# Questions tagged [acceleration]

Questions regarding acceleration - the rate and/or direction by which an object's speed or velocity vector changes with respect to time.

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### How much time would an astronaut experience accelerating to .9999x the speed of light at an acceleration of 1G from the astronauts perspective?

So if the astronaut is experiencing a constant 1g acceleration, how much time would pass for them before an outside observer would measure their speed at .9999C? I saw this question and noticed that ...
1 vote
294 views

### What can possibly accelerate space elevator to these types of extreme velocities?

Is it possible for a space elevator not to just reach speeds of a few hundred km/h, but much faster. Since in the future, people might want to go up to GEO to maybe work there and come back home on ...
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### Are rockets deliberately throttled back towards the end of the burn to spare crew and airframe g-forces?

Throughout its burn, a rocket gets lighter as propellant is consumed. As a result, acceleration (and g-force) increase. In the shuttle, the SSMEs were throttled back towards the end of the burn ...
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### Difference in using flat earth or round earth model for equation of motion

according to the book of Mr. Peter H. Zipfel (Modeling and simulation of aerospace vehicles) for high speed or/and long flight applictions kinematic simulations should be done by round rotating earth ...
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1 vote
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### Use local acceleration and angular velocity to calculate rotation matrix

Can I ask if there are any python packages that can fuse local acceleration and angular velocity and get rotation matrix? Thank you!
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### Non-spin space station at 1g?

The discussion about spinning space stations to achieve 1g artificial gravity is well known. What about space stations with constant linear acceleration of 1g at Earth orbit /assuming we have the ...
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### How to account for burned fuel mass when calculating spacecraft acceleration?

I thought I could simply remove half of the burned fuel mass to account for the mass lost during the engine burn. But I could not find a Newton's Second Law formula Calculator that would allow that, ...
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### Thrust & acceleration produced by a rocket engine

For given propellants, with their mass flow decided by the rpm of the turbo pump, what decides the thrust and acceleration produced by a rocket engine? Can we control them independently?
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### How fast can a rocket with constant thrust but changing mass travel a linear distance with limited delta V?

Background I am developing a game / simulation that has spacecraft with advanced albeit at least not physically impossible drives travelling in the solar system. As operation time should be far more ...
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### Will the initial velocity of an object in space get multiplied if a constant acceleration is applied? [closed]

Imagine an object travelling in space in the speed of 60 Kmph which took acceleration x if accelerated with the same x, will the object travel faster than 60 Kmph or travel in the same speed cuz of ...
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### What is the optimal acceleration for a direct ascent to the moon? [duplicate]

If a rocket flies to any object using a direct ascent it is best for it to reach the needed speed as soon as possible because of the Hohmann effect. When it launches from the ground there is air ...
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### Fuel economy on orbital launches

To achieve fuel economy during orbital launches (for a particular orbital altitude), do we select the first stage (its thrust), in such a way so as to achieve the desired altitude above the Karman ...
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### Is there any major difference between acceleration of solid propelled and liquid propelled rockets during launch

Few days ago, ISRO launched its PSLV-C53, which had solid first stage. (Clip here) Also, the SpaceX's starlink launched on 24th July, 2022, having liquid first stage. (Clip here) Is there any major ...
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### Can something like SpinLaunch actually work?

Can something like SpinLaunch actually work? It appears that Spinlaunch attempts to accelerate a capsule to very high speeds and then basically throw it into space. A regular rocket is moving slowest ...
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### How many particles per acceleration cycle in a cyclotron? [closed]

particle accelerators accelerate ''beams of particles'' - do cyclotrons accelerate single particles or a batch of particles per accelerating cycle? How many particles can be accelerated in a batch per ...
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### Why do rockets have multiple stages?

I guess, almost all the rockets have multiple stages. But, I was wondering, why do they have multiple stages? Couldn't they have just 1 stage? With more stages, they would require more engines (...
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### Will DART fire its ion engine to accelerate prior to impact?

