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Questions tagged [fuel]

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

43
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2answers
3k views

Using ozone as oxidizer

The bond energy of $O_2$ is 498kJ/mol. The bond energy of $O_3$ is 364kJ/mol. That means the energy to break up the particles into 3 moles of monoatomic oxygen (which then binds with fuel to release ...
0
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3answers
6k views

What is the formula to calculate how much fuel is needed for a rocket?

I'm theoretically trying to launch a rocket for a school project and therefore I chose Saturn V. I took its weight of 140.000kg (308 647 pounds) and I'm trying to calculate how much fuel it'd take to ...
4
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1answer
610 views

Is it correct to say that a LH2/LOX rocket uses water as propellant?

The title more or less sums it up. A rocket engine works pretty much by combining fuel and oxidizer, and expelling some propellant resulting in foward motion as described by Newton's third law of ...
12
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2answers
3k views

Why use Kerosene?

According to SpaceX's website, the Falcon 9 uses kerosene as fuel. According to Wikipedia, diesel fuel beats kerosene in energy density in terms mass by 2.8 MJ/Kg and in volume by 5.6MJ/L, so why ...
1
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1answer
487 views

Comparison between solid rocket fuels. Which are better by performance and cost? [closed]

I am interested for a comparison of solid rocket fuels by their performance and cost. Comparison by specific impulse (Isp), energy that gives (which one is more energitic), density, cost to ...
2
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2answers
347 views

Is HAN-water propellant “green” enough to ever be used in a cubesat?

I just read about the "green" propellant Hydroxylammonium nitrate writing this answer. It will be tested in the Green Propellant Infusion Mission (also see GPIM AF-M315E Propulsion System). Catalytic ...
6
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2answers
610 views

Why does the BE-3 use hydrogen as fuel?

We've covered why the BE-4 uses methane as fuel; what I want to know is, why did Blue Origin go with hydrogen for the BE-3? Liquid hydrogen is notoriously hard to work with; it seems like an odd ...
3
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1answer
966 views

What is the spherical tank in this drawing of the BFS?

The big news in this article is the extremely large carbon-fiber fuel tank. However, the drawing in the article does not show it well. Instead what stands out like a sore thumb in the drawing is the ...
4
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1answer
870 views

Why does Juno use “mixed oxides of nitrogen” oxidizer for propulsion? Which ones?

In the recent Spaceflight 101 article Rocket Burn postponed for NASA’s Juno, to remain in elongated Jupiter Orbit until December it says: Juno uses a bi-propellant main propulsion system with ...
6
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3answers
2k views

Combination of liquid hydrogen and liquid oxygen

For the Apollo missions in the 1960s, NASA used a combination of kerosene and liquid oxygen to get the rockets out of Earth's atmosphere. Why did they do that? If you look at the statistics, the ...
2
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0answers
157 views

Are there any complications of the position of the oxidizer injector on Orbitec's vortex rocket engine?

Orbitec's vortex rocket engine injects oxidizer from near the nozzle up the wall of the engine chamber in a vortex. The oxidizer injector being in this position seems unusual. Are there any ...
3
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1answer
265 views

What proportion of a rockets fuel remains unburnt?

Presumably liquid rocket combustion is never 100% efficient, so what proportion of fuel does typically remain unburnt, venting into the atmosphere, and does this vary for different rocket designs and ...
5
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2answers
1k views

Is the pressurization of propellant tanks necessary for structural integrity?

Propellant tank pressurization is a critical aspect of liquid propellant rocket design. Many designs use high pressure helium, heated and recirculated, however the propellant gases themselves can be ...
0
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0answers
40 views

Can we build a sling in space to shoot a ship to Mars faster? [duplicate]

Is this concept covered somewhere I'm curious about resistance and tension and velocity in space versus tons of chemical fuels? If I've missed that can you point me to it?
3
votes
1answer
709 views

Limit to reduction of G-forces during reentry?

I was wondering whether there is a limit to the amount in which the perceived g-forces during atmospheric reentry can be reduced by trading fuel consumption for smoothed out deceleration peaks. To ...
6
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1answer
233 views

Can Falcon 9's fuel be ignited by static discharge?

