Linked Questions

28 votes
3 answers
3k views

Why are RTGs different colors?

This is an image of the radioisotope thermoelectric generator (RTG) for Cassini: This one was for one left on the Moon: And this one is for the Multi-Mission RTG, used by Curiosity on Mars: One is ...
PearsonArtPhoto's user avatar
  • 121k
26 votes
4 answers
5k views

Does the NK-33 engine require subcooled kerosene so cold that it turns to wax?

It was mentioned in this answer and in several other places on the internet that the kerosene fuel used by NK-33 engines needed to be subcooled enough so that it reached the same density as the LOX, ...
uhoh's user avatar
  • 149k
18 votes
3 answers
4k views

How does SpaceX plan to deal with boiloff on the trip to Mars?

Both BFR (Big Falcon Rocket) booster and BFS (Big Falcon Spaceship) are to run on Raptor engines, fueled with liquid methane and liquid oxygen - cryofuels. The trip to Mars will take at least a couple ...
SF.'s user avatar
  • 55k
15 votes
1 answer
43k views

What's the typical temperature of a satellite orbiting the Earth?

I've been reading about "cryogenic" vs. "storable" propellants, and specifically the issue of boil-off: If the storage temperature gets above the propellant's boiling point, the propellant boils off ...
bjnord's user avatar
  • 253
12 votes
2 answers
9k views

Temperature of a satellite orbiting in low Earth orbit

I am working on a project for science fair that involves a deployable component that will not be heated on a CubeSat. I am trying to find data for the skin temperature of a satellite (or the ISS) over ...
Matthew's user avatar
  • 223
8 votes
6 answers
3k views

Methane internal combustion engines for rovers on Mars and Moon. Feasibility?

It seems possible to produce methane and oxygen from the atmospheric CO2 and icy soil on Mars, and from icy regolith in the polar craters of the Moon. It has been suggested that CH4+O2 could be used ...
LocalFluff's user avatar
16 votes
2 answers
2k views

What aspects of reentry heating 'scale as the 8th power'?

Elon Musk just commented in the post Falcon Heavy Test Flight press conference that reentering at interplanetary velocities means dealing with 'some of the heating things that scale to the 8th power'. ...
kim holder's user avatar
  • 21.4k
8 votes
2 answers
2k views

What are these very large, square panels on Inmarsat 5?

Question: What are these very large square panels on Inmarsat 5's? They seem to each have an extremely reflective mirror-like flat/smooth tiled-appearing side, and a nearly black side with a lot of ...
uhoh's user avatar
  • 149k
1 vote
1 answer
824 views

What is the solar flux on Titan?

I' trying to solve for the surface temperature Ts=((n+1)So(1-A)4)1/4, and thus So=L/4𝞹a2 but I cannot seem to find the value for solar flux or its luminosity.
Haley's user avatar
  • 15
3 votes
2 answers
591 views

What liquids last the longest in space?

I am trying to find something that is somewhat stable as a liquid in space. What happens to various liquid elements and compounds in a vacuum? Is there a list or table of the effects of local space ...
Muze's user avatar
  • 1
4 votes
1 answer
587 views

How do you find the temperature of an orbiting aluminum sheet 10x10 cm

I'm trying to find the temperature of a CubeSat in orbit at 140km. I'm trying to use the Stefan-Boltzmann law but don't know how to incorporate the energy from sunlight. I'm using this as a check for ...
mojojojo's user avatar
  • 141
4 votes
1 answer
308 views

What was the cause of the second explosion in SpaceX's pad "Fast Fire"?

This is well after the first and second stage were gone, so I suspect it was something about the pad itself that resulted in the second explosion event. Any ideas?
PearsonArtPhoto's user avatar
  • 121k
2 votes
1 answer
504 views

How might an internal combustion engine generate substantial external thrust?

This answer mentions the proposed use of an internal combustion engine (ICE) in ULA's ACES upper stage to extract energy from LH2/LOX in multiple forms for multiple uses, which is described further in ...
uhoh's user avatar
  • 149k
1 vote
1 answer
457 views

Cooking in Space

Someone in the Worldbuilding SE asked How to Build a BBQ for the ISS. My first through was: Why not just stick it in a sealed container out in direct sunlight for a bit? It'll get plenty cooked ...
ShadoCat's user avatar
  • 910
3 votes
1 answer
226 views

Can James Webb see Kuiper Belt Objects like 2014 MU69 (Ultima Thule)?

In this paper, we learned that Hubble is the only telescope in the vicinity of Earth that can detect Ultima Thule directly. Hubble will eventually fail, and will be somewhat replaced by James Webb. ...
PearsonArtPhoto's user avatar
  • 121k