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10 votes
Accepted

How do you find the propellant mass needed to reach an specified altitude? (altitude at end of burn plus altitude during coast)

How do you find the propellant mass needed to reach an inputted altitude?(altitude at end of burn plus altitude during coast) The first thing you should be considering for any rocket mission is the ...
A McKelvy's user avatar
  • 2,492
4 votes

Would that asteroid transport be possible?

If we assume that the asteroid's orbit is similar to the kind of orbit one would take when traveling from Earth to Mars, then we can get a rough idea of the delta-v needed to capture the asteroid from ...
phil1008's user avatar
  • 6,108
4 votes

Some exercise questions about Tsiolkovsky's Rocket Equation and Thrust Equation

For problem 3.27 not enough information is given. Assuming constant mass flow rate, the burn time is: $$\tau = \frac{R-1}{R} \frac{c}{a_0}$$ where R is mass ratio ($MR$), $c$ is exhaust velocity, $...
W H G's user avatar
  • 706
3 votes

What is missing in the conversion of specific impulse from units of seconds to thrust/mass flow rate?

But I can't figure out why you must introduce g into the equation as it doesn't appear during the dimensional analysis. g is required because the use of specific impulse in seconds comes from using ...
Russell Borogove's user avatar
3 votes

In principle, could the oxygen tanks of an 'air breathing' rocket, be filled during ascent?

I know I'm late to the party here, but this concept was actually researched in the 60s as part of early hypersonic glide vehicle programs. https://apps.dtic.mil/sti/citations/AD0348937 The most ...
Great Canadian Moose's user avatar
3 votes

How can I use the Rocket Equation and Staging for a ballistic flight?

Short answer: Yes, you can use energy balances for this problem and the rocket equation can also be rewritten in a way to include thrust (force), the mass of the fuel and optimal staging. Long answer ...
The Rocket fan's user avatar
2 votes

Engine most likely to be available in the next 80 years to accelerate a craft at 1G for 4 weeks

A Pure Antimatter Rocket. The "within 80 years" requirement makes a number of different technologies possible. For example, if we assume that by then we can manufacture a small army of space ...
phil1008's user avatar
  • 6,108
2 votes

Engine most likely to be available in the next 80 years to accelerate a craft at 1G for 4 weeks

"Realistically", the only engine type that might be able to achieve performance levels near this and which currently has a non-zero TRL, is probably Project Orion style nuclear propulsion. ...
Dragongeek's user avatar
  • 19.2k
2 votes
Accepted

What should be the fuel mass of a hypersonic (Mach 7) rocket using APCP fuel that would deliver a 50 gram payload?

Probably around in the thousand of kgs. Some quick noodling with the simulator open rocket suggests even with the highest spec tube motors you will be maxing out around mach 2, which makes sense since ...
GremlinWranger's user avatar
2 votes

Do lower pressure pressure-fed rockets get more Delta-V?

A shorter answer. Yes a "lower pressure" pressure fed rocket would have a lighter tank, Isp falls but this maybe compensated by the fall of dry mass from a lighter tank leading to an ...
John Ashcroft's user avatar
1 vote

How to calculate the optimal mass ratio for a multistage water rocket?

There is not going to be a simple solution here, since the math involves complex details of the construction, the drag of the rocket and details of separation and if goal is optimal build cost, final ...
GremlinWranger's user avatar

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