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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Is it possible to use Bose-Einstein condensate for propulsion with today's tech?

Can one use the Bose Einstein condensate which we can produce today for space propulsion, as many theoretical concepts need negative mass and that is a property of Bose Einstein condensate, how ...
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Is kinetic energy relative? [duplicate]

Assume there is a rocket with 10 kg of fuel in a large empty space without any external forces such as gravity. Rocket burns 1 kg of fuel and gets a $v_1$ velocity gain. Now it is moving in $v_1$ ...
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When trying to find the optimal volume of water for a bottle rocket, do I use constant or increasing pressure?

I am conducting an experiment to find the optimum amount of water for a given rocket. For each trial, do I keep the pressure same or do I increase pressure with increasing volumes.
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Reaching outer space using earth's air pressure, then rockets

Please correct me in my methodology if I am wrong, I am only in Physics I right now... This question has been daunting me for some time, but wouldn't it be a whole lot more efficient to send cargo ...
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Calculating the exhaust velocity using conservation of momentum [closed]

I was just wondering if i did this correctly $$p_{exhaust}=-p_{rocket}$$ $$m_{e}v_{e}=-m_{r}v_{r}$$ $$v_{e}=\frac{-m_{r}v_{r}}{m_{e}}$$ I used data from a Saturn V simulation by Robert A. Braeunig ...
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Variable acceleration relativistic rocket

I was wondering how a realistic fusion-or-something rocket would fly... More specifically, I wonder about the time dilation that would be experienced (say in the classic example of two twins). So, of ...
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Is the physics behind planetary travel simpler than atmospheric travel?

I've been watching a bunch of documentaries lately and had a question that I couldn't really figure out the answer to online. When spacecraft travel through space, are the equations and physics used ...
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Placement of the spaceports on our Earth

Why are spaceports located at certain points (site/place) on our Earth? Is there a physical reason I don't really know about?
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Where does the energy used to fight gravity go?

Imagine the following scenarios: A. We have a spaceship at x distance from a star. It faces directly away from the star, and fires its engines such that it ...
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How would one calculate velocity with respect to time in Case 2?

Case 1. : The rocket is weightless in space. It's fueled with propellant. It's wet mass is starting mass $m_s$ and dry mass final mass $m_f$. Suppose rocket's initial velociti is 0. The rocket ignites ...
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U-turn in Deep Space

While writing a physically realistic game ( "Asteroid Defender" ) a physical question came up whether Diag.1 or Diag.2 or Diag.3, correctly depicts reality. In deep space (away from other celestial ...
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Sound from a rocket

I have been watching programmes commemorating the Apollo 11 mission. One obvious feature of the launch is the sound. It was mentioned that water was sprayed into the pit below the rocket not (...
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Do I do zero net work if I start and stop a spaceship in vacuum?

As question states, I start and then stop a spaceship in vacuum by using orientable thrusters. In the acceleration phase, I am doing positive work, but in the deceleration phase I am doing negative ...
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Can you derive the Tsiolkovsky rocket equation without calculus?

Can you derive the Tsiolkovsky rocket equation without calculus?
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Why is the onboard trip shorter when riding on a relativistic rocket as compared to a Newtonian rocket? [duplicate]

In the top answer for this question on the Space Exploration StackExchange, it's calculated that a rocket traveling at constant 1g of acceleration over 100,000 light years would, under Newtonian ...
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How fast can we get to Alpha Centauri?

Suppose in the near future we send an Antimatter rocket that is capable of constant $1g$ acceleration to our nearest star, Alpha Centauri, $4.3$ light years away and suppose we want the spacecraft to ...
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Can you predict how much fuel you need to launch a rocket based on conservation of energy?

I was just wondering if there was a way to calculate how much fuel you need for launch, possibly to do with chemical energy to kinetic energy. Thanks
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Mass required to accelerate to relativistic speed

What would the rest mass of a rocket need to be if it carries a payload of 1kg and is accelerated to 1/2 c and then decelerated to a stop. Assume: 1 - energy required is obtained via fusion of ...
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Water from air concept – is this plausible?

Here’s an idea I had: Consider how a rocket stove works.. There is an inlet where wood is fed into the stove and an outlet for which the exhaust can vent. Very simple but very effective. Now apply ...
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Why do cylindrical rockets require a roll and pitch maneuver?

On the space shuttle, I understand that the quick roll and pitch maneuver wins because it increases payload, aligns antennae, etc. But if one looks at the Apollo missions on a Saturn V, why is this ...
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Change of orbit with tangential impulse

I see a similar question: Change of orbit with a radial impulse. The answer to that question seems fine to me. In the answer, mention is made of this similar question, but it is not fully treated. ...
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Why haven't we yet tried accelerating a space station with people inside to a near light speed? [closed]

Is that something we could do if we use ion or nuclear thrusters? Wouldn't people in the station reach 0.99993 speed of light in just ...
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Help with Gravity Assist [closed]

In our scenario, a spaceship of mass 70,000 kg and velocity $v_o$ is planning on slingshotting around Earth and we're supposed to find what the exit velocity will be. The Earth is the origin in our ...
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Can satellites stay in orbit when the Earth is being accelerated?

In a TV show I'm watching, the people of Earth have decided to leave the solar system, and take Earth with them, so they've built a large number of powerful rocket engines on one side of the Earth (as ...
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Could one theoretically use the expansion of the universe to travel through it? At least in one direction?

Could one theoretically use the expansion of the universe to travel through it? At least In one direction? That’s it that’s my question. I’m not a physicist but I do get ideas. I also wonder if one ...
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If fuel was provided by an autonomous side ship, how much fuel would be required for a 10 metric tons rocket to reach the ISS?

