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votes
1answer
119 views

Magnetic force-driven propulsion system for an interplanetary/interstellar spacecraft

I have come up with a conceptual idea of a magnetic force-driven space propulsion system. What I believe is very unique about this propulsion system concept is that its working principle should not ...
1
vote
1answer
207 views

Could a CubeSat be propelled by this low-tech electromagnetic propulsion system?

I have come up with a conceptual idea for a low-tech electromagnetic propulsion system for a CubeSat, and I would like to know if it would create (on a theoretical basis) a net force strong enough to ...
0
votes
0answers
42 views

Exit pressure for Rocket Lab Curie engine

What do you think the exit pressure for rocket lab curie engine could be?and the area ratio as well? its a kickstage engine and it is said that it has about 25lbf thrust.
0
votes
1answer
57 views

Exit pressure value for vacuum nozzle [duplicate]

What value of exit pressure should I use in the design equations for a small liquid rocket engine nozzle for 200km-500km operating conditions? Since using zero as a value is not possible or else ...
25
votes
9answers
6k views

Would a grinding machine be a simple and workable propulsion system for an interplanetary spacecraft?

I am wondering if any space agency has ever considered using a grinding machine as a propulsion system for an interplanetary spacecraft. This system would not be used to lift the spacecraft off of a ...
2
votes
1answer
191 views

How do you determine what the temperature will be in the combustion chamber of a rocket engine?

I am guessing it is dependent on the fuel and oxidiser and the chamber pressure but is there an equation that would calculate the chamber temperature?
6
votes
1answer
195 views

Why did the MarCO space probes use fire extinguishant as their propellant?

In many news articles, it's mentioned that the MarCO spacecraft, launched with InSight, used fire extinguishant as the propellant for its cold gas thrusters. I originally assumed that this was ...
4
votes
1answer
120 views

What's the actual oxidizer/fuel ratio in the combustion chamber of the Vulcain?

I'm working on a simple exercise on the Vulcain, but I'm having a hard time figuring out what the real O/F ratio is, in the combustion chamber. I need the mixture ratio in the chamber to calculate the ...
17
votes
2answers
1k views

How do you confirm ignition in the combustion chamber of a rocket?

Is ignition confirmed using a temperature sensor, pressure sensor or another device?
5
votes
1answer
574 views

How are the combustion chamber length and diameter decided

How are the combustion chamber length and diameter decided? Are there any proper formulations or procedures?
10
votes
1answer
176 views

When regenerative cooling is used, how is the nonuniform radius of the combustion chamber handled?

As the combustion chamber necks down and flares out, the 1-D cross section past which which fuel must pass as it cools the wall of the chamber will change. If there are lots of tubes, they will bunch ...
3
votes
3answers
324 views

At what size does a bigger solar sail stop increasing your acceleration?

Is there a point where the larger solar sail would not add more thrust? What is the most thrust a solar sail can produce? Can a solar sail be added to an ion engine and work better?
4
votes
1answer
334 views

Which of the orientation is preferred for static fire testing of a liquid rocket engine - vertical or horizontal?

Liquid rocket engine's hot fire testings are performed both vertically and horizontally. Vertical orientation - Falcon heavy, Falcon 9, Rutherford engine, UCSD Engine test from 2014 , Merlin 1D, ...
5
votes
1answer
337 views

Which is the preferred mode of liquid rocket engine cutoff - fuel lean cutoff or fuel rich cutoff?

When a bi-propellant liquid rocket engine receives a command to shut down, will the fuel gets cut off first and then the oxidiser - a fuel lean cutoff? Will the oxidiser gets cut off first and then ...
2
votes
1answer
84 views

Rocket engine power vs. Sound

Is there any relationship between the sound emitted from a rocket engine and the amount of thrust it gets at surface temperature and pressure?
5
votes
0answers
139 views

What is the droplet size that is desirable for pintle injectors?

The pintle injectors tend to generate droplets after impingement of the fuel and the oxidiser stream and I understand that the droplets will be premixed. In such a case, even a larger premixed ...
6
votes
0answers
178 views

Trade-offs in developing larger engines vs using more smaller engines

Looking to explore the inverse point of this question: What challenges are there for more, smaller liquid fuel engines instead of one large? As stated in the answer to the above question, fewer, ...
3
votes
2answers
313 views

What are the choice of materials for LOx pumps casing and impellers?

Given the highly corrosive nature of LOx and the extremely low temperature, what materials are usually used for the LOx pumps? Steel, Copper, and many alloy tend to be flammable in liquid Oxygen ...
3
votes
0answers
131 views

Does LOx stay as liquid when entering combustion chamber?

Given the heat from combustion and increased temperature, would the LOx still be in liquid form after emanating from the injector? Or will it instantly transform into gas? Are injectors cooled using ...
2
votes
1answer
631 views

Why spray LOx into combustion chamber, if GOx is more effective?

Are there any issues in transforming the liquid oxygen into gaseous oxygen before injecting into the combustion chamber? Gaseous Oxygen will be readily available for combustion and will mix well with ...
5
votes
0answers
541 views

Pulse Rocket Engine

How feasible would a rocket engine that ignited fuel in fast, high pressure pulses be. This type of engine would be especially applicable for low thrust burns such as for the raising of a small ...
8
votes
1answer
2k views

What are the advantages of Ox-rich staged combustion?

