3 ms·

> Of course you have the issue of how you decelerate at the other end. This is a not-insignificant problem that probably rquires sending automated probes ahead

> Of course you have the issue of how you decelerate at the other end. This is a not-insignificant problem that probably rquires sending automated probes ahead to construct the necessary infrastructure to decelerate you. But how do you get the probes where you’re going in a reasonable time frame? You can’t use the light sail method because of the same deceleration problem. So you’re stuck with the whole operation taking tens of thousands of years, which means you might as well have sent the original payload with whatever sublightspeed mechanism you would use to send the probes.

pmontra 3y ago
I can't remember the book (maybe one by Egan?), they transported the endpoint of a wormhole to its final destination with a normal slow spacecraft and then started using the tunnel for FTL. I guess the crew used the wormhole all the time to refuel the ship and to go sleeping at home :-)
jmyeet 3y ago
People require life support and don't want to spend 80,000 years travelling 4 light years. Automated probes don't have that problem, although they still need to last that long in the hostile conditions of space, which is another not-insignificant issue. At the other end, an automated probe could both accelerate and decelerate at significantly higher than 1G if desired. So automated probes have a vastly wider set of possible mission parameters available to them. You can deploy a solar sail to decelerate as you approach another star. This limits how fast you can go as you need sufficient time to decelerate. Additionally, you have drag in interstellar space anyway just from dust and gas particles slowing you down. Fun fact: to accelerate beyond about 0.86-0.9c your ship would need to be aerodynamic because of the decceleration effect of the interstellar medium. What you're really building here is what's often called an "interstellar highway". If fusion ever becomes viable you can extend this to having waypoints to accelerate or decelerate (as required) a spaceship along the path but that's not strictly required. So building such a system will likely take hundreds, possibly thousands, of years but ultimately result in something where you can travel between the endpoints in a few decades.

pmontra 3y ago

I can't remember the book (maybe one by Egan?), they transported the endpoint of a wormhole to its final destination with a normal slow spacecraft and then started using the tunnel for FTL. I guess the crew used the wormhole all the time to refuel the ship and to go sleeping at home :-)

jmyeet 3y ago

People require life support and don't want to spend 80,000 years travelling 4 light years. Automated probes don't have that problem, although they still need to last that long in the hostile conditions of space, which is another not-insignificant issue. At the other end, an automated probe could both accelerate and decelerate at significantly higher than 1G if desired. So automated probes have a vastly wider set of possible mission parameters available to them. You can deploy a solar sail to decelerate as you approach another star. This limits how fast you can go as you need sufficient time to decelerate. Additionally, you have drag in interstellar space anyway just from dust and gas particles slowing you down. Fun fact: to accelerate beyond about 0.86-0.9c your ship would need to be aerodynamic because of the decceleration effect of the interstellar medium. What you're really building here is what's often called an "interstellar highway". If fusion ever becomes viable you can extend this to having waypoints to accelerate or decelerate (as required) a spaceship along the path but that's not strictly required. So building such a system will likely take hundreds, possibly thousands, of years but ultimately result in something where you can travel between the endpoints in a few decades.