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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How is trajectory prediction done on guided missile (which control systems for stabilization and changing trajectory) for application in Air defense? [closed]
I was just exploring ways to predict impact prediction of an incoming missile, I wanted to know how it is determined if a missile launched from a source point is detected by a radar will hit inside ...
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Unclear negative sign in rocket propulsion equation
The usual proof of Rocket propulsion goes something like this (University of Central Florida, Rocket propulsion)
$mv = (m-dm_g)(v+dv) + dm_g(v-v_{rel})$
where:
m - initial weight of rocket
v - ...
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Regarding Speed of launched rocket inside the atmosphere
I am a 15 yr old, so please forgive my mistakes as I have not entirely read rocket mechanics.
I have been wondering why rockets accelerate to mind-boggling speeds, (mach7-8 or even more)when that must ...
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Time for a Parachute to Reach Terminal Velocity?
I've been trying to derive a formula for the time it takes a scale parachute (for model rockets) to reach its terminal velocity, but it has largely been to no avail.
I have $v_T = \sqrt{\frac{2mg}{\...
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How would one go about writing the momentum equilibrium for a rocket whose thrust is equal to the force of gravity? (The rocket's "hanging" in the sky
My question specifically is where do we look for the "missing" momentum. If I understand the situation correctly we have some momentum from the exhaust of the rocket. Where do we get the &...
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Power when work is 0
Imagine a rocket of mass m that is at a constant altitude. Gas velocity v. It is necessary to find the power P of the engine. I have a problem: to find the power, you need to divide the work by the ...
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Have rocket float into upper atmosphere via balloon [duplicate]
I'm assuming a majority of the fuel used in a rocket to say get to the moon is involved in escaping earth's gravity.
So why can't we create a smaller weighing rocket, with less fuel to carry and ...
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Could a Relativistic Rocket convert the heat of Doppler shifted Cosmic Background Radiation into usable energy? [closed]
This page on mathdept.ucr.edu about relativistic rockets states:
As you approach the speed of light you will be heading into an
increasingly energetic and intense bombardment of cosmic rays and
other ...
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The Orion Project --- do the predicted speeds violate the Tsiolkovsky Equation?
I understand that a conventional rocket may move faster than its thrust but IIRC the equation developed in the 19th century the speed is limited to 4/3 the thrust speed.
Now, I understand that the ...
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Why does the speed of efflux depend on container pressure in rocket propulsion?
I know that the speed of efflux, $v_{efflux}$, is given by the application of Bernoulli's principle. The formula for the speed of efflux as given in my textbook, Physics—Part II, Textbook for Class XI,...
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What speed would a rocket below $1.5R_s$ require the least thrust to remain at constant radius?
Take a rocket travelling in a circle at less than $1.5R_s$ away from a black hole.
At that distance, no orbit is possible and the rocket must produce continuous force to stay outside the black hole. ...
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How can I remove a layer of Silica from a rough IN718 surface?
Our rocketry group is designing a biliquid ethaLox Inconel 718 additively manufactured chamber.
We are looking into using Tetraethyl orthosilicate as a fuel additive to reduce the heat flux in our ...
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Is the density of air inflow at room condition the same as stagnation density in a combustion chamber of a rocket system
We know that the density of air doesn't change for air speed very less than mach one at the nozzle, and the stagnation density is the density at zero air speed. my question is, does this mean that the ...
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Reverse Rocket Equation Not Valid [closed]
Consider a truck of mass $M$ on a sheet of ice; assume that friction between the tire and the ground is negligible. Suppose you (fixed to the ground) begin throwing rocks of mass $m$ at speed $u$, ...
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Rocket lift off and relative velocities
Say we had a rocket that was moving in the air at a velocity $100m/s$ (I know this isnt realistic at all but its to keep the maths easy) and the fuel was being ejected at a velocitiy $-10m/s$, ...
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Does $F = dp / dt$ apply to a rocket ejecting mass?
In Sean Carroll's book "The Biggest Ideas in the Universe, space, time, and motion", he makes the following claim:
$$\overset\rightarrow{F} = \frac{d\overset\rightarrow{p}}{dt}$$
Not only ...
