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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Does the outflowing water create a thrust on the bucket?

Let's consider the the bucket with water, which has a small hole at the bottom. Let the bucket lift up with a constant force $\vec F$. Water in the bucket, of course, flows out of it. Questions are ...
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1answer
83 views

How many days it takes to travel to Cygnus? [duplicate]

BACKSTORY I read today newspaper and made discovery of planet Cygnus (in news paper of course :v) that human can live there! The distance is 1400 Lightyear. Assuming I travel with the world fastest ...
6
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2answers
228 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 ...
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5answers
3k 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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24 views
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2answers
49 views

Saturn V horizontally attached to Earth

If the Saturn V rocket were attached to the ground facing in the opposite direction of the Earth's spin, would it in anyway slow the Earth's spin on its axis? How significant of an impact would it ...
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0answers
51 views

How does NASA determine the position of their probes?

I'm currently following New Horizons visit to Pluto. I'm just wondering how does the Probe/NASA determine the Position of the Probe? I would assume using earth's GPS wouldn't have the necessary ...
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3answers
128 views

Intuition behind Ideal rocket equation

If a rocket expels propellant at a velocity of $v_e$ decreasing its mass from $m_0$ to $m_1$, then according to the Tsiolkovsky rocket equation the change in velocity of the rocket ($\Delta v$) is: ...
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1answer
33 views

Rocket equation derivation, question about signs

My question is about signs in the derivation of the rocket equation. Considering a rocket of mass $m$, its momentum at time $t$ is $p(t)=mv$. At time $t+dt$ it ejects a quantity $dm$ so its momentum ...
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0answers
43 views

What's the fastest you can slingshot from one black hole to another? [on hold]

Let's say you have your spaceship orbiting around a black hole. Its orbital velocity is arbitrarily close to the speed of light (or you can just set it to c*0.99 if it makes it easier.) There is ...
3
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1answer
147 views

Trying to modify the Tsiolkovsky rocket equation for the real world

Everyone knows about the famous Tsiolkovsky rocket equation. However, he formulated the equation neglecting many things. So, here, I am trying to find the real equation. My thinkings: Suppose, the ...
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0answers
33 views

What factors are influencing a woosh rocket?

Not sure if this is too much chemistry, but I'll try: If I fill a plastic bottle with a small amount of rubbing alcohol, shake it around and hold a match to the bottle neck, I'll get a flame wooshing ...
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0answers
34 views

Rotational dynamics equation for a variable mass system?

I'm searching for the formulation of Euler's rigid body dynamics in the case of a variable mass system. I'm reading the book Mechanics of Flight by Warren F. Phillips (2nd edition) and unfortunately ...
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2answers
36 views

Velocity of Rocket Exhaust

i recently learned a bit of rocket propulsion.It wasn't much complex but was explained in simple terms.The only problem i had understanding it was that in calculating the thrust of rocket the velocity ...
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2answers
106 views

“Suicide Burn” rocket problem [closed]

THIS IS NOT HOMEWORK. I'm actually in Physics I atm, and am an avid player of Kerbal Space Program. I hope to do my CS masters thesis several years from now on something space related. But none of ...
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2answers
71 views

Is it possible to reach outer space with this method? [duplicate]

Could we use a hot air balloon to carry a rocket and send it into orbit at a higher altitude? That is, do I need to reach a specific speed to be completely free of Earth's gravity, or can I just ...
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0answers
25 views

A simple detailed book on how/why model rocket engines and parachutes work

I'm planning on getting a model rocket in the near future to fire off w/ my 2 daughters (9 and 11). I'm going to require first that they learn how/why rocket engines and parachutes work (so they can ...
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3answers
439 views

How much fuel is required for star travel considering relativistic time dilation?

John Rennie's Q&A How long would it take me to travel to a distant star? discusses about interstellar travel taking into consideration. There was a case that discussed about constant ...
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4answers
2k views

What Problems for 50 year space probe to Alpha Centauri?

I'm thinking speculatively. NASA is doing experiment with ion thrust tech. Assuming, that inside the next 5 years, we could create a probe which would take on the order of 30 to 50 years to reach ...
2
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2answers
295 views

Delta-V of ion thrusters

So I recently started a podcast along with a cohost. It's all about spaceflight. We ran into a question we couldn't quite resolve due to conflicting information on the internet. Put simply: Can ...
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0answers
28 views

Is a “cathode ray drive” feasible?

When I saw the headline, Fuel Free Spacecrafts Using Graphene, I thought it was another reactionless drive, but it turned out to be a bit more plausible :) Original paper here. Long story short, ...
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1answer
120 views

What forces carry hovering objects around the earth with its rotation?

My questions are: a) What significant forces “carry” flying objects around with the rotation of the earth, b) How do each of those forces contribute to that “carrying”, and c) How relatively ...
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1answer
66 views

Why don't we build helicopter based space shuttles?

As seen in this video: the principle of the helicopter does work in space. So we could make a helicopter based space shuttle! It would be easier to navigate with it than with propulsors.
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1answer
48 views

Where would be the source of thrust for a rocket thruster in space?

I am making a game that involves spaceships and I was building an engine block. That engine block spawns a "thruster fire" under it that represents the...thruster fire. My question revolves around ...
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2answers
133 views

What is third cosmic velocity?

