Rocket Definition and 1000 Threads

A rocket has length L with a separate head on top. The rocket lands in a cilinder on Earth with height L with speed v. From the point of view of the rocket, the cylinder undergoes a Lorentz contraction. The rocket will therefore collide with the bottom of the cilinder and damage it. From the...

DISCLAIMER: I am not entirely sure whether I should open this thread here or in #general, but I will try! :') Hi guys, I am a freshman in aerospace engineering and i have taken part into a competition consisting in engineering a rocket so that it reacher 1km altitude and manages to touch back...

Hi, *Excuse the crude visualization and possibly imprecise description - I'm not a rocket scientist :) So, I have a friend that has come up with a "new" concept for a rocket propulsion design, and although I have a hunch that it might not work better than existing designs I cannot really...

If you've seen it, they chose one point in the combustion chamber and the other in the exhaust nozzle. I think they're assuming that we have a gas both places. They say that the pressure in the nozzle is atmospheric pressure, or it you're in outer space, zero. That makes perfect sense...

https://arstechnica.com/science/2022/01/an-old-falcon-9-rocket-may-strike-the-moon-within-weeks/ https://www.projectpluto.com/temp/dscovr.htm

I calculated the time for the velocity before ground impact, which is v = -189.23 and the velocity at end of engine burn time, which is 120.996. I also calculated the max altitude (y = 1826.94), and the time to reach the max altitude was t = 23.0823 seconds. So from this information, I did: t =...

Speed of rocket after moving 0.5 km = ##\sqrt{u^2-2gh}=\sqrt{120^2 - 2 \times 9.81 \times 500}=3\sqrt{510}## m/s Then I try to consider conservation of momentum to find the speed of the object after being released. Total momentum before the object is released = total momentum after the object...

Hi, I've posted recently about multiphoton Breit-Wheeler matter production. The goal I had in mind for producing a large quantity of positrons and electrons was so that a rocket could make its own propellant without having to carry any propellant along with it. Ultimately, the goal being to...

Consider a rocket with mass ##m## in space is going to move forward. In order to do so, it needs to eject mass backwards. Let the mass that is ejected has velocity ##u## relative to the rocket. What is the equation for the final velocity? It is said that after ##dt## second, the rocket will...

Hello! I have recently found this fascinating article: https://zenodo.org/record/3596173#.YJ1ttV0o99B The author claims that classical equation for rocket thrust in incorrect because F is not equal to ma for a changing mass. Neither my professors nor me can see any errors. Do you think this...

Hello, I'm wondering how I could make an isopropyl alcohol rocket engine. Currently I'm testing with plastic bottles, and that's not quite exciting. The alcohol quickly burns out because it is just some vapor in the bottle. There also isn't enough oxidizer, as the bottle quickly fills in with...

Hello, forums! So I recently have been getting into chemistry stuff. my latest endeavor is the "sugar rocket fuel" thing where you mix potassium nitrate (stump remover) and sugar (granulated) together to make something that when lit on fire, burns very quickly while releasing tons of hot...

A question to physicists: What sort of real world scenario / image would *best* depict the increase in gravitational potential energy in a radial field? Would a rocket traveling through the Earth's atmosphere suffice or are there better alternatives? This image would have to be relevant to the...

Sutton writes that the mass ratio of a multistage rocket is the product of the individual vehicle stage mass ratios, does it mean the expression below? $$MR=\prod_{i} \frac{m_{f,i}}{m_{0,i}}$$

I picked up the book Fundamentals of Spacecraft Attitude Determination and Control (F Landis Markley and J.L Crassidis), but this is quite a theoretical reference and I'm also trying to research the design of the electronic components and measuring devices and also how to write the software for...

I tried A with the solution of 9.73 and 8.69 both wrong.

I’m writing a 3DOF sim for a rocket. I’m having a hard time visualizing centrifugal effects from the Earth's rotation on the rocket while it is moving along the rail (acceleration > 0). I know that once it has left the rail I no longer need to account for it since it’s in the ECI frame and...

