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1500 questions
22
votes
1 answer
Why aren't the ISS's nor Space Shuttle's radiators black?
As we know, from a surprising corollary to Kirchhoff's law of thermal radiation, just as darker* objects absorb more light (and therefore energy), darker objects also radiate more light (at lower temperatures, in the infrared) and therefore…
geometrian
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22
votes
2 answers
Why does SpaceX have a launch window for a pad abort test?
SpaceX has announced a pad abort test for the Dragon crew capsule on May 5th. They have a 4 hour launch window for the test.
There is no destination, so why would there be a launch window in this case?
kim holder
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22
votes
5 answers
How much does it cost to fill an ion thuster with Xenon for a spacecraft propulsion system?
Ion engines are touted as a great source of propulsion for high deltaV missions that can afford an ample power supply and need low thrust maneuvers; and they are great. But I'd like to know how much they cost.
I can't seem to find any pricing…
marked-down
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22
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2 answers
How did NASA Conclude that the General Theory of Relativity was not Needed for Earth-Moon Flight Path Computation?
This question is wholly seeking historical evidence and not about physics. It is a follow on from the Physics Stack Exchange question:
Could we send a rocket to the Moon without knowledge of general relativity?
The answer is a definitive yes. A…
Selene Routley
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22
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2 answers
Why does the interior of the ISS appear so disorganized?
I have noticed that interior of the ISS appears to be very disorganized.
Let me clarify what I mean by that. I grew up watching Star Trek, and the Enterprise was the reference of clean space-faring vehicle. Things were in drawers, hidden. Or…
Earl Grey
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22
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2 answers
How are EVA's in LEO affected by being at the night side of Earth?
Orbital periods in LEO are quite short, about 92 minutes for the ISS. So every other almost 46 minutes it is in Earth's shadow. Not only is it then out of direct sunlight, I suppose that the night side of Earth doesn't reflect any useful light…
LocalFluff
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22
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2 answers
How do the sizes of the various proposed manned capsules differ?
How do the overall dimensions, internal volume, mass of the various manned capsules being developed compare?
Apollo (as a good baseline)
Orion
Dragon
Dragon V2
CST-100
Soyuz
For bonus points, ISS cargo vehicles.
Cygnus
ATV
HTV
Progress
geoffc
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22
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3 answers
Is any space station planned to be put in orbit in decade 2014-2024?
ISS will be closed by 2020. Are there any other space stations planned to be put in orbit in decade 2014-2024 that have really chances to be built?
user55
22
votes
3 answers
What is the probability of impact?
Space Track is a website dedicated to passing along information about satellites to consumers, primarily satellite operators. The information comes from the US military. In addition to providing the Two Line Elements that inform operators of exactly…
PearsonArtPhoto
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22
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1 answer
How far did Pan Am go with its plans to have passenger trips to the Moon?
It is well known that Pan American World Airways took more than 90,000 reservations for future passenger flights to the Moon from 1968 until its fall into bankruptcy. How far beyond that did Pan Am go? Did they hire engineers to determine, at least,…
Bruce James
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22
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1 answer
How much does air on the ISS cost?
I was reading an article which broke down some of the methods of oxygen creation on the ISS. This was in response to my daughter commenting that "air is free," and being curious about counterexamples.
How much does it cost to produce the oxygen…
Cort Ammon
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22
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1 answer
Could an acid-proof, solar-powered aircraft stay aloft on the sunny side of Venus more-or-less indefinitely?
The length of Venus's solar day is 116.75 earth days ($t$ = 10,087,200 s) and it's radius, $r$, is 6051,800 m, so in theory an aircraft would only need to travel at a ground speed, $s$, of...
$$s=2\pi r/t=2\pi(6051800)/10087200 = 3.77 m/s$$
...to…
phil1008
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Why can't lunar rovers survive long duration nights?
I saw that some missions end with the lunar night time, and the rovers are trashed permanently instead of trying to survive the night.
The concerns have to do with trying to keep the rover at operating temperatures without a power source.
However, I…
sergbot
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4 answers
How do space probes find their way and how much fuel do they use to travel?
How do space probes find their way, for example, to explore dangerous planets like Jupiter or Saturn that have powerful magnetic fields? Do scientists control it from stations in NASA or they have a built in predefined program?
My second question…
C.F.G
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2 answers
Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem?
When a rocket launch fails, typically launches for that rocket type are halted while an investigation takes place to identify and correct the root cause of the failure. However, it is possible that the cause of the failure couldn't be conclusively…
kgutwin
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