# Tag Info

Accepted

### When did the concept of "stages" enter rocketry?

The first multistage rocket is much older then one might think. Its from the 14th century CE. Huolongchushui or fire dragon issuing from the water (Chinese: 火龙出水; pinyin: huolóngchushui; literally: ...
• 6,852
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### Why not keep the engine for multi-stage rockets?

There are some major challenges with this. For starters, the engines of the first stage produce far too much thrust for the last stage, which would require extra structural mass to allow the rocket to ...
• 4,538
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### Why do rockets have multiple stages?

The basic reason: tossing an extra stage can be far, far, more of a mass-savings than trying to make one stage that can do everything. There's a handful of reasons for this: Engines weigh much less ...
• 10.3k

### Why do rockets not glide back?

As with most things space, it all comes down to tradeoffs. The most efficient rocket is one that is purely expendable and has no mass that does not contribute to getting the payload towards orbit. If ...
• 19.2k
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### What would be necessary in order for us to achieve a single stage to orbit, reusable rocket?

I am referring to rockets capable of taking supplies and humans to other planets. For an interplanetary single-stage rocket with tens to hundreds of tons of payload capability, no existing propulsion ...
• 164k
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### Is Asparagus Staging Possible

It's possible, but not as easy in real life as it is in KSP. To maintain proper tank pressurization, the crossfeeds have to be pump-driven; the fuel and oxidizer crossfeed lines have to be pretty ...
• 164k

### Why not keep the engine for multi-stage rockets?

Nathan's answer is good and cover almost everything but let me add a last bit: An engine nozzle can be optimized for only one given altitude ambient pressure. This has a great impact on the rocket ...
• 12.5k

### What would be necessary in order for us to achieve a single stage to orbit, reusable rocket?

Rockets are basically devices which exploit Newton's Third Law, for every force there is an equal and opposite force. By throwing mass out the back as fast as possible this imparts an equal force that ...
• 7,936
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### Why did the Saturn V stage fairing appear to burn after separation?

The From the annotated Apollo 8 Flight Journal, in the notes after the 2:36 mark, we see that the interstage separation happens well after the J-2 engines on the second stage are running: If, at ...
• 164k

### Why do rockets have multiple stages?

Then why not use only 1 stage? Because we don't know how to do that. That we don't know how to do make a single stage to orbit is a consequence Tsiolkovsky rocket equation and of the fact that some ...
• 71.4k

### For a typical Shuttle mission, how much solid fuel is leftover at SRB separation?

The SRBs are pretty close to burnout when they separate: SRB separation is initiated when the three solid rocket motor chamber pressure transducers are processed in the redundancy management ...
• 123k
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### What do we mean by rocket stages?

To get a rocket to space, you have to build it to be really light while containing lots of fuel. This is called the mass fraction: In most rockets, more than 90% of the starting weight is fuel, the ...
• 123k

### Is it possible for the Space Shuttle Solid Rocket Boosters (SRB) to hit the Space Shuttle after jettison?

The SRBs have smaller solid separation motors, 8 on each, which simultaneously fire to push the boosters safely away from the orbiter/ET. Here's a video showing them in action -- they're powerful ...
• 164k

### For a typical Shuttle mission, how much solid fuel is leftover at SRB separation?

Offered as a supplement to the other answers, here are some data about SRBs thrust profiles and operation. Thrust of a SRB is function of the area of the solid fuel burning, as shown below: You can ...
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### Is it possible for the Space Shuttle Solid Rocket Boosters (SRB) to hit the Space Shuttle after jettison?

No, they don't have sufficient thrust when they're jettisoned to catch up with Space Shuttle accelerating away: The SRBs are jettisoned from the space shuttle at high altitude, about 146,000 ft (...
• 76.1k

### When did the concept of "stages" enter rocketry?

I would mention works of Konstantin Tsiolkovsy. I think that he was first, who proposed to use multistage rockets for space flights. His most important work, published in May 1903, was Exploration ...
• 2,994

### Why do rockets not glide back?

Wings are heavy. They also add mass to the rocket's structure, because it is loaded horizontally when flying with wings rather than vertically as it is at launch. At the time Energia was developed, ...
• 461
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### Developing intuition about altitude and velocity in multi stage rockets

I will argue that your simulation outcome is not reasonable. Consider what happens if we decouple your multi stage rocket right at launch, making no use of the first stage at all. That is, just using ...

### A cryo tank within another cryo tank...is it a sound engineering concept?

...is the tank within a tank a sound engineering concept for rocket stages? I take this to mean that you are not talking about pressurant bottles or other small devices submerged in the propellant ...
• 171k
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### What is the most number of stages, including fractional stages?

There actually aren’t that many different stage counts, but the variation comes because different missions have different delta-v requirements, and different propulsion technologies yield different ...
• 164k

### Could rockets launched from the ground use wings in the stages?

Could a slower or smaller rocket take advantage of lift if all the stages had wings? Wings on the first stage can be useful; the Pegasus air-launched rocket has wings on its first stage that provide ...
• 164k
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### Does a high staging number have diminishing returns? Is there a way to address that mathematically?

Any multi-stage rocket design has to obey three rules to achieve good performance: Fuel type and engine design must allow for a high specific impulse. This is equally valid for single and multi ...
• 1,162

### Highest stage count that are used one right after the other?

As far as I can tell, the most ever used in sequence is 5 on India's ASLV. It only ever succeeded once, though. Wikipedia mentions a possible 5th stage for Titan IVB but I haven't seen actual ...
• 241
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### Why was the Minotaur V built as a 5-stage design?

It's always easier to create a new launcher by making a small modification to a reliable existing launcher. Small solid rocket stages are relatively simple and reliable, so building up a launcher from ...
• 164k
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### What types of decoupling mechanisms to separate spacecraft are used in spaceflight?

According to The Logic of Microspace: Technology and Management of Minimum-Cost Space Missions by Rick Fleeter (Microcosm & Kluwer, 2000), p.130, the de-facto standard mechanism for separating ...
• 421
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### What are the “nacelle” like protrusions on the first stage of Black Arrow?

You can see these in the diagram (from here): Which clearly indicates that these are the 4 'siskin' separation (and ullage) motors.
• 6,143
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### Using lower stage as reaction mass

The additional speed you can gain from this is too small to be of any use. Here is why: First of all, the stage and payload is not designed to withstand acceleration larger than few g, e.g. 5g. That ...
• 14.3k

### What do we mean by rocket stages?

The major limitation to the performance of chemical rockets is the amount of fuel they must carry to reach high speeds. To reach higher and higher speeds you need to carry exponentially more fuel, ...
• 164k
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### Why does PSLV use four stages to get to LEO, and why do they alternate solid, liquid, solid, liquid?

PSLV is a bit of a weird duck because it's a transitional step from small solid-rocket designs to larger ones that rely more heavily on liquid rocket engines with higher specific impulse. It doesn't ...
• 164k
Other answers address the core construct of the rocket equation with words and equations, but here it is visually: Where the Y-axis is the $\Delta V$ and the X-axis is the propellant mass. $b$ is a ...