Questions tagged [rocket-science]

Colloquially referred to as one of the hardest professions, rocket science is actually a common name for spacecraft/space-systems engineering. However, one can also generalize this to include all forms of rocketry, including rockets that are not capable of space travel.

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Conservation of momentum and work

Consider the following scenario: I am alone in space with a ball. I threw the ball at a certain speed such that i am propelled backwards (like a rocket is) as to conserve momentum. Now, since my ...
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How is the kinetic energy change during a throttling process negligible?

Reference:https://web.mit.edu/16.unified/www/SPRING/propulsion/notes/node16.html The throttling process is a constant enthalpy process, in which the pressure decreases. So, $$h_1 = h_2$$ $$u_1 + ...
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Lift force on a rocket [closed]

How is the lift force is generated on a rocket? I've tried to find answer online but all efforts were in vain.
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Why aren't rockets launched in movement? [closed]

Rockets launched to reach orbit usually start from a stationary position, engines are started and the rocket slowly gain acceleration upwards, eventually reaching orbit. What I'm thinking is that the ...
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How to calculate temperature change of a decompressing gas canister?

I am currently trying to find the temperature drop of a decompressing gas canister for rocketry club to make sure that it doesn't get too cold to affect nearby components like electronics. The ...
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Derivation of Tsiolkovsky rocket equation

My textbook derives the rocket equation from conservation of momentum like so: $$\begin{align}p_i&=p_f \tag{1}\\ mv&={(m-dm_g)}{(v+dv)}+dm_g(v-u)\\ mv&=mv+m\,dv-dm_g\,v-dm_g\,dv+dm_g\,v-...
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Physics of Project Orion

I was reading the book "Project Orion" by George Dyson. For those who are unaware, Project Orion was basically a plan to launch a spaceship by flinging bombs out the rear and detonating them. The ...
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Is it possible to use the Sun's gravity to gain significant delta-v?

Someone asked here whether Sun's gravity has been used for delta-v gain, and from the answers it's not clear whether this is possible at all. There is this rule of thumb that "burning fuel inside a ...
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The Tsiolkovsky equation derived via the Lagrange funtion [closed]

I wanted to derive the Tsiolkovsky rocket equation using the Lagrange formalism. $$ T = \frac{m(t)}{2}\dot{\xi(t)}^2 + \frac{\mu(t)}{2}(\dot{\xi(t)} - u)^2$$ $m$ - mass of the rocket $\xi$ - some ...
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What are the theoretical limits of ion propulsion? [closed]

What is the theoretical limit in terms of thrust and energy efficiency a ion thruster can have? Will they ever be able to lift humans on earth? If so, what would the minimum required conditions to do ...
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Travelling in outerspace

Firstly, is it correct that for travel in outer space, the distance that can be travelled with a given amount of fuel is determined by the energy required to overcome the following forces: gravity ...
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Antimatter propulsion

I was reading about antimatter propulsion systems on the internet, and apparently they would work by letting matter and antimatter react and then the reaction would be (magnetically) channeled out ...
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Does it take 41 Hiroshima “Little Boy” bombs worth of energy to send ISS in orbit? [closed]

I calculated the amount of energy needed to send ISS to orbit. It seems crazy expensive. I'm approximating my calculation with the following equation: $$\begin{align} E_\text{tot} &= E_\text{kin} ...
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Do rockets require stabilization so they don't wobble or even spin?

I have watched many videos of large but "amateur" (not military or NASA) rockets and I would have guessed that without some sort of stabilizers like gyroscopes or fins the rocket might wobble or show ...
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Can the Tsiolkovsky rocket equation be translated directly into two dimensions with constant gravity?

