Questions tagged [propulsion]
Systems for propelling a spacecraft from one place to another, such as rockets.
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I've looked at the Science involved but have doubts this would work, how can you generate momentum with-in a sealed system to produce propulsion? [closed]
Could you use a magnetic super-capacitor compound which is charged so it gains the maximum amount of weight\mass then is pushed away from the main object down a chamber using a magnetic field. As the ...
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Mars Sample Return Earth Return Orbiter — which propulsion system for what?
Many sources (eg this one) show the Mars Sample Return Earth Return Orbiter with both ion and chemical propulsion, and also state that it will be launched on an Ariane 6, but I can't find a clear ...
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How to send a 6-km mirror close to the Sun to propel a light sail?
I have written a paper about a crewed interstellar spacecraft that I propose.
I suggest to use either a laser, a Fresnel lens or a mirror to propel the sail of the spacecraft with sunlight.
I have ...
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Is there any possible reason to direct the electron gun specifically towards the ion trail behind an ion thruster?
This answer to Neutralization of ions in the ion thruster quotes the introduction to Wikipedia's Ion thruster:
Temporarily stored electrons are finally reinjected by a neutralizer in the cloud of ...
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Freezing problem of hydrocarbon fuels in a LOX cooled engine
I assume that in a LOX/RP-1 engine where RP-1 is used as a coolant, we need not consider the freezing issues. The reason for my assumption is that we need not bring the chamber and injectors to the ...
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How to predict reaction of propellants at chamber temperature and pressure? [duplicate]
I would like to understand how to calculate the complete reaction of propellants at chamber temperature and pressure.
For instance taking ethyl alcohol (75%) and LOX combustion with mixture ratio of 1....
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Where are Falcon 9 1st stage GN2 tanks located?
Is nitrogen propellant for the two cold gas thrusters pods contained in the interstage? The view we have from the B5-B1050 recovery shows several small COPV(s)
pic1
Here you can see where the cold gas ...
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Is the concept of the Epstein Drive based on actual theorized scientific research which is considered plausable?
I've always found it interesting when we see real life taking its cues from fictional arts, especially when it comes to Science Fiction technology. There are plenty of examples of classic books, TV ...
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Anyone know of a “N71” Hall Effect Thruster currently in production or development?
In a NASA Goddard Q&A transcript for an upcoming proposal, the NASA representative mentioned that the mission designers were considering the "N71" Hall Effect Thruster as an option for an upcoming ...
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Ion Lifter Thrust Calculation Problem
I've recently started building an ion lifter. I tried calculating the thrust the lifter produces but I came to a value that is way to high for such a small lifter. I'm using a 40kV at 1800mA AC ...
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Why might krypton have a lower utilization fraction than xenon for ion propulsion, and what can be done to improve it?
A comment below Why will Starlink satellites use krypton instead of xenon for electric propulsion? links to the 2011 preprint A Performance Comparison of Xenon and KryptonPropellant on an SPT-100 Hall ...
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Why is rocket engine flame usually clear/transparent at the nozzle?
This is a followup to a question about why the Falcon 9 second stage flame was invisible when out of the atmosphere. See: Why is the flame of the Falcon 9's 2nd stage invisible?.
That was well ...
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single thrust vs. multiple thrust
Does using one 5000 pound thrust engine give the same amount of thrust as five 1000 pound thrust engines? I am asking in terms of effectiveness not efficiency. Do the two different configurations ...
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Is thermal soakback from the engine a problem for rocket stages? Especially ones that complete several burns over several hours (e.g. S-IVB, Centaur)?
Thermal soakback is a phenomenon whereby a hot, operating engine transfers heat into the spacecraft, usually conduction through the engine mounts. I've only ever seen this problem discussed with RCS ...
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Why aren't rockets launched in movement? [duplicate]
Rockets launched to reach orbit usually start from a stationary position, engines are started and the rocket slowly gain acceleration upwards, eventually reaching orbit.
What I'm thinking is that the ...
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1answer
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Delta V/Fuel Cost for Satellite Rotation
How would you figure out the fuel cost or delta V for spinning up a S/C to match the orbital period of 27.32 days (moon orbit)? Given that the S/C is initially not rotating about any axes.
