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 ...
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  • 3,372
83 votes
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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 ...
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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}\ \...
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43 votes
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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 ...
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  • 8,715
39 votes
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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, ...
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38 votes
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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 ...
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  • 23.6k
32 votes
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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, ...
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28 votes
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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 ...
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25 votes
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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 ...
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  • 122k
23 votes
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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 ...
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  • 15.2k
23 votes
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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 ...
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  • 65.6k
23 votes
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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, ...
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21 votes
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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 ...
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  • 18.9k
19 votes
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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 ...
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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 ...
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  • 57.7k
18 votes
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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 ...
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  • 148k
16 votes
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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 ...
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  • 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 ...
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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,...
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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 ...
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  • 15.1k
14 votes
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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 ...
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  • 18.9k
14 votes
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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 ...
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  • 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 ...
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  • 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 ...
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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/...
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  • 16.1k
13 votes
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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 ...
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  • 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 ...
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  • 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 ...
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  • 57.7k
13 votes
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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 ...
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  • 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 ...
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  • 4,515

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