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64 votes

Why doesn’t NASA build its rockets using graphene?

The Technology Readiness Level (TRL) of graphene is at 2 or 3 as far as I can tell. And that is TRL as related to making very tiny stuff. Anything used to build a structure for aircraft or spacecraft ...
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39 votes

Why doesn’t NASA build its rockets using graphene?

Besides the fact BradV pointed out that we don't have the technology to do this yet, the fact is that graphene on a macroscopic scale would not perform as well as the numbers you cited suggest. All ...
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29 votes

Why doesn’t NASA build its rockets using graphene?

Many processes being used to make graphene only yield small and irregularly shaped flakes with a lot of defects. The size of those flakes is barely enough to render them visible for the naked eye, and ...
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17 votes

What makes aluminum aerospace grade?

Read David Hammen's comments below the opening question. once you get past the (well deserved) sarcastic humor he absolutely nails the answer. There is no checklist for getting an alloy of anything to ...
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8 votes
Accepted

What is the purpose of the shrouds surrounding these rocket engines?

They are structural supports for the combustion chamber. I didn't find a specific reference for those engines, but the Space Shuttle Main Engine (SSME) has a similar support, although it isn't ...
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8 votes
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Why isn't oil used for rockets?

Because 'oil' is basically what most rockets already use for fuel. To be a useful fuel you want a high energy density so your rocket is not lifting 'stuff' that does not burn, ideally both in terms of ...
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6 votes
Accepted

Resources on Coking?

In addition to the paywalled paper Investigation of Heat Transfer and Coking Characteristics of Hydrocarbon Fuels (which is cited by Sutton among others), I found this openly available one. Heat ...
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5 votes

Could oxyhydrogen (2:1 H₂/O₂ mix) be used as a rocket fuel?

Oxyhydrogen is not fuel in the strict sense of that term. Instead, it is an explosive mixture, made from stoichiometric proportions of fuel and oxidizer. As such, it could theoretically be used in ...
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5 votes

Is engine thrust noticeably increased near the ground?

In the context of your question, whether there is a thrust-enhancing ground effect either during take-off or terminal landing, the answer is apparently "no". Citing "Mars Exploration ...
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5 votes
Accepted

What is the point of having a central rocket engine when it receives performance losses?

You would need to quantify the loss to find out. If the loss were something like 90%, then of course adding it would be foolhardy. If the loss were 1% on that one engine, then you might not be able ...
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4 votes

Insights about launch vehicle engine configuration

I think the answer lies in analysis of failure, rather than optimum performance. Individual engine failures can produce a spectrum of knock-on events from simple single engine shut-down through thrust ...
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  • 6,410
4 votes

Resources on Coking?

RP-1 can be simplistically thought of as a mixture of hydrocarbon chains with an average carbon chain length of 12 and an average of 26 hydrogen. In idealized stoichiometric combustion with oxygen, ...
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  • 6,410
3 votes

How many times has SpaceX reused Falcon 9 first stage until now?

According to Wikipedia 13 Falcon 9 Full Thrust and Falcon 9 Block 4 boosters were reused. The remaining 83 are Falcon Block 5 boosters. So, a total of 96 boosters have been recovered as of May 20, ...
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3 votes

Why doesn’t NASA build its rockets using graphene?

Just because a substance has impressive specific strength, doesn't mean it has all the properties needed to make it generally useful. Specific strength, the ratio of strength to weight, is a very ...
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3 votes

Would it be practical to catch a rocket's exhaust to reuse it as fuel?

No, it would not be practical to do that. It is theoretically possible to convert exhaust into fuel back again. I know rockets use different fuel/oxidizer compounds, like for example hydrazine and its ...
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  • 563
2 votes

Has asparagus staging (fuel crossfeed) ever been studied by a space agency?

As far as I am aware, asparagus staging has not yet been attempted by any space agency. However, Vladimir Chelomey proposed the so called 'UR-700' Rocket as an alternative to the N1 Soviet Moon Rocket....
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2 votes

Has asparagus staging (fuel crossfeed) ever been studied by a space agency?

The big problem with asparagus staging is that it only works for vehicles that have multiple liquid tanks in the same stage. The problem with this is that multiple smaller tanks weigh more than 1 ...
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2 votes

Would it be practical to catch a rocket's exhaust to reuse it as fuel?

The original question referred to a scheme to "catch the fuel as you go" but did not state whether the line connecting a rocket image to a "colector" [sic] image indicated that two ...
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2 votes
Accepted

Why does Vandenberg have the most launches?

Vandenburg does what the Cape cannot: polar and retrograde orbits. These are very popular with a very large customer: the military.
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2 votes

Why doesn’t NASA build its rockets using graphene?

Because it is carbon with high reactivity. It burns at fairly low temperatures in the presence of oxygen: "Graphene combusts at 620 K." Supersonic skin would burn up. Descending through its ...
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1 vote

What makes aluminum aerospace grade?

"Aerospace grade" is a marketing term that has no meaning. I think that the question and the other answers so far may have meant "What makes aluminium MilSpec". Which means, to ...
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1 vote

Why isn't oil used for rockets?

Oil, whether vegetable or petroleum based, does not burn nearly as cleanly as other types of fuel used for rockets. One of the types of rocket fuel are those based on hydrazine and its derivatives; ...
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  • 563
1 vote

Does NASA really report the power of rockets in horsepower?

Using the inappropriate unit horsepower for rocket engines has a very long tradition. When the V2 A4 rocket of WWII was presented to ignorant NSDAP government officials by the Wernher von Braun team, ...
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