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1500 questions
21
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2 answers
Why will Starlink satellites use krypton instead of xenon for electric propulsion?
The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says:
With a flat-panel design featuring multiple high-throughput antennas and a
single solar array, each Starlink satellite…
uhoh
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How can Trident be so inexpensive? Will it orbit Triton or just do a (slow) flyby?
The recent NY Times article Neptune’s Moon Triton Is Destination of Proposed NASA Mission says (in part):
HOUSTON — Is it time to go back to Neptune?
Scientists representing NASA’s Jet Propulsion Laboratory proposed a spacecraft and mission on…
uhoh
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How does Rosetta "wake-up?"
Rosetta has been in hibernation mode for most of the last three years. As far as I am aware, "sleep" means using minimum resources since there is nothing for the probe to do during its long transfer orbit. When sleeping, it must still be able to…
Stu
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What happened to Apollo 13 LM descent stage?
I see in the accounts of the Apollo 13 mission that the descent stage engine of the LM were used to propel the joined spacecraft into a return trajectory to earth and that the crew remained in the LM ascent stage until shortly before reentry and…
TomKat
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What are these things fired away from a ballistic missile at launch?
Here is a youtube video of the start of a Russian Topol-M ballistic missile.
A lot of little strange things are fired away from the rocket body when the rocket is half-way from its transport-launch container:
What could these be?
Code Complete
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Was water ever taken outside a spacecraft?
Has an astronaut (or cosmonaut) taken water out of a spacecraft to see if it boils or freezes?
Laird Grayson
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Why did China land a rover on the moon?
Why did China land the Chang’e-4 rover on the moon? What was it supposed to accomplish or explore?
Aaron
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Why did rendezvous on Gemini 4 fail so badly?
I can't for the life of me understand why commander Jim McDivitt thought he could eyeball a rendezvous - point the nose and thrust. The futility of that technique is one of the first things even amateurs like me learn about orbital dynamics. They…
DrTris
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Who were the youngest and oldest persons in space?
In recent years there has been much talk about the possibility of establishing a permanent space colony somewhere in the solar system. If that happens it's plausible that within the next century somebody is going to live their entire life in…
kasperd
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If a Voyager crashes into something, would we know?
A recent question asked about the feasibility of using Voyager 2 to detect objects in the Oort cloud. The answers indicate, among other issues, the instruments on-board the Voyagers would likely be insufficient to perform such detection.
However, in…
Kamil Drakari
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Why not use Sparklers on Delta-4 Heavy launches to burn off the hydrogen?
With three CBC (Common Booster Core) modules firing their RS-68A engines simultaneously, a Delta 4 Heavy launch is an impressive sight.
The RS-68 is a LOX/LH2 engine. As part of the launch sequence, a fair bit of hydrogen is run through the…
geoffc
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Can Curiosity pay InSight a visit?
InSight landed “just” 600 kilometers from Curiosity’s landing site. Can Curiosity make its way there for a rendezvous? Are there any plans for this?
apollo
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How is thrust transmitted from strap on boosters to the central core?
Strap on boosters of a lot of heavy launch vehicles seems to be attached with just a few "flimsy" struts.
Here are few images for reference :
Some of the possibilities:
These support structures from the strap-ons are extremely strong and well…
karthikeyan
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What are the reasons Soyuz's lifespan in orbit is limited?
Following the recent Soyuz failure news, I found out that the currently docked Soyuz expires in the foreseeable future, leaving the crew with no means to return back to Earth.
What are the reasons behind Soyuz having a limited lifespan in orbit?…
Denis Kulagin
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Decay of a corpse in space?
This is not nice perspective, but eventually it will happen. An astronaut falls out of spaceship because of damage caused by collision with other object, or because of suit decompression. The fluids from the body would evaporate, and if any bacteria…
user43