New answers tagged rockets
4
votes
How cheap would rocket fuel have to be to make Mars colonization feasible (according to Musk)?
To make spaceflight 10,000 times cheaper, rocket fuel wouldn't just have to be free; you'd have to be paid for using it.
To calculate cost per trip, and avoid debates about how long the rocket will ...
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8
votes
How cheap would rocket fuel have to be to make Mars colonization feasible (according to Musk)?
Frame challenge
This number has no basis in reality (other than possibly being a reverse calculation on the base of an available budget, see below). The quote is typical provocative Elon talk, just ...
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-3
votes
Was VentureStar a bad design or simply ahead of its time?
The tank was the first big problem. Aluminum tanks would likely have worked. But the payload would have been too small and limited to LEO. However the X-33 should have made an ideal two stage system ...
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22
votes
Accepted
How cheap would rocket fuel have to be to make Mars colonization feasible (according to Musk)?
A very rough calculation suggests that \$$100$k/tonne of Martian payload is close to the propellant costs alone. A more detailed calculation using more refined assumptions is likely to make that ...
- 1,540
4
votes
How do I learn more about rocketry?
According to Eric Berger's inspiring Liftoff, SpaceX had a pattern of hiring cheap but sharp engineering rookies who stand out from the crowd.
It is advantageous to not have a family, be somewhere on ...
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6
votes
How do I learn more about rocketry?
Supplementary answer:
Review the following in Space Exploration Meta:
Community Policy Repository (scroll down to "Resources")
Educational resources to accompany Space Exploration
Resources ...
- 149k
14
votes
Accepted
How do I learn more about rocketry?
You've asked several excellent questions, each of which could be explored in detail. To provide a clearer overview, I'll divide them into two parts: A) Where can I learn more about rocketry and B) How ...
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4
votes
How do I learn more about rocketry?
Getting into NASA or a similar space agency is like launching a payload into orbit — requires precision, timing, and lots of preparation. Gain experience in the aerospace industry, ideally working on ...
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1
vote
Accepted
How much payload could the Falcon 9 send to geostationary orbit?
The delta-v that you need to get from GTO to Geostationary Orbit can be found with
$$\Delta V= \sqrt{V_\mathrm{t,a}^2+V_\mathrm{GEO}^2-2V_\mathrm{t,a}V_\mathrm{GEO}\mathrm{cos}(\Delta i)}$$
(ref)
...
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10
votes
How much payload could the Falcon 9 send to geostationary orbit?
First, the Encyclopedia Britannica is wrong.
According to SpaceX themselves, F9 puts 8300kg into GTO, not GEO.
The difference is that GTO (Geostationary Transfer Orbit) is the step that comes before ...
- 20.9k
1
vote
Are there any hand-sized rocket engines?
A space shuttle Vernier Reaction Control System thruster was about a foot long (~30 cm) and weighed 9.4 pounds (~4.25 kg). It produced 24 pounds (~100 N) of thrust.
Reference: Space Shuttle ...
- 188k
9
votes
Accepted
Are there any rockets that leave extra fuel as a backup?
All of them have it. Because either the engine is turned off when there's still fuel left, or the engine is turned off because there's no fuel left. The former is under control ,the latter is not.
3.2....
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-2
votes
Why doesn’t NASA build its rockets using graphene?
Graphene lacks density, compared to graphite and the cost would be more expensive than using Pure Silver if using pure Graphene. Now if you were to melt Titanium, Stainless Steel, and Graphene powder, ...
9
votes
Why, if gravity were higher, would designing a fully reusable rocket be impossible?
It is also important to realize that it is very hard to reach orbit even with disposable rockets. In excess of 90% of the mass of a chemical rocket has to consist of propellant to get to orbit and ...
- 10.1k
13
votes
Why, if gravity were higher, would designing a fully reusable rocket be impossible?
There's a pretty strong correlation between gravity and the delta-v that you need to get to orbit, so mathematically, what he's saying is that...
$$\exp{\left({{\Delta}V-\text{a little} \over V_\...
- 9,246
23
votes
Accepted
Why, if gravity were higher, would designing a fully reusable rocket be impossible?
Impossible is too strong a word. But it would certainly be harder, for five reasons that exacerbate each other. These are basically the reasons why getting to space from Earth is hard, but worse.
...
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11
votes
Accepted
How does a closed-cycle rocket engine keep the chamber pressure from stalling the pump turbine?
At least in the Space Shuttle Main Engine, the high-pressure pump turbines didn't stall because the preburners operated at much, much higher pressure than the main combustion chamber.
The preburners ...
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