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1500 questions
24
votes
2 answers
Did the designers of Voyager neglect the angular momentum of the tape recorders?
I have heard many times that the designers of the Voyager spacecraft neglected to account for the angular momentum of the tape recorders (on which data was stored). To compensate for it after launch, they were forced to use external thrusters every…
Chris Mueller
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23
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Could you feel the wind on Mars?
The air pressure on Mars is about 1% that of Earth's at sea level. But wind speeds on Mars can be higher, up to maybe 60 mph sustained (actually I have come across several different figures, some going very high indeed.)
So if you hold your hand…
Koko the Talking Ape
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23
votes
1 answer
How often, if ever, was "software" updated in the shuttle orbiter?
It dawned on me that the tragic STS-107 disaster of (my favorite shuttle) Columbia was after more than 20 years of service.
Computers in 1981 were of course significantly inferior to what I had in my phone in 2003. I'm picturing our old 1980s Tandy…
Mikey
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23
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How did NASA remotely fix the code on the Mars Pathfinder?
In 1997, NASA remotely fixed a bug that caused priority inversion on their Mars Pathfinder. How did they go about doing this? What kind of communication protocols are used? How do they update the source for an operating system, compile it, and run…
kkopsa
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23
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2 answers
What is the largest naturally occurring body that could be hollowed and safely lived in?
Some proposals for living in space envision finding an asteroid that is a solid chunk of something (i.e. Nickel Iron), hollow it out, slap on an air lock, and you have a home. Add a drive and you have a space ship. Of course the reality is a…
James Jenkins
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23
votes
3 answers
Does Mars space suit have to be pressurized?
Various sci-fi movies treat Mars atmosphere differently, anywhere between "you just need oxygen rebreather" and "Your eyes will pop out and your head will explode". Meanwhile, I haven't seen any solid scientific data on human surviving requirements…
SF.
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23
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3 answers
Was Starship’s “launch window” administrative, rather than due to orbital mechanics?
According to Wikipedia,
a launch window is the time period on a given day during which a
particular rocket must be launched in order to reach its intended
target.
SpaceX’s internet launch coverage stated there was a 20 minute “launch window” for…
Woody
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23
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2 answers
Does space flight have any positive effects on the human body?
It is well known that there are a number of negative health issues (loss of bone density, muscle mass, (eyesight degeneration1, etc.) that can impair astronauts who spend long periods of time in space. That said, are there no positive effects on the…
coleopterist
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23
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3 answers
Why aren't the radiators on the ISS straight?
The radiators look like a highly stretched paper accordion. Is it just because of how they decomposed, or is there a deeper reason?
Saturn V
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23
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3 answers
Maximum survivable long term g-forces
I assume this hasn't got a precise answer, but I was wondering if anyone had an indication of the maximum survivable long term g-forces, if the persons positioning was optimal?
For example, could you accelerate a craft 3g for say, 16 hours a day…
Clinton
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23
votes
3 answers
How does Titan have hydrogen in its atmosphere?
Titan's atmosphere contains few tenths of a percent of hydrogen.
This seems odd to me, as Earth with a 4x greater escape velocity cannot retain hydrogen or even helium in its atmosphere.
Titan is 3x colder then Earth, but this shouldn't be anywhere…
blademan9999
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23
votes
3 answers
Is it possible to map the caves of Phobos?
Having read that Phobos at 27 km long is around 30% porous, I am going to assume that there are a number of voids large enough for human entrance. If it turned out there was a void large enough and close enough to the surface somewhere on Phobos, it…
Phil H
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23
votes
8 answers
Why didn't JWST include any sensors capable of blue and green visible wavelengths
JWST wavelength sensing starts at 600nm, corresponding to red/orange visible light, and then into the IR. It seems there is no sensor or filter included below 600nm meaning that green and blue light cannot be imaged at all, meaning all images must…
TopCat
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23
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2 answers
Since L2 has no visible marker, how will James Webb's ground control determine its relative position and velocity for station keeping?
James Webb will be in a halo orbit, station keeping around the Sun-Earth L2 point. This means it needs to monitor its position with regard to L2, for periodic station keeping purposes.
But L2 isn't an object in space that it's orbiting. Its path is…
Stilez
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23
votes
3 answers
How do we know the precise position of the JWST?
How does NASA know the exact position of James Webb Space Telescope at a given time? NASA has to be able to issue the mid course correction burns.
Since they are now up to MCC2, how do they determine the exact time and force required to enter the L2…
andro
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