Community Digest

Top new questions this week:

Why did the Soviet Union decide to use 33 small engines instead of a few large ones on the N1?

The N1 was a big disappointment after exploding on every single launch attempt. From what I have read, it seems like most of the attempts went wrong because one of the 33 engines exploded causing a ...

engine-design saturn-v soviet-union n-1 f1  
user avatar asked by The Rocket fan Score of 30
user avatar answered by SE - stop firing the good guys Score of 53

Were any of the Apollo astronauts smokers and did that cause any problems?

Onboard the Apollo capsule, the astronauts probably weren’t allowed to smoke because of the risk. Apollo 1 blew up because of a small spark in a pure oxygen environment. Even though NASA changed the ...

nasa apollo-program astronauts health astronaut-lifestyle  
user avatar asked by The Rocket fan Score of 30
user avatar answered by TrySCE2AUX Score of 33

What is SpaceX doing differently with Starship to avoid it exploding like the N1?

Both Starship and the N1 have more than 30 rocket engines. The N1 exploded after having a chain reaction from a failed engine. N1 rocket engines: Starship’s rocket engines: Unlike the N1, SpaceX has ...

spacex engines spacex-starship testing n-1  
user avatar asked by The Rocket fan Score of 23
user avatar answered by geoffc Score of 48

Why keep expending SpaceX boosters?

SpaceX has only (to my knowledge) landed one Falcon Heavy booster. All others were expended. SpaceX also said during the early days of the company that each Falcon 9 booster could fly up to 1,000 ...

spacex reuse  
user avatar asked by Xenon Score of 16
user avatar answered by Dan Hanson Score of 46

How does NASA have permission to test a nuclear engine?

In this article on ( it mentions that NASA will test a nuclear rocket engine for future crewed ...

testing nuclear nuclear-pulse-propulsion  
user avatar asked by The Rocket fan Score of 12
user avatar answered by Slarty Score of 21

Did any astronauts smoke within a spacecraft while in space?

A recent question yielded the image below that appears to show Buzz Aldrin smoking a pipe in space. Is there any confirmation that the contents of the pipe were ignited or was he just posing with it ...

astronauts spaceflight-firsts astronaut-lifestyle  
user avatar asked by WaterMolecule Score of 6

With increased space exploration missions, are we affecting earth's mass?

This questions may seem naive, but, worth pondering: As humans keep sending more and more missions to space (outside earth's system), the earth is being affected in the following ways: Earth is ...

spacecraft mission-design earth future-missions mass  
user avatar asked by anurag Score of 5
user avatar answered by David Hammen Score of 12

Greatest hits from previous weeks:

Why did Apollo mission numbering skip 2,3,4,5 and 6?

Apollo 1 was a ground test that ended in a fire. The next Apollo mission I have any reference to is Apollo 7. What happened to Apollo 2,3,4,5 and 6?

user avatar asked by PearsonArtPhoto Score of 38
user avatar answered by Andrew Rennie Score of 34

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 ...

orbital-mechanics gravity planetary-science physics moons  
user avatar asked by Lucile Bellamy Score of 51
user avatar answered by Anthony X Score of 98

What will be the effect if we stand on Jupiter?

As we all know Jupiter is a gaseous gas giant and it has a large mass, almost twice the sum of all other planets in the Solar system. So, if it happens that we go to Jupiter, and, as we know it does ...

planetary-science atmosphere jupiter physics gas-giant  
user avatar asked by SpringLearner Score of 75
user avatar answered by TildalWave Score of 123

What is the fastest speed ever reached in space travel as measured from the point in space from which it was launched to its current/final position? lists the New Horizons to have the fastest rocket. Is this info still valid? 7 light hours in 11 years at 50,000 km/h?

spacecraft interstellar-travel pluto travel  
user avatar asked by KingsInnerSoul Score of 26
user avatar answered by marked-down Score of 43

How to programmatically calculate orbital elements using position/velocity vectors?

I would like to build some orbital mechanical software from scratch. I feel that this would be a great way to learn the steps required to calculate different Kepler orbital elements of an object, plot ...

orbital-mechanics mathematics orbital-elements  
user avatar asked by Stu Score of 36
user avatar answered by PearsonArtPhoto Score of 6

Why would SpaceX not use parachutes for the final descent of the first stage?

According to what I've read, SpaceX tried to use parachutes to recover the first stage of the Falcon 9, but it did not survive reentry. Now they plan to use 2 separate rocket burns to land: Reentry ...

spacex falcon-9 reuse first-stage  
user avatar asked by neelsg Score of 66
user avatar answered by TildalWave Score of 65

What happens to the Falcon 9 second stage after payload separation?

In a Falcon 9 launch, the second stage looks like it achieves orbit along with the payload. But is that impression accurate? Does SpaceX need to do anything to deorbit the stage? I can see a few ...

launch spacex falcon-9  
user avatar asked by Hobbes Score of 95
user avatar answered by marked-down Score of 104

Can you answer these questions?

Payload ideas for an 1U CubeSat

Our school has taken up a project on launching a CubeSat and I am part of the 45 contributing students. We are supposed to research on a suitable payload for the CubeSat. We were thinking of some ...

cubesat payload  
user avatar asked by Golden_Hawk Score of 2

Request for high quality Titan II turbopump audio

I'm making a historical spaceflight mod and I'm close to starting work on Titan II. Does anybody have high-quality audio clips of the Titan bwoop? All I have right now are the news broadcasts for ...

history sound project-gemini turbopump titan-rocket  
user avatar asked by Brioche Score of 2

Recent GPS III Launch Intended or Unplanned Venting?

Between 14:01 and 14:14 in the following video, there is a significant gas vent happening behind the engine bell: Is this working as intended, or does that appear to ...

spacex falcon-9 engine-design  
user avatar asked by HumanJHawkins Score of 3
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