Questions tagged [rockets]

Questions regarding the boosters or thrusters used to propel man-made objects.

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2
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1answer
78 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....
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2answers
666 views

What is the most number of stages, including fractional stages?

Falcon 9 clearly has two stages, but the smaller two-stage Electron has a "kick-stage" so some might call that 2.5. The question Quantitative benefits of Atlas II's engine-dropping or 1.5 staging? and ...
5
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1answer
104 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 (...
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2answers
66 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?...
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4answers
2k views

Why does spinning help stabilisation?

I don't really understand why do we use spin stabilisation for rocket launches? If I understand correctly, the idea is to make the rocket spin really fast so that any asymmetry in the thrust/...
2
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2answers
281 views

How to reserve places on a SpaceX, Chinese or Indian rocket to send small satellites?

As in a title, I'm searching for a way of reserving a place on a rocket to send small satellites into space. Can it be only done by some kind of launch broker company? Is there any information on how ...
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 ...
5
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2answers
1k views

Will the Rocket Lab's Electron rocket really be an effective launch system?

Rocket Lab, a company from New Zealand is working on a small rocket (18 m tall, 10 tonnes), for which there are already over 30 launches lined up at US $5M each. From Wikipedia: In July 2014 it ...
21
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4answers
5k views

Why 31 engines for the BFR?

I understand the philosophy of using relatively many smaller engines so that a single engine failure has minimal impact on the mission (provided you can keep the shrapnel from shredding the others) ...
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0answers
51 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: ...
45
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7answers
6k views

What technological breakthroughs were required to land booster stages?

It is only recently that SpaceX developed first stages that can land again, and be reused. The (until recent) non-existent landing of re-useable rockets is presumably, partially, due to a lack of ...
4
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1answer
126 views

Why does the SpaceX strongback outgas 60 seconds before launch?

I was watching the live stream of the Iridium-5 / SpaceX launch and they mentioned that the strongback would outgas a minute before launch. I assume it was to prevent the strongback from exploding ...
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1answer
457 views

very low Be4 chamber pressure

How does Blue Horizons be4 manage to achieve such low chamber pressure compared to the SpaceX raptor engine or the shuttle main engines and yet still deliver more thrust given it does not appear to be ...
23
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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
187 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 ...
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6answers
25k views

Who coined the phrase 'Rapid Unscheduled Disassembly'?

Usually simply abbreviated as a RUD, and also sometimes expanded as Rapid Unplanned Disassembly, and being a way of understating that a rocket exploded. I saw it attributed recently to Elon Musk, ...
7
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1answer
487 views

How do rocket propellant combinations rank in terms of “brightness”?

While a booster on the shuttle had a bit more than twice the thrust of the shuttles engines at take-off, I'd venture a guess that it produced on the order of a thousand time more visible light. In ...
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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
32 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
75 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 ...
8
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1answer
232 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 ...
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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.
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3answers
2k views

Oberth effect for Earth vehicles

I don't understand this and must ask a probably very stoopid question here: The Oberth effect says that a rocket is much more efficient when (and in the orbital direction of) a payload when it ...
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3answers
652 views

What would be the configuration and performance for Saturn V with all stages RP-1/LOX?

Saturn V had RP-1/LOX 1st stage with 5 F-1 rocket engines. The 2nd and 3rd stage used LH2/LOX J-2 rocket engines, 5 and 1 respectively. At that time NASA had an advantage to launch heavy payloads ...
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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 ...
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2answers
79 views

Trying To Understand This Characteristic Velocity To Force Problem

Having problems trying to solve part b of this problem. Rocket Propulsion Elements 8th - Chapter 2 A jet of fluid hits a stationary flat plate in the manner shown below. (a) If there is 50 kg of ...
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1answer
48 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.
3
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1answer
80 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 ...
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1answer
99 views

Ambient pressure for vaccum nozzle design

How do I find out the ambient pressure for designing a vaccum rocket engine? I am using the propellant combustion charts from the braeunig website. But I cannot figure out the ambient pressure for ...
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1answer
46 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 ...
12
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1answer
447 views

Was the R-7 the first two stage rocket of the Soviet Union?

The first US two stage rocket was bumper, a combination of a german V2 liquid fuel rocket with an US second stage. The Soviet Union had the R-1 and R-2 based on the V-2. In this list, the R-7 is ...
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1answer
113 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.
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1answer
235 views

how reusable are electric pump fed rocket engines like Rutherford Engines of Electron rocket?

In electric pump fed rocket engines, propellants are pumped by two electric motors. So there is just one combustion chamber and that is the main combustion chamber. I guess electric pumps are fairly ...
3
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1answer
99 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?
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3answers
278 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 ...
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3answers
5k views

Why are the very reliable rockets Atlas V and Ariane V not rated for human flight?

During the last ten years all 100 or so launches by Atlas V and Ariane V together have been successful. (One Atlas V payload entered too low orbit, but that would hardly have risked the life of a crew)...
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1answer
262 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 ...
4
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2answers
102 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, ...
6
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1answer
252 views

Understanding Von Braun's Math: Theoretical Isp

I've just read Wernher Von Braun's Project Mars: A Technical Tale, and I'm trying to understand the math in the back. I can follow some of what he's doing, but other parts I just can't tell where his ...
2
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1answer
167 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 ...
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4answers
409 views

Does “What happens beyond Kármán, stay beyond Kármán”?

The title refers to the promotional slogan "What happens in Vegas, stays in Vegas." The question How much CO2 would city-to-city rocket flight produce compared to airliners? seems to be focused on ...
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0answers
38 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 ...
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0answers
43 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?
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2answers
364 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 ...
13
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1answer
285 views

How far have autophage rockets been developed?

Ars Technica reports on a May 24 phys.org press release/precis on a University of Glasgow paper in Journal of Spacecraft of Rockets about a solid rocket intended to consume itself during use rather ...
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0answers
285 views

Why is SpaceX's Raptor's design so simple in comparison to SSME?

What is especially striking to me is how simple Raptor is in configuration compared to SSME. The Raptor doesn't have an LP fuel or oxygen pump. What's even more surprising, if we are to compare the ...
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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 ...
7
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1answer
120 views

Is the gyroscopic effect created by high rpm turbo-pumps an issue for rocket attitude control?

Is the gyro effect taken into consideration in the control strategy or is it somehow mitigated?
4
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1answer
208 views

Why is LOX on top in the Space Shuttle external tank instead of the other the way round? [duplicate]

Why is oxygen placed on top of hydrogen? Does this have anything to do with letting the warmer and not the colder liquid have a non-spherical bulkhead and thus more surface area to reduce boil-off?
6
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1answer
117 views

How is the height of a rocket measured?

How is the height of rockets measured? For example, the Saturn V is 363 feet tall, but is that 363 ft from the tip of the launch abort tower to the bottom of the engine bell or is it from the tip of ...