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4
votes
1answer
162 views

Is the fuel burn for a satellite launch affected by the position of the moon relative to the launch site?

The gross mass of a satellite rocket is tiny compared to that of Earth, and Luna. Between them, however, the two bodies set up tides in bodies of water which itself is again considerable mass. At ...
12
votes
4answers
272 views

Why are spacecraft made to “spin” after launch?

At some point after launch, usually just before or after separation from the last booster stage, spacecraft are often made to "spin" (about the axis of their trajectory)? See e.g this You Tube video. ...
2
votes
1answer
74 views

Why is the Pegasus launched from a subsonic airplane?

Considering that the reason typically given for launching spacecraft from sea-level as opposed to mountains is that the limiting factor is velocity, not altitude, then why isn't the Pegasus rocket ...
4
votes
0answers
137 views

Saturn V F-1 engines and beyond

I read that the F-1 engine from the 1st stage of the Saturn V rocket is the most powerful engine ever created by mankind, delivering ~200 gigawatts of power. Thus, I have got two questions: Will ...
6
votes
4answers
306 views

How do aerospace engineers choose a landing system? (Curiosity rover)

The Sojourner rover with the Mars Pathfinder used a entry, descent, and landing system involving airbags to land on Mars. The Spirit and Opportunity rovers each used more-or-less the same system ...
0
votes
0answers
156 views

What is the optimal weight ratio of a two-stage rocket?

I've been researching this for some time now and I got stuck. The best resource I've found is this book. The "optimising a multistage rocket" part talks about a three stage rocket but it seems ...
4
votes
2answers
363 views

How much thrust would be needed to turn a hobbyist weather balloon into a deep space probe?

I was reading the article Weather Balloon Space Probes that says you can put your own balloon probe at 65,000 ft temporarily. Is it even remotely possible to raise the probe high enough using ...
2
votes
1answer
107 views

neutron transport approximations for nuclear rocket modelling

I'm pretty ignorant regarding neutron and nuclear transport modelling, but i'm interested in trying to pursue it for a particular pet project. It regards modelling of nuclear reactions like those ...
16
votes
2answers
4k views

What is the possibility of a railgun assisted orbital launch?

Basic facts: The world's deepest mine is 2.4 miles deep. Railguns can acheive a muzzle velocity of a projectile on the order of 7.5 km/s. The Earth's escape velocity is 11.2 km/s. It seems to me ...
5
votes
1answer
175 views

Orbital mechanics and rocketry: Is it ever a good idea to intentionally lower periapsis?

tl;dr: Hohmann Transfer appears to be the optimal way to achieve a circular-to-circular orbit, but is it possible to lower the periapsis in order to achieve a more elliptical orbit with apoapsis at ...
-3
votes
1answer
97 views

How fast will I get if I burn a comet? [closed]

Assuming I have a spacecraft which is $30,000\,\mathrm{kg}$ (roughly the size of the Apollo spacecraft). If I take a comet and (theoretically) electrolize it perfectly to hydrogen and oxygen. I know ...
0
votes
1answer
120 views

Liquid oxygen how do they use it as fuel?

Rockets are said to be using liquid oxygen as fuel. How do they use liquid oxygen since it's just oxygen, it only helps in the combustion process. How can it be a fuel on its own?
1
vote
1answer
100 views

Is a purely vertical or almost vertical orbital launch possible?

Is it possible, for the sake of argument, to launch a payload into an orbit around the earth by putting almost all the energy going at a 90 degree angle? What velocity would it take, and what ...
5
votes
2answers
593 views

What causes acceleration of particles in the expansion section of a De Laval nozzle?

A De Laval nozzle has a compression section, where the propellant is compressed (and thereby accelerated) as it moves towards a narrow section (the throat). After the throat, the nozzle widens out ...
1
vote
3answers
131 views

What limits the velocity of ships such as voyager 1?

Voyager 1 travels at a small fraction of light speed. I've read it's fueled by hydrazine, which is a cheap combustive. Questions: What factors limit the speed of voyager 1 and similar rockets? Are ...
1
vote
2answers
337 views

Can Outer Space be used for Waste Disposal?

