Questions tagged [propulsion]
Systems for propelling a spacecraft from one place to another, such as rockets.
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Science Contest Topic (space exploration)
I'm thinking of entering the Breakthrough Junior Challenge. It is a global science video contest in which participants have to explain a hard science/math topic in a 3 min video. Right now I'm ...
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1answer
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Kinetic reaction from emission of electromagnetic radiation
If an object is emitting 1 watt of electromagnetic radiation directionally and has negligible black body radiation, how much thrust is produced? How can you calculate this generally?
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2answers
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Specific impulse and delta-v in Tsiolkovsky's rocket equation
According to Tsiolkovsky's rocket equation, it is possible to calculate the delta-v of a multistage rocket if you know the characteristics of each stage of the rocket. In my case, the only ...
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1answer
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Does better satelite propulsion help selling secondary payloads?
Generally orbital inclination change is said to be (fuel) expensive so everyone is trying to reach their final orbit straight from the launch vehicle.
Small launch vehicles (Rocket Lab etc.) reach ...
3
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0answers
159 views
How do you “make” a soliton? (recent peer-reviewed theoretical work in FTL travel)
I've just read an Article on the new approach on Warp Drives Dr. Erik Lentz describes. Instead of creating a bubble with negative energy density, he describes a Soliton in spacetime, which he ...
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1answer
23 views
Powering pulsed Ion Thruster
The thrust of an Ion Thruster is directly proportional to the Input power. I've done some experimenting with DIY versions, and I was wondering: Since Power is simply Energy/Time, if I shot incredibly ...
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1answer
41 views
Attitude control with cold gas thrusters
Consider the cold gas thrusters on a Falcon 9.
There are two thruster pods on stage 1 and two on stage 2.
Each pod has four orifices to fire along the x, y, and z axes of the scacecraft. By varying ...
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2answers
229 views
Why are the rocket plumes on SN10 different colors?
At about 7:53 (T+2:30) in this official video of the SpaceX Starship SN10 test flight, the engines are shown in the lower right, with clearly different colors in the plumes. The one on the right is ...
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2answers
144 views
Using lasers to reach the Karman line
I've just seen this Anton Petrov video: New Type of Laser Levitation Could Help Us Explore the Mesosphere. It's about this new form of levitation that uses lasers to heat up the air underneath a craft,...
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How long can the dawn probe‘s ion thrusters burn?
The title pretty much summarizes the question.
Weirdly, googling „dawn spaceprobe burn time“ and similar things didn‘t turn up anything useful (at least for me), so I was wondering if maybe someone ...
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2answers
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launch rocket like bullet from steam/air rifle?
I've included an image depicting how exhaust energy from a rocket launch can be recouped by turning it into a large scale pressure cooker by the use of some kind of platform=sabot (thanks @...
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1answer
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How do I calculate thermochemical properties of mixed gases?
I'm working on a rocket project, and my design of engines is stalled. I need to be able to calculate the Cp, Cv, and R for mixtures of O2/CH4 (stoichiometric or fuel-rich mix) and CO2/H2O (result of ...
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118 views
If a company/agency has already developed a kerolox/hydrolox rocket, is it wise for them to switch to an all-methalox rocket? (to lower costs)
Multiple rockets, such as the Atlas V or Saturn V, have used the combination of a kerosene/liquid oxygen (kerolox) lower stage for higher density and thrust within the atmosphere and a liquid hydrogen/...
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1answer
144 views
How much power do radiation-based engines produce
I heard that the Voyager satellites used a radioactive source to power the computer and sensor systems. How much power can this technique produce nowadays? Could it power, say, a fighting robot? ...
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1answer
36 views
nozzle throat area calculation for choked flow
I am quite confused for my sugar propellant rocket nozzle. I have designed a CD nozzle by hit and trial method. It worked but produced so less amount of thrust .I have used 2.3 kg propellant which ...
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1answer
191 views
What all practical propulsion technologies exist?
We are all too familiar with chemical rockets that burn liquid fuel and control ejection of exhaust gases to achieve propulsion for the rocket.
What other (practically implementable) propulsion ...
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3answers
1k views
How to move in space with just solar panels or without them?
What are the technologies known to humankind, to do propulsion in space, with a spacecraft having solar panels, when:
It is under ample solar flux?
