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59

As long as neither spacecraft nor the astronaut are accelerating or decelerating, the relative speed of the spacecraft and the astronaut remains the same. So the astronaut will hover near the spacecraft. The actual velocity is irrelevant here, it's the same principle with every spacewalk: the ISS is moving at about 27,600 km/h, yet the astronauts do not "...


35

It turns out that outer space is not a perfect vacuum: there are a few hydrogen atoms per cubic centimeter. (reference) For large X, non-relativistic physics, the astronaut and spacecraft will stay close enough to each other. Once X gets small, and you approach the speed of light, these hydrogen atoms could slow down your spacecraft. Therefore, to maintain ...


31

The shuttle (and ISS) EMU (Extravehicular Mobility Unit) has a condensing heat exchanger as part of its ventilation loop. The condensate is stored, used for cooling, and the excess is drained after each EVA (Extravehicular Activity). Reference: Shuttle Crew Operations Manual: https://www.nasa.gov/centers/johnson/pdf/...


29

They did. Apollo 15, 16, and 17 has an EVA to recover film from cameras in the Scientific Instrument Module Bay (SIMBay) on the Service Module to bring back inside. This table, linked, shows all the Apollo EVA's. Table of EVAs Worden (Apollo 15), Mattingly (Apollo 16), and Evans on Apollo 17 spent about 3 hours total on EVA. Some good articles on these ...


21

I feel this sort of question benefits from a series of thought experiments. Imagine instead that you've got two astronauts, side by side, zipping through space at some constant speed. They're kind of sweet on each other so they're holding hands. Awwwww. But then they suffer a cruel change of heart and stop holding hands! What do you imagine would ...


17

I went on a quest to try and get the sources for all the citations for that article; I was partially successful. I have FOIA requests out for the documents I was not able to find on the internet, and thanks to a fantastic librarian at UC San Diego I got a scan of the document that I think spurred this. “The First Egress of Man Into Space” (NASA TT F-9727), ...


15

Considering how all the usual docking/berthing ports at the station are occupied, Santa would likely arrive in a Dragon Crew/V2 or a Boeing CST-100 vehicle. These are the next US vehicles that will be manned and due for first launches in 2019. The Russian side uses their own style of docking port that Progress, Soyuz, and the ESA ATV vehicles dock. These ...


13

There have been four non-LEO EVAs performed by the Apollo astronauts. Wikipedia has a nice list. Apollo 15 - one in lunar orbit (visual identification of landing sites), one on the return flight (collect film from exterior of spacecraft). Apollo 16 - on the return flight to collect film and experiments from exterior of spacecraft Apollo 17 - on the ...


11

I'm sure there are different techniques for different space suits, but here's an example of how it is done for the ISS suits: The key to handling body heat and sweat is the Liquid Ventilation Garment, or LVC. This is essentially what looks like a full body thermal underwear, but it is lined with tubes that pass water through them. If you heat up, cold ...


9

Another way to think is to consider two space walking astronauts; one inside the ship and one outside. Neither is touching the ship, both are moving at essentially the same speed in the same direction. All three pretty much stay together. However, there could be a teeny tiny amount of acceleration experienced by each. For example, at an extremely high ...


8

You can't open an airlock hatch to vacuum until the pressure inside is essentially zero. The hatch opens inward and is held closed by tons of force if there is any appreciable delta pressure. Airlocks are designed for safety and reliability, not circus stunts.


7

In addition to the scheduled EVAs on the later Apollo missions, if the lunar module was unable to securely dock with the command module after returning from the moon, the commander and lunar module pilot could have EVA'd back to the CM. This procedure was never required during the program. (The Soviets' tiny 1-seat lunar lander, the LK, had no docking hatch, ...


6

Yes. First pull the tank gently in some direction until it has moved at least 1m. Now pull it in the opposite direction until it comes to rest. The tank with the liquid will require much less force initially to deccelerate it, but then will need more force (or may even start moving again after stopping) later. The solid tank will need a steadier force. ...


6

None of them were particularly far. The first flight shows a distance of 325 feet (99 m). The best record I can find for STS-41-C says the shuttle came within 200 feet (63 m) of the satellite, and the last was done via the MMU. and the best guess I have from STS-51-A is 35 feet. The tests of SAFER on STS-64 was just around the robotic arm, so I'm assuming ...