If harmful toxic, nuclear and other wastes are dangerous if improperly disposed on Earth, can't they be launched into space? If a large, tightly bound mass of waste were to be propelled into outer ...
2
votes
1answer
167 views

What if Felix Baumgartner went the other way?

How much harder would it have been for Felix to use some powered sled and head for the ISS when he stepped out of his capsule? He was already above most of the atmosphere. BTW, Is that capsule still ...
-4
votes
3answers
249 views

Speed of an object in air versus in vacuum

Okay, imagine that you are shooting a rocket down a tunnel that is 60 miles long and the rocket is travelling at 60mph, so the rocket should reach the end of the tunnel in a hour, right? Yep, in an ...
1
vote
1answer
363 views

At what launch angle will a (model) rocket keep flying straight?

When a model rocket is launched straight up with an angle of 90degrees to the ground it will do a 180 flip when it reaches the apex of its flight and then dive straight down to Earth. If I were to ...
2
votes
1answer
142 views

Sideways motion between a vertical launch from a planet and landing [duplicate]

I saw a video some days ago (Hello Kitty in Space) of a schoolgirl successfully launching a balloon into space which later popped and landed ~47 km from launch site. If I vertically launch an object ...
1
vote
2answers
761 views

Can someone explain the Hall effect thruster to me?

I am in high school, and am doing a major research project on Russia. Part of that is a section on the space race, and ion engines/hall effect engines have come up several times. Unfortunately, Google ...
1
vote
2answers
233 views

Will a rotating object traveling along a linear path continue to rotate forever in space?

Suppose engineers built a cylinder-shaped space ship which rotates to create artificial gravity: ...
3
votes
3answers
432 views

Does launching a rocket in lower density air require more or less fuel?

Given two environments that are identical, except for air density (e.g. Cape Canaveral, but at Mount Everest's height), would launching a rocket require more or less fuel at the lower air density?
2
votes
2answers
430 views

Which is the heaviest present day lifter (rocket)? And is it comparable to the Saturn V rocket?

I know of the Ariane 5 ECA, the Delta IV rocket and a few more, but which of the present day's rockets is the top heavy lifter, say, to low Earth orbit (LEO)? Although it is not a certain fact, I ...
5
votes
1answer
90 views

What is the most convenient rocket engine to use exclusively in space?

I mean what parameters should a rocket engine that is used exclusively in space (last stage of a lunar rocket for instance) have?
0
votes
1answer
291 views

Space Rocket Lift Efficiency and the Gyroscope?

I'm no physicist apart from basic 3d web animation, I'm just curious and please feel free to correct my misuse of terms or inadequate speculations. I've been reading a lot on gyroscopes and ...
12
votes
5answers
3k views

Why do rockets have multiple stages?

What is the advantage for rockets to have multiple stages? Wouldn't a single stage with the same amount of fuel weigh less? Note I would like a quantitative answer, if possible :-)
5
votes
1answer
633 views

The most distant point from the earth that a space shuttle has reached

What is the most distant point from the Earth that a space shuttle has reached? When did this happen?
3
votes
1answer
298 views

Nuclear Salt Water Rockets: viability and follow-up

This is the original paper by R. Zubrin proposing the Nuclear Salt Water Rocket design. Basically the design is that a capillar set of pipes store a uranium salt-water solution, inside a cadmium ...
1
vote
3answers
208 views

Dynamics of a Rocket

I am interested in modelling the trajectory of a rocket from the Earth to the Moon by solving a differential equation numerically. Below are some key facts and assumptions I am using. I want to make ...
1
vote
3answers
127 views

Do spacecraft engines suffer from carbon accumulation the way typical petrol/kerosene engines do?

Just wondering whether the spacecraft engines/drives, or their booster rockets accumulate carbon the way car/truck engines do. What about ion/methane drives?
5
votes
1answer
58 views

Why do rockets need a cosmic ray detector?

I was watching the video Video camera installed on rocket that reaches 121,000 ft., and this rocket has a cosmic ray detector. Why is this needed in a rocket?
5
votes
3answers
280 views

What sort of propulsion would we require for interstellar travel?

