Most Popular
1500 questions
22
votes
6 answers
Why is it not concerning from a cost perspective to have so many engines on Starship?
Starship is meant to imitate (to a degree) the affordability of passenger jets. This applies to Earth-to-Earth travel as well as space travel.
Jetliners started with 4 engines, but have since migrated to using 2, regardless of size. Where the number…
Abdullah is not an Amalekite
- 2,839
- 1
- 13
- 38
22
votes
2 answers
Is this white stuff seen by the Mars Phoenix Lander water or carbon dioxide ice?
Source
Here is an image which shows ice is evaporating over time. They use the word "ice".
1st: I'm not sure what they are talking about. Are they talking about the white stuff (like milk) which is present in both Sol 20 and 24 OR is it the 3-4…
Vikas
- 371
- 2
- 8
22
votes
3 answers
Were decommissioned Cold War missiles repurposed for peaceful spaceflight?
Those formerly on either side of the Iron Curtain can now admit that the Cold War had its plusses and minuses. The key minus, of course, is that the United States and the Soviet Union constructed enough nuclear devices to destroy the world many…
HDE 226868
- 3,227
- 1
- 19
- 44
22
votes
1 answer
Does the ISS team plan cargo flights when at half crew on purpose?
A number of times now, the cargo vehicles (Dragon, Cygnus, or HTV) seem to have arrived while the station was between crew switchovers.
With indirect crew handovers, three crew depart in a Soyuz, reducing ISS Crew size from 6 to 3, and a week or two…
geoffc
- 79,523
- 12
- 227
- 419
22
votes
2 answers
Do Falcon 9s get a thorough wash or a fresh coat of paint (they look clean pre-reflight)?
Before/during reflight, the boosters look white and clean, but after, they don't. I'm not sure if that's soot and/or burned paint.
I looked but it doesn't seem to have been asked before.
RE Is Falcon 9 repainted before reuse? It does not address…
ymb1
- 2,423
- 11
- 35
22
votes
1 answer
How does Ingenuity measure its altitude when flying?
The Ingenuity folks at NASA and lots of viewers on the internet I'm sure were pleased to see the first data from "the first flight of powered aircraft on another planet" (by humans at least); the output of the helicopter's altimeter.
Question: How…
uhoh
- 148,791
- 53
- 476
- 1,473
22
votes
1 answer
How hard is it to receive direct signals from vehicles on the surface of Mars, and has anyone other than the DSN done so?
Almost all communication from vehicles on the surface of Mars is relayed by spacecraft in orbit around Mars. However vehicles on the surface do communicate directly with Earth.
This communication, for NASA and related missions, is handled by the…
user21103
22
votes
5 answers
Does upper atmosphere rotate with earth?
Basic question that I should know the answer to but sadly don't.
The lower atmosphere must rotate with the earth because of friction---at least the very bottom of it.
But what about 30 miles up? There the effects of friction are well gone. Does the…
user36480
22
votes
4 answers
Why didn't NASA simulate the conditions leading to the 1202 alarm during Apollo 11?
If I understand it, the alarm during the first Lunar descent was due to the computer being overloaded by too much RADAR data. That sounds like something that they would have thought to simulate, but it seems that everyone was surprised by it. Why…
Michael Stachowsky
- 6,250
- 1
- 21
- 40
22
votes
1 answer
Identify these mission photos
My grandfather who was involved with the DFVLR (now DLR) had all sorts of space-memorabilia in his basement, including a roll of pictures I've found. Does anyone know what mission they are from and what planet/body is shown (I assume it's probably…
Dragongeek
- 18,658
- 2
- 63
- 109
22
votes
4 answers
Why are the very reliable rockets Atlas V and Ariane V not rated for human flight?
During the last ten years all 100 or so launches by Atlas V and Ariane V together have been successful. (One Atlas V payload entered too low orbit, but that would hardly have risked the life of a crew). Why is that not enough for them to be…
LocalFluff
- 26,981
- 8
- 82
- 222
22
votes
2 answers
What is the marginal cost of *landing* on the Moon?
The question How useful is placing an asteroid in the Moon's orbit? quotes a news article saying the Obama administration is opposed to a lunar landing mission because of the cost of such a mission:
The Obama administration is opposed to another…
user
- 7,310
- 2
- 43
- 93
22
votes
3 answers
How long can a 2 person crew survive on ISS totally cut from Earth?
Something goes bad on Earth, ISS is cut from any kind of supply and the escape pods can't be used. If there are 2 people on board at that time, how long can they survive there? Did someone write a protocol for this type of situation?
symbiotech
- 953
- 7
- 15
22
votes
2 answers
What's after Pluto for New Horizons?
I have read that the New Horizons probe plans on visiting some other Kuiper-belt objects once it passes Pluto, but not sure which ones. This brings up a few questions:
Are there any leading KBO candidates?
Are they just looking for objects in…
Stu
- 5,928
- 9
- 34
- 80
22
votes
1 answer
How many and/or what kind of animals have ever been on the ISS?
I am doing a science project for school and i was wondering if anybody could help me out. I need to know how many and what kinds of animals have been on the iss.
Dwayne
- 229
- 2
- 3