6

Short answer: These "sounds" consist of vibrations produced by the astronaut's movements and his suit systems and transferred through his space suit, camera enclosure and PCB the microphone is soldered to plus electrical and digital noise added by the sound processing pipeline. Long answer: Microphone is an electromechanical device, that converts ...


6

We have an answer for Shuttle, and an answer for ISS. Here is the answer for Apollo. The main strategy was to prevent sweating in the first place. The astronauts wore a Liquid Cooling Ventilation Garment (LCVG), which was essentially long underwear with closed tubes that circulated cooling water. Heat was discarded through the sublimator on the suit's ...


5

no, conservation of momentum is retained (an object in motion will remain in motion unless something acts upon it)...similar to being in an airplane and throwing a ball up in the air...seems like it should fly to the back of the airplane, but it won't...it'll act just like you were on the ground.


5

There are 330 objects with an international designation starting with 1998-067, the first of which is the ISS. All of these are associated with the ISS, either being intentional or unintentional satellites released, or other related objects. Many of these are called "ISS Deb". It can be difficult to trace exactly which one corresponds to a particular object, ...


4

From looking at the patent, there are triangular or wedge-shaped cutouts in the heel of the shoe which interface with "bolts" protruding from the floor. Current US EVA suit boots have "foot restraint interfaces" that look like a heel as explained here: Why do astronauts wear heels?. But that does not look much like the Jackson patent. Skylab astronauts ...


4

After cross-comparing the Wikipedia List of Spacewalks (split into several pages) and the List of International Space Station expeditions, I have discovered the following: Timothy Kopra, on Expedition 46, arrived at the ISS on December 15, 2015 at 17:33:29 (all times UTC). He then conducted a spacewalk at December 21, 2015 at 13:45. That's 5 days, 6 hours, ...


4

Lots there. Do you break off the EVA half an hour in if you get a headache? No. Do the EVA suits have an Aspirin dispenser in the helmet? No. Has anyone ever vomited into a helmet on EVA? No. (at least NASA astronauts). Nausea is a huge no-go, and has resulted in cancellation of EVAs. Are there any documented cases of people getting sick on ...


4

Look at Santa's sleigh. See anything resembling a docking collar? No?--then why do you think he has any use for a docking port?? It's obvious he gets there via EVA. The ISS airlocks aren't blocked. Given his normal speed of travel it's pretty obvious he's not simply breathing the ambient air as he flies anyway, it's perfectly reasonable to figure that ...


4

Does sunlight warm an astronaut's face during a spacewalk? Perhaps a little, but not much. Most About 40% of the power in the Sun's spectrum is in visible wavelengths (not a coincidence, in several ways) so if the astronauts can see, then the Sun can see them too! There's no such thing as a one-way mirror. Looking at the photos in the question, you can't ...


4

The correct and complete answer is distributed among many previous posts. I try to condense them here, without attempting to reference all of you guys. All of the below information was provided in the previous answers. The main point is that neither the ship nor the astronaut tend to brake in empty space because of Newton's law. Additionally, there are ...


4

A brave Astronaut is leaving the spacecraft to a space walk, while not being attached to the spacecraft. Will the astronaut hover near the spacecraft at the same speed as it (1/X of speed of light), or be quickly behind the spacecraft and will watch it disappear in the black horizon? Newton's First Law of Motion ("an object at rest stays at ...


3

A person in a free fall environment can rotate and change their orientation with complex body movements, similar to how a cat can rotate mid-air so that it always lands on it's feet. However, it is impossible to permanently gain acceleration in any direction without 'throwing' something away. Without an EVA manuverability pack or other thruster system, the ...


3

Let's tackle this with a slightly different question: Which falls faster? A bowling ball or a feather? Now, everyone knows the feather will fall slowly, but that's because the feather has a massive surface area to catch the air around it. Without air resistance they fall at the same rate (see the video below for a most impressive display of that ...


3

Most of the publicly available procedural information you seek is on the Johnson Space Center Flight Data File page. It may help to briefly review the organization of the EVA checklist documentation. The EVA Checklist document is just a list of all the documented procedures. The Cuff Checklist is a sub-section of the EVA checklist and mostly deals with ...


2

There were indeed special circumstances in each case. For the Expedition 46 EVA, this was an unscheduled EVA. Scott Kelly had inadvertently engaged a brake on the Crew and Equipment Translation Aid (CETA) cart during a prior EVA. This cart moves along the ISS "railway" used by the Mobile Base Servicer (MBS) (part of the station robotics system) and the ...


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