Questions tagged [rockets]

Questions regarding the boosters or thrusters used to propel man-made objects. For rockets firing opposite the primaries, see [retrorockets].

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19
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2answers
4k views

Is the mass of paint relevant in rocket design?

(Prompted by this answer): Do the designers of large rockets* (have to) take the mass of the exterior paint into account? If so, do we have examples of actual design changes/decisions based on this (...
20
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2answers
2k views

Do liquid propellant rocket engines experience thrust oscillation?

I know SRBs have a quite bit of thrust oscillation, and it's pretty much part and parcel of burning solid propellant. Do liquid-propellant engines experience something similar albeit at a much smaller ...
2
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1answer
114 views

Does any US rocket, historical or current, besides those using LH2 as fuel apply thermal insulation for propellant?

Besides those using LH2 in a booster and/or sustainer stage, that is. EDIT: I should have made it clear that this applies to launch vehicles, not spacecrafts flying deep space mission. EDIT: OK, I ...
3
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1answer
104 views

Why is the relative axial position of oxidizer vs fuel tank inverted in the upper stages of most rockets?

In the first stages of most rockets, e.g. Atlas V, Delta IV and Falcon 9, the oxidizer tank is stacked on top of the fuel tank, with the usual explanation that such an arrangement gives the rocket a ...
1
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1answer
104 views

How are space launches controlled? Automatically, or from ground level?

In my perception, by predetermining speed, distance and other parameters including a rocket's thrust and mass, a trajectory could be calculated ahead of time. How have rockets actually followed the ...
5
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2answers
120 views

Can anyone give feedback on the following design system architecture for the electrical component of a rocket test stand?

My rocketry team and I are currently designing the system architecture for the electrical component of our rocket test stand for a static fire test. We have not started implementing this and I would ...
1
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2answers
134 views

How to shoot a raspberry pi mini computer into orbit

I'd like to shoot a raspberry pi into orbit. How difficult is this and is this something that could be achieved by hobby rocket scientists?
23
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2answers
4k views

Golfball Dimples on spaceships (and planes)?

The best of us get stupid ideas which run through our heads day in and day out without finding an answer. That's why I came here: A golf ball has dimples to reduce drag and increase flight distance (...
5
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1answer
98 views

What is the origin of the name “Skylark”?

I read that the name Skylark was one of a long list of names submitted to replace "CTV5 Series 3". But what I'm really interested in is whether there's any connection to the "Skylark" series of sci-fi ...
3
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1answer
101 views

Why RFNA is used in orbital rocket and why it leaks?

The red fume can be seen in some ballistic missile tests and of course here for the case of Chinese KZ-1A orbital launcher. i wonder what's the usage and why it leaks.
2
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3answers
410 views

Why don't launcher rockets ordinarily have names?

There are names for the class or family of launcher, e.g. Delta IV, Electron, Falcon. Sometimes the launcher is "named" for a specific configuration of a class, e.g. "Delta IV Medium+ (4,2)", "Chang ...
52
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5answers
12k views

Why doesn't the Falcon-9 first stage use three legs to land?

The immediate thought that would probably come into your mind would be "Because 4 legs is more stable than 3." However that is not always true. 3 legs offer the same or in some cases more stability as ...
2
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1answer
61 views

What are/have been some dedicated launchers for the 100-1000 kg to LEO(sub 1000 km)payload market?

Today's satellites are between 50-500 kg mostly apart form cubesats and their larger versions(3U-16U), which have brought the demand for microlaunchers. Rocket Lab's Electron, is one great example. I ...
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2answers
91 views

Whats the difference between cryogenic and cryo storable rocket engines

I've read about cryogenic storable liquid rocket engine but since it doesn't refer to its fuel, I want to understand the difference between a cryogenic and a cryo-storable engine. The term cryo-...
3
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1answer
243 views

How did skeptics of rocketry think rockets work?

About 50 years ago, the New York Times retracted an unsigned editorial from 1920, in which it was argued that rockets cannot work in vacuum. See this blog, or wikipedia. (alas, I was not able to ...
4
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2answers
393 views

Launch capabilities of GSLV Mark III

What are the parameters of determining the launch capabilities of a rocket? Also, How does ISRO's GSLV Mark III fare against rockets like N-1, Proton, R-7 etc?
4
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1answer
528 views

Why isn't LOX/UDMH used in staged combustion rockets now-a-days?

