83
votes
Time at 1 g acceleration to travel 100 000 light years
Nonrelativistic solution
The variables used will be
$x$ for the distance travelled
$v$ for velocity
$a$ for acceleration ($1~\mathrm{g}$)
$t$ for the time
$c$ for the speed of light.
Non braking
...
- 3,372
83
votes
Accepted
Can Voyager 1 reach the Andromeda Galaxy?
Technically, yes
While Voyager 1 lacks the velocity necessary to escape the Milky Way galaxy, it doesn't actually need to. Because the Milky Way galaxy itself will collide and begin to merge with the ...
- 886
75
votes
Can Voyager 1 reach the Andromeda Galaxy?
no.
Voyager 1 is currently orbiting the center of the Milky Way, which has an escape velocity of $550 \ \text{km}\ \text{s}^{-1}$ at the Sun's position, while the Sun orbits at $\sim 220 \ \text{km}\ \...
- 2,385
43
votes
Accepted
What is the fastest speed ever reached in space travel as measured from the point in space from which it was launched to its current/final position?
Velocity relative to what? There's no central universal point to measure velocity at, so your answer is likely going to change based on your frame of reference.
New Horizons did indeed have the ...
- 8,715
39
votes
Accepted
Speed to maneuver with flaps and ailerons in interstellar dust
It is not only how fast the airfoil has to travel, but also how large the airfoil must be to even have fluid-dynamics-like behavior. Because of the low density of particles in the interstellar medium, ...
- 1,839
38
votes
Accepted
Do things get dirty in space?
Spooky
This one is subjective. To some, just finding an abandoned spaceship would be spooky. I'll say there's probably not a lot that has to happen to evoke this feeling.
Rusted
Actually, unless ...
- 23.6k
32
votes
Accepted
Interstellar Travel Thought Experiment
Does this logic make sense? Has anyone thought of this before?
Yes, it's been considered. In the literature it's known as the "incentive trap".
There are a couple of academic papers on it, ...
- 161k
28
votes
Accepted
What processes create an object with an interstellar velocity?
The answer to 'how can it come blazing in with enough energy to exit again' is that if it started outside the solar system it would have been unusual for it to NOT leave again, since it would have ...
- 17.3k
25
votes
Accepted
Why didn't the Pioneer probes maintain communications with Earth as long as the Voyagers have?
Why the Pioneers didn't last as long:
The Pioneers were a low-budget mission just to test if flying to the outer planets was feasible
They used a smaller radio transmitter (8 W vs. 23 W) and antenna ...
- 122k
23
votes
Accepted
Gravity Assist braking
The speed of the probe doesn't change with regard to the assisting body. It is direction that is changed.
If a hyperbolic orbit about the sun comes in with a Vinfinity of 5 km/s, it will exit with a ...
- 15.2k
23
votes
Accepted
Overcoming the speed of light thanks to ion thrusters
The expression $v_e = \sqrt{\frac{2Vq}{m}}$ is a non-relativistic approximation. This is quite valid when the exhaust velocity is small compared to the speed of light, which is the case for ion ...
- 65.6k
23
votes
Accepted
What is the most fuel efficient way out of the Solar System?
The most fuel efficient way to leave the solar system at present, is to launch into a trajectory that (like that used for Gallileo) may well involve one or several gravity assists from Earth or Venus, ...
- 19k
21
votes
Accepted
Can we use interstellar hydrogen as a fuel for interstellar travel?
It's theoretically possible to collect fuel from near empty space, the bussard ramjet is an example of an engine designed to do just that. The principle is that you use magnetic fields to collect and ...
- 18.9k
19
votes
Accepted
What limits the speed at which rocket fuel is expelled?
The core of your question is about real, "normal" engine exhaust velocities. The fastest we get so far from practical, in-production engines is about 4,440 m/s, Space Shuttle main engines with liquid ...
- 18k
18
votes
Collecting antimatter from Van Allen radiation belts
The total antimatter in the van Allen belts is estimated to be 160 nanograms. Annihilating that with matter would produce a whopping 8 kW-hr of energy. A quarter of a gallon of gasoline has that much ...
