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1500 questions
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Why do nuclear rockets (e.g. NERVA) have such poor Thrust-to-Weight ratios?
Nuclear fission releases far more energy per kilogram of fuel than conventional hydrocarbon sources. However, proposed nuclear rocket engines like NERVA (https://en.wikipedia.org/wiki/NERVA), while having potentially 2x the $I_{sp} $ as chemical…
user34435
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How do the Starlink satellites shine?
As we can see the Starlink satellites with the naked eye as they pass by. I was wondering about what makes them visible.
Do they have large mirrors that reflect the sunlight making them look as if they have lights on board or do they actually have…
John
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Has Luna been used for gravity assist for interplanetary probes?
The Earth's natural satellite has a great deal of angular momentum that seems to me could be used to derive a considerable boost for leaving the local SOI. Has any probe used a Lunar flyby as part of its flightpath? Are there reasons why this…
Jerard Puckett
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What is the oldest orbital satellite we can contact?
Vanguard 1 holds the record for being in space longer than any other man-made object, along with the upper stage of its booster. It was launched on March 17, 1958, but was last heard from in May of 1964.
What still-orbiting satellite that is still…
Jerard Puckett
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Challenges Facing Hybrid Rocketry
The concept of hybrid rocketry is very interesting, and seems like it has many advantages over its solid and liquid forebears. But having only a superficial idea of the challenges preventing it from mainstream use (namely combustion instability and…
InquisitiveInquirer
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Why is the Falcon Heavy center core recovery done at sea?
Why does SpaceX attempt sea recoveries of the Falcon Heavy center core instead of staying at altitude and performing a land based recovery at a different site?
Xorkumentary
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What does 'Rocket is in self align' mean?
I've noticed during SpaceX streams (this could happen with other LSPs but I've only noticed it with SpaceX) that shortly after the vehicle goes to internal power the controller says "Vehicle is in self align". What exactly does this mean? My best…
Seth Kurkowski
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Do liquid propellant rocket engines experience thrust oscillation?
I know SRBs have a quite bit of thrust oscillation, and it's pretty much part and parcel of burning solid propellant. Do liquid-propellant engines experience something similar albeit at a much smaller magnitude? If so what is the main cause of this…
Meatball Princess
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Is there any way to land a rover on the Moon without using any thrusters?
Is there any way to land a rover on the moon without using any thruster, with the help of Thermocol, Cotton, Bubble wrap or any other packaging material, like we can receive from online shop?
gaganyaan
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Has any object launched from Earth gone into the Sun?
I've seen a lot of questions about the $\Delta V$ required to reach the Sun from the Earth (~22-30 km/s if I remember correctly), firing a bullet into the sun, etc.
But has this ever happened? Has any object launched into space from Earth…
CJ Dennis
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Why don't we use Cavea-B
Raiz Aerospace raised an interesting question during one of his KSP Realism Overhaul play throughs.
If the RCS propellant Cavea-B is better than hydrazine and less toxic why does no one use Cavea-B, while hydrazine is a defacto industry standard for…
DJ319
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How does the Saturn V Dynamic Test Stand work?
This photo instantly provokes a ton of questions in me:
It shows the Dynamic Test Stand at Marshall SFC with the Enterprise, which was a Space Shuttle test vehicle, suspended for vibration testing. It was built to test the Saturn V in the same way.…
kim holder
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How far off did Apollo 11 land?
Armstrong wasn't able to land exactly in the designated landing location, as far as I know it was too rocky. So he had to fly a bit farther to find a suitable spot. But how much farther from the designated location did he land? A few hundred meters?…
DarkDust
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Why isn't there research to build a standard lunar, or Martian mobility platform?
While many terrestrial mobility platforms have been very successful, why are we spending millions to every rover device making it unique?
Sure enough, different worlds offer different conditions, but why not build a more or less general purpose…
J. Doe
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How did the Vostok ejection seat safely eject an astronaut from a sealed space capsule?
Wikipedia's Yuri Gagarin says:
At about 23,000 feet (7,000 m), Gagarin ejected from the descending capsule as planned and landed using a parachute.
and the section Vostok_programme; Vostok 3KA says:
After one orbit, the descent module…
uhoh
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