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Questions tagged [rockets]

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

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1answer
100 views

Could a “nuclear turbo-jet” be built?

Being familiar with jet engines myself, I wonder whether a similar device could be built to provide high $I_{\text{sp}}$ and high thrust in vacuum and space. Using the tried-and-true turbojet formula ...
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What is the minimal distance of clearance in the direction of flight path for a rocket?

Usually the rocket launch sites are placed on a coast or a place where there's basically no civilian buildings in the direction of flight path. Is there a standard/regulation on the minimal ...
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1answer
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What differences exist between the pressurants and their associated systems between a pressure fed and pump fed liquid rocket engine

There is an apparent need to have pressurants in both pressure fed and pump fed systems. However, since pump fed systems can create the necessary pressure, they can work with less pressurants and ...
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0answers
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How is this engine put together? [duplicate]

I'm going through How to DESIGN, BUILD and TEST SMALL LIQUID-FUEL ROCKET ENGINES and am confused how their sample engine is physically built together. This is a picture of their assembly where the ...
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Falcon 9 Landing Speed

I wanted to know what the fastest speed is that a Falcon 9 can land at and thus the max force the landing legs can withstand. I assumed the mass when landed is 26,000 kg (I once heard that somewhere). ...
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1answer
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Using weather patterns as a primary criteria, would South America be an ideal place to launch rockets?

I was looking at a map of historic hurricane travel the other day and noticed that South America doesn't really get them. Florida gets a lot of hurricanes. Texas gets them too. It also occurred to me ...
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3answers
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How are fuel tanks filled with cryogenic hydrogen?

Cryogenic hydrogen can react with the atmospheric Oxygen to produce an explosion: as well as being cold enough to liquefy (and possibly solidify) atmospheric oxygen, which can be an explosion ...
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0answers
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How to create a new reactant Ammonium Dinitramide NH4[N(NO2)] in NASA CEA?

Ammonium Dinitramide(ADN) is a compound used as a green propellant for spacecraft propulsion applications. ADN-blends like LMP103S and FLP-106 are currently under development. However, performing a ...
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Why are hexa airfoils used on rockets despite having more drag that diamond airfoils?

I was doing a study on airfoils shape for a rocket. I tested the diamond and the hexagonal airfoil with Missile DatCom, RasAero and the Shock Expansion theory and from my results it seems like the ...
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2answers
146 views

What causes those curtain-like hot and cool spots in the 2nd stage nozzle of this Electron ELaNa 19 launch?

Here is a GIF that I made of the recent Electron Launch from frame grabs in the Rocket Lab video ELaNa 19 Launch - 12/16/2018 It is about 4M, so it won't fit in SE's normal image import. Frames are ...
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2answers
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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 ...
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2answers
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Highest stage count that are used one right after the other?

Two questions inspired this question: Highest stage counts in actual launchers? Answer: Saturn V six stages to the Moon Does a high staging number have diminishing returns? Is there a way to address ...
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Could a fat rocket be used on Mars?

Since Mars' atmosphere is around 2% the density of Earth's then could a much wider rocket achieve orbit? Could the rocket be in the shape of a capsule or an optimal shape for reentry on Earth?
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Cooling jacket calculation issue [duplicate]

I'm going through How to Design, Build, and Test Small Liquid-Fuel Rocket Engines. The reference explains how to calculate the water flow gap for the cooling jacket that surrounds the combustion ...
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1answer
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Globally extensive overview of rocket startup companies

Is there any known report, website or other source from where one can get a comprehensive overview of almost all startup companies related to space rockets or hardware that's dedicated to space ...
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3answers
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How much Energy is required to put 1 kg in LEO?

I was wondering, what is the minimum amount of energy required to put 1 kg of payload into LEO?
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1answer
1k views

What exactly is the purpose of connection links strapped between the rocket and the launch pad

I am curious on what are those multiple connection cables latched between the rocket and launch pad. What exactly is the purpose of it, I am aware that one should be for filling up the fuel. But ...
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187 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
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Reducing the aerodynamic drag of multi-engined rockets: aft wake area

Have there ever been thoughts of reducing the aerodynamic drag that results from the empty space between rocket engines? More precisely, this extremely low-pressure area sucks up ambient air and ...
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3answers
1k views

Are cold gas thrusters viable for model rockets?

Lately I've been exploring the idea of cold gas thrusters, or in this case cold gas rocket engines, to be used in model rockets. I've read that nitrogen gas can get 73 seconds and helium can get 2.5 ...
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2answers
145 views

Issue with units for a rocket nozzle throat area problem

I'm working through How to Design, Build, and Test Small Liquid-Fuel Rocket Engines. The guide explains calculating a rocket nozzle throat area using Eq. (7): $$A_t = \frac{w_t}{P_t} \sqrt{\frac{R ...
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1answer
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How do you determine what the temperature will be in the combustion chamber of a rocket engine?

I am guessing it is dependent on the fuel and oxidiser and the chamber pressure but is there an equation that would calculate the chamber temperature?
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1answer
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Weight Flow Rate

I read in the book INTRODUCTION TO ROCKET SCIENCE AND ENGINEERING by T.S.T that Rocket Engineers design how big the throat of the nozzle should be based on the Weight Flow Rate. So my question is HOW?
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2answers
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Ion Thruster Thrust Calculation Problem

Trying to calculate the impulse of a little ion thruster I'm putting together. An old version of it can be found here, I'll be polarizing the AC current and putting in copper nails on the next ...
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2answers
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What is the ideal shape for a rocket?

Obviously there are many factors that go into the design of a rocket. However, to me, many rockets seem very tall and skinny. What I mean is that an ideal rocket would have as little mass used for ...
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2answers
243 views

Cheapest rocket to go to space?

