Unanswered Questions

1,420 questions with no upvoted or accepted answers
19
votes
0answers
247 views

What is the current location of Link-built Apollo Mission Simulators?

There seems to be confusion about the final disposition of, and even the number of, Apollo Mission Simulators built by Link Flight Simulation Division. This question is not about any simulator built ...
17
votes
0answers
357 views

Was Jules Verne the first to propose the retro-rocket concept?

In his novels 'From the Earth to the Moon', and 'Around the Moon', Jules Verne writes about a set of rockets fitted to the spacecraft he imagined, that were intended to be fired in order to slow down ...
15
votes
1answer
907 views

What is the value of the cross-track angle between the two designated CRS-4 first stage recovery zones?

For the SpaceX Falcon 9 launch on its Dragon/CRS-4 cargo delivery mission to the International Space Station, according to Spaceflight 101, two downrange safety zones have been identified: The SpX-...
15
votes
1answer
2k views

How many astronauts have had spiritual experiences while in space?

In the video Overview 5 astronauts talk about having powerful spiritual experiences in space, and their descriptions match enlightenment experiences. This strikes me as rather more important than you'...
14
votes
0answers
199 views

What were the Top 10 Shuttle Risks in John Young's “famous letter”?

Whilst reading A Technical History of the External Tank I ran across this comment: Although the problem has not recurred, John Young, in his famous top ten Shuttle risk letter ...
13
votes
0answers
302 views

How did “the kid” (John Meisenheimer) calculate that there was a wave in the jet stream and Explorer 1 would be okay to launch?

The tough but timely question NASA at sIxty years, will there be a new moonshot mandate? links to the NASA YouTube video NASA 60th: How It All Began which shows a lot of really nice, historical file ...
12
votes
0answers
194 views

Have there ever been any incidents where something valuable was unintentionally throw out with the trash?

In "What do astronauts do with their trash on the ISS?", a commentator asked the title question and was encouraged to make it a new question, but apparently never did. The linked question is ...
11
votes
0answers
116 views

What caused STS-129's low energy condition on the HAC?

I've never heard anyone comment on the trouble STS-129 seemed to experience during the Heading Alignment Cone (HAC) phase. I was hoping someone who was involved with the program might know why it ...
11
votes
0answers
158 views

How does increased environmental radiation affect medication potency, long and short term?

The issue of the effects of radiation on medication potency is not only important for long term stays in the ISS, but also very important for longer duration journeys and even for colonization. One ...
10
votes
0answers
93 views

Why did GRACE mission have launch window?

GRACE mission which was launched on March 17th, 2002 had a 10 minutes launch window. The mission was to launch a couple of earth observation satellites. And interestingly, NASA's GRACE Launch Press ...
10
votes
0answers
418 views

How are the Voyagers' thrusters configured in a novel way to minimize accelerations along Earth-spacecraft axis?

I've just read in Eshleman et al 1977 Radio Science Investigations with Voyager that the voyagers have: ...a novel attitude-control thruster configuration that minimizes accelerations along the ...
10
votes
0answers
124 views

Is loss of flexibility a concern with crew on the ISS?

Videos of people on the ISS make it clear how little they need to bend or stretch, and how their joints stay in their neutral position most of the time as they float around - elbows, knees and hips ...
10
votes
1answer
207 views

Why are balloon tanks used by so few rocket designs?

Balloon tanks, first used on the MX-774 sounding rocket (the direct, though distant, ancestor of the Atlas family of missiles and launchers), are structurally stabilised by internal gas pressure, ...
9
votes
0answers
112 views

How does the Dragon nose hinge work?

The Dragon nose has a fairly elaborate hinge. I've read it's actuated by a hydraulic cylinder. Is that what I see in the picture below by the green line? Is it perpendicular to the longitudinal axis (...
9
votes
0answers
81 views

Do the ISS docking ports require maintenance?

Is it neccessary to maintain the docking ports of the ISS? Inspection, cleaning, lubrication, replacement of worn out parts like O-ring seals? Where are the seals, on both sides or only at the ...

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