I have been studying Gravitation chapter and there I found one term : Third cosmic velocity which is also known as interstellar speed. So what is it ? What it really tells about? I tried to gather ...
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1answer
474 views

Was Einsteins work with relativity necessary for successful space travel?

So I know that Einstein and general relativity had huge impacts on the way we view the world, but how crucial were these scientific advancements to the success of our space programs? Would Newtonian ...
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0answers
56 views

What are the evidences that support the EmDrive? [duplicate]

Firstly, I'd like to point that I’m from Brazil, so forgive me for any errors in my writing. Today, i found myself reading a journal who said that NASA is closer to detecting Warp Bubbles predicted ...
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5answers
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Is there any disadvantage to sending rockets straight up?

When we send satellite into space using a rocket, logically we consider the shortest path which is a straight line perpendicular to Earth's surface. My question is do rocket takes the shortest path to ...
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0answers
71 views

Has the Pioneer Anomaly been experienced by Voyager?

I came across the Pioneer Anomaly recently, and a quick search here showed there now a theory that fits everything observed. My question is, should we expect a similar effect from the design of the ...
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2answers
75 views

What sort of propulsion technology would allow spaceships to lift off the surface of the Earth and ascend into space like we see in sci-fi movies?

In many sci-fi films, spacecraft are easily capable of lifting off the surface of a planet like a Harrier and ascending into space. It's clear that the propulsion system/jet engines aren't your ...
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1answer
167 views

Why is specific impulse measured in seconds?

Specific impulse is usually defined as: $$I_{sp} = \frac{F_T}{\dot m ~ g_0} $$ This comes out in seconds. I interpret it as follows: If I want $F$ Newtons of thrust, every second I must burn a ...
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2answers
172 views

Rocket Altitude Calculation

Assignment Basic data I was launching a rocket model and I tried to calculate the reached altitude. The engine (C6-0) impulse is 10 Ns Total weight is 65,7 g (includes the engine) I calculated ...
81
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6answers
9k views

Could we send a man safely to the Moon in a rocket without knowledge of general relativity?

I'm wondering if it's possible to send a man to the Moon using equations consistent with Newtonian gravity and without the elaborate tools of Einstein gravity. Are the predictions made by Newtonian ...
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10answers
6k views

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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2answers
117 views

How do rockets spin and pitch at the same time

How do rockets spin and pitch at the same time? Thrust vectoring using a gimbal which basically just always faces down, so that shouldn't cause it to pitch. Since the rocket is spinning, using the ...
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1answer
67 views

rocket propulsion [closed]

As I understand it, in rocket propulsion a converging/diverging nozzle is used to convert the random velocity vectors of the combustion chamber gases into a mostly unidirectional velocity field at the ...
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2answers
275 views

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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1answer
77 views

Do we need Escape Velocity [duplicate]

This may seem silly a lot but I really need some clarification on the necessity of escape velocity for a rocket leaving the Earth's gravity. A stone thrown vertically upwards reaches to a certain ...
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3answers
8k views

Why doesn't a cigarette lighter generate thrust?

The way thrust is created by a rocket is discussed here: How does fire create thrust in rocket? If you look at a typical rocket, say V2, it has two primary tanks — one which stores the fuel and the ...
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4answers
1k 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?
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5answers
2k 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 ...
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2answers
356 views

What are the main issues that are preventing a human mission to Mars? [closed]

Is it just because it'd be very expensive? Or are there serious problems that need to be dealt with, studied and solved? If so, what are they?
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0answers
52 views

Accelerating rockets by periodic explosions? [closed]

Since in the outer space friction is almost 0, couldn't we accelerate a rocket to reach much faster speeds than that of the current limit by periodically starting and stopping the engines? I think ...
2
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1answer
1k views

Why doesn't NASA use RAMJET rockets to get into space?

I would think an open cylinder type rocket where the rocket fuel gets injected into the "hollow" cavity that air is going through would be a more effective than the rocket fuel just burning itself. ...
4
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1answer
503 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?
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1answer
100 views

Thrust and specific impulse of a rocket

A picture of the question this originates from is given below. Note: I normally work with SI units and am mostly unfamiliar with those used here. The specific impulse of a rocket can be calculated ...
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2answers
304 views

Rocket Propulsion, delta V, acceleration and time. How do they relate?

I'm trying to understand rockets in a vacuum. As I understand it the, Tsiolkovsky rocket equation gives me the change in velocity of a rocket + payload after expelling a certain amount of fuel. But ...
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1answer
125 views

How can I caculate the time to traverse a distance with the Tsiolkovsky equation?

Using the Tsiolkovsky equation I know what the change in velocity is after burning x amount of fuel. $$ \Delta V = V_e \dot\ log(\frac{m_1}{m_1-m_2}) $$ $m_1$ is my starting mass and $m_2$ is the ...
2
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2answers
122 views

How to find a condition that ensures that the rocket immediately takes off?

For the rocket in a constant gravitational field, how to find a condition that ensures that the rocket immediately takes off? Update: I apologize. Let's try again. So my question: For the rocket in ...
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0answers
36 views

Rocket in constant gravitational field [duplicate]

A Rocket in a constant gravitational field, what are the conditions required for the rocket to take off immediately? (in terms of $m_0,μ,g,v_r$), where $m_0$ = mass of the rocket at $t=0$ $μ$ = mass ...