Reading Twitter comments about the recent Falcon 9 pad explosion, some postulated the problem was that a static discharge ignited the fuel as it was being loaded. Since TEA-TEB is required to ignite ...
3
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0answers
364 views

What could be wrong in the ground support equipment to cause the Falcon 9 AMOS on pad explosion? [closed]

The AMOS-6 mission Falcon 9 had a RUD (Rapid Unscheduled Disassembly) event on the pad, and it is initially postulated that it was related to fueling the second stage. We know that SpaceX revamped ...
3
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3answers
822 views

Amount of fuel for accelerating a spaceship

Suppose I have a spaceship and fire up its engines, accelerating to 10000 km / h. Now I turn off my engine and see I have consumed 10 % of my fuel (90 % left). How much fuel does it take to ...
1
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2answers
268 views

ULA: bringing propellants from Earth “Avoids Earth's Deep Gravity Well”?

I read SpaceX’s biggest rival is developing “space trucks” to ferry cargo in an orbital economy in Quartz which linked to this April 2016 outline of ULA's view of Transportation Enabling a Robust ...
-1
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2answers
979 views

Falcon 9 fuel use [closed]

How much fuel does a Falcon 9 rocket used by SpaceX use, for a trip to the International Space Station? Any possibility of Teslas batteries being used in the future?
1
vote
1answer
172 views

Different LNG (methane) combinations with oxidizer

I was looking up oxidizers in two aspects, economy and power. Since much of math goes over my head, I got almost nothing. What would be most economical and most powerful potent oxidizer choice ...
10
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1answer
759 views

Why is the Deep Space Industries Prospector 1 using water propellant instead of hydrazine?

A lot of satellites use hydrazine propellant but the Prospector 1 is using water. What are the benefits and drawbacks of that decision?
12
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1answer
979 views

How would the Saturn V have differed if the first stage was also LH2/LOX?

Since both Kerosene (RP-1) and liquid hydrogen (LH2) continue to be important liquid fuels used with liquid oxygen (LOX), something can be learned by comparing how they are used. This is covered well ...
6
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2answers
2k views

Pros and Cons of LH2/LOX vs Other Fuels

As I stated in the answer to another question, LH2 suffers some serious drawbacks compared to other fuels. Off the top of my head, they are Extremely low density, resulting in: Lower mass-fraction ...
9
votes
1answer
507 views

What is the ortho/para issue with LH2 as a fuel?

I remember reading somewhere that a catalyst was used to change the ratio of ortho- vs para-hydrogen before it is loaded as LH2 propellant on a rocket. What is this exactly, and why is it necessary? ...
9
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2answers
797 views

Making propellants on Mars: Why not just LH2/LOX instead of methane?

In this cool video of a presentation about SpaceX's GPU-based computational fluid dynamics, there is a slide early on about making rocket fuel on Mars - specifically using water from the ground and ...
1
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2answers
243 views

Back to oribt from Mars - how many km^2 yr of solar power to make enough propellant?

In this cool video of a presentation about SpaceX's GPU-based computational fluid dynamics, there is a slide early on about making rocket fuel on Mars - specifically using water from the ground and ...
9
votes
1answer
2k views

How does an Electric Solid Propellant rocket work?

I saw the section in Wikipedia about Electric Solid propellants but I can't figure out what it really is, and how it works. It sounds like a solid propellant rocket that you can start and stop ...
10
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5answers
885 views

What limits burning speed of solid propellant?

SRBs and missiles use grain to regulate thrust over time, as only exposed surface of the propellant burns. But what causes propellant to burn only on the surface, and regulates the speed at which the ...
9
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4answers
789 views

What typically ends a satellite's life?

It has been my opinion that running out of station keeping propellent is what usually ends a satellite's useful life. Is this true? How much do different factors play in a satellite's lifespan? Some ...
4
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0answers
64 views

What is the icy formation on these rockets? [duplicate]

I've sometimes seen icy formations form and break off of spacecraft. In today's SpaceX launch, there are a couple examples (times based on video) at 51:55 where you can see it growing: Two similar ...
12
votes
1answer
10k views

Why is TEA-TEB chemical ignition used instead of spark ignition?

Both the Saturn V and the Falcon 9 use TEA-TEB to ignite their kerosene-fueled engines. TEA-TEB is pyrophoric, igniting spontaneously on contact with air. This poses handling issues; it must be stored ...
0
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1answer
136 views

What are the issues encountered when placing a ladder up the middle of propellant tanks?