By taking the Tsiolkovsky rocket equation $$ \Delta v=v_{\mathrm{e}} \ln \frac{m_{0}}{m_{f}}$$ where $ v_e $ is velocity at which mass is being dispersed, can the same be done with vectors such that $...
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Confusion about energy conservation

Suppose a rocket at rest turns on its jet and is now moving with kinetic energy $\frac12 mv^2$ in the lab frame. Suppose the efficiency was maximum so that exactly $\frac12mv^2$ of chemical energy was ...
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Is it true that a machine that generates thrust without blowing anything out not invented yet?

If yes. Am I correct to to say such machine does not conflict with the law in Physics and thus, it can be possibly invented? I mean a machine that does not rely on external forces such as a machine ...
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Why it takes more energy to pull satellite towards Earth than pushing it away?

Newton's law of motion states that satellite in orbit stays in orbit unless external force is applied, so we shall apply the force through it's thruster to deorbit. Strangely, it takes more energy to ...
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Are ENU Attitude Errors equivalent to Azimuth, Elevation and Roll Errors in my Rocket Body Frame?

If I have known attitude error around my East, North, and Up axis in the ENU frame, how does that relate to my attitude error in my rocket body frame. My rotations are the following: ECI-ECEF (rotate ...
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Finding parameters of a Gravitational Assist

I am trying to answer a simple question: If a rocket performs a gravitational slingshot around a body of mass m, altitude h, and angle $\theta $ and initial velocity ${ v }_{ sun }$, what will be the ...
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Derivation of the rocket equation [closed]

I have read many different rocket equation derivations but I do not understand them. Here is my derivation: At time $t$, assume we have an accelerating rocket with mass $m$ and velocity $v$. At time $...
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2nd Phase water rocket launch equation feedback

So, recently I asked a question here around the equations for the maximum height reached by a water bottle rocket. I'm still trying to figure out the first phase (when the rocket is propelled by the ...
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How can I create an equation that gives the maximum altitude of a water bottle rocket? [closed]

I’m doing my extended essay on the physics of a water bottle rocket. Particularly the maximum flight altitude and what amount of water will give this result. I’ve been working for weeks, going ...
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The Vertical Launch of a Rocket

From Q7 on Pg.22 of "Upgrade Your Physics" by BPhO/Machacek A rocket of initial mass $M_0$ is being launched vertically in a uniform gravitational field of strength $g$. (a) Calculate the ...
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Maximum Speed for Space Travels

Considering a hypothetical spaceship that has an unlimited amount of fuel, traveling within the solar system planetary plane, what would be considered a safe maximum speed for traveling around ...
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How is a rocket modeled?

I hear that rockets are "not pushing back on anything" but I couldn't find any clear explanation of what they push and what push back occurs. They expel matter but then the limit of what's "the ...
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Is the trajectory of a fire rocket inherently chaotic?

All of you: a happy and physics-rich new year! When I looked at the firing rockets launched at 00:10 2020, most of them went straight up. Some exploded before time. Some made strange movements. So ...
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Why doesn't NASA try using high-explosives to fuel rockets?

For a smoothly burning liquid-vapor mixture, I understand that burning hydrogen and oxygen is the best possible solution, not just for now but even theoretically. (?) But I read about ideas, that ...
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Calculating Rocket Engine Power from Force and Burntime

I am struggling to relate power to force. The example that I am working on in my head is a model rocket. This model rocket (sans engine) has a mass of 50g. Its engine has a mass of 10g (for the ...
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Boost to satellite in elliptical orbit in order to reach the maximum radius? [closed]

If there were a satellite in an elliptical orbit, at what point in its orbit should a booster rocket be fired to kick it to its max radius? I was thinking whennit was closest to the plant/object ...
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How can I isolate the drag constant (C) for vertical motion with quadratic drag from the equation for peak height?

Some background on my problem: I have calculated the peak height of a rocket (with quadratic drag). As this will be used for a PID software application, I need to have the equation be expressing peak ...
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How to calculate pressure exerted by a rocket's exhaust on a surface from a certain altitude?

