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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Launching a unpropelled rocket

I have read about the application of railguns and other ground powered launch, where there is no need to carry any propellant in the rocket. I am wondering, to what velocity should the vehicle ...
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Calculating a spacecraft's deflection angle [closed]

There is a spacecraft with mass $M_1$ moving in a certain trajectory with a constant speed $V_r$. To modify its trajectory, a engine is turned on and starts ejecting gas at a speed $V_g$, which is ...
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Ideal suborbital hop

This is actually regarding Kerbal Space Program, but it's more of a physics question than one about the game. If I have a rocket on the surface of a rotating spherical body without an atmosphere, ...
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Do I need to take weight of the rocket into account when calculating escape velocity?

Here there is the old problem. I know from the old problem that the work $W_v$ that I need to make a rocket fast enough to reach the escape velocity is $$W_v= G \frac{mM}{r}$$ therefore because ...
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How long would it take me to travel to a distant star?

Suppose I wanted to travel to one of the recently discovered potentially Earth-like planets such as Kepler 186f that is 490 light years away. Assuming I had a powerful rocket and enough fuel, how long ...
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279 views

Travel duration from Earth to a star at 9.8 m/s² acceleration

How much time would it take for a traveler (in traveler's perspective) to reach a star at distance $d$, if it accelerates at 9.8 m/s² (for a comfortable travel)? I understand that $V = V_0 + a\times ...
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Rocket launch from a mountain

If we were to build a high speed rail up the side of a mountain like in some ScFi movies, what is the velocity needed at the point of living the mountain excluding angular momentum from earth’s ...
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About the speed of light

If Mr. E is aboard a spaceship traveling near the speed of light the usual reason for the spaceship not going faster than $c$ is the (relativistic) mass of the ship increases without bound, I think. ...
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Why do rocket engines have a throat?

Diagrams of rocket engines like this one, (source) always seem to show a combustion chamber with a throat, followed by a nozzle. Why is there a throat? Wouldn't the thrust be the same if the ...
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Why don't rockets tip over when they launch?

Rockets separate from the launch pad and supporting structures very early in flight. It seems like they should tip over once that happens. Why don't they tip over? Is it due to a well designed ...
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397 views

How do I calculate the time it would take for a space craft launching from earth to reach another planet?

I am making a matlab program the my final project for my programming class in college. I have chosen this problem, but I am bashing my head against the wall trying to figure out the equations and how ...
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How could a solar sail be powered 'Upwind' by craft's own (laser) light source?

I've just watched a Discovery Science program - Alien Encounters featuring SETI luminaries such as Jill Tarter, Frank Drake and Nick Sagan. A serious discussion on how to interpret ET messages coupled ...
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Is a scaled-up aircraft carrier 'ski-ramp' a viable system to impart enough velocity to significantly assist a spacecraft to orbit? [duplicate]

Not a boost straight up to escape velocity, just sufficient added momentum to make a significant economic saving on fuel cost, mass and complexity of a standard launch. It seems ludicrous to me how ...
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920 views

How to calculate the velocity needed for a rocket to get to a L1 point (escape a body without orbiting)?

I'm looking to calculate parameters around launching, say, a model rocket STRAIGHT to the moon. This does not mean through orbital insertion into a stable ~17,000 MPH relative to earth's surface and ...
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273 views

Max altitude of rocket [closed]

A rocket is launched perpendicularly with an initial acceleration of 10 m/s2, if the fuel runs out after 1 minute, what will be the maximum height reached by the rocket?
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What is the cheapest way to land a grain of sand on the moon? [closed]

I have a payload that is the size and density of a grain of sand. I want to land it intact on the moon, but I am not particular about location beyond that. What is the least expensive way to get it ...
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197 views

How do scientists place satellites into orbit?

How do scientists place satellites into orbit? How do they calculate the gravity acting on the spacecraft in order to generate exact opposite force by means of Kinetic energy to keep the satellite ...
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167 views

Variational calculus problem

I've been wondering lately about a problem that comes from, among other places, an old video game "Lunar Lander". In the game there is a spaceship that has a small tank of fuel, and you're supposed to ...
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Why does it take so long to get to the ISS?

I don't understand why when first launched Space X's Dragon capsule had to orbit the Earth many times in order to match up with the ISS? Was this purely to match it's speed, or to get closer (as in ...
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Break speed of light with infinite mass

I've heard that a spacecraft could never exceed the speed of light because it's (relativistic) mass quickly approaches infinity and therefore there could never create a big enough rocket to propel it ...
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114 views

How much power would a space craft's magnetic shield require? [closed]

I've read over the decades that a magnetic shield might protect a spacecraft from cosmic radiation. Its a fascinating idea that might only be theory or science fiction at the moment. In regards to ...
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59 views

Theoretical Space Station components [closed]

Having read some of the other answers and seeing that there is a theoretical maximum on payload with current technology, what would be the optimum dimensions of a space launch vehicle if all you ...
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156 views

Movement in outer space via Newton's law of every action has an equal and opposite reaction

What is more effective for travel in outer space ignoring all other factors like air radiation etc. I have a 10 kg bag of rice would I travel faster throwing the whole bag at once or throwing a grain ...
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What happens if we place a hydraulic platform under rocket exhaust

Imagine I place a hydraulic platform mechanism under a rocket where its engine exhaust is placed.This hydraulic platform is fixed on the ground. During propulsion we actuate/lift platform to certain ...
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146 views

Best EM/Photon rocket using avalable tech?

