All Questions
34
questions
3
votes
0
answers
199
views
Does Starship run on Slushies?
Cryogenic slush (a mixture of liquid and solid) can potentially store propellants at higher density than cryogenic liquid. For instance, hydrogen slush is 16-20% denser than liquid hydrogen. https://...
- 22.8k
9
votes
1
answer
713
views
How is SpaceX planning to avoid fuel sloshing on IFT3?
SpaceX is about launch IFT3 and during IFT2, the booster exploded probably due to sloshing and an engine having something block its fuel supply.
What has SpaceX changed to avoid fuel sloshing?
- 370
-4
votes
1
answer
237
views
How does SpaceX prevent fuel from cluttering together in zero G [closed]
What is the solution to stop fuel inside starship collecting in center of the tank during zero G flight? Here is a rough sketch of starship with rudimentary diaphragm system to control flow of fuel ...
5
votes
1
answer
270
views
Why did the June 2016 SpaceX launch run out of propellant?
In other words, what caused SpaceX to miscalculate the amount of propellant required to safely land the booster. They had landed successfully on the drone ship in April. So what went wrong here? What ...
2
votes
1
answer
288
views
Why do the Falcon 9 fairings have soot on them?
On nearly every SpaceX webcast since 2020 they explain that the Falcon 9 booster has soot on it because, during the entry burn, it flies through its own exhaust plume very quickly depositing the ...
10
votes
3
answers
3k
views
Why do $\text{CH}_4$ (Raptor) engines produce less soot than RP-1 (Merlin) engines?
SpaceX's Merlin engine, which burns RP-1 and LOX, has soot visible after the first stage lands. Many articles on the web say SpaceX's Raptor engine, which burns methane and LOX, is clean. ...
- 2,888
17
votes
3
answers
3k
views
Why don't Raptor engines use CH3Cl instead of CH4?
The boiling point of CH3Cl is -24 degrees Celsius, whereas the boiling point of CH4 is -160 degrees Celsius.
The density of CH3Cl is 2.3 g/cm3, whereas the density of CH4 is 0.6 g/cm3.
CH3Cl is polar, ...
- 411
11
votes
4
answers
3k
views
Why RP-1 and not Methane for Falcon 9's Merlin engines?
I've seen methane described as the best of both worlds---the worlds being hydrogen's energy density + pain-in-the-ass factor and RP-1's lower energy density + ... ease of use?
And this has me ...
user39728
3
votes
1
answer
156
views
Could another fuel be used in the SpaceX Starship header tank?
A memory of hexane and water in a separatory funnel brought to mind the issue of helium and LNG in the header tank while the Starship flips and does its powered landing.
There was discussion of the ...
- 1,088
4
votes
1
answer
1k
views
How long does it take to refuel a rocket?
I've been wondering how long the refueling of a rocket, say the falcon 9 takes.
That's it.
- 41
21
votes
2
answers
23k
views
Why will Starlink satellites use krypton instead of xenon for electric propulsion?
The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says:
With a flat-panel design featuring multiple high-throughput antennas ...
- 148k
4
votes
2
answers
551
views
How could a hydrazine and N2O4 cloud (or it's reactants) show up in weather radar?
Question: How could a hydrazine and N2O4 cloud (or it's reactants) show up in weather radar?
Tweet:
This is what an ‘anomaly’ looks like on weather radar.
Tweet (with GIF):
Dragon's static fire ...
- 148k
4
votes
1
answer
457
views
What type of propellant does Spacex plan to use in Starship for long duration missions?
For long duration missions such as ones to mars what type of propellant would be best suited?
4
votes
1
answer
2k
views
Why doesn't the Merlin 1-D use higher LOX to RP-1 mixture ratios?
So I've been screwing around with CEARUN, which is the chemical equilibrium with applications program created by NASA. I've been using it to calculate theoretical Isps for rocket engines using RP-1 ...
- 201
11
votes
1
answer
16k
views
How much fuel does the Falcon Heavy use? What is the price RP-1?
Does anyone know how much fuel the Falcon Heavy can hold, the RP-1 fuel and liquid oxygen as oxidizer, and how much of that will it use to get to a certain point?
I don't know how i would calculate ...
- 175