I'm visualizing a vehicle with a tube that travels the length of the vehicle, top to bottom, going through both propellant tanks. Is this feasible? What are the issues with such a design?
2
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1answer
115 views

What would be the incremental cost of launching 1 ton of LOX/LH2 into LEO? [duplicate]

I am asking this question in a context of feasability of orbital fuel depots. I understand that cost/kg estimates exist (2-14 k$/kg): What is the current cost-per-pound to send something into LEO? ]),...
6
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0answers
378 views

How long does it take to chill the LOX and RP1 for Falcon 9 V1.1 Full Thrust?

The new version of the Falcon 9 v1.1 Full Thrust, or as SpaceX would like everyone to start calling it "Falcon 9", uses super cooled LOX and RP1 to improve the density of the fuel for better ...
3
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1answer
116 views

Desirable qualities of a propellant used in Electric Rockets

When I was looking into electric rockets I found out that the propellants used were Helium, Nitrogen, Argon, Krypton etc. The above elements are noble gases (with the exception of Nitrogen) but I also ...
2
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2answers
146 views

Is it possible to load propellant during the lift off? [duplicate]

Falcon 9 rocket consumes approximately 30 tons of fuel for the first 15 seconds of flight while it's still less than 350 meters in altitude. Is it possible to build a giant tower near the launchpad, ...
6
votes
2answers
279 views

chemical propulsion with separate fuel and propellant?

In most of chemical propulsion engines the product of burning fuel and oxidizer is the propellant; in some cases the ratio between the two is non-ideal, in which case some unburnt fuel acts as ...
10
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1answer
3k views

How did the Space Shuttle keep its cryogenic fuel cold?

As I understand it, the Space Shuttle used cryogenic fuel in its main engines and it kept a supply onboard for the duration of its mission for a deorbit burn. Since Space Shuttle missions often lasted ...
4
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2answers
292 views

Can landing modules use left over fuel from earlier stages?

I just read a comment by @RussellBorogove about the Apollo 11 abort options that the landing module had about 700 pounds of fuel left on touchdown. I assume that this is the intended behavior for any ...
4
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1answer
69 views

XIPS purity requirements?

What purity of xenon is required for the xenon ion propulsion system? Does the purity impact the efficiency of the engine?
25
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3answers
3k views

Does the NK-33 engine require subcooled kerosene so cold that it turns to wax?

It was mentioned in this answer and in several other places on the internet that the kerosene fuel used by NK-33 engines needed to be subcooled enough so that it reached the same density as the LOX, ...
2
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1answer
180 views

Density impulse of monopropellant hydrazine?

I only found sources (like this ) giving impulse density of hydrazine used as a bipropellant in conjunction with various oxidizers, but I was unable to find any that would give me density impulse of ...
6
votes
1answer
431 views

SpaceX Webcast - What is visible in this clip? [duplicate]

I've just watched the SES-9 Launch Webcast and was wondering what is visible at about 37:15? Does the Falcon 9 have cameras in the kerosene (or LOX) tank?
9
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3answers
735 views

Is the Paramagnetism of Liquid Oxygen Ever Considered in Engine or Tank Design?

NOTE: I'm asking if this material property is ever considered. I'm not asking "do you think it should be considered". I'm pretty sure someone has considered it, and I am hoping to track down some ...
11
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2answers
664 views

How long can a vehicle stay fueled before the liquid oxygen gets too warm?

On February 28 2016, Falcon 9 attempted a second launch for its 22nd flight. However, it was put on hold for about 20 minutes at T-01:33 and had its countdown reset to T-11:44, giving a total of about ...
6
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1answer
259 views

Could oxygen be used in a resistojet in a vacuum environment?

Resistojets heat a compressed gas or vaporize a liquid to expand it through a nozzle for thrust. They improve a bit on the performance of cold gas thrusters. This experimental water resistojet managed ...
7
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2answers
556 views

Why were the Titan II's Flames Clear?

I've seen multiple sources attribute the clear flames to the use of hypergolic fuels for propulsion, but I have been unable to find any explanation for why hypergolic fuels burn clearly. (Image ...
3
votes
1answer
302 views

How much fuel remains in a booster such as the one used for Jason-3

Building off of this question, I am curious as to how much (just a simple magnitude of order) propellant remains inside a booster to cause such an explosion? Considering cost, I would expect very ...
6
votes
1answer
111 views

How much energy does it take to extract water from silicate?

Browsing Asterank, it seems that people believe many asteroids have large amounts of iron or magnesium silicate. These compounds may come in a hydrated form which contains water, but it is chemically ...