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Can relativistic mass increase be used to increase propulsion momentum?
If the propellant used in a rockets is accelerated to near relativistic speed before being ejected from a space craft (accelerating the propellant molecules in a loop before releasing them), can the ...
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What is the optimal mass for deflecting an asteroid? [closed]
What is the optimal weight to launch at an asteroid to deflect it? Since kinetic energy increases with the square of velocity, it would seem that a very small mass going at a relativistic speed might ...
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Resources for Rocket propulsion
I am a Mechanical Engineering student who is very much interested in Rocket propulsion. Lately I have been searching for good resources to learn concepts about rocket propulsion. I'd be glad to get ...
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How to determine the Delta-v for orbital changes around a Kerr black hole?
What's the Delta-v required to change between the Marginally bound orbit and the innermost stable circular orbit around a Kerr black hole.
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Delta v of a trans-Mars injection (TMI)
Why does it only take about 600 m/s more than Earth's escape velocity to have an encounter with Mars while it takes much more Delta v (about 3 km/s) from a solar orbit (same as Earth orbit) to have an ...
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Would an ICBM be visible? [closed]
From the ground, would an ICBM warhead on terminal approach be visible to the naked eye before it detonated? I'm thinking it would be at reentry speed so would look like a big fireball.
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Why does a rocket engine that produces a constant thrust over a set period of time have less energy if it has more mass? (Zero-$g$) [closed]
A rocket engine with the thrust of 1N working for 10 seconds will add more kinetic energy to the rocket if it is attached to a 10kg rocket and less if it is attached to a 20kg rocket. The rocket ...
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Momentum of the exhaust of a rocket
I was set out to derive the equation of motion of a rocket under the influence of a uniform gravitational field. The equation is as follows
$$m\frac{dv}{dt}=-v'\frac{dm}{dt}-mg$$
where $v$ is the ...
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$\Delta v$ to raise the apogee of an orbit?
I was just wondering why it takes more delta v to increase the apogee of an orbit from 1000 km to 11000 km than to increase the apogee of an orbit from 200000 km to 210000 km (from a fixed perigee at ...
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How does the thrust achieved in my model differ from a rocket engine?
I am experimenting with a design that looks this,
using both straight and 90 degree curved pipes:
I am supplying compressed air marked by yellow arrows and the pipe is producing a very small force in ...
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Would metallic hydrogen be powerful enough to fuel a 1g rocket?
I have read that the issue with a 1g rocket is that no fuel in existence is powerful enough to provide a constant acceleration of 9.8 meters per second for years on end, and it would take hundreds of ...
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Can a rocket be taken to the edge of space with balloons so it can fly from there? [duplicate]
Can we have a (I assume very large) airship or balloon to take a rocket ship all the way to the upper atmosphere so it can use a lot less fuel from there to go to space/other planets. We could even ...
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Relativistic Rocket with Constant Acceleration [duplicate]
How long does it take to (constantly) accelerate to a relativistic velocity?
Inspiration from [0] and [1].
Assume you are sitting in a spaceship. To make you feel home, the spaceship accelerates such ...
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Newton's 3rd law and rocket nozzles
For a given solid propellent charge the energy given off by the charge is equivalent in all cases. Yet by varying the throat of the nozzle, the rocket velocity will be different for each individual ...
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How to calculate deltaV due to residual thrust
I'm trying to script a hover slam in a simulated environment using generic kinematic equations to calculate the correct throttle values I should be matching. I cut the throttle of my engine when my ...
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Projection of the force beams on the missile
We know that $∑F = ma$ and the forces that affect the rocket is drag and weight and thrust and lift.
I need to know what is the projection of these forces on the three-dimensional world
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Why does burning propellants off of the stoichiometric ratio improve performance?
According to Page 91 of Ignition!: An Informal History of Liquid Rocket Propellants by John D. Clark in the Chapter 7: Performance:
"If you're burning a hydrocarbon with oxygen, or if you're ...
