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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How much fuel is needed for a constant-acceleration rocket?

My son and I have been discussing the concept of a constant-acceleration rocket, as described here and here. We're willing to assume advanced technology such as a fusion rocket, which, according to ...
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Escape velocity of satellites

I know that the equation for it is $$v^2 = \frac{2GM}{r},$$ and with that, the rocket should be launched at that speed. But could it go much slower spending much more fuel to escape from gravity ...
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Launch roll program for the Saturn five rocket [migrated]

I have seen many questions answered about the roll program with relation to the shuttle launch and reducing stresses on the launch vehicle and various other reasons, but why was the roll program ...
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Is it possible to build a huge spaceship like the one of of Star Trek or Prometheus?

Ok, so theoretically, is it possible to build a spaceship like the ones we see off of Star Trek or Prometheus or will physics not allow it? What are some challenge faces such an task. Also, is there ...
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spacecraft thrust through means other than liquid propellants

Is there any way of achieving effective thrust in space without using conventional fluid or gas propellants such as rocket-fuels or supercooled material? For instance: gaining thrust through solar ...
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38 views

Can we use water as fuel for nuclear thermal space propulsion?

As I know, the working fuel of choice is Hydrogen because of its low molecular mass. When it comes to escape velocity, the estimate vary too much, from $8$km/s to $50$km/s (gas core reactor). ...
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How can Excel be used to model the flight of a rocket? [closed]

Firstly, sorry for any silly mistakes or improper use of this website - this is my first time using it! I am trying to use Excel to model the flight of the Apollo 11 Saturn V rocket using the real ...
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20 views

How did Goddard's rocket reach 41 feet in under 2.5 seconds?

I'm working on a simple rocket flight simulation, and am trying to reproduce aspects of Goddard's first successful rocket flight. My sources put the empty weight at 5.75-6lbs, loaded weight 10.25-10.4 ...
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Is interstellar flight possible in near future in a way that would keep our civilization alive?

Is interstellar flight possible in the near future in a way that would keep our civilization alive? I mean is it practically possible to obtain technology that would enable us to travel to nearby ...
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94 views

What's the point of NASA's impossible space engine? Wouldn't a mirror work better?

My understanding (which is very little) is that the point of NASA's recent virtual-particle engine is to convert solar energy into momentum. That's fine, but what's the point? If the spacecraft is ...
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NASA's “Impossible” Space Engine

Recently, there was some news that said that the researchers at NASA have come across some impossible kind of space engine which does not require any fuel. I have read at a few places like here, here ...
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Ziolkowsky Rocket Equation

I've looked at multiple sources on the internet and just can't wrap my mind around it. If I reference the wikipedia page on it; http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation I am getting ...
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Terrestrial Space Elevator Construction - Plausability

Framework If there was a cable constructed at the equator about the circumference of the Earth, and if this cable had sufficient strength to remain intact while erect, call this tensile strength T. ...
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How to calculate launch angle for tangentially launched satellites?

What is the value of theta for a satellite not falling back to the Earth if it is launched from the direction tangent to the surface of the Earth? I have found the escape velocity which is 11.18km/s, ...
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635 views

Would a craft travelling increasingly close to the speed of light appear to be decelerating?

I've been pondering the implications of time dilation. Is it right to assume that if a craft was travelling at a speed very close to the speed of light (>= 0.9999c for example), that to an external ...
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2answers
76 views

Is there an upper limit to a rocket's size/payload? [duplicate]

It's obvious that as you increase the payload of a rocket, you need to also increase the amount of rocket fuel. Yet, as you increase the amount of rocket fuel, you are also increasing the overall mass ...
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191 views

How should I throttle my rocket to reach highest altitude? [closed]

"Real world" problem. Suppose we want to launch a rocket equipped with an engine which can be throttled as we prefer. Suppose also that the amount of fuel burnt per time is directly proportional ...
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62 views

How much time passed for the passenger traveling with at speed-of-light spaceship? [duplicate]

Let's suppose we have a spaceship with the exact speed of light. If a traveller takes this spaceship to go to proxima centauri (approximately 4 years light away from Earth) and come back, we (as ...
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Will a rocket produce more thrust if fired in air, rather than vacuum?

I've been in an argument with a friend. He claims that when a rocket engine is fired in air, it get significantly more thrust due to the rocket pushing gas into the atmosphere, and the atmosphere ...
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1answer
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Why speed of Mangalyan is constant?

I have learned in school regarding the relationship between speed,acceleration and distance is $$v^2-u^2=2as $$ The initial velocity of India's Mars Orbiter Mission, MOM, is 32 km/s source and now ...
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39 views

thrust-bursting towards a destination in space

<--burst of thrust------|ME in a ship>----->>--<<--laser radar--<<---->>---||destination In the above, I imagine myself in a ship, marking my speed to a far off destination with laser ...
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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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When a planet has a high gravity, is it impossible to build and launch a successful chemical rocket to space?

Just recently a a large rocky planet has been discovered. "Astronomers have discovered a new type of rocky planet beyond the solar system that weighs more than 17 times as much as Earth while being ...
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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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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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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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73 views

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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130 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?

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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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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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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2answers
105 views

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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161 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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101 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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1answer
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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122 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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86 views

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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1k views

Can we escape Earth's gravity slowly?

I had a recent conversation with my girlfriend, who is a physics grad student. She was kind enough to listen to me rant about an idea concerning escape velocity. Unfortunately, I am still thinking ...
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2answers
323 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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154 views

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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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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3answers
150 views

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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Why are rockets so big?

I'm curious why rockets are so big in their size. Since both the gravitational potential one need to overcome in order to put thing into orbit, and the chemical energy burned from the fuel, are ...
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212 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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1answer
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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?