Questions tagged [mass-fraction]

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6
votes
6answers
2k views

If money weren't an issue, what's the best way to get maximum mass to LEO in 1 year? 5 years? 10? [closed]

I can kick this over to World Building if it's more appropriate, but I was hoping to get an actual technical examination of this. So here's the question: if money were not an issue and for some reason ...
1
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0answers
92 views

How much of a deep space spacecraft's structural mass is useless dead weight after launch? Any plans to shed it in the future?

After seeing this in Security SE Magnetic core memory isn't quite extinct yet. The two Voyager spacecraft used it and are still functional. Core was/is certainly non-volatile. I did some ...
2
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1answer
511 views

Does a fully fuelled Starship in LEO have 0kg payload to Jupiter?

So I was looking into the payload mass a fully fuelled Centaur V could send to Jupiter and used the formula in presented in this answer to create a C3 graph. For a bit of fun I also looked into the ...
12
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1answer
508 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 ...
6
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2answers
712 views

How much fuel, (in tons) will a dedicated tanker be able to deliver to a starship in LEO?

The starship tankers that will refuel starships in orbit will only carry fuel. I’ve heard it described that at first they will simply be normal starships, but with more fuel leftover when they reach ...
2
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1answer
250 views

mass of propellant required + rocket equation

I'm doing some research for a class project and I have a questions about the use of the rocket equation to get the propellant mass required. If $m_1$ is the final mass, and $m_0$ is the initial mass, ...
5
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1answer
191 views

Are there active (as of 2020) developments in liquid-fuel tank technology?

This question was broken off from previous mega-question located here. I am aware of the broad liquid fuel tank types: V-2-style steel fuselage Integral steel Integral aluminum (with varying types ...
2
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0answers
90 views

Can you help me fill in the gaps in my liquid-fuel rocket propellant tank technology knowledge? [closed]

I am currently aware of the following types of propellant tank technology: Steel fuselage, used in the V-2/A-4 & other rockets of its era (essentially a plane body) Integral steel tanks, first ...
3
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1answer
486 views

What are Mass Rate(∆v)/∆v, Mass Rate(Isp)/Isp and time of burn(MR)/MR graphs?

I have some problems about Tsiolkovsky's Rocket Equation and some graphs. Firstly, I didn't get what I can do with Rocket Equation formulas as seen below, Also, what these three graphs try to mean? ...
5
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1answer
421 views

Would the Space Shuttle External Tank have made orbit as a VT SSTO with 6 SSMEs?

Dropping the external boosters and also the entire 75-100 ton orbiter from the picture, would the tank all by itself have made orbit? This would require bolting at least 5, better 6, perhaps even 9 ...
8
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5answers
3k views

Conceptually, the lower the propellant mass fraction the better, right?

Rocket Propulsion Elements, 7th ed. Sutton, pg 30 states: "A high value of the propellant mass fraction is desirable." - I tend to disagree with this statement as described in that section ...
2
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1answer
243 views

Problem in finding Propellant Mass using Rocket equation where total mass includes components dependant on Propellant Mass

Formulation - $$e^{\Delta v/v_{exhaust}} - 1=mass_{fuel}/mass_{structure}$$ $\text{let } k=e^{\Delta v/v_{exhaust}} - 1 $ $$\implies mass_{fuel}= k \times mass_{structure} $$ According to SMAD (...
3
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0answers
95 views

Understanding the multi-stage mass tables in Wiesel's Spaceflight Dynamics

In Wiesel's Spaceflight Dynamics, 3rd Edition (2010) Chapter 7.5 (pg 220), there is a table of mass values for Von Braun's 1951 design for a three-stage space station supply rocket. In the book, the ...
14
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1answer
1k views

Flying fuel tanks! Which deep-space spacecraft had the largest fuel mass fraction?

The Los Angeles Times' Deborah Netburn just wrote a really nice retrospective; ‘OK. Let’s do it!’ An oral history of how NASA’s Cassini mission to Saturn came to be with plenty of photos and quotes ...
7
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1answer
799 views

Why will SLS Block I bring less mass to LEO than the STS shuttle system did?

The Space Transportation System (STS) could bring a fully loaded shuttle orbiter of 109 tons to orbit (or maybe empty+payload 68+25=93 tons). The Space Launch System (SLS) Block I is based on STS, but ...
6
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2answers
4k views

Fuel needed for rocket lift-off as a function of the altitude

Suppose I want to send a rocket to Mars, or to the Moon, from earth. How much fuel (in percentage of the full load) is needed for the rocket lift-off as a function of the altitude? I don't know if it ...
5
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2answers
582 views

How much fuel can Falcon 9's upper stage bring to orbit, without any other payload?

I wonder how useful SpaceX' second stage would be as a propulsion stage docking in LEO or so with separately launched payload. It seems to carry 92 tons of propellant on the launch pad. How much could ...
3
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5answers
433 views

Could fuel be "hosed" (pumped) from the ground to a launcher?

Most fuel on board a launcher is used during the first couple of minutes. Most of the propellant is needed to carry other propellant. For example, Saturn V (kerosene) and Delta IV (hydrogen) use about ...
1
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1answer
306 views

How does the mass of launchers change over time between ground and orbit?

I would like to see some comparison between different launchers wrt how quickly their mass is reduced over time (or altitude or velocity). There are differences in overall size class, propellant type, ...
4
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0answers
583 views

Falcon 9 v1.1 Full Thrust Specifications

Does anyone know what the dry mass and mass ratio of the Falcon 9v1.1 Full Thrust Stage 1 is? The best info I've been able to find was by taking the specified burn time and multiplying it by the mass ...
15
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3answers
4k views

Is this a correct understanding of Tsiolkovsky's rocket equation?

When I graph the rocket equation, substituting arbitrary values for v(exhaust) and m1, so m0 because m1 - m0, the graph implies that increasing propellant mass past a certain point does not increase ...
13
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2answers
2k views

How much mass could the Saturn V rockets have landed on the Moon if nothing was coming back?

What dry mass could have soft-landed on the Moon if a Saturn V had been reconfigured to launch a robotic mission going entirely to the surface? Obviously, that wasn't possible at the time, but for a ...
13
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4answers
2k views

Why are rocket mass on the launch pad and payload mass to LEO not strongly correlated?

What explains the relation between how much a launcher weights on the launch pad, and how much mass it can lift to orbit? I had expected that more payload requires more fuel to be launched and that a ...
8
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3answers
3k views

How is "payload to LEO" estimated for a launcher?

Payload to LEO is commonly used as the bottom line of what a launcher can accomplish. But it must depend on factors which are not launcher specific, such as launch location and orbital characteristics....
5
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1answer
576 views

Why are pressure-stabilized rockets not more common?

The Atlas rockets and Centaur upper stages (often used in combination) successfully use(d) pressure-stabilized tanks to minimize dry mass. This technology was not used in any other rocket stages I'm ...
4
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1answer
763 views

Most energy efficient mass ratio of a rocket, or exhaust velocity

In the process of thinking about some hard science fiction, I need to substitute some mass fractions that will minimize the amount of energy used in order to be maximally generous to the author. So ...