Liquid rockets usually use a propellant pair of fuel and oxidizer. I've seen some rockets from 1960's that used LOX/UDMH as propellant pair but why they are not used any more although it is mentioned ...
8
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1answer
503 views

Sea level static test of an upper stage possible?

As we know that for the upper stages of the rocket, we need high propulsion efficiency thereby high specific impulse. For that we employ a nozzle with higher expansion ratios. Now, if we conduct the ...
1
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0answers
35 views

Mass/weight information about stage separation mechanism

How can I get mass/weight information about rocket stage separation mechanisms that are used in multi-stage rockets? I plan to create an excel table to compare stage separation mechanisms by weight ...
6
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1answer
195 views

Which unit system was used by german rocket scientists at NASA for calculations?

There were numerous german rocket scientists at NASA, see wikipedia 1, 2. They were used to the metric system which they used when working for the V-2 at Penemünde. But what unit system did they use ...
15
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4answers
8k views

Are rockets faster than airplanes?

Rockets are fast. Faster than anything else somebody could fly with - at least intuitively to me. But - airplanes are fast too. A rocket typically flies vertically, an airplane mostly horizontally. ...
13
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8answers
4k views

How much did all the space agencies spent on rockets launching and space exploration? What are the benefits for me and you? [closed]

I thought about how much does one rocket cost to build and launch and it came up with roughly $500 million including everything. That made me pause and wonder for myself what it is that's out there ...
-8
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4answers
251 views

What pushes back on rockets? [closed]

Revised question: Please address all answers and votes to this revised version of the question. A rocket taking off on a launch pad sends a dense plume that pushes on the launch pad and is being ...
7
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1answer
394 views

Why alcohol had been selected as fuel for the first American space rockets?

I was surprised to read that Redstone used 75% ethyl alcohol as a fuel. Looks like this idea was abandoned later, and modern rockets use rectified petroleum or liquid hydrogen instead for burning with ...
3
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1answer
191 views

What size and shape is an SL-16 R/B and for how long will they orbit Earth?

This night I've seen two SL-16 R/B on the sky with my binoculars. These where part of some Zenit rockets that launched satellites in the 90s. They travel at altitudes that double the ISS, uncontrolled....
6
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1answer
145 views

Why aren’t rocket stages modular and interchangeable?

Being an avid player of Kerbal Space Program, it is intensely frustrating to return to the real world and have to remind myself that rocket stages can’t generally be swapped out between rockets (...
0
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0answers
91 views

PID Controller for Thrust Vector Controlling of High Power Rocket

We are trying to design a Thrust Vector Control system for a High Power Rocket using PID Controller. Can anyone guide us what approach should we use to create this Controller? Rocket Details: Mass: ...
21
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1answer
3k views

What happened to the Apollo 1 rocket?

On January 27, 1967, a tragic fire killed the crew of Apollo 1 and destroyed the Command Module. I've read detailed reports about the engineering team that disassembled the Command Module. I haven't ...
24
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5answers
9k views

Why doesn't SpaceX land boosters in Africa?

Apart from the obvious answer that it'd take too long to get the booster back across the Atlantic, why doesn't SpaceX leave the main or centre booster in space a little bit longer and guide it to land ...
7
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1answer
206 views

Did the Falcon Heavy center core miss the drone ship or abort?

On the recent Space Test Program-2 Falcon Heavy launch, the center core crashed into the ocean. Unlike the test flight, however, it was not due to running out of TEA-TEB lighter fluid. From the video ...
17
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5answers
5k views

Reusable spacecraft: why still have fairings detach, instead of open/close?

Why do reusable rockets (e.g. SpaceX Falcon 9) still utilize detachable fairings? SpaceX keeps trying to find a way to recover the $6M fairings for obvious cost saving reasons, why not have them ...
2
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0answers
36 views

How much higher could g be before we couldn't launch rockets? [duplicate]

Obviously having a higher gravitational acceleration makes it harder to get rockets into orbit / escape. How much stronger could earths gravity be before we would no longer be able to do the sort of ...
3
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1answer
86 views

Why does the RD-180 route the preburner exhaust directly into the LOX boost pump turbine?

