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66

It's about as standard procedure as crossing your legs when you're sitting. Arms in microgravity, without conscious effort to keep them by your body, will tend to extend the elbows to the sides - just like holding knees together when sitting, at least for men, requires active (if minor) effort. Holding arms like this simply prevents sticking elbows into the ...


50

Offered as a supplement to @SF's answer: This shows the fully relaxed arm position obtained by a sleeping astronaut. From here


50

It definitely does, and not just one person - except these people are ground-based. The astronaut crew is only a small fraction of the number of people operating, controlling and maintaining ISS. While astronauts operate in shifts, and usually (though not always) at the same time, periods when everyone on the station is asleep aren't anything infrequent. ...


39

Look at the STS-122 video. How many astronauts do you see? I see six. Seven astronauts landed with STS-122. The six you see were the crew of STS-122 who spent twelve days in space. They could walk because twelve days in zero g isn't enough time to take a significant toll on musculature, bones, and blood. The seventh returning astronaut, Daniel Tani, who you ...


38

The answers to all your questions are described at length in section 6.4 (page 173) "Possibility of Rescue or Repair" of the CAIB Report. Appendix D-13 "STS-107 In-flight Options Assessment" is a very detailed description of the process that was utilized to come up with the self-repair and rescue options. Major elements of the process: Assumptions were ...


32

It's standard procedure in Russia. Here's an article reporting on Scott Kelly's taxi ride to his year-long mission to the ISS in 2015: The barricades to faith fell along with the Berlin Wall and religion now thrives in Russia and the cities and nations of the old empire. That includes Baikonur, where cosmonauts Gennady Padalka and Mikhail Kornienko and ...


30

During the Gemini missions, when we started sending more than one person at a time in a spacecraft and also doing thinks like EVAs, these eventualities were discussed in detail. Body retrieval - wouldn't happen. SOP, if a crew member becomes separated from the ship (alive or dead) and cannot return to it, is to leave him behind. Energy, such as fuel, is a ...


27

There are usually 6 crew members, and 2 Soyuz spacecraft on station. Each Soyuz carries 3 astronauts. If there is an issue redocking during the move procedure, the backup plan is to return to earth. If they cannot redock and someone is left on the station, they would be stranded and cause all sorts of downstream issues. So no, you do not need 3 to move ...


26

That's not a Ziploc bag, but the retroreflector's dust cover. Here is a larger image of it removed:     And here's an image with the cover still attached to the retroreflector:     The clue is in the use of the red markings along the edges of the part in question, in spaceflight commonly used to indicate parts that need to ...


23

This kind of situation, while not exactly frequent, has happened on ISS multiple times. With the large amount of debris out there, tracked objects do intersect the ISS orbit from time to time. There are procedures in place on precisely how this is handled. Generally speaking, this is how it works: ISS flight controllers get regular conjunction updates ...


20

In some Mercury flights, the astronaut had a personal parachute with them. The Gemini program used ejection seats, which could be used during launch and reentry. Later on, they realized that igniting a rocket-propelled ejection seat wasn't a good idea in a pure-oxygen atmosphere. The Vostok capsule also had an ejection seat, but not as a backup: the ...


19

The Space Shuttle Orbiter had a flight mode whereby, at or below ~50,000 feet of altitude during the reentry (or, in the event of an ascent abort, the gliding, unpowered phase of flight), the commander could command an autopiloted, wings level glide at about 190 knots equivalent airspeed (KEAS). The plan was then, while the Orbiter was gliding, that the ...


17

No. Most International Space Station (ISS) spacewalks last in the order of several hours, often up to 8 hours during more difficult and time-consuming repairs and installations, and some nearly 9 hours*. And the station, in its roughly 93 minutes orbit is never in Earth's shadow for that long. There are both advantages as well as disadvantages to ...


15

The idea that NASA would intentionally under-represent the lifetimes of those (cherry-picked) missions implies that somehow they knew those lifetimes before launch. Nothing could be farther from the truth. You can't just calculate a lifetime. There is extensive testing and associated analyses performed on the hardware to provide sufficient confidence that ...


14

That blue box is a wired receiver unit for the wireless microphone (they currently use a Sennheiser handheld with SKP-100 wireless transmitter, but they did or still do use also products from other companies, inc. e.g. Shure that I know they flew during some STS missions to the station). The box also hosts its own microphone because the wireless microphone ...


