Questions tagged [performance]
The performance tag has no summary.
39 questions
3votes
0answers
202views
How much denser could Earth's atmosphere be before rockets wouldn't work?
As the atmosphere gets denser, any rocket trying to fly through it would experience more and more atmospheric drag. How much denser could Earth's atmosphere be before rockets wouldn't work (or would ...
1vote
0answers
135views
Does an overexpanded nozzle behave like a suction cup?
It is generally said that, to obtain optimal specific impulse, a nozzle should be just the right size that the exhaust pressure is equal to the ambient pressure. Quoting this answer, a relevant ...
10votes
3answers
5kviews
Do larger rockets tend to have a better mass ratio due to the square cube law?
Do larger rockets tend to have a better mass ratio due to the square cube law? I mean, larger tanks have a better surface-to-volume ratio, so their weight-to-volume should be improved
- 153
7votes
1answer
1kviews
Nitrogen trifluoride as a high density oxidiser
Nitrogen trifluoride (NF3) is a liquid between 66K and 144K and has an incredible density of 1.885 g/cm2. It has a pretty great specific impulse, although combustion temp is a bit high, and AFAIK is ...
- 832
3votes
0answers
453views
Using CEA for monopropellants
CEA (Chemical Equilibrium with Applications) calculates chemical equilibrium compositions and properties of complex mixtures and is the industry standard. Applications include assigned thermodynamic ...
- 832
1vote
0answers
44views
How to calculate combustion temp? [duplicate]
I was reading about a propellant combination using ethanolamine(19.9% propellant fraction w/ 1% Copper Chloride) and 90% HTP(80.1%). I am trying to design a hypothetical engine around the propellant, ...
- 832
3votes
1answer
315views
How Intuitive Machines' engines "crank out unmatched performance in the space domain" allowing "transit of Van Allen belts once, unlike competitors"?
According to https://www.intuitivemachines.com/propulsion LOX/Methane Engines Our LOX/Methane engines are unique for in-space propulsion, in that they offer safety in handling and testing here on the ...
- 153k
2votes
1answer
301views
How could Starship "deep space variants" improve payload performance by "orders of magnitude" (Elon Musk)?
Replying to Scott Manley's tweeted table of payload mass for a given geocentric C3, Musk tweeted: We could stretch the Falcon Heavy upper stage & increase this a lot, but FH already covers all ...
- 153k
6votes
0answers
249views
What are the various ways that rockets measure the instantaneous thrust of each engine?
@DavidHammen's answer to Engine failure: how to detect? mentions thruster sensors. This intrigued me and so I thought I'd ask about how this is done. Thrust is a critical parameter to know in real ...
- 153k
9votes
3answers
414views
Is there a formula for converting a rocket's performance for one orbit to another? E.g. SSO performance to GSO?
If a rocket can take 1,000 kg to SSO at 500 km, is that enough information to determine what its capacity to, say, GTO or GSO would be? If so, how would one calculate it?
4votes
1answer
977views
What were/are the stingiest and most generous vacuum nozzle? (records for the smallest and largest expansion ratios)
Vacuum nozzles are huge compared to their sea-level or atmospheric counterparts, as can be seen by comparing the first stage engines on an Electron or Falcon-9 to their second stages, where a big ...
- 153k
8votes
2answers
1kviews
What happened to tripropellant rockets?
IIRC, tripropellant rockets can deliver superior performance compared to bipropellant rockets (at the cost of added complexity). Now, I know that there is the Li/H/F combo, but it isn't used because ...
- 183
3votes
1answer
229views
How can I use the Rocket Equation and Staging for a ballistic flight?
I want to calculate the a) thrust b) mass of fuel c) optimal staging of a rocket, which shall fly up to for example an altitude of 50 km in a ballistic flight trajectory. In school I learned the ...
- 31
6votes
2answers
1kviews
Could HIBEX propellant be used for amateur rockets?
The HIBEX rocket was a precursor to the Sprint missile system deployed briefly back in the 1970s. The rocket was only 18 feet long but had extraordinary performance(an acceleration of 100 G's!). But I ...
- 193
2votes
1answer
268views
Can a lighter rocket lift more than a heavier rocket?
Let us consider two launch vehicles - "A" and "B". If "A" has a larger wet mass than "B", does this imply "A" has a higher payload capacity to a particular orbit, from a particular launch site than "B"...
- 3,356