It is interstellar under negligible solar flux?
...
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Sources for values for realistic thrust calculation exercise?
I want to use this simplified equation to calculate the thrust of multiple different real engines:
$$F = \dot{m} V_e + (p_e - p_0) A_e$$
Source: https://www.grc.nasa.gov/www/k-12/airplane/rockth....
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1answer
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How many ion thrusters would be needed to accelerate a 1000 tonne craft at 9.8m/s²?
If we assembled an array of today's best ion thrusters in orbit, (the x3?) how many would be needed to accelerate a 1000 tonne spacecraft at 1g?
I'm thinking Space Tug, for repeated Mars missions. ...
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What is the maximum force a deep space spacecraft experiences after launch?
The premise of How much of a deep space spacecraft's structural mass is useless dead weight after launch? Any plans to shed it in the future? is that the forces a deep space spacecraft experiences ...
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Where can I read about Lucy's complete propulsion system?
Wikipedia's /Lucy (spacecraft) says nothing of propulsion, and it's SWRI home page for the spacecraft http://lucy.swri.edu/mission/Spacecraft.html gives specification and enumerates what's on Lucy’s ...
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1answer
157 views
What if we launched rockets from space using the slingshot method and centripetal force? Would that be possible?
Would we have to build a orbiting launch station that uses centripetal force to launch the rockets? Or a station that freely floats through space not in a planets orbit? Would something like this ...
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Design a cold gas ACS nozzle
I have the total thrust required to be F=16.9 KN. I am using nitrogen gas, and the stored temperature in the nitrogen gas cylinder is 155 bars with a temperature of 325k. How would I design the nozzle ...
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Moon Mission - Mars Mission
They can stay on the moon only around for 3 days because of the fuel but they need around 6 months to reach Mars. Now they are working on the Propellant depot project to be able to reach the moon and ...
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31 views
Calculating Pressure Inside Combustion Chamber
I am trying to calculate the pressure inside a combustion chamber of a rocket candy. My "engine" is made out of PVC with an internal diameter of 1/2 in. Are there ways for me to calculate ...
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Technological challenges to sending a high altitude balloon to space and orbit from 50 km?
Below At what altitude would I have to go in a lighter than air balloon to be above all wind and just have the earth rotate underneath me? there is a comment:
If you want to be above all winds, you ...
4
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1answer
58 views
Does the volume of hydrazine propellant stored at 22 bar change?
I'm working on an extracurricular project and I'm trying to determine what volume of propellant tank I need to 12.14 kg of hydrazine propellant stored at 22 bar. I researched and found this pressure ...
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1k views
When has hydrogen peroxide been used in rocketry?
Peroxide is apparently a very good propellant, but I can't seem to find any instance of it being used. Has it ever been used and if not, why hasn't it? What's its downsides?
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1answer
145 views
Compressed Air Spaceship
Imagine a people who live within the debris ring of a planet. They make their homes on rocks that are only dozens of miles in diameter, so escape velocity is not a concern. They also do not need to ...
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1answer
467 views
What is that white smoke coming out of the bottom of the Starship?
What is that white smoke coming out of the SN8?
It comes out at the bottom and it starts when the first engine stops, why is that?
I think I have seen it coming out from the top too:
This is also ...
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1answer
53 views
Small liquid rockets are hard/expensive to build, but what about to use them?
It's become a sad and oft-demoralizing truism that it's quite difficult and expensive to design or build even low-performance liquid-fueled rocket engines, and that amateurs -- even those with skills ...
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1answer
84 views
How much additional thrust could the electron gun produce for electric sail propulsion?
Suppose there is an electric sail in LEO, do the electrons coming out of the gun produce an additional thrust? to produce a net thrust the electrons should NOT return to the satellite (which is at a ...
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Why can't we use the same tank to hold fuel for both the RCS Thrusters and the Main engine for a deep-space mission?
Basically, I just want to know that why we design different tanks for storing the main engine fuel and the RCS thrusters fuel. If we are using the same fuel for both the main engine and RCS thrusters (...
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3answers
2k views
Using nuclear detonations for propulsion
The proposed orion propulsion system used nuclear explosions to push against a giant shock absorber and propell it, but from my understanding, nuclear explosions only produce heat and rely on the ...
