Questions tagged [escape-velocity]
The speed needed to "break free" of the gravitational attraction of a body without spending more propellant.
80
questions
3
votes
0
answers
161
views
What is the cheapest/simplest way to deliver a camera to the moon? [closed]
The primary objective is this: to deliver a camera to the moon that live streams to Earth throughout the journey AND once it arrives on the moon.
A bonus is if it can then move around on the Moon.
An ...
- 31
-4
votes
1
answer
134
views
At what point does an object lose 50% of escape velocity?
I find the kalman line an unsatisfactory definition of space. Instead, I will use 50% of escape velocity.
At what distance does this happen? If escape velocity is 11 km s and gravity is 9.81, I am ...
- 1
1
vote
1
answer
105
views
When a spacecraft reaches the event horizon of a black hole, what happens to its residual gravitational potential energy?
A spacecraft falling from infinity directly towards a celestial body accelerates until it impacts the surface at the surface escape velocity. For any celestial body, the escape velocity is ...
- 17.6k
0
votes
1
answer
64
views
Does the payload capacity of an interplanetary launch rocket increase with decreasing fuel mass or with increasing escape velocity?
Does the payload capacity of an interplanetary launch rocket increase with decreasing fuel mass or with increasing escape velocity? I was thinking that the escape velocity has nothing to do with it ...
- 403
6
votes
1
answer
487
views
What is the relationship between the radius of the Hill sphere and escape velocity?
I'm currently working on a video game that will make use of a heavily simplified patched-conic model of the Solar System.
I was wondering about some discrepancies between my own calculations as well ...
- 83
3
votes
0
answers
49
views
Regarding planets capturing gases from space with their gravitational pull;
We know most (or all) planets suffer atmospheric escape.
Now, can planets gain atmosphere from drawing in gases drifting in space? Is there a formula for that?
Is there a cutoff point between gravity, ...
8
votes
3
answers
3k
views
Is escape from earth, hyperbolic in reality?
I have been reading on orbital mechanics and its strewn everywhere that beyond the escape velocity from any orbit around the earth, the trajectory is a hyperbola that approaches V_infinity and with ...
- 118
2
votes
2
answers
161
views
Is it (theoretically) correct to apply an equation that is derived from a hyperbolic trajectory, to an elliptic transfer orbit?
The equation in question is this one:
$$v^2 = v_e^2 + v_{\infty}^2$$
and it is showed in this answer.
The Escape velocity page on Wikipedia mentions a link (num. 4) to the book "Fundamentals of ...
- 7,493
3
votes
1
answer
385
views
What's the escape velocity at the near/far end of Phobos considering tidal forces?
At the Roche limit tidal forces disintegrate bodies. A rock or a human would just float away from the points nearest/farthest from Mars. The tidal forces must be higher for rigid bodies than rubble ...
- 421
1
vote
2
answers
183
views
How much easier is it, to explore space from a low orbit satellite, than from Earth?
Note: in this question I'm considering cost in both money and fuel terms, and looking for answers that consider both.
So we know that using chemical rockets to reach the moon, or further into space, ...
- 1,886
14
votes
4
answers
4k
views
Why is it so hard to build crewed rockets/spacecraft able to reach escape velocity?
Why are we still not going farther than to Low Earth Orbit? Orbital velocity is about 4.8 mi/s (7.7 km/s) and escape velocity is about 7 mi/s (11.2 km/s), about 45% faster. Why is it so hard to reach ...
- 274
3
votes
3
answers
523
views
Bucket loop between Earth and Moon?
Please don't bite my head off. If this is so stupid that it deserves to be squashed, I'm quite happy to delete the question. I mainly would like to know whether anyone's ever suggested this (I ...
- 343
10
votes
1
answer
1k
views
Are there any accurate velocity plots of all spacecraft that achieved escape velocity from the solar system? (Pioneers, Voyagers, & New Horizons)
The answer to this question provides a seemingly accurate plot of the velocity of Voyager 2 over distance along with the heliocentric escape velocity.
Are there similar graphs for the other 4 ...
- 977
11
votes
7
answers
6k
views
How fast is fuel escaping a rocket for it to reach the escape velocity 11 km/s?
I was having a discussion with a person and we were talking about whether or no the fuel had to be pushing out of a rocket at 11 km/s in order for the rocket to reach 11 km/s.
I said it has to be ...
- 111
73
votes
5
answers
24k
views
Why is it easier to escape the solar system than get to Mercury or the Sun?
It has been mentioned several times on this site that it is "easier" (less delta-v, and hence less fuel) to reach the escape velocity of the solar system, than to reach the planet Mercury or ...
- 47.7k
5
votes
1
answer
1k
views
Would a sniper bullet fired on Ceres reach orbital or even escape velocity?
What would happen if you fired a sniper bullet horizontally from the top of Ahuna Mons, the highest mountain of Ceres? Once I read somewhere that if you fired a bullet on the Moon in the correct angle,...
