Unanswered Questions

1,188 questions with no upvoted or accepted answers
21
votes
0answers
1k views

Where is the TEA-TEB stored for the Merlin engines onboard Falcon 9?

The Merlin 1D engines can restart up to four times, they use the pyrophoric mixture of TEA-TEB (Triethylaluminum-Triethylborane) to ignite the engines. My question is where is this stored in the ...
15
votes
1answer
874 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-...
14
votes
0answers
275 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 ...
13
votes
0answers
286 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
607 views

Does the FAA still license the people who fold human-rated reentry parachutes?

One of the links in the question International Orange? is the History.com article The Amazing Handmade Tech That Powered Apollo 11’s Moon Voyage which says of Apollo capsule re-entry and landing ...
12
votes
0answers
115 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 ...
12
votes
0answers
194 views

At what surface gravity can't astronauts do full steps anymore?

We know that on the Moon in ~1/6 g the Apollo astronauts couldn't make full steps because they jumped with each step. At what surface gravity could you walk more like on Earth and at what gravity ...
11
votes
0answers
175 views

Reentry without pressure suits in Apollo: was there a formal risk assesment?

In Apollo 11 Flight Journal the following is stated: The crew will make re-entry without suits or helmets on. Although this was a controversial decision on the first Apollo flight, Apollo 7, when ...
11
votes
0answers
113 views

Launch to orbit delta-v penalty from Venus compared to Earth?

Thinking about the no atmosphere caveat here made me think of Venus, which is the opposite of no atmosphere for solid/rocky bodies in our solar system. Earth's low orbital velocity is about 7.8 km/s. ...
11
votes
0answers
152 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
115 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 ...
9
votes
0answers
112 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 commentor asked the title question and was encouraged to make it a new question, but apparently never did. The linked question is referring ...
9
votes
0answers
75 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 ...
9
votes
0answers
62 views

Examples of space research applied to Earthly manufacturing

I remember reading utopian predictions about space manufacturing. It's clear that factories in space delivering consumer goods for your local retailer is not going to happen in the near future. But I'...
9
votes
0answers
103 views

Detailed information about the Soyuz descent module connection box?

Anyone have some detailed information about how all this connectors, located in the soyuz descent module? Are they used only when they setup the Soyuz or they are ...

15 30 50 per page