44

The Mars Society has a good indication of what the most serious medical issues have been in space flight. These include: A number of cases where the gloves leaked in an EVA. (STS-37, Mir Space Station) The STS-37 was possibly the most serious, only the fact that the astronaut was also bleeding kept this from a much more serious issue, similar to how Mark ...


25

Neil Armstrong thought they had a 90% chance of survival, but only a 50-50 chance of landing on the first attempt. I've seen one source that says Aldrin was less optimistic, estimating 2/3 chance of survival and 1/3 chance of success. At that time, Apollo spacecraft had flown several missions safely, including two lunar orbit missions, so presumably he was ...


24

The question misinterprets the comments of Elon Musk, who is trying to set expectations appropriately. That is, this is a new vehicle, and there are issues that are next to impossible to model on the ground, nor test on the ground. They have tested and planned for everything they can, but they accept there is complexity for which they cannot prepare. So ...


23

The crew of Apollo 7 were all ill. The commander, Wally Schirra, developed a cold and the other two crew members suffered prolonged motion sickness. Due to the illnesses, the crew failed to perform their duties (such as perform the live television broadcast) and all were retired from spaceflight. Even today, it is not publicly known if they performed the ...


17

While I'm not sure it would qualify as a physical, bleeding injury, there was a near-death from drowning in space. Luca Parmitano, was an Italian NASA astronaut who nearly drowned during an EVA in July, 2013. It was so unexpected that NASA hadn't even planned emergency procedures for an incident like this. After all, what are the chances of drowning in ...


14

It's not dangerous. The core would never be operated on Earth, and so would not become radioactive like you're thinking. A nuclear reactor on Earth that has been in operation is extremely radioactive due to the fission products, but the original fuel was not. The unburned U-235 fuel has a half-life of 700 million years, which means that its ...


14

Some crewmembers have been incapacitated by Space Adaptation Syndrome (SAS) as they adapt to the free fall environment. The most publicized case of this was "Payload Specialist" Jake Garn who was so sick on his space junket that his name became the standard unit of spacesickness, where 1 garn = completely incapacitated. Less severe cases have caused mission ...


12

Apparently the battery is only prone to explode while used. So when turning the satellite off, the risk appears to be mitigated sufficiently (I expect the battery to be discharged. A battery storing no energy can't cause an explosion, as an explosion is simply the uncontrolled and rather sudden release of said energy). This means the main risk of a GEO ...


12

A relatively large number of US astronauts who performed EVAs have injured their shoulders badly enough to require surgery. At the time this study was performed (2012) there was no definite conclusion as to whether the injuries resulted from orbital EVAs or training. full presentation here


12

It is well known that finger injuries sustained during EVA plagued a lot of astronauts. The Lunar Surface Journal for Apollo 15 has some good references to this at 126:08:40, with links to post-mission photographs of Dave Scott clearly showing the damage to this fingernails and giving a good indication of the extent of the blood blisters that formed. In ...


10

I think the worst injuries sustained have been the deaths of the crew of Soyuz 11. The crew capsule depressurized during preparations for reentry.


9

Yes, this could cause issues. Normally about 5 people are required full-time for maintenance. They need 6 people to get any science done. So they're going to be looking at contingency plans right now. The handover planning may be caused by a shortage of docking ports (you'd need 3 Soyuz docked simultaneously to have 9 people on board). But I don't know ...


9

According to Rich Zurek, Mars Exploration Program chief scientist at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA whose statement was quoted in recent NASA's press release titled NASA Preparing for 2014 Comet Watch at Mars (January 28, 2014): Our plans for using spacecraft at Mars to observe comet Siding Spring will be coordinated with plans for ...


8

If that were your only criteria, then you would lower the risk even further by not going at all. The goal is for each mission to have an acceptable risk and acceptable reward, to build crewed experience in deep space (i.e. to not have 30 years of uncrewed missions and one big bang at the end of that), and to have the overall developments fit within an ...


8

You may want to read: Legal Aspects of Space Commercialization - K. Tatsuzawa. A few quotations follow... Costs have been insured: In 1982, ESA insured the Marecs-A and B satellites for \$90 million, for a premium of \$6.7 million (7.5% of the insured capital). Insurance would cover only a second failure, meaning that payment would occur if both ...


8

Referring to moving to the designated graveyard orbit as de-orbiting is a little odd - perhaps autocorrect or a sub-editor had a go when they saw "re-orbiting" Moving to the graveyard orbit significantly mitigates the risk of damage to other operational satellites from explosion, as it is highly unlikely that neither of the apsides of resultant debris will ...