For ...
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How much thrust is “high” thrust (for orbital transfers)
I understand that chemical rockets and nuclear thermal rockets (and possibly very high power electrical thrusters) are considered to provide "high" thrust for orbital transfers, while electrical ...
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1answer
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Could the kinetic energy in the Sun's solar wind power an ion propulsion system for an interplanetary spacecraft?
I am wondering if the kinetic energy of the Sun's solar wind could energize heavy ions to the point in which they would produce enough momentum to propel an interplanetary spacecraft.
To help ...
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Are there substances that can effectively mined from asteroids that can be used for ion thrusters?
The most popular ion thruster design seems to use Xenon. Unfortunately, due to it's low boiling point Xenon isn't easily available in space.
Are there other materials from which ion thrusters could ...
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1answer
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Pump requirements in rotating detonation engines
The recent Wired article After 60 Years, Explosion-Powered Rockets Are Nearly Here about progress on rotating detonation engines contains the following quote:
A rotating detonation engine doesn’t ...
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Why does this formula say rocket efficiency depends on velocity?
Wikipedia gives the following equation for the efficiency $\eta_p$ of an engine here:
$$\eta_p= \frac {2\, (\frac {v} {v_e})} {1 + ( \frac {v} {v_e} )^2 }$$
where $v$ is the rocket speed and $v_e$ ...
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Could moon ice be used to fuel a steam powered jetpack for EVA in space or high altitude exploration on the moon?
For long term moon operations, would it be practical to have a jetpack that used steam as a source for EVA on the moon surface and above it in orbit?
I imagine a scenario where lunar ice deposits ...
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1answer
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Would an incandescent light bulb be more efficient than a laser for photon propulsion?
In an incandescent light bulb pretty much almost all of the input power is radiated as photons. While perhaps 10% of the power is useful for human vision and the rest are longer wavelengths, it's all ...
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1answer
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Could a carbon arc lamp help to propel a spacecraft through interstellar space?
I would like to know, on a theoretical basis, if the electron flow entering into the anode of a carbon arc lamp would impart enough kinetic energy to the anode, and thus to the spacecraft, to help ...
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For a DAWN-like solar-electric deep space mission, would using propellant particles much heavier than xenon atoms be beneficial?
For deep space missions using ion propulsion that are power-limited, this answer explains that a large mass/charge ratio ($m/q$) species is desirable. The solar-electric propulsion system used by the ...
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Injectors Diameter and Numbers
how would you determine the diameter and the number of injectors if unlike doublets elements are used? The Data given is:
Isp =286 s
Chamber pressure= 25 bars
Propellant pair: Fuel= Hydrazine and ...
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1answer
127 views
Proposed spacecraft propulsion with particle accelerator
With the new particle acceleration technology of plasma accelerator, electrons or protons can be accelerated to relativistic speed in a device much smaller than current Linac (According to wikipedia, ...
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Why did SpaceX swap the LOX and CH4 tanks between Mk1 and SN1?
According to most sources, the Starship Mk.1 had its LOX main tank (not talking about the header tanks here) on top and its main methane tank below. But it seems the SN1 revision, and all subsequent ...
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X-248 cape catastrophe [closed]
I was responsible for changing the ignition system on the fatal x-248. It was a result of poor igniter design and especially dangerous procedures by Cape personnel. I am looking for some facility of ...
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1answer
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Going to Eros; what to consider choosing between ion and chemical propulsion?
When planning a mission to a close approach to the asteroid Eros and to remain nearby, what are the factors that one would need to consider when choosing between ion propulsion and chemical propulsion?...
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Can a strong magnetic field be used to propel a spacecraft towards Mars and outer planets in Solar system?
Sun is bombarding us with ionized particles and these particles are moving towards outer planets. During solar flares this effect is intensified greatly. If we are able to create very strong magnetic ...
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Could a horseshoe magnet help a satellite stay in orbit?
If a horseshoe magnet was attached to a satellite orbiting the Earth, would the interaction of the Earth's magnetic field and the horseshoe magnet's magnetic field result in the magnet being propelled ...