I'm an avid KSP player. Like some of them, I've been playing the DART simulation on the game. I've typically achieved impact velocities of 5-7 km/s, the higher end being achieved by propulsive ...
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### Could you survive very high G's if your whole body was accelerated uniformly?

Could you survive high g's if your whole body was accelerated uniformly (not just by the seat of a rocket pushing on your back)? Your body is really only affected by gravity if you are touching ...
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### How do vibrational isolators reduce the g-forces of a payload on a launch vehicle?

Launch vehicles often use vibrational isolators to reduce g-forces to protect delicate payloads. How are g-forces reduced on the payload while both the payload and the launch vehicle maintain the same ...
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### Why did the space shuttle's altitude go down after reaching 108,000m?

I recently took a look at this little data sheet by NASA: Math and Science @ Work; Space Shuttle Ascent Time Altitude Velocity Acceleration Comment (s) (m) (m/s) (m/s^2) 20 1244 139 18.62 40 5377 ...
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### Term disambiguation: acceleration with/without gravity

I'm ashamed to ask this. But a free-falling accelerometer in a gravitational field will read a nice round zero. And if that accelerometer is given some thrust, it will read the acceleration produced ...
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### Which nD accelerometer symmetric configurations on a cubical LEO spacecraft can serve as a makeshift 3D gyro resolving tumbling from tidal forces?

As they often do @DavidHammen's comment has got me thinking about the following question, which is a mathematical exercise rather than a realistic scenario. On a hypothetical large cubical spacecraft ...
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### What do ISS astronauts do while the ISS gets reboosted? [duplicate]

For its orbit to not decay, the ISS reboosts itself to higher altitudes once in a while. During the reboost, I wonder how much gravity is felt by the astronauts onboard, and what do they do to avoid ...
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### Average acceleration of a rocket given average mass and thrust

If we assume that a small scale rocket is launched perpendicularly to the ground and ignore the drag, how can I calculate the average acceleration given that I know the burn time, the average thrust, ...
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### Lagrange coefficients orbit acceleration

I have an initial position, velocity and acceleration (in x,y,z coordinates) for a certain orbit, and I need to compute the next position, velocity and acceleration after a certain time interval (I ...
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### How much anti-matter is needed for an anti-matter propelled rocket to reach $P$ % ($P\lt{100}$) of the speed of light (c)?

I think this is a tough one. Imagine a rocket is produced which is propelled by a matter-anti-matter device. Its sole purpose is to reach high velocity. Which means the mass can be kept low, say $m$ ...
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### Fastest rocket to reach space?

Spaceloft XL can reach space - 100 km - in 60 seconds So I wonder which rockets can reach that limit fastest Balloon-launched sounding rockets count but separately (from the moment they launch from ...
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### Did the Perseverance rover's Atlas 5 really "leap off the pad"? If so, was it because the payload is tiny, or because it's going to Mars?

Spaceflight Now's ULA’s Atlas 5 is NASA’s go-to rocket for nuclear-powered space probes quotes Tory Bruno, president and CEO of United Launch Alliance: “This rocket is going to leap off the pad with ...
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### How to calculate the maximum heliocentric speed during a flyby?

The following graphs are related to the Voyager 2 / Jupiter flyby occurred on July 1979 (I did the calculation with the SPICE library and NAIF’s data files). We see that the maximum speed relative to ...
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### Supersonic flow of non-compressible fluids

Will the non-compressible fluids, travelling at Mach 1, at the throat of a CD nozzle, accelerate after they leave the throat?
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### Is centripetal acceleration around an ellipse with constant tangential velocity always pointed towards the center of the ellipse? [closed]

I've tried to find answers online but surprisingly couldn't find any.
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### Did any spacecraft ever use the Sun's gravity for acceleration?

Space probes often use planets to accelerate onto a trajectory towards their goal(s) without having to consume too much fuel. But the fastest acceleration would be made through the Sun's gravity if ...
1 vote
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### How much is a typical reentry vehicle decelerated by heatshield ablation?