14

In the case of Falcon 9 / Orbcomm OG2 launch from SLC-40, Cape Canaveral Air Force Station, FL that's now scheduled for Dec. 20th at 8:29 p.m. EST (01:29 a.m. UTC), according to Spaceflight Now: Sources said only an instantaneous launch opportunity is available Sunday due to restrictions imposed by the Federal Aviation Administration, which may be ...


13

To answer the first part of your question, have historically multiple spacecraft launched on the same date from geographically distinct locations, yes. In fact, it just happened last Wednesday, September 18, 2013 when two rockets were launched on the same date, and both from different facilities in the United States: Complex 41 at Cape Canaveral Air Force ...


13

Currently unclear According to the Verge: It's possible that the [static fire] test could come early next week. But the Falcon Heavy’s launchpad is located at NASA’s Kennedy Space Center, and limited staffing at the site could pose a problem. SpaceX told The Verge on Friday that the company is not expecting the shutdown to affect its operations. ...


12

A planned hold adds flexibility to the schedule. The hold at T-4 was planned to be 10 minutes long if everything went without a hitch. If a problem had cropped up (e.g. weather suddenly deteriorates and goes outside the launch limits), the hold would have been longer. If there were delays earlier in the countdown, the T-4 hold might have been shorter. The ...


12

To add to @aramis' excellent explanation on clarity and ability to discern the go/no-go launch status check polling, these seem to have been introduced to NASA's (and U.S. in general) launch terminology during the first manned spaceflights of Project Mercury. I wasn't able to find a good example for Project Mercury launches, but I did find this video of ...


12

Having worked mission communications in CAP for live Search and Rescue operations, on the radio, go/no-go is VERY clear. It's one syllable versus two. (Three is the interrogative.) The longer "affirmative" "negative" are 4 and 3, and not as clear, and further, subject to more interference due to length. Note that this usage parallels the morse use of C (-.-...


12

To answer the last part of your question: yes, it was normal to throw away stuff that was no longer needed. On Apollo 11 alone, the astronauts left behind more than 100 items, including four urine containers, several airsickness bags, a Hasselblad camera, lunar overshoes and a complete moon-landing step. The astronauts left behind as much as possible, to ...


12

One prominent example are the original Apollo hatches which opened towards the inside of the capsule and took a minimum of five minutes to open. During a ground training mission, a fire broke out inside the capsule. The pressure increased and the astronauts inside couldn't open the hatches to escape. Had the hatches opened towards the outside and had a ...


12

Yes, I am a source for this information :) Here are some pictures I took of the escape system while standing on the launch pad tower during the STS-124 Terminal Countdown Demonstration Test. The idea was that the crew would egress the Orbiter and run down a walkway to this platform. Then jump into the baskets, 2 people per basket. You can see the sign ...


11

Consider that, in order for the escaping crew to survive outside the re-entering capsule, they'd need a heat-shielded, thick-walled escape pod; in order not to hit the ground at fatal speed, the escape pod would need to be broad and blunt in order to bleed off speed via aerodynamic drag. You'd basically be talking about another re-entry capsule inside your ...


11

The shuttle post landing activities took a while to complete, and this would include the flight surgeon boarding to check the crew over before leaving. This would enable the crew to stretch their legs and recover a bit. For interest, the crew operations manual has a list of post landing activities the crew go through (Section 5.5 - no timeline but this ...


11

A few additions to Organic Marble's answer. The plan detailed in the CAIB report shows how difficult it would have been to mount a rescue mission. Even though Atlantis was being prepared for the next mission, they would have had to cut mission preparation time in half. No time for tests and checks. Everyone working frantically under gigantic pressure ...


10

Yes, some testing and all launches except for those critical to national security have to be postponed. By now, I’m sure you are well aware that a budget agreement was not reached last night resulting in a government-wide shutdown effective today. Many in our workforce recall the impacts of the 2013 shutdown, and now 5 years later, we find ourselves in ...


9

In answer to one of the OP's questions ("If they had known (or even suspected) the damage to Columbia would have resulted in catastrophe upon re-entry, what process would have taken place?"), if NASA had had insight into the extensive damage Columbia had been dealt during ascent, they would have certainly considered a different reentry plan - most logically ...


9

For the first time it was in 1994, when Mir commander Alexander Viktorenko asked a priest to bless his rocket before launch See https://meduza.io/cards/zachem-osvyaschayut-rakety (in Russian, use Google translate)


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