How do you calculate the pressure that is exerted on a surface (say from a rocket engine) at an arbitrary altitude? For example, pretend I know the exit velocity and pressure of a rocket engine at an ...
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On two requirements in order for an equation describing the propulsion of a rocket to hold

A rocket moving with a velocity $v$ releases a mass $\Delta m$ (fuel exhaustion) at a speed $v_{0}$ in a time interval $t$ and $t+\Delta t$, and increases its velocity by $\Delta v$. If we apply ...
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Spacetime and its contribution to space science

Does the launching of a satellite need the consideration of the general theory of relativity (GR)?
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Why can't we fly aeroplane or shuttle directly into the space (beyond 100 km height above Earth's surface)? [duplicate]

Without rockets can we go beyond Karmans line by shuttle or plane?
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NASA's “Impossible” Space Engine, Take Two [closed]

This question seems to be a close parallel of this one, but it's about a different design by a different author. I read a news article about a "helical engine" design by NASA engineer David Burns. ...
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Black hole Travel [closed]

Asking out of curiousity. All answers appreciated. You have a machine that generates micro black holes on the outside of it which evaporate quickly and then are immediately generated again upon ...
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Free return trajectory versus burning rocket

It is said that Apollo was set to the free return trajectory while leaving earths gravity, heading to moon.Now the Free return trajectory is the one in which satellite uses moon gravity to return back ...
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Why is the body of the rocket so long and does it effect the flight?

so my qustion is that why are rockets body so fricken long it is crazy all the rockets body are so very long and I need an answer to the question please tell me it is for science and i really need ...
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Escape velocity and orbital velocity confusion

If orbital velocity is reduced when we want to put a satellite in a higher orbit, and if to achieve a lower orbit we need to increase it's velocity, then how come by increasing the speed of the ...
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Inserting Wind effects on a rocket trajectory simulator

I`m more used to the math.stackexchange so i really don't know how much information about my problem i should provide, if it is not enough i'll add more. So, basically i already have a 6DOF ...
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Water Bottle Rocket Thrust - two calculation methods not matching

I have been launching water bottle rockets with my kids and we are in the process of creating a simulation of the launch using numerical methods. I am a mechanical engineer, but fluid dynamics is not ...
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What is actually breaking the ozone layer?

My question is about the ozone layer. Is it possible that sending rockets out to space can damage the ozone layer?
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Structure of Mach diamonds in supersonic and hypersonic flows (SpaceX raptor engine video of Sept. 28, 2019)

Last night, SpaceX held another show and tell, and there was a nice long, almost 1 minute burn of a raptor engine. The flow stabilized really nicely, and you get an absolutely fantastic view of the ...
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Can a nuclear weapon destroy another nuclear weapon in flight? [closed]

I was thinking the other day, we have quite a few nuclear weapons in our arsenal. Say a country uses ballistic or cruise missiles on us. Can't you send up another nuclear weapon and detonate it within ...
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Dominant component of drag in a streamlined body (sounding rocket) at 0.8 Mach

We are currently working on CFD solutions on ANSYS Fluent for the drag on our sounding rocket. We are modeling its drag profile through out its velocity range. We currently hit a top speed of approx ...
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Can we deorbit space trash into the sun by splitting it in two?

So there's an issue of deorbiting stuff because if you just deorbit it a little, it'll enter a more elliptical orbit but still hit you in the back when you return to this place a year later. Size and ...
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How does adding high energy density metallic nanoparticles increases the burning rate during a combustion process?

I have been reading about combustion and oxidation, and I have found out that by adding metallic nanoparticles (e.g aluminium nanoparticles) the burning rate of the propellant increases while the ...
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Why aren't spaceships (usually) torn apart

This may have already be ask forgive me if it has but why aren't spaceships torn apart when in the vacuum of space? Is it just because they are strong enough not to be torn apart or because they are ...
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Will a can filled with vacuum move when we let in air? [duplicate]

This picture is from L.C.Epstein's book Thinking Physics. The upper can is filled with compressed air, and, when an opening is made on the right, the air comes out and the can shoots left. The ...

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