as possible-- the point from which you departed.
- Now that you are looking back at ISS, establish attitude hold again with the ISS in your line of sight.
- Using translational thrusts only (via your hand controller) --up/down, right/left, to ISS/from ISS (obviously to ISS is your best choice!)-- and your knowledge of orbital mechanics, slowly fly back until you are close enough to grab on to something!
Now that you are reattached, I'm guessing your heartrate is extremely high, along with your breathing rate. For me, it would be a good time to pause, take a deep breath, and recollect my thoughts. Then, having done all that, it would be time to apologize to the Mission Control Center team profusely, thank the VR Lab and EVA for the awesome training, and begin to dejectedly head inside ... all the while thinking about your upcoming retirement and moving to some secluded spot in Montana.
After all, that was probably your last spacewalk.
Keep lookin' up!