Questions tagged [fuel]

Questions about rocket oxidizer, propellant, reactive mass, or other fuels used in spacecraft or rockets.

Filter by
Sorted by
Tagged with
12
votes
2answers
1k views

Nuclear thermal rocket specific impulse calculation uses 1 amu, is that wrong?

Following the parameters in the Wikipedia nuclear thermal rocket article, it seems to paint somewhat of a shaky world view. Consider these quotes: Current (2010) 25,000 pound-thrust reference ...
33
votes
3answers
6k views

Why do the exhaust flames from cryogenic stage engines appear to be separated from the nozzle?

Why do the exhaust flames from cryogenic stage engines appear to be separated from the nozzle?
9
votes
3answers
737 views

What are the deal-breakers with a preheated Hydrogen gas tank orbital rocket?

Consider this thought process: In selecting the propellant for a reaction engine, lower atomic mass is better because equipment is largely temperature limited, and lighter gas will get higher ...
17
votes
2answers
578 views

Can solid fuel leak?

Recently the ISRO GSLV launch was called off on account of a fuel leak. Other launches too have, on occasion, been called off for similar reasons. Fuel used to launch a craft to orbit may be solid, ...
13
votes
5answers
5k views

Can a rocket motor be shut off after ignition?

After ignition, if any problems occur such as fuel leakage, can a rocket motor can be shut off?
31
votes
3answers
17k views

Why are hydrogen-fluorine fuels not used for rockets more frequently?

Many rockets use hydrogen- and oxygen-based propellants as fuel. Why are hydrogen-fluorine fuels not used? It has a specific impulse of 390 seconds, higher than hydrogen-oxygen combustion (360 ...
12
votes
1answer
229 views

Are there any proposals to vacuum up gases in orbit for use as propellant?

Space stations like the ISS orbit at an elevation that puts them squarely in the Thermosphere, and while this has extremely rarefied gas (which is probably more accurately a plasma at many times), it ...
14
votes
1answer
2k views

Are MMH and UDMH interchangeable?

Can Monomethylhydrazine and Unsymmetrical dimethylhydrazine be used one in place of another for the class of the existing orbital maneuver engines (with reduced performance may be)? Such as Shuttle's ...
8
votes
2answers
528 views

Could waste methane be recycled as propellant on the ISS?

Under standard condition methane burns with oxygen in stoichiometric ratio of 1:2 to liberate 891 kJ/mol of energy. Why is the ISS not making use of the methane, which is expelled as waste instead? ...
15
votes
1answer
2k views

Changes made to ISRO GSLV-D5's CUS and FBTP since GSLV-D3's LH2/LOX CUS failure to sustain ignition?

The launch of the ISRO GSLV-D5 launching India's GSAT 14 advanced communications satellite (weighing 1,980 kg) is slated for 19th of August, 2013, flying in the GSLV Mk.2 configuration with an Indian-...
8
votes
2answers
841 views

Is it safe to use a coilgun or railgun as an engine inside the solar system?

Given a large iron body and a coilgun or railgun to impart thrust, You can turn an asteroid into a fuel tank (sort of). Sending large or small bits of iron at high speed towards someone is likely to ...
16
votes
3answers
3k views

In a cryogenic fuel rocket, at what pressure is the fuel injected into the engine?

The pressure in the Space Shuttle's main engines must be very high to get the vehicle off the ground (with the SRB assist, of course). With such high pressures inside the engine, how do you inject ...
11
votes
3answers
4k views

How much fuel would one need to launch a 1kg object from 100,000 feet?

Back in the old days of the cold war the US and Russia were trying to develop a Nuclear powered aircraft. Problems with radiation shielding and "safety" held them back. Let's say that they got this ...
16
votes
2answers
718 views

How does the launch risk posed by plutonium compare to the launch risk posed by propellants?

For outer solar system exploration, virtually the only feasible power subsystem are Radioisotope thermoelectric generators (RTGs). These include plutonium, which may carry considerable risks (see ...
16
votes
1answer
808 views

At what travel distances are ion engines faster and more efficient than conventional fuel engines?

According to Scientific American (February 2009), ion engines start off slow, but build up speed as they travel. At what travel distance would an ion engine (such as an ion thruster, a Hall thruster, ...
10
votes
3answers
567 views

What creative orbital maneuvers might I do to save fuel for a geosynchronous spacecraft?

I've heard that there might be some creative ways to get to Geosynchronous Orbit that could save a lot of fuel. How might I manage to make this happen?

1
4 5 6 7
8