The law of action and reaction is the explanation that I see everywhere. But I can't find anywhere what exactly pushes the balloon in the opposite direction as the air coming out. Air molecules come out to where pressure is less. What exactly moves the rubber balloon in the opposite direction...

If an infinite amount of energy were available to create the lift mechanism for a space launch. What would be required to fire a 200lb object into low Earth orbit(160km) after speeding it up in a way similar to how the large hadron collider speeds up a particle. Assuming the launch vehicle...

[Moderator's note: Spin-off posts from previous thread have been included in this new thread. Also, the OP's re-post of the scenario for discussion has been moved to this top post for clarity.] Yes. Physically, scales measure a force (and indirectly the energy) in their frame. Consider the...

Can you give both intuitive and mathematical explanation please.

Consider an observer on Earth (Neglect any effect of gravity). Call him A. Let 2 rockets be moving in opposite direction along x-axis (x-axis coincides with the x-axis of A) with uniform velocities. Call them B and C. At t=0, in A's frame, the rockets are separated by length ##l## . Let ##V_a##...

Hi guys. I am studying the relativistic implementation of the standard Tsiolkosvky rocket equation, but ran into some doubts. Doesn't special relativity apply only to inertial frames of reference(non-accelerated)? Then, how could it be used for the rocket equation, which speaks of a ##\Delta...

I am studying through online resources some principles of spacecraft propulsion, since it really fascinates me, and makes me want to know a bit more about it :) For rockets, thruster, I found the Tsiolkovsky rocket equation: $$\Delta v=v_e ln(\frac{m_0}{m_f})$$ Of course, rockets can travel...

I'm doing my homework about the Inverted Pendulum and I'd like to know how a rocket flies and why it's related to an Inverted Pendulum.

I know that this should be a very simple problem, but I don't understand how to solve it without knowing the height at which the tank is separated from the rocket. I will be very grateful for any hint.

help

I thought I'd start by writing the problem in a tensor formalism. I have identified with ##S## the Earth and ##S'## the rocket. Since the acceleration provided is in the rocket's frame of reference, I can write the following four-vector. $$ a'^\mu=(0, a, 0, 0) $$ Since we are interested in the...

I once read that if the Apollo 11 rocket had been misaligned by even half a degree on the launch pad that the lunar landing would not have happened. I would like to find this information again to use it as an example for my students in their life planning, i.e. if they make small mistakes now...

I first began to identify the various events in the problem. I call the rocket ##S'## and the Earth ##S##. Sending signal Tail signal reflection Head signal reflection Tail signal return Head signal return For the Earth I know that: ##t_4 = T## ##t_5 = T + \Delta T## Since the two events...

Heard talk about He3 on the Moon and launching a fusion rocket. Is this all just a mashup of Sci-fi ideas?

Equation for rocket motion: $$\frac{d \mathbf{P}}{d t} = M\frac{d \mathbf{v}}{d t} - \mathbf{u}\frac{d M}{d t}$$ But $$\mathbf{F}=\frac{d \mathbf{P}}{d t}=M\frac{d \mathbf{v}}{d t}$$ So $$M\frac{d \mathbf{v}}{d t} = M\frac{d \mathbf{v}}{d t} - \mathbf{u}\frac{d M}{d t}$$ And $$-...

Hello! I've done the following to solve this problem. a) Here I simply put in the time in the equation, s0 is = 0 and after that it was pretty much done $$s(t) = 42 *1 - \frac {9,81*1^2} {2} = 37,09m $$ b) Now here to see when the rocket reaches it maximum altitude and what height it is...