Have you ever heard of the old movie Salvage? The TV movie, “Salvage,” aired on January 20, 1979. The film begins with Harry successfully bidding for a vintage bi-plane and then reselling it in pieces ...
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3answers
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Why is that max-Q doesn't occur in transonic regime?

Is there any reason why the maximum dynamic pressure should not occur in the transonic regime. It is clear from this answer that the max-Q for various rockets occur outside the transonic region Do ...
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3answers
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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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4answers
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Do the propellant tanks of actual (not planned) expendable vehicles' upper stages have relief valves?

This question was inspired by the answer to this question. The answer, in part, states that overpressurization of propellant tanks is a cause of upper stage explosions, leading to orbital debris. ...
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3answers
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Effect of atmospheric drag on rocket launches and benefits of high altitude launch sites

What is the approximate influence of atmospheric drag on the cost of rocket launches? Is it beneficial to have launch sites located at higher altitudes? Cape Canaveral is at sea level, but I've ...
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5answers
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How much bigger could Earth be, before rockets would't work?

hint: Apparently the Tsiolkovsky rocket equation does not actually say that you can launch a conventional rocket into orbit around an arbitrarily large and massive body. Question: "How much bigger ...
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0answers
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Why is the exhaust plume of Falcon 9 upper stage shaped the way it is?

The (single) Merlin 1D vacuum engine's exhaust plume has a symmetric shape, comprising of six distinct "inner" plumes. Why does it have this shape? Is it due to the shape/configuration of fuel ...
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1answer
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Can a first stage be a booster?

Wikipedia defines booster as"A booster rocket (or engine) is either the first stage of a multistage launch vehicle, or else a shorter-burning rocket used in parallel with longer-burning sustainer ...
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1answer
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Can we use liquid propellants in amateur rockets?

Is it possible and worth it to use liquid propellants like liquid oxygen and liquid hydrogen in amateur rockets? What are the other types of liquid fuel used? Moderator's Note: Remember discussion ...
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2answers
853 views

What tonnage can current heavy rockets land on the Moon?

Mass to LEO is somewhat of a standard in superficially comparing the payload capacity of different rocket, at least for the googling general public. There are many LEOs and it depends on where the ...
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1answer
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Ballistic missile typical trajectory - along which path is it supposed to travel between Russia, China and US?

Today I was puzzled when my son was holding a school globe asking me to show with my finger a trajectory of a (nuclear) ballistic missile flying from US to China and Russia and vice versa (from Russia ...
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1answer
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What is that strange light ball appearing during launch of Russian Burevestnik nuclear-powered cruised missile?

In this video of the Russian Burevestnik rocket launch (uses nuclear power) 1) What is that light spot moving backwards (contrary to the rocket trajectory, backwards towards the launch fixtures): Is ...
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2answers
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What are the pros and cons of expansion-deflection nozzle?

From the Wikipedia, E-D nozzle works similarly to aerospike nozzle which compensates the exhaust gas in the atmosphere to increase specific impulse.
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1answer
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What launch vehicle will be used for Exomars rover Rosalind Franklin?

I know that for TGO/Schiaparelli, Proton was used, but I don't know what will be for Rosalind Franklin.
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3answers
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What is the formula to calculate how much fuel is needed for a rocket?

I'm theoretically trying to launch a rocket for a school project and therefore I chose Saturn V. I took its weight of 140.000kg (308 647 pounds) and I'm trying to calculate how much fuel it'd take to ...
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4answers
304 views

How to measure thrust of experimental ion engine

I have a science project about how different propellants affect the thrust of an Ion engine so I have 2 questions: 1 How can I measure the thrust of a diy ion engine ( technique or tool that I need ...
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2answers
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What are these things fired away from a ballistic missile at launch?

Here is a youtube video of the start of a Russian Topol-M ballistic missile. A lot of little strange things are fired away from the rocket body when the rocket is half-way from its transport-launch ...
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1answer
152 views

Advantage of full-flow staged combustion vs conventional staged combustion engine

Referring to the question in this thread. What is the advantage of full-flow staged combustion (FFSC) vs conventional staged combustion rocket engine? In FFSC we feed the full volume of fuel and ...
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3answers
291 views

How could dense clouds or storms change the trajectory of rocket?

I know turbulence is a thing for aircraft etc. but I am not sure how even the dense clouds affect the flight path of a rocket? I know the storm winds might affect the flight path of a rocket but if ...
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2answers
153 views

Is presssuized gas absent in a turbopump-driven rocket engines?

For RL-10 rocket engines, are the propellent pumps able to provide the propellent without a source of pressurant gas?
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1answer
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How does the chamber pressure affect the performance of a Rocket Engine?

I am under the assumption that higher chamber pressure results in increase in exhaust velocity. Is this true?
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1answer
4k views

Why are spaceship capsules frustum shaped?

Why do spaceships have a frustum (portion of a cone) shape like e.g. the pressure capsule of the SpaceX Dragon on the image below?     I think there is some engineering stuff behind ...
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0answers
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How do international students attend the SA Cup sounding rocket competition?

How do the international students carry the rocket along with propellants to this competition, if Airport Authority does not allow flammable substances?
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1answer
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How is the exit velocity of the flow in a sounding rocket nozzle?

How is the exit velocity of the flow in a sounding rocket nozzle? Is it subsonic or supersonic? Is a de Laval nozzle required for sounding rockets? Bonus Question: What about Model Rockets?
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0answers
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Payload fairing separation- Event based or time based?

Refer the answer for this question How strong and "hot" is the wind on the payload after the fairing is deployed at ~110km? It is clear that the fairings are separated when the free ...