- 57.7k
18
votes
Accepted
Where is Voyager 1 now (2021)?
Voyager 1 and 2 are still in the "neighborhood" of our solar system and very close to our Sun compared to any other star. They are roughly three times farther from the Sun than Neptune and ...
- 148k
16
votes
Accepted
Are there any planned extra-solar missions by NASA or others?
You are forgetting Pioneer 10, Pioneer 11, and New Horizons. Pioneers 10 and 11 respectively operated for 28 years and 16 years after completing their primary missions. New Horizons, which has yet to ...
- 65.6k
16
votes
How much light is there on the way from Earth to Proxima Centauri?
No, the power collected by solar panels is reduced by the square of the distance from the light source.
At the Earth's distance from the sun, the energy of sunlight is about 1300 watts per square ...
- 161k
15
votes
Technology for unmanned spacecraft to exoplanets
There are incredible, mindboggling distances involved in merely reaching an exoplanet. Alpha Centauri Bb, the closest known exoplanet, is 4.365 light years away. That's 41,295,000,000,000 km (25,660,...
- 7,401
15
votes
Travel Speed in Space
Currently functional and proven technology is limited to basically no interstellar travel at all. To reach one of our stellar neighbors (like Proxima Centauri), one of the fastest space probes we have ...
- 15.1k
14
votes
Accepted
Could Von Neumann probes be forbidden by technological limitations?
There's no reason a Von Neumann probe could not be built once a civilization reaches the appropriate technology level, it's a matter of desire. When a civilization becomes advanced enough all it needs ...
- 18.9k
14
votes
Accepted
If a gas giant is far enough away from a sun will it freeze solid?
There is an answer on wikipedia: Rogue planet:
It is calculated that, for an Earth-sized object at a kilobar hydrogen atmospheric pressures in which a convective gas adiabat has formed, geothermal ...
- 2,041
14
votes
Are there interstellar Lagrange points?
Lagrange points do exist between stars. In case of single stars, they are too far away from the stars to have any practical effect.
However, in case of the binary stars, the Roche Lobe has its apex ...
- 1,540
14
votes
Can we speed up spacecraft to suitable interstellar travel speed using oscillating gravity assists on planets on opposite sides of the solar system?
Accumulating 0.1c (30000 km/s) with gravity turns alone within the bounds of Solar system isn't possible. Reason is: system escape velocity (sometimes referred to as third cosmic velocity) is about ...
- 387
13
votes
Realistic space battle, how it could looke like? No hollywood version or videogames like
I would like to firstly echo the suggestion to read Project Rho. Throughout the entire site, there is a tremendous amount of hard science and it is all deeply entertaining.
http://www.projectrho.com/...
- 16.1k
13
votes
Accepted
Do we have the technology to colonize the nearest habitable planet by sending hundreds of people with spacecraft?
Do we have the knowledge, technology and resources to colonize it?
Simply put, no.
First off, you need to forget about knowledge, technology and resources and look to biology, sociology, and ...
- 65.6k
13
votes
Cyclotron engines as a means of thrust for interplanetary travel?
A cyclotron is a type of Ion engine. Cyclotrons (in the classical sense of the word) haven't been used because they have a very low power-to-weight ratio (tons of magnet to accelerate tiny amounts of ...
- 122k
13
votes
Is it pure luck that the voyager 1 survived to travel beyond our solar system in interstellar space?
It can't be pure luck, seeing as how both Voyager spacecraft are still operating today. If it were just one, you might chalk it up to luck. Both still working means they must have been built really ...
- 57.7k
13
votes
Accepted
How might Earth's location be referenced in stellar terms?
Like the lower left part of the image below.
Define a set of pulsars through describing proportions between their frequencies. Define distances from each of them. This uniquely identifies a point in ...
- 52.7k
13
votes
What limits the speed at which rocket fuel is expelled?
The nozzle is the part of a rocket that limits the speed of the exhaust velocity. (It's also the part that converts the pressure and temperature of the expanding propellant into velocity.)
The speed ...
- 4,515
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