Isn't there $\mathsf{CO_2}$ and $\mathsf{H_2O}$ in the oxygen-rich preburner discharge? Why aren't the Russians worried that these two would freeze when the discharge is re-condensed into the LOX ...
23
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3answers
4k views

Why does the Saturn V have standalone inter-stage rings?

Why are they not integral to the lower stages, e.g. like the Falcon 9? This applies not only to the ring between the first and second stage and also to the shoulder between the second and third stage.
2
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2answers
76 views

Oxidizer Line Pressure of DIY Hybrid Rocket Engine Limits Thrust?

So I’ve seen engines like these which use gaseous oxygen as an oxidizer and then a solid tube as a fuel. But do these types of hybrid engines have any possibility of creating a useful amount of thrust?...
16
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2answers
4k views

Does anyone recognize these rockets, and their location?

I clicked an advertisement in the sidebar of an Economist article and it took me to this infomercial from Mitsubishi Heavy Industry Group's Spectra website How new technology is democratizing access ...
3
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1answer
89 views

Testing of a first stage using dummy upper stages?

The first stage of the Saturn I was tested three times using dummy upper stages filled with ballast water, see Project Highwater and this question. The first two flight tests of the Saturn V (SA-501 ...
0
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1answer
55 views

GLOM of a launch vehicle

What do you mean by GLOM of a launch vehicle? When I googled about it, it says it is a type of mass but I am unclear about it.
0
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1answer
58 views

Exit pressure value for vacuum nozzle [duplicate]

What value of exit pressure should I use in the design equations for a small liquid rocket engine nozzle for 200km-500km operating conditions? Since using zero as a value is not possible or else ...
6
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1answer
119 views

Apollo SM RCS specific impulse?

What is the specific impulse of the RCS thrusters on the Apollo Service Module? This document cites 281 seconds for the LM's RCS thrusters, but I cannot find similar specs for the SM.
3
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1answer
122 views

Rocket Launch Simulation Source Code Locations

As you can take from the title, does anyone know where I could find the source code for a working launch simulation type application such as FlightClub for example?
8
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1answer
248 views

Why is multi-spool pump very rare on rockets?

The only one I know of is the LP LOX pump on RD-0120. A multi-spool design is already a default for jet engines, which are basically turbine-driven air pumps. A multi-spool pump can save at least the ...
8
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1answer
279 views

Why were Spirit and Opportunity separate launches?

In reading this question (Why A=2 and B=1 in the call signs for Spirit and Opportunity?), it prompted me to wonder why Mars probes Spirit and Opportunity were launched separately, even though their ...
1
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3answers
335 views

Just how pointy does a rocket's nosecone need to be?

There are some beautiful images of the Qu8k rocket launch on this web page and I show a few below. There's a video (below) and the PDF Qu8k Final By Derek Deville, November 27, 2011 The stainless ...
8
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5answers
260 views

Why isn't there a rocket to launch a single cubesat?

I find the business model for RocketLab interesting. It is said that they fill a niche in the market by using smaller rockets. And it is true, in comparison to e.g. Falcon 9's payload of 9,500 kg, ...
2
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1answer
212 views

Why we don't use cyclotron for ion thrusters?

We know that the advantage of thruster is high efficiency and 'everlasting' propulsion. Which It can not provide a sudden huge propulsion during launch like chemical fuel is its biggest problem. I ...
1
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0answers
49 views

How does the inter-propellant seal works in kerosene/LOX and UDMH/NTO rockets?

I get that the inter-propellant seal on the SSME LOX HP pump is simply a series of cascading regular seals trying to eliminate bleed-through by venting and letting boil at each stage, so that when ...
1
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0answers
44 views

How much more hardware is needed in a cross-fed CBC rocket than a non-cross-fed one?

Is it just a matter of adding a multi-in fuel manifold?
4
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2answers
368 views

Have there been any examples of re-usable rockets in the past?

I am writing a piece about re-usable rockets and I'm wondering, apart from SpaceX, have there been any re-usable rockets in the past, success or 'failure', as in didn't perform as expected. Obviously ...
9
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2answers
2k views

Is it possible to create different colors in rocket exhaust?

Would it be feasible in any rocket engine (liquid or solid) intended for flight above the atmosphere to add one of the following elements: barium, lithium, sodium, copper, or calcium to create ...