I would like to write a program to calculate the equilibrium concentrations of 10 or more chemical species at any axial location along a quasi 1D isentropic methane-liquid oxygen rocket nozzle. Is anyone aware of any good textbooks that cover this topic in depth, specifically dealing with large...

https://techcrunch.com/2020/12/03/space-startup-aevum-debuts-worlds-first-fully-autonomous-orbital-rocket-launching-drone/ The Ravn X launch vehicle is 80 feet long and has a 60-foot wingspan, with a total max weight of 55,000 lbs including payload. Seventy percent of the system is fully...

I was reading this: https://www.cnbc.com/2020/12/01/elon-musk-highly-confident-spacex-will-land-humans-on-mars-by-2026.html It just seems that the Delta-V requirements - especially with a spacecraft that is stocked with supplies for a few years or for the Hohmann transfer helio-orbits - will...

Question: Solution: Issue: I would like to know why ##\Delta m=-\Delta M## rather than ##=\Delta M## if minus signs have been used in the second equation. Thank you.

I am a little confused with the text above. Actually, all is ok until 2.51, i think i am missing something. What is this? Another way to define gamma? (The doubt is not about the raising indices, neither about "n00 = -1", is just where does the equation came from. That is, the equation is easy...

How do we maintain the RPM of turbo pumps in liquid rocket engine ? and how do we control it ? and in the case of electric pump fed engine (like rocket labs's rutherford engine) is easy but how we do it for other liquid propellant engines ?

Why do vacuum rocket engine always producing high thrust than sea level rocket engine ? for example spacex's merlin vacuum engine produce more thrust than merlin sea level engine. And it is due to the big nozzle with large area in vacuum engine because when the flow reaches mach 1 in the throat...

Lets imagine that I will put the recording camera and ticking clock into a box and so that camera can record this clock all the time ticking. I will put then this box to the speed of 1/2 speed of the light, after a minute of mine I would stop this box and take the camera from it. As it was at...

Hi All, I'm trying to get a better understanding of the momentum thrust given by an over-expanded rocket nozzle (I realize this case voids the isentropic flow assumption used for the 1D isentropic gas expansion equations typically used for rocket engine design since the normal shock is not an...

Now this is how I've tried to solve this $$ v_e = u0 \cdot ln \frac {M} {M- μ \cdot t} $$ After putting in the values I get this; $$ v_e = 200 * ln 0,36 $$ $$ v_e = 73,54 \frac m s $$ Now I'd say that this is the correct way to do it, but this part is confusing me "What is the speed of the...

I am interested in research on hybrid rocket technology and I would like to know if anyone has a known ideal way to measure the required parameters to find the below items. I am particularly interested in a cold flow test involving: Characteristics of the Oxidizer Flow Turbulent Intensity...

With increasing numbers of small private rocket companies that is in many cases not based in the USA (so no FAA rules, regulations and procedures) how do they notify their launches so countries does not mistake them for a ballistic missile attack like in the Norwegian rocket incident in 1995...

Hi all, I'm working on programming a simple 2D method of characteristics program to design the nozzle wall contour for a supersonic rocket nozzle. I'm wondering roughly what sort of difference I should expect from a 2D vs 3D method of characteristics program and where I could find a good...

This is what I tried and it makes perfect sense to me. When i plug in the numbers to what I ended up with, I get an imaginary number for U initial... Work is attached below.

A person standing a distance 𝑑 from the rocket launch site shoots a projectile at 𝑡=0 at an initial speed 𝑣0 at an angle 𝜃0 with respect to the horizontal as shown in the figure above. The projectile hits the rocket just when the rocket reaches its maximum height. The downward gravitational...

Hi! I'm a high school physics student. I really, really love physics, especially rocket science, and I had an idea about a rocket design, but I don't know how feasible it is. I was hoping you guys could give me some feedback. So I was learning about electricity, and as far as I know, electric...

I know that a=-9.8, I am having trouble aplying the motion equations. For example, I can't use equations that have velocity (either initial or final), so I can rule out those equations. I am then left with no equations to use. I am extremely stumped.