- 2,233
3
votes
1
answer
335
views
When doing an interplanetary Hohmann transfer, are additional escape and capture burns necessary in addition to the two Hohmann Transfer burns?
When doing a Hohmann transfer, it takes a burn to change from a low orbit to the Hohmann Transfer Orbit (HTO), and a second burn to change from the HTO to a high orbit. I know how to find the delta-v ...
- 45
0
votes
2
answers
198
views
Did a spacecraft ever use an atmosphere to accelerate away from a planet?
If a spacecraft enters flat enough into the Earth's (or another planet's) atmosphere it will "bounce off" the Earth at a higher speed. That method can be used if a spacecraft has not enough fuel to ...
user35272
16
votes
6
answers
4k
views
Non-orbital takeoff and landing?
I know it is a naive question, but somehow I couldn't find where it is answered here earlier.
There have been a number of questions and answers detailing how spacecraft need to achieve high orbital ...
- 419
1
vote
1
answer
243
views
Confusion with direction (vector) of minimum velocity required to reach an orbit and escape velocity
In order to achieve a stable orbit around Earth, a spacecraft has to travel at velocity not smaller than approximately 7.8 km/s.
If my understanding is correct, this figure refers to component of ...
- 6,382
11
votes
6
answers
3k
views
What kind of mission objective would make a parabolic escape trajectory desirable?
As far as I can tell, a trajectory with zero excess velocity would place it (essentially) in nearly the same orbit around the sun as earth (assuming it even departs far away enough for the sun’s ...
- 1,994
10
votes
1
answer
505
views
what happens to particles that escape the atmosphere on planets in the solar system?
What happens to particles that escape the atmosphere of planets? (not just earth).
Do they eventually form a uniform distribution of particles overtime? Do they inevitably to fall into the ...
- 603
1
vote
1
answer
162
views
Where can I find simple-ish math(s) about Moon launches from Earth and fuel consumption etc.?
I'm intrigued by the idea of launching from the top of a space elevator perched on the top of a Ecuadorian mountain, launching Eastwards to take advantage of Earth's spin.
I'd like to just understand ...
- 343
4
votes
1
answer
293
views
Sulphur Hexafluoride atmosphere for Ceres?
So, I have read that the escape velocity of Ceres is 514 m/s, and orbital velocity(for a low orbit) is 360 m/s...
Now, the RMS(Root Mean Square) velocity of Sulphur Hexafluoride at 72 $^o$F (23 $^o$C,...
- 355
13
votes
1
answer
640
views
Are there any possible methods for keeping surface water on Mars?
I've been reading this wikipedia article on terraforming Mars. One of the major issues with terraforming Mars is essential molecules and elements escaping the planet. There have been several ...
- 603
6
votes
2
answers
7k
views
What are the G forces leaving Earth orbit?
What were the G forces experienced by the Apollo astronauts during the translunar injection burn? Was there a lot of vibrations during the TLI burn?
Is there estimates of the G forces an astronaut ...
- 6,907
3
votes
1
answer
322
views
Could escape velocity be achieved in the atmosphere?
When rockets launch for orbit they travel up and the air thins respectively to the speed increasing.
How fast can a rocket for travel at sea level before it would fail or the elevation would have to ...
- 1
2
votes
1
answer
714
views
Astrophysics on "The Martian"
In the movie the martian what was the purpose of the hermes crew in blasting a part of the ship?
Was that explosion on the front or back of the ship?
After the explosion what happened to the speed ...
1
vote
3
answers
432
views
What is the maximum orbital speed beyond which the orbit around any large object in the Solar System becomes unstable?
How fast is too fast to stay in orbit around any particular large body in the Solar System?
- 1
15
votes
4
answers
5k
views
What is the most fuel efficient way out of the Solar System?
I understand with current technology we can't just fly a straight line out of the solar system but which way out would need the least fuel?
Currently to navigate the solar system it is a dance ...
- 1
2
votes
1
answer
280
views
Has any human had the capability of leaving the Solar System?
Inspired by Has any human ever had the choice to leave Earth permanently? and the answers and comments there, has any human had the capability of leaving the Solar System?
I'm thinking of Apollo ...
- 121
45
votes
3
answers
14k
views
Has any human ever had the choice to leave Earth permanently?
Far beneath the ship / The world is mourning
They don't realize / He's alive
No one understands
But Major Tom sees / "Now the light commands
This is my home / I'm coming home."
Peter ...
- 1,939
3
votes
3
answers
3k
views
Apollo Missions - Travel time to moon [duplicate]
I must be missing something - escape velocity is about 25,000mph. The distance to the moon about 240,000 miles. That computes to about a 9 hour flight. Why did it take 3 days for Apollo missions to ...
- 51
16
votes
8
answers
11k
views
Why didn't Voyager 1 and Voyager 2 crash on into Jupiter or Uranus when they approached near to these massive planets?