Given 10-1000 Watts of electrical power (and no other consumables), what is the current best way to turn it into thrust? Just running it through a heater on an insulating pad would result in an IR ...
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406 views

Rocket/Thrust/Gas/Free Expansion of Gas

We know, the rockets in space use Newton's 3rd law to increase their velocity and hence move. What I don't understand is how it is possible in space aka vacuum-state without air? From what I know, ...
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What is the optimal burn direction to lower periapsis of hyperbolic orbit?

I am an engineering student who is interested in orbital mechanics. I am doing some self study before taking some orbital mechanics courses next year. I was learning about various orbit types ...
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598 views

Deriving the rocket equation

Recently I decided to brush on the those parts of classical mechanics that always gave me trouble. One of those parts was the rocket equation so I figured that I would try to derive the appropriate ...
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Low-temperature hobby rocketry

I work with a lot of Boy Scouts who want to complete the Space Exploration merit badge. It's a great program, and one of the coolest requirements is building, launching, and recovering a model ...
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Term for “atmospheric ricochet” due to wrong “angle-of-attack”

I watched "Apollo 13" yesterday, and they had the "angle-of-attack" problem that had to be manually solved, to prevent the ship from "ricochet[ing] off the atmosphere like a rock skipping off a pond". ...
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How big would a rocket without stages have to be?

Using currently available fuels and technology and an unlimited budget. How big would a rocket without stages have to be to make it to a stable orbit? and how big would a rocket without staged have to ...
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Inertia and Rocket Propulsion

We were taught in school that the law of inertia indicates that an object tend to stay the way it is, so if you throw something in space it will tend to go on forever and ever. The reason an object ...
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217 views

Will a relativistic rocket be destroyed by incident photons?

I have read, that as a rocket approaches light speed, objects in front of it become blue shifted and also intensity of light increases. Does this mean that at some point any rocket will be destroyed, ...
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How to calculate thrust ratios for an object with a non centered mass [closed]

I am trying to figure out a formula that, given an initial thrust value, will give me the thrust value that I need to apply to each thruster (red) to make the overall thrust be straight up with no ...
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Why do space crafts take off with rockets instead of just ascending like an aircraft until they reach space?

I guess it's not a very educated question, but I never quite understood why spacecrafts have to shoot up and can't just reach space by simply continuing an upwards ascent like an airplane.
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How long does it take to travel 36 light years with tolerable acceleration and deceleration?

The recent discovery of HD85512b only 36 light years from Earth has promising attributes to harbor life. Assuming we want to travel there, we cannot instantaneously jump to light speed, (StarTrek ...
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What sort of rocket propulsion would be required to send and retrieve ores from our solar system's asteroid belt, within a 2 year period? [closed]

I am looking for a form of propulsion to achieve a fraction of C that could send and retrieve mining robots to our solar system's asteroid belt. Does this type of propulsion even currently exist?
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What alternative shapes may a rocket heading into orbit have?

It looks like most rockets that head out of Earth, or even into orbit are pencil shaped (or nearly so). I would take this to mean there is some mass of air such vehicles push out of their way. What ...
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Where to find information about rocket launches (speed, height, trajectory)?

I want to find experimental data from real launches, with some description of a rocket like full mass, fuel mass, thrust and so on. Just trying to model it. Where to read about precise methods of ...
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Can the technology behind Particle accelerators can be used for space propulsion?

As I understand, the kinetic energy of the proton beam in a hadron collider is quite large. Can you build a space propulsion system that is based on accelerating a proton bean to relativistic speeds ...
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How to travel between tidally locked binary planets

Two planets of roughly the same volume and mass are orbiting each other. What would be the most efficient way to travel from one to the other? Seems unlikely, but could a rocket positioned at the ...
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Why is there a space between the flame and the nozzle on the space shuttle?

Why is there some space between the flame and the nozzle on the space shuttle? (see above picture)
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187 views

How does fire create thrust in rocket?

All big rockets are burning either gas or fluid to create thrust. While this is so, I have filled up a plastic bottle with air at high pressure, and it can go long distances by blowing the pressurised ...
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What happens when the spacecraft velocity equals the velocity at it's exhaust?

So there I was resting me eyes thinking about rocket drives, and what-not. The thought struck me that, perhaps, even before Mr. Einstein interferes with the increasing velocity of the spacecraft Mr. ...
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424 views

What is the maximal height for a water rocket's flight?

A water rocket works like this: there is a circular slot of area $A_1$ at the bottom centre of a cylinder of cross-sectional area $A_0$ and height $L$ that is filled with water to an initial height ...
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181 views

Saturn V specific impulse issue in velocity modelling with Tsiolkovsky's equation against actual values?

I've been trying to model the Saturn V's velocity using Tsiolkovsky's ideal rocket equation, and in the process, I think I may have made a mistake with regards to the specific impulse? I've come up ...
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How much Bicarbonate of Soda and Vinegar would I need to reach space?

So here is my problem - as part of my job I present some science demonstrations to children and one of the tricks I regularly use is the bicarb/acetic acid rocket. I thought the other day that a ...
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Would a super-hot object launch itself into the air?

In this XKCD What If, an indestructible hairdryer outputs 2 GW of power, turning the earth under it into gas: Periodic explosions of gas beneath the box launch it into the air, and it starts fires ...
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What is the optimal diameter for the exhaust hole in a pressurized vessel to deliver highest acceleration ?

Imagine you have a sealed cylindrical vessel with a given radius with a compressed gas inside. Let's give some numbers, 5 cm radius and 100 atm pressure. You poke a hole in the vessel and the gas will ...
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Oberth Effect in deep space

Does the Oberth effect only apply when in orbit of a planet or would a rocket generate more and more thrust (if kept on) even in deep space? Wikipedia explains that the faster the rocket goes, the ...