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1500 questions
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6 answers
Is it possible for a moon to have a higher surface gravity than the planet it is attached to?
Is it possible that a moon has a higher surface gravity than its planet? I guess it would mean that the moon has a higher mass, but then it would be the planet gravitating around the moon and the roles would be exchanged...
Still, is there a way?
Lucile Bellamy
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Why do space operations use "nominal" to mean "working correctly"?
In common parlance, "nominal" means "in name only", "small (amount or quantity)" or "stated, but not necessarily reflective of reality".
So, the general sense is that "nominal" means something that should not be taken at face value.
How and why,…
Dancrumb
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7 answers
Can you tack against the sun using a solar sail?
Solar sails are a great, inexpensive way to move out from the sun, if you’re not in a hurry. Ocean going ships are able to tack against the wind, and to move up wind. Could a solar sail gain inbound (towards the sun) momentum by tacking?
James Jenkins
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Game for teaching basics of orbital mechanics
I am looking for a game that would be suitable for teaching basic orbital mechanics concepts to primary school students (grades 6-8). Contrary to most of the questions here asking about spaceflight simulators and such, I am not looking for super…
ben
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51
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1 answer
Did a Soyuz fly with a Union Jack?
In this schematic of a Soyuz rocket, the payload fairing is depicted with the flag of the USSR on one side, and what appears to be the flag of the United Kingdom on the other.
Did the Soyuz ever fly with the UK flag on it?
Russell Borogove
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1 answer
In Starman's roadster, where's the Towel?
Did Starman forget his towel? A towel is the essential thing every explorer needs to carry, right? Can't get very far without it.
Jake J
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7 answers
How would it be possible to kick start Mars's magnetic field?
Jumping from this question about terraforming Mars, how would one mitigate the main obstacle, namely Mars's lack of a magnetic field? Are there any hypothetical processes that might restart Mars's magnetic field (assuming it had one in the past)?
System Down
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1 answer
How long is the ISS out of reach of all ground stations?
This is a followup to a recent question and answer discussing ground-based monitoring of the International Space Station, specifically in the context of an astronaut crew that is all asleep.
How often is the ISS outside of reach of all ground…
A. Rex
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3 answers
Why would GPS availability be reduced by high demand (or solar eclipse)?
This Newsweek article states that "GPS...will likely be nonexistent near the eclipse zone" because of all the people going to that area. While it makes sense that cell towers might be overloaded and it might be impossible to download maps or…
WBT
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How possible are 'space jumps'?
Have you seen the first of the two new Star Trek movies? Kirk (Chris Pine), Sulu (John Cho) and a red shirt perform something really awesome in this film: They jump from space down to a planet, basically only protected by some suit.
My question(s):…
s-m-e
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Why is it so hard to land on the Moon?
Successful landings on the Moon happened 50 years ago. Technology (satellites, computer, ML) has come a long way during this time, so why did Israel and India fail recently to land a probe there?
Is the chance of successfully landing a manned…
George W.
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2 answers
Why were the Voyager spacecraft numbered "out-of-order"?
Voyager 2 was launched on August 20, 1977. Sixteen days later, Voyager 1 was launched on September 5, 1977.
Why was the first spacecraft numbered #2 and the second spacecraft numbered #1?
Clarification: One would expect that the first spacecraft…
DrSheldon
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50
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1 answer
How did the Russians get moon rocks?
I've read somewhere that the Russians have moon rocks. How did they get them?
Gabriel Fair
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50
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3 answers
Why would NOAA restrict the ability of SpaceX to live stream the second stage?
I was watching the live stream of the Iridium-5 launch and they mentioned that NOAA had restricted their ability to live stream the second stage and that SpaceX was working to remove this restriction.
Is there any information why this restriction…
Machavity
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How does the SpaceX Falcon 9 first-stage straighten for landing?
I just saw this video of supposed "SpaceX Rocket Camera Landing Footage Fakery" with over a million views.
The narrator repeatedly says it's complete garbage because he doesn't understand and would like to know:
Now, you got a rocket at the bottom,…
Hugo
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