Hmm I haven’t thought carefully about the numbers but I think the big thing you’re forgetting is the importance of deceleration (or “decel” as the cool kids are calling it).
Anders’ paper is called Eternity in 6 hours, assuming technological maturity and even then it’s at 25% of a day efficiency, despite assuming “only” 30g probes and also substantially slower (like .5c iirc).
no because for a probe you don’t have a reverse launcher on the receiving end, which means that to decelerate:
you can’t use some of the “long-launcher” technologies Claude was referring to, like a particle accelerator or a E-M railgun.
If you’re planning to decelerate via fuel, you need to ~square the single-burn mass ratio, thanks to the rocket equation. iiuc it gets a bit worse with relativity.
You might be able to decel without carrying deceleration fuel (eg with magsails), but this also adds weight to your payload.
I thought that there were mechanisms for using the same particle beam to decelerate as to accelerate?
Something like “You put a mirror that can be deployed at the front of your probe. When you want to start slowing down, you aim the beam at the mirror, and it bounces off and hits the probe, now adding thrust away from the direction of motion.”
Hmm I haven’t thought carefully about the numbers but I think the big thing you’re forgetting is the importance of deceleration (or “decel” as the cool kids are calling it).
Anders’ paper is called Eternity in 6 hours, assuming technological maturity and even then it’s at 25% of a day efficiency, despite assuming “only” 30g probes and also substantially slower (like .5c iirc).
Isn’t decel just a difference of a factor of 2?
no because for a probe you don’t have a reverse launcher on the receiving end, which means that to decelerate:
you can’t use some of the “long-launcher” technologies Claude was referring to, like a particle accelerator or a E-M railgun.
If you’re planning to decelerate via fuel, you need to ~square the single-burn mass ratio, thanks to the rocket equation. iiuc it gets a bit worse with relativity.
You might be able to decel without carrying deceleration fuel (eg with magsails), but this also adds weight to your payload.
I thought that there were mechanisms for using the same particle beam to decelerate as to accelerate?
Something like “You put a mirror that can be deployed at the front of your probe. When you want to start slowing down, you aim the beam at the mirror, and it bounces off and hits the probe, now adding thrust away from the direction of motion.”