Most spacecraft (or parts thereof) intended to survive atmospheric (re-)entry use an ablative heatshield, which, when exposed to the strong aerodynamic heating of (re-)entry, gradually ablates away, ...
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### calculating the terminal velocity of a theoretical solar sail when reaching a distance d where acceleration is insignificant

I am trying to calculate the terminal velocity of a solar sail starting at distance 1AU. I know that my sail will accelerate and its acceleration will be inversely proportional to the distance squared....
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### Tacking a solar sail to increase duration of acceleration

Because the utility of a solar sail diminishes the further it travels away from the sun (max. distance ~50 AU), the longer it can stay in closer proximity to the sun the longer it can accelerate. Is ...
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### Average acceleration of a rocket

Given a rocket has a minimum acceleration with full tanks of say 1 g and a max acceleration with empty tanks of 3g, what's the average acceleration? Is it just 2
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### Could Breakthrough Starshot proposed propulsion system be used in a regular size probe to accelerate it faster than any probe has been before?

Supposedly Breakthrough Starshot project wants to accelerate a capsule of the size of a mobile phone - according to one source - and of the size of the chip of a mobile phone - according to another ...
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### What lateral and rotational accelerations can a spacecraft achieve?

I've found information like the Space Shuttle Orbiter has so many thrusters each generating so much force to maneuver "with redundancy" in orbit. But without knowing something like how many thrusters ...
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### What precisely was the character of the non-gravitational acceleration of Oumuamua?

When exactly did Oumuamua accelerate, when did it begin, when did it end, was it uniform across that period, and at what vector did it occur? I've seen some vague references to it lasting 100 days, ...
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### Apply forces such that a satellite reaches a given point in space

I'd like to find out a strategy for solving the following simplified problem. A small spherical craft at $t=0$ has a position and velocity vectors $\mathbf{x_0}, \mathbf{v_0}$ in a zero gravity ...
125 views

### How was InSight's vertical seismometer (accelerometer) tested in Earth's stronger gravity?

The BBC article InSight Diary: The silence of space tells an interesting story and has an interesting audio recording of InSight's seismometer signals sped up to audio frequency, made while in ...
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1 vote
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### Ion thrusters trip time

Suppose we had a fully equipped nuclear powered ion thruster starship. If it had a constant rate of acceleration of 1g, taking into account the fact that at the half way point you would have to turn ...
1 vote
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### How long will it take me to get to Mars?

I am a spaceship travelling from Jupiter under constant acceleration of 1g (9.8meters/sec2) provided by fusion drive to Mars. I departed at exactly the same time as an identical ship, travelling the ...
3k views

### Orbital Railgun for launching deep space probes

I've perused some of the articles and questions on magnetic acceleration using rail guns and they all seem to say that it's possible just not practical. I wanted to know what are the drawbacks to ...
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### Outgassing as a viable explanation of Oumuamua acceleration excess

A recent paper on Oumuamua claims the following: 'Oumuamua (1I/2017 U1) is the first object of interstellar origin observed in the Solar system. Recently, Micheli et al. (2018) reported that '...
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### What forces and motion would astronauts experience in a spacecraft in Earth-Moon L1 & L2 Lissajous orbit?

What is the maximum velocity they would experience? Would they be aware of the movement based on the positions of the Earth, Moon, or stars, or would it be too slow to notice? Would they feel any G ...
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### What could possibly happen if an object accelerates 9.81 m/s^2 upwards if it started from the ground ? [closed]

Will the acceleration of the object and the acceleration due to gravity cancel each other and that object remains at the same space coordinate?
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### Is there an optimal accelaration for first stage going in LEO?

I know every engineering works is based on compromises, and rocket design is no exception. A rocket should go as quickly as possible to high altitude to avoid flying for a long time and at high speed ...
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### How do I calculate a rockets burn time from required velocity?

Say my rocket could produce F newtons of thrust while consuming M1 kilograms of fuel per second. It's mass at start is M0, and it keeps burning until it reaches V velocity. How would I find out the ...
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