Interstellar Travel Speeds

The cluster focuses on discussions of spacecraft velocities, including current probes like Voyager, future initiatives like Breakthrough Starshot aiming for 20% of light speed, relativistic effects from high accelerations, and travel times to nearby stars like Proxima Centauri.

📉 Falling 0.5x Science
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Keywords

breakthroughinitiatives.org space.com DE stackexchange.com FTL starshot.html ISS math.ucr SR rocket.html speed light speed probe light speeds craft acceleration mph solar 000

Sample Comments

katsura Mar 28, 2023 View on HN

The Breakthrough Starshot initiative plans to travel at 20% of the speed of light, so that could shorten the time necessary to get there.https://www.space.com/laser-sail-centering-breakthrough-star...

thriftwy Nov 21, 2023 View on HN

They will not have to work with relativistic effects. Nobody is going to fly faster than 0.1C. It is prohibitively expensive energy-wise and there is no point of doing that. Just accelerate to 0.01C, and arrive at the neighbouring system in 400 years. 400 years is a blink of eye, anyway.

kbelder Aug 10, 2021 View on HN

5g acceleration for 37 hours will get you up to 1% of the speed of light. Constant acceleration with no fuel limits gets you into the realm of relativity very quickly.

rsynnott Mar 25, 2019 View on HN

If we could travel at (just below) the speed of light, then getting to the next star would take somewhat under four years from the point of view of the travelers assuming an acceleration of 1g (or no noticeable time at all assuming serious magic, with close to infinite acceleration). Of course, the energy to make the acceleration is the big problem...

acqq Apr 26, 2013 View on HN

> If you took 100,000 years that would be a speed of 0.00014c. That is pretty pessimistic - we have put objects into space that are travelling away from earth faster than that already!Citation needed. http://en.wikipedia.org/wiki/Voyager_1 travels now at 17 km/s which is cca 6e-5 of c, twice slower than your 1.4e-4. However the bigger the object, the inertia is bigger too, so it is harder to speed up the bigger things, es

pomtato Sep 12, 2023 View on HN

so you're implying speed atleast 10x the speed of light? i think you'll have better luck increasing the human lifespan instead.

almosthere Nov 27, 2025 View on HN

Is there a way to bypass Voyager with a new craft in some reasonable amount of time if we put enough thrust on it

Intralexical Aug 10, 2024 View on HN

Eh, they're moving at 3-5% the speed of light. Just don't point it towards the planet.

shkkmo Mar 7, 2022 View on HN

From the body of the paper:> Such a craft accelerating at a constant 1000g for half of the trip and decelerating at the same rate for the remaining half would reach Proxima Centuri within 5 days’ ship time due to the fact that it would have been traveling at relativistic speeds for most of the trip (Figure 7B). However, for those of us on Earth, or anyone on Proxima Centuri b, the trip would take over four years.

tlb Aug 6, 2013 View on HN

At 1G acceleration, you can accelerate to a large fraction of the speed of light in about a year. A suitable rocket engine does not yet exist, but g-forces and human lifespans don't prevent travel to nearby stars.