6

The Curiosity rover covers an area of a little less than 8 m². Spirit and Opportunity only cover about 4 m² each. The whole mars has a surface area of 144,798,500 km². or 144,798,500,000,000 m². When you think of an asteroid as a point-impact which only affects the exact position where it lands, and you assume that each asteroid can hit anywhere on Mars ...


6

Is Starman/Roadster in any danger of asteroid belt? Honestly? No. The Asteroid belt does contain lots of asteroids. But this is deep space. These things are not close together in any sense. Think of it this way: If Starman had been set adrift on the Pacific Ocean, how likely would he be to collide with another ship? Pretty low? The ships on the ocean are ...


6

Musk himself talked about some of the challenges “One of my biggest concerns is booster-to-booster interaction,” Musk explained. “You’ve got a lot of dynamics going on there. Those rockets are very flexible; if they flex in unexpected ways they could potentially impact one another.” With three Falcon 9 cores, the acoustical noise generated by the launch is ...


4

Every orbital rocket launch comes with a risk of failure; modern, proven rockets are running about a 98%-99% success rate. I imagine that SpaceX is well over 90% confident in the success of this flight; the Falcon Heavy builds on the design of the Falcon 9 so there are fewer unknowns than there would be in an all new design. By reminding people that this ...


4

50 years old abort routines are hard to come by, but the NERVA-specs (unclassified 9/8/1970) clearly specify a malfunction mode in which the engine should be able to provide a minimum of thrust and impulse. The values stated (thrust of 30000 pounds, impulse of 10⁸ lb-seconds) are enough to direct the upper stage away from densely populated areas, towards a ...


4

Communications blackout was because they phased orbits of Mars orbiters to be "behind Mars" when at greatest risk of cometary dust impacts. MOM phased its orbit too and so did NASA's / ESA's Mars orbiters. Depending on their orbit, this communications blackout should last roughly 40 minutes. With MOM's highly elliptical and over three Earth days long (nearly ...


4

The Constellation program is the first that comes to my mind. It was started in 2005 with the ambition of crewed missions to the Moon and Mars. A crewed mission to a near-Earth asteroid was also planned at some point. It was cancelled in 2010, with budget overrun and schedule slip given as primary motivations. Some parts of the program live on in e.g. the ...


3

To some extend, these are very helpful. For instance, Mercury taught the United States a lot of valuable lessons about spaceflight, and in general each mission was safer than the previous one. Each Apollo mission learned from the lessons of the previous missions. This incremental ability allowed the mission to succeed. Personally, I don't think a manned ...


3

It isn't that risky, if the proper precautions are taken. The key item, as it is in most cases with spaceflight, is redundancy. There is a larger chance of single event upsets during a geomagnetic storm. This can be mitigated by hardware redundancies. In addition, geomagnetic storms only really become an issue for most spacecraft when they are beyond LEO. ...


3

Faster travel is generally better: less time for random or wear-down mechanical failures, less exposure to cosmic rays, lower probability of collisions. Direction and relative velocity of collisions with meteoroids is highly variable and essentially random. Going faster might make the average impact energy of collisions infinitesimally higher, but not ...


3

Test fires have many purposes. The engines themselves were individually fired at the McGregor, TX facility, then shipped back to Hawthorne, CA to be mated to a stage. That entire stage was shipped to McGregor, TX and test fired as a stage. Then it was shipped to CCAFS, Florida or Vandenburg to be launched. Product may settle in shipping? Things can ...


3

Consider the XS-1 An experimental reusable flyback first stage. Boeing collected several grants to build this vehicle from DARPA. However, in 2020 Boeing announced it was ceasing its role in the program. There were no test flights, and presumably, very little hardware. https://en.wikipedia.org/wiki/XS-1_(spacecraft)


2

The ISS, Shuttle, and Mir have all had hand-held fire exinguishers. Mir actually used them. Shuttle also had built-in fire extinguishers in the avionics bays that were discharged remotely. ISS portable fire extinguisher Shuttle portable fire extinguisher I think you over-estimate the difficulty of using them. Their nozzles are not optimized for maximum ...


2

Hopefully someone comes along with a sourced answer, but until then here's one that's just reasoned out: When exhaust first leaves a spacecraft, it's hot and relatively dense. As it gets further away it expands, both because the particles have varied starting directions and because they'll hit each other and go their merry ways. It'll also cool down over ...


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