Further to this question I asked recently, lgritz makes a very astute observation about the massive fuel requirements to travel 36 lt yrs with known fuel technology today. So, if conventional rocket ...
1
vote
3answers
849 views

Max rocket speed in interstellar space?

Interstellar space propulsion...if a spaceship were to get beyond our Sun's gravitational pull and since there is no atmosphere/wind/friction in space...does that mean, if an engine was constantly ...
4
votes
4answers
943 views

Why are there more vertical takeoff than horizontal for spacecrafts?

Vertical takeoff requires disposable rockets (would it a satellite rocket), which is a money loss, and also a lot of fuel, because initial velocity is zero. Also vertical takeoff seems risky, involves ...
4
votes
1answer
73 views

What is the mass of the LEGO figurines being launched with spacecraft Juno?

What is the mass of the LEGO figurines being launched with spacecraft Juno? How much additional fuel will be needed to get them to Jupiter?
8
votes
1answer
123 views

What is lighting up Space Shuttle Endeavour's main engines?

Al Jazeera has a terrific collection of Space Shuttle photos. In photo #11 we can see something bright in each Space Shuttle Main Engine (SSME) as Endeavour lands. What might that be? A reflection off ...
4
votes
2answers
594 views

At what fraction of the speed of light have people traveled?

I'm guessing that, this would be someone in a rocket or something... When they hit their top speed, at what fraction of $c$ are they traveling?
3
votes
1answer
231 views

Home-made Shock diamond

Is there any way of creating a "home-made" effect of shock diamond phenomenon that I could take a picture of? If so, How could I make one?
1
vote
2answers
172 views

Get into orbit from the Redbull jump position to a satellite position by using a cord/rope?

Its difficult to put this into the title. I was watching the Redbull Jump and noticed that the height of this is at 39 kilometres (24 mi) the atmosphere pressure is at I believe about 0.4% of that at ...
1
vote
1answer
86 views

Why is there no oxidizer in space?

Just as a thought experiment. One factor in the economies of space exploration is that of fuel. This may be split as MSL - Earth Orbit Earth Orbit to Inner Solar System Beyond. In each of ...
3
votes
3answers
418 views

Conservation of Energy in Different Frames of Reference

Say I have a bucket of fuel that can produce 150J of energy by combustion. No matter what frame of reference an observer or the bucket of fuel is in, since the configuration of molecules stay the ...
0
votes
1answer
286 views

What path would advanced spaceships take to move between planets? [closed]

Right now, space travel is all about carefully moving between orbits. If you want to go from Earth to Mars, you wait until the two planets are correctly aligned, and then place yourself into an ...
2
votes
0answers
81 views

Reaching the speed of light, rockets [duplicate]

Possible Duplicate: Double light speed Someting almost faster than light traveling on something else almost faster than light Well I've been wondering quite a long time about this ...
1
vote
1answer
288 views

Rotation of Rockets

I referred the Roll program in space shuttles. But, I can't understand the mechanism. So, They rotate during the launch in order for proper alignment. I know that only tilting, gimbaling or using ...
1
vote
2answers
1k views

Difference between deltaV and specific impulse

When reading any literature regarding space propulsion, I keep getting about these terms deltaV and ISP or specific impulse. I know specific impulse is supposed to be the velocity the propellant mass ...
4
votes
3answers
183 views

How empty of fuel are spacecraft booster rockets typically?

A recent XKCD What-if article mentions the situation where each additional kilogram of cargo to LEO requires an additional 1. 3 kilograms of fuel, which in turn requires fuel to carry ...
6
votes
6answers
1k views

What are the most realistic ways of high speed space propulsion?

Liquid and solid chemical fuels in rockets are very expensive and inefficient. I have heard of solar sails but what are the most realistic space travel fuels that will be used in the future to get ...
4
votes
3answers
639 views

Why do rockets accelerate fastest horizontally?

I've heard that rockets accelerate fastest when travelling horizontally to the ground, not downwards or upwards. Is that true, and why?
1
vote
3answers
128 views

Rocket needed to send 100 gram of mass to outer space? [closed]

What kind of rocket would be needed to send 100 gr of mass to outer space? The mass can be moulded in any shape, but it would need not raise above 40 °C of temperature during the ...