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0answers
29 views
Effect of delaying electron ion recombination in ion engine plumes; is a tiny additional thrust component available?
I have a follow-up question in response to this answer by @uhoh, basically asking about higher order effects alluded to in their answer.
If the ion exhaust plume coming off an ion engine remain ...
3
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1answer
82 views
Do pulse detonation rocket engines require any type of nozzle?
Rocket nozzles are used to convert slow moving gas under high pressure and temperature into hypersonic gas under approximately ambient pressure. From many videos of experimental Pulse Detonation ...
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Can we just throw a satellite in to mars orbit with a very high spin?
I am thinking about this scenario of throwing a satellite to Mars orbit with a high spin, Can we just throw that? one hypothesis can be that high-frequency spinning generates apparent gravity so it ...
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1answer
34 views
What is the maximum payload in terms of mass delivered to LEO by launch vehicle which used pressure fed cycle in all stages?
Launch vehicles can use pressure fed cycle in any stage of the rocket, but here i am interested for those vehicles which used this cycle in all stages. What is the current record in terms of mass of ...
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114 views
Viability of beamed regolith propulsion?
This question is inspired by two existing spacecraft propulsion concepts.
Beam-powered propulsion involves a spacecraft being propelled by a beam of some kind, and one potential type of beam would ...
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1answer
59 views
Spacecraft propulsion, Thrust, Delta V
For a spacecraft on an interplanetary mission (e.g. Mars), after deciding the propellant ISP value and Delta V required, how do you calculate the thrust required?
$$F = \dot{m} V_e + (p_e - p_0) A_e$$
...
0
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1answer
140 views
Can a spacecraft be propelled by two electromagnets of different size? [duplicate]
I watched a video of a toy car moving with 2 magnets, one bigger than the other. The answer I received was that the video was real, the toy car indeed moves.
So, I was wondering, if an object with 2 ...
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1answer
62 views
Who won the first round of Limitless Interstellar Initiative Grants?
Wired's NASA's EmDrive Leader Has a New Interstellar Project also mentions
White’s research pedigree may sound like it was cribbed from a mad scientist in a pulp sci-fi novel, but most of his work ...
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499 views
How does tankage mass really scale?
A problem that frequently shows up is estimating the mass of the propellant tanks of some hypothetical rocket configuration. This need arises from the important role of the dry mass in a rather famous ...
asked Oct 8 '20 at 6:34
SE - stop firing the good guys
28.6k2 gold badges96 silver badges170 bronze badges
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183 views
What was the influence of the military in the decision to use kerosene as fuel for LOX?
When it comes to hydrocarbons almost all state owned space agencies use kerosene in combination with LOX in bi-propellant rockets. But many hydrocarbons (such as methane, ethane, propane, ethylene, ...
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1answer
185 views
Why can I not use stoichiometry to calculate the O/F ratio of my rocket? [duplicate]
I am attempting to calculate the oxygen to fuel ratio (O/F) for my hybrid rocket engine (paraffin wax and gaseous oxygen). I know I can use the oxidizer to fuel equation to calculate this, but my ...
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150 views
Could pressurized ionized oxygen be used as a fuel source for an ion thruster?
I am wondering if a canister of pressurized oxygen could be used as a fuel source for an ion thruster.
To show how this could work on a conceptual basis, please reference the following drawing:
I ...
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Is the propulsion for the Scorpion nuclear-thermal-electric ship concept viable and credible?
Recently I've come across the proposal for the "Scorpion" spacecraft -- I originally ran across it on Project Rho (ctrl-F for it) but it looks like the article was published in the journal ...
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Is “nuclear electrothermal” a recognized term for a specific technology?
Is the term "nuclear electrothermal" recognized as referring to a specific type of propulsion technology (specifically, the nuclear thermal rocket with heat engine and arcjet afterburner)?
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Options for (high-thrust) RCS with Isp beyond that of chemical?
There are a number of potential options for high-performance engines in the future: nuclear pulse propulsion, NTR, gas-core NTR, nuclear electrothermal, and potentially even fusion rockets.
However, ...
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235 views
How much krypton is stored on a Starlink satellite?
How much krypton (fuel) is there for the krypton-powered ion thrusters on Starlink satellites and how long does it last?