In the context of staged combustion, I understand that burning ox-rich creates complications associated with having hot, high pressure, oxidizer. Some engines, notably the RD-170 and RD-180 family run ...
1
vote
0answers
93 views

Simulation of Rocket chambers like in Hall Effect Thrusters

I started learning Solidworks in hopes of being able to run simulation to study rocket chambers. Currently, I am studying the flow of plasma and its interaction with the magnetic field, but ...
4
votes
0answers
104 views

Electromagnetic engines in heavy radiation regions

What sorts of peculiarities might affect an electromagnetic rocket (VASIMR or Magneto-Inertial Fusion) crossing Jupiter's radiation belts? Could all of that energy fry a magnetic thrust chamber and ...
4
votes
4answers
1k views

What kind of engine does this Isp = 1600 refer to? Is it cubesat-friendly?

These two good answers (one and two) to the question "Is there a maximum Isp for 'exothermic chemical reaction rockets?'" put the limits around 500-550 seconds for the limits of practical chemical ...
10
votes
1answer
6k views

Rocket Engine Plumbing: Still don't understand the Full Flow Staged Combustion Cycle

I just found this incredible video KSP Doesn't Teach: Rocket Engine Plumbing and ran through it a few times. It's very helpful in the way it outlines the various issues first, and then designs the ...
11
votes
4answers
2k views

Do rocket engines have shock absorbers?

With a million pounds of thrust and many g of acceleration and a significant fraction of a g of vibration, connecting the engine to the rocket can't be trivial. At launch the mass is very high and ...
10
votes
3answers
2k views

What are the phases of ignition (and flameout) of a liquid fuel engine?

As I observed ignition of several rocket engines (Shuttle, AMDE, Lynx Suborbital, Saturn V) they all come through a couple phases - emitting various vapors, unfocused flame, etc, before the proper "...
7
votes
2answers
522 views

What challenges are there for more, smaller liquid fuel engines instead of one large?

Some questions popped up about difficulties of creating throttleable liquid fuel engines. I wonder why the obvious alternative isn't more common: multiple engines, from which only some will be lit; ...
6
votes
0answers
457 views

What upgrades does the Merlin 1D need to increase its time between overhauls to 1000 hours?

This is a question I've been pondering for the last few weeks after I back-calculated the details of the Merlin 1D engine. Just as a thought exercise, I wanted to see what upgrades the Merlin 1D would ...
6
votes
1answer
130 views

Is pogo oscillation a risk in hybrid motors?

Is pogo oscillation accounted for in design of hybrid motors? I'm thinking particularly about hybrids that use Nitrous Oxide as the oxidizer because the weird triple point effects that one experiences ...
16
votes
3answers
912 views

Pumped propellant propulsion - is it viable?

A recent article on Slashdot got me thinking. While the article is about using electric turbopumps for moving fuel from tanks to engines during launch phase and is just a small, incremental ...
4
votes
3answers
610 views

Could the Bloodhound Rocket Car be launched into orbit?

The Bloodhound SSC (Supersonic Car) currently being constructed to break the 1000 mph barrier is powered by a Hybrid Rocket (Solid fuel + HTP) and a Rolls-Royce EJ2000 Jet Engine: Considering the ...
19
votes
7answers
9k views

Can ion thrusters be scaled up?

All ion thrusters are quite small. Having read through the more approachable information about them, as they use physics pretty beyond me, I don't understand what it is about them that makes it ...
9
votes
1answer
178 views

Do modern CFD codes reduce the number of test firings in an engine program?

Given the complexity of liquid propellant rocket engine development, I wonder if (and how much) modern Computational Fluid Dynamics (CFD) codes help to reduce overall development costs. Do they ...
17
votes
1answer
2k views

Why the non-symmetric design of rocket nozzles?

Although I have seen many perfectly symmetric nozzles, I have also seen designs such as this (Virgin Galactic) which is only symmetrical about one axis: Why is this?
6
votes
1answer
2k views

Does the Falcon 9 v1.1 form a shock diamond when in flight?

How does the Falcon 9 v1.1 form this exhaust pattern with its nine Merlin 1D engines? Is it a bigger, rougher shock diamond? I am trying to learn more about how one could form with a cluster of ...
7
votes
1answer
418 views

Have the micronewton thrusters developed for the LISA mission been flight tested yet?

JPL together with Goddard and a private company called Busek Company Inc. developed a new type of propulsion system known as micronewton thrusters for the LISA mission (which has since had a name ...
23
votes
7answers
15k views

Why aren't linear aerospike engines in common use?

Linear aerospike engines are an old idea that seem so full of promise. Why are they not widely used today by the likes of Boeing, SpaceX, etc.?
13
votes
5answers
4k 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?
13
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 ...
13
votes
2answers
15k views

Efficient types of nozzles used in rockets

Is there any other type of nozzle other than common convergent-divergent nozzle (see picture below) which is used in many rockets?             ...