The point here is that the rocket weight should never include fuel. It can take off from any departure base of your choice. The fuel provided by the side ship would then be used only to lift the ...
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What percentage of a rocket fuel is used to lift fuel itself?

I don't need an exact number, also it can be to travel to the ISS or the moon, it's not important. I just want to get an idea of how much fuel is used in a «recursive» sort of way. Edit: I am asking ...
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How did most of the math and physics formulae that govern our lifestyle and help us in space exploration come into being? [closed]

I realise that this isn't a very academic question, but after watching movies like First Man and Interstellar, it got me wondering: How did all these formulas that we use on a regular basis come into ...
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What is difference between Impulse and Thrust in Physics/Rocket Science?

The question is clear. What is the difference between Impulse and Thrust in Physics/Rocket Science as meaning?
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Why don't we use ionized neon for arc jets?

On a typical arc jet there is a cone in the proppelent stream (ammonia or hydrazine) that acts as an anode and the the nozel itself is the cathode. But why don't we use ionized neon as the cathode and ...
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Nuclear Propulsion

I am watching a video on nuclear rocket engines, specifically the Nerva engine. It has a propulsion efficiency of 750-800 Isp versus chemical rockets which are only 350-400 Isp. The follow on NRX ...
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Model Rocket Stabilisation

I am designing a model rocket and am using 3 B6-4 Engines. Inevitably there will be perturbation of its trajectory by wind and engine/thrust inconsistencies. The way that I currently understand the ...
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Is a rocket engine most efficient when its velocity is equal to the exhaust velocity?

I was reading Dale's answer on this question and from the answer I concluded the following: 1- When the rocket is traveling at a velocity much less than the exhaust speed, most of the chemical energy ...
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Rocket Leaving Earth's Gravitational Field

I stumbled across this seemingly simple question that really stumped me on further thought: A rocket is intended to leave the Earth's gravitational field. The fuel in its main engine is a little ...
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Chemical energy

A physics problem I am solving has a rocket which launches and releases a certain chemical energy $u$. What is chemical energy? How would I incoporate it into the equations of conservation of energy? ...
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Would it be possible to do a “slow” translunar injection, lasting an hour or more

Part of my sci-fi novel takes place on a spaceship with centrifugal pseudogravity (initially at ~1g), designed to make passengers comfortable on a week-long voyage to the moon. With that being said, I ...
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Rocket propulsion equation

The equation $$V_{rel} \frac{dm}{dt} - mg = ma $$ what is the meaning of m in the given equation is it the mass of the rocket and the point with which we are concerned or is it the initial given ...
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Can the pressure term in the general thrust equation be negative?

In the general thrust equation, it looks like the pressure term can be negative if the ambient pressure is greater than the nozzle exit pressure: $$F=\dot m\cdot V_\mathrm e+\left(p_\mathrm e-p_\...
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Is there a minimum range for an Intercontinental Ballistic Missile? [closed]

To be more concrete: Would it be possible to fire a ICBM Minuteman III from Malmstrom Air Force Base in Montana (USA) to hit Helena (the capital of Montana) about a hundred kilometers away? If not, ...
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Lagrangian of Rocket [closed]

While solving equation of rocket motion with Newton's law in 1-d,I pondered to apply Lagrangian method on this. However, I didn't get correct result. Because I can eliminate last 2nd equation using ...
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How do rocket engines work in EMPTY space? [duplicate]

So I just read this and it didn't make any sense It is not necessary for the rocket exhaust to push against anything EXCEPT THE SHIP ITSELF. You see, when the combustion of fuel takes place ...
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Optimal trajectory of rocket with variable specific impulse and constant power

I am trying to derive trajectory of rocket with variable specific impulse and given power of engines $P$ that minimizes the total time. The specific impulse is given as time-variable effective exhaust ...
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How was the equation for a gravitational assist derived?

Im currently writing a paper about a hypothetical probe meant to escape our solar system and I want to analyse how gravitational assists would be beneficial for its mission. I found a website with an ...
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How do ion thrusters create a force against the spacecraft?

I recently saw an old thread, How do reaction engines create a force against the rocket?, get bumped up, and it asks a good question: in a chemical rocket, the fact that the rocket exhaust gets ...
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How do reaction engines create a force against the rocket?

I'm fairly new to physics, so please forgive me if I lack basic understanding. I'm wondering how rocket engines actually work. I know the answer of "actio est reactio", but I feel like this is a ...
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What would happen if I used a jet pack that accelerates at $g$ but always upward?

I'm trying to imagine what would happens if gravity is cancelled. I assume that without air, if the effect of gravity were to disappear I would fly off Earth on a tangential line. But with the air ...
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How does a rocket gimble work?

I'm trying to understand how a rocket Gimble turns a rocket using unbalanced resultant forces . For simplicity lets say a compressed air rocket. If the rocket is straight ahead the escaping gas ...
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Standing waves in raptor rocket engine test

Stopping the video of the recent test of the raptor rocket engine, one can see a standing wave forming in the exhaust gases: https://youtu.be/MAAzbjG_Duc?t=23 I was wondering what might cause a ...
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How this equation happens and what it describes?

I'm having some trouble with Momentum and Impulse, In this equations, Thrust = F = m * a = dp / dt = m * (dv / dt) + v * (dm / dt) How is the, m * (dv / dt) + v * (dm / dt) Happens, and what it ...
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Aerospike Nozzle Geometry

I have searched the site and my search for the results I want yielded 16 results, none of which seemed to be very helpful. I have searched the internet several times but I do not have the knowledge or ...