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Lift force equation of a rocket and Lift curve slope
I'm trying to determine the lift curve slope of a rocket to get the lift coefficient, using L/qA . the lift equation I'm using is thrust-drag-mgsin(alpha). to me this seems correct as it essentially ...
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Is there a function or equation that can trace the trajectory of a space rocket's motion on the three coordinate axes $(x ,y ,z)$?
To be honest I'm working on a project at the university which is a simulation of launching a rocket into space The problem here is that this simulation needs to be realistic enough for my programming ...
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Will a spacecraft with angular momentum have to course correct if it thrusts along the same axis as its rotation?
For the sake of illustration, let's say you have a cylindrical spacecraft, sitting "at rest" in space, relatively speaking. It has a thruster on one end. If it fires the thruster, it goes ...
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For someone staying on Earth, what is the minimum possible time to send a spaceship to Alpha Centauri and have it back?
Suppose we want to send a spaceship to Alpha Centauri and calculate the minimum possible time it will take for us here on Earth to have the spaceship back. We are not interested in how fast the time ...
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Can a balloon start from Earth and fly to the Moon, using Helium for lift to the top of the atmosphere and then as propellant?
The JP Aerospace's Tandem airship achieved a record-breaking 28,982 meters for the highest airship flight.
After reaching this height, can the helium balloon be used as a propellant, the same way if ...
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Quantifying how much would Jupiter heat up if you accelerate Jupiter out of orbit around the sun using fusion candles? [closed]
So, I responded to a post of someone saying that you could turn Jupiter into a spaceship using fusion candles. I mentioned that doing so would dramatically heat up the planet, especially if you were ...
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Questions about the derivation of the rocket equation
Let us derive the final velocity of a rocket facing straight up that is attempting to leave the earth's surface. Basically, we are deriving Tsiolkovsky's rocket equation.
We can see that initially, ...
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Energy to momentum
Is there anyway to convert energy to motion IN SPACE? Let's say a satellite collects electric energy from sun using solar panel. Is it possible to convert it to Linear motion? The only way I know to ...
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How fast would a rocket have to go to maintain in the earth orbit without falling down? And how frequent would rocket boosters be needed? [closed]
I was thinking how fast would a rocket have to go to maintain in the in earth orbit? I was thinking of the ISS going 7000kph with rocket boosters every 6 months. What is the most efficient way to ...
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What would happen if a spaceship would pass near a completely stationary astronomical object?
Imagine a completely stationary astronomical object (e.g a planet) and assume it has no movements of any kind (no rotation, no orbits around a star or even a galaxy... a completely still planet)
If a ...
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Linear acceleration, gravity, and flipping 180° to slow down
In The Expanse ships use linear acceleration for gravity with the decks placed perpendicular to the thrust vector, this creating a "floor."
When it comes time to decelerate a ship would need ...
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How can satellites change direction without any medium in space? [duplicate]
How can satellites change direction without any medium in space? How do spaceships move in space if there is no medium?
How does Newton's third law of motion work in space?
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Thrusters in space
Suppose we propel ourself using thrusters in space. If we have two thrusters pushing against each other like this:
Nothing will happen. We can imagine the "strain" on the vehicle chassis; ...
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How can I calculate the intercept direction of a constant accelerating missile?
I'm simulating missiles in 3d space and want the missiles to intercept a target which has constant velocity.
Given the targets velocity is "u" a vector and the missiles acceleration rate is &...
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Can a rocket travelling in free space really travel arbitrarily far, with fixed fuel, by slowing down the rate of emission? Intuition vs calculation
$\newcommand{\d}{\mathrm{d}}$So for A-level physics we were given some very basic Newton's third law rocket thrust questions. I noticed that one of the formulae involved the natural log, and I reverse ...
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What is the extra kicks to accelerate a spacecraft during gravity assist?
Suppose a spacecraft coming from behind a planet during a flyby, it gets a boost in speed and also change in direction of travel but where does this extra kicks come from? Now that I understand ...
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Would a relativistic rocket need more fuel if it were powered externally?
If a relativistic rocket is pushed by a laser sail, in the frame of reference from which the laser is being fired, the ship is gaining mass and needs more and more energy to accelerate it any further, ...
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