63

Are there failure modes that cause loss of pressure but not rapid, unplanned disassembly? Yes. The 3-man crew of Soyuz 11 died when a valve was jolted open, venting out all the cabin air supply. Soyuz was redesigned after that accident to carry two crew in pressure suits instead of 3 crew in shirtsleeves. (I believe they now carry three in pressure suits.) ...


35

The Venus flyby does indeed make the mission shorter, but it has some pretty serious negative consequences as well. The mission spends much more time in deep space. Approaching the sun will increase the amount of radiation exposure by a large amount. The thermal design would need to be rethought to survive that close to the Sun. The time on Mars for a Venus ...


19

Why this wouldn't work? It works for the Earth; the reason why it is not implemented in space is purely in the engineering limitations. Cyanobacteria live in water, humans live in air. Gravity is good at separating water from air, leaving a surface for the gas exchange. Microgravity is very good at mixing everything, so we should think about another ...


17

TL;DR: It was so busy getting stuff done, it didn't care. Being old, slow, massive and inefficient (by any modern standards, not by those in 1965) is a huge benefit when it comes to radiation hardness. Let's start with the memory: Changing a bit in current S(D)RAM cells is trivial - introduce a bit of charge in the wrong place and the bit is lost. This ...


15

@Russell hit the most important point (cabin decompression), but there are some others: Protection from small fires or chemical fumes. These are irritants to the eyes and respiratory tract, and can hinder an astronaut's ability to function, if not injure or kill. The suits are fire retardant, so they will not burn like some clothing will. They provide ...


12

The crew of the nonfunctional spacecraft would have to wait without an escape capability until a Soyuz replacement or a Shuttle arrives (either of which could take days to months depending on timing). (Nowadays read Crew Dragon for Shuttle) Final Report of the ISS Independent Safety Task Force p.52


11

Another engineering aspect is controllability. Most electrical/mechanical/chemical life support systems can be throttled to anywhere between 0% and 100% of production capacity within minutes, if not seconds. In particular you can shut the system down for repairs and also carry a fully inert system as a cold spare. And since the atmosphere inside a spacecraft ...


8

Environmental Control, and Life Support Systems need to be tailored to their application. There are many tradeoffs such as how much they weigh, how complex they are, how reliable they are and how efficient they are. As a general rule the longer the duration of the mission, the greater the gains from life support closure. So missions of a few days can get by ...


8

Yes, Apollo 8 in 1968 reentered at night, splashing down a couple of hours before dawn. After splashdown, the crew were secure in the capsule, so they simply waited for sunrise for the recovery operation to proceed.


7

tl;dr Plans existed for medium-term occupancy by a crew of 13 which would bump up to 17 briefly. The highest planned occupancy I know of would have resulted from a Contingency Shuttle Crew Support (CSCS) case. This was possible for shuttle flights to the ISS (after the STS-107 failure) when the Orbiter's heat shield started being inspected on-orbit. If ...


5

The most recent Crew Dragon mission had a near miss with a piece of space debris on its way to the ISS The 4 astronauts on board were instructed to put their suits back on in case of a collision "For awareness, we have identified a late breaking possible conjunction with a fairly close miss distance to Dragon," SpaceX's Sarah Gilles told the ...


5

What mission is this photo of Chris Hadfield associated with Expedition 34/35, specifically the Soyuz TMA-07M launch crew. and what is the location of the photo? The Gagarin Cosmonaut Training Center in Star City, Russia What is that ~30 cm mirror-like thing to their right (our left)? It's a frame for the insignia of the training center. Here's a ...


5

Air is very different from water. It is much less dense, and it is much less viscous. When you thrust your outspread arms back under water, the water can't "get out of the way" of your arms very easily, so you succeed in forcing a decent volume of water back relative to you; and because water is heavy (per unit volume), you don't have to accelerate ...


5

There are ham radios on the ISS, so it would be difficult or impossible to prevent the free exchange of information. Some ISS crew members make random, unscheduled, amateur radio voice contacts with earth-bound radio amateurs, often called "hams". They can make radio contacts during their breaks, pre-sleep time and before and after mealtime. ...


5

Continuing to Mars was actually considered. Before the first moon landing, President Nixon ordered a study of the U.S. space program. It recommended sending men to Mars and the other planets: Early in 1969 the new President appointed a Space Task Group to study the space program, calling for a report in six months on alternatives for the post-Apollo ...


4

The Apollo Guidance computer (AGC) controlled the jet propulsion and thus maintained the spacecraft's altitude and navigation. As you pointed out, any defects or errors in the AGC could result in a crash or the crew becoming stranded in space. Once the spacecraft left Earth's atmosphere, the risks increased exponentially due to large amounts of radiation ...


3

Such a technique, while possible, is very impractical. This is in part because, in leo and even at the karman line, the atmosphere is so extremely rarified that it no longer acts as a fluid and instead is simplified to the interactions of individual molecules. Gas molecules collide 100,000,000,000 each second and travel 500 times the length of the atoms ...


3

As the narrator says almost immediately afterward, they're looking at using water as shielding, not gaseous hydrogen; you need to bring water along anyway, might as well store it around the crew spaces to serve as radiation shielding as well. Some groups are also investigating hydrogen-rich polymers as a possible barrier to GCRs.


3

For all practical purposes the "maximum occupancy" of the complex formed by the station and whatever craft are docked to it is the number of seats available for deorbiting people in case ISS must be abandoned. Not all of them would be in the ISS proper at the same time, except for the traditional group photo op. Obviously in an emergency (e.g. ...


3

In light of a very recent news item I thought I'd turn my comments into answer so the information isn't lost should comments be deleted. Having visited a mineral processing plant that used bacteria to treat ground up minerals from a mine, two things struck me about plants that rely on bacteria to do useful work. The first is the bacteria usually need a ...


3

Western propaganda simply painted the race as over. The soviets went on to launch space station after space station throughout the 70s and 80s, gaining thousands of man-hours of low earth orbit experience while the US barely got skylab to work. By the time the joint construction of ISS started in the 90s, the soviets/russians had spent 6336 days manning ...


3

To be completely honest, I don't think saying that one side "won" the Space Race is entirely correct. More to the point of the question: it did not "end" at Moon per se, but just slowly ramped down. The support that NASA had in the initial stages of the space race was there because of the political reasoning - USSR put the first satellite ...


2

If it's impossible to make any headway, why don't we ever see that fact demonstrated? Here you go: At about 00:16, you can see swimming in space demonstrated. It doesn't work very well.


2

While Mike's answer is very well researched and written. I disagree with its challenges (though I don't disagree with his conclusions). The biggest challenges that SpaceX will need to solve in my opinion are. 1. Re-entry heat shielding and Earth landings. It is still working on mastering the landing flip without losing fuel flow. But it also has to show that ...


1

No. Rope ladders would not be very practical or safe. They might use an electric hoist as a back up, but the plan is to use a lift to reach the surface. One possible solution is shown in the SpaceX Starship user guide (see bottom of last page). https://www.spacex.com/media/starship_users_guide_v1.pdf This is not the only configuration possible, but is ...


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