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What is the most efficient way to go to Titan? [closed]
With ionic motors? or chemical engines? liquid propellant (LH2) or gas? What is the most compact way to make the trip? in the smallest possible rocket, for example the SS-520-5 is a 2-stage rocket, 11....
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1answer
165 views
What are the most effective deep-space propulsion systems?
I am looking for a powerful propulsion system for deep space missions. I am between a powerful ionic motor or a VASIMIR (variable specific impulse magnetoplasm motor). What do you think? The idea ...
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What is the load path for thrust in a rocket engine? [duplicate]
This may be a duplicate of this question but I wasn't sure if I could hijack that one to clarify or regenerate interest there.
What is the distribution of axial force in a combustion chamber? My ...
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183 views
How does LOX-lead startup prevent hard starts?
In my experience with hybrid rockets, the igniter is always triggered prior to or concurrent with the oxidizer flow into the chamber (which already has fuel in it, hopefully lit). This is to prevent ...
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1answer
163 views
Continuous staging? [closed]
In industrial chemistry it's well known (Armagnac vs. Cognac) that continuous processes are more efficient than batch processes.
In-game microtransactions have competed so favorably with just ...
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Help on Rocket Injector Equation
Hello can someone explain me how can I get the value of (6340) because when I try to solve the given values on the book I get (6423.980075) when I round it off it is still not the right answer can ...
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What is the precision attitude estimation strategy for satellites, under impulsive thrust manoeuvres?
Satellites mostly rely on star trackers and gyros for precision attitude knowledge. Under impulsive thrust manoeuvres, I expect the star trackers to blur and provide no attitude knowledge. What is the ...
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1answer
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I need a guidance about reading Rocket Propulsion Elements
I'm 1st grade physics student. I have learnt about units, vectors, kinetics, kinematics, Newton's laws of motion, galileo frames of references: galilean transformation, conservation of energy, ...
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Could you carry around with you a rocket pack to get off Mimas?
This question was inspired by the one here:
Is there a self-rounding celestial body from which an Olympian could jump into space?
regarding the, apparently shown infeasible, idea of jumping off what ...
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1answer
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Is the Helical Engine EM-Drive a real aproach to spacecraft propulsion?
I read that the first test was a failure but another theory says that could be done but it may violate the laws of physics. Is this engine a near future possible propulsion system or is just theory ...
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Thrust in Newtons to specific impulse
I'm almost certainly missing something here so I'd be grateful if someone could explain but how do I convert thrust in newtons to specific impulse?
thanks.
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1answer
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Help on Nozzle Throat Area Calculation
This is the equation of the nozzle throat area
This equation is based from a book called HOW to DESIGN, BUILD and TEST SMALL LIQUID-FUEL ROCKET ENGINES
This is the solution
The problem is I don’t ...
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1answer
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How was the S-IVB stage configured for the post-extraction retrograde dump?
When answering How exactly did the separation between Saturn V stage 3 and the Command / Lunar Module work? I first wrote that the retrograde dump after LM extraction happened "through the engine".
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Do colloid thrusters generate thrust by using only droplets or pure ions as well? If they only use droplets, how are they the same as electrospray?
In all of the research literature I have read so far, I've seen colloid thrusters explained as devices that gain thrust by releasing only charged droplets from ionic liquids as the exhaust mass. ...
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Can jet engines be used to launch a rocket?
Following up on my previous question Can a VASIMR Plasma engine be used to launch a rocket?, I was told that VASIMR plasma thrusters are inefficient in an atmosphere. I then had the idea of using jet ...
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Can a VASIMR Plasma engine be used to launch a rocket?
When I was in primary school, I spent countless hours designing spaceships that probably wouldn’t work. It’s only now that I’ve stumbled across some of the old drawings and actually thought if it ...
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When did ion propulsion first see some serious development efforts?
In the video below at about 01:35 Dr. Marc D. Rayman, Chief Propulsion Engineer, NASA JPL mentions that the first time he had heard about ion propulsion was on the ...
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VASIMR - Propellant usage data?
So I am using the VASIMR data of approximately 5N of force per 250kw of power draw. As far as I can see, this scales fairly linearly, so 500kw would result in 10N of force. (Might require two engines, ...