I was reading about gravity assist and I read that both the Voyagers used gravitational force of these planets to speed up.
But I wanted to know why weren't they completely attracted by their ...
- 327
3
votes
1
answer
405
views
How to achieve escape velocity from Ceres?
If I am interested in a sample return mission to Ceres using a similar propulsion technology package to Dawn, what kinds of additional propulsion would be required to land and then return?
...
- 283
13
votes
1
answer
2k
views
Largest radius sphere with Earth's surface gravity on which you could jump at escape velocity? Bigger than B612?
In the book Le Petit Prince by "French aristocrat, writer, poet, and pioneering aviator Antoine de Saint-Exupéry" the main character lives on an extremely tiny asteroid with the name B612. It is this "...
- 149k
11
votes
3
answers
5k
views
Could a human jump off Mimas without return?
A similar question has already been asked on dwarf planet Ceres:
Could a Human reach escape velocity by jumping from the surface of Ceres (a dwarf planet)?
Ceres has 2.9% of Earth's gravity. Saturn's ...
- 414
31
votes
5
answers
10k
views
How could an object barely exceeding escape velocity from the Moon eventually reach the Earth?
Since NASA is once again targetting low-cost missions to the Moon, I was thinking about low-cost methods of getting stuff from the Moon back to Earth.
Although it seems reasonable to assume that ...
user21233
6
votes
4
answers
3k
views
How much Delta-V would be required to escape the Gravitational Influence of the Earth without entering orbit?
As impractical as it sounds (and it's definitely impractical) I was wondering what the Delta-V required to leave Earth's influence would look like if we launched "just straight up" into the Earths ...
- 9,377
5
votes
2
answers
3k
views
Apollo 11 mission report shows velocity well below escape velocity thousands of km on the way to the Moon
This is from the Apollo 11 mission report. It says the vehicle was going at 7.6 km/s when the CSM separated from the third stage. It was not in orbit at this point, it was thousands of KM from earth.
...
- 67
-6
votes
1
answer
167
views
benefits of higher rocket speed [closed]
what benefits will a rocket get if it is made to go at a speed close to light... like 3 X 10^6?
if the rocket is supplied with more efficient fuel and designed to obtain lesser drag there are ...
2
votes
0
answers
155
views
At what gravity would the rocket equation mean "cannot reach orbit from the surface"? [duplicate]
I remember reading (a long time ago in a library far, far away...) that, if Earth's gravity were that much stronger, the rocket equation (?) would mean that it were impossible to actually reach orbit ...
- 199
-3
votes
4
answers
2k
views
How did the Roadster get high enough to take a whole-Earth picture?
According to telemetry as seen in videos of the event, the car was ejected from the Stage 2 rocket at 114km above Earth.
Anything less than 160km will immediately enter a rapidly decaying orbit and ...
- 23
9
votes
2
answers
473
views
Could Starman get ejected from the Solar System?
This is not about a prediction of Starman's fate, although it might be interesting to find it so.
This is about any object having similar aphelion and perihelion values to Starman (Elon Musk's Tesla ...
- 17.4k
30
votes
10
answers
14k
views
How many times do you have to circle the Earth to break orbit?
My science teacher asked us this, and nobody in my class knew. We guessed it would be three, but with no evidence.
(Edit: The asker has not returned to clarify if they meant leaving the Earth-Moon ...
- 309
6
votes
1
answer
277
views
What speed did the (interstellar) comet C/2017 U1 PANSTARRS have at perihelion?
C/2017 U1 PANSTARRS is a comet with an eccentricity of close to 1.2, so it is a strong candidate for having interstellar origin. It's perihelion was at 0.25 AU.
What speed did it have relative to the ...
- 26.9k
13
votes
2
answers
1k
views
Is there a theoretical limit to the size of launch vehicles?
Is there a limit to the size (mass, structural issues) of boosters that can be launched either to orbital or escape velocity? I am asking about such constraints as the required thrust to weight ratio ...
- 131
2
votes
2
answers
3k
views
Would it be possible to go beyond Jupiter without making any slingshot?
It is said that we do not have such advanced technology in order to send a spacecraft out of the solar system. (Source: Everyone around)
When a spacecraft is launched from Earth and aims to leave the ...
- 612
9
votes
3
answers
9k
views
How do we come up with the gravity assist (or slingshot) formula?
When you search up in google gravity assist formula, it comes up with the simplest version:
Which means that: Final velocity = Initial velocity + 2 (velocity of the planet)
Then if we do some more ...
- 612
1
vote
2
answers
923
views
What is the characteristic time to reach a hyperbolic excess velocity within a sphere of influence?
When departing a planet using a hyperbolic trajectory, one should ideally reach the sphere of influence boundary with an excess velocity needed for interplanetary transfer. Of course, the true excess ...
- 1,994