[Space/Spaceships] Getting the velocity/Delta V I want with the tech I want

[scc]

Originally Posted by Johnny1A.2

This is an odd situation to start with. If this is a relatively 'hard' setting, then it's very odd to have two inhabited worlds 400 AU apart, varying only by 44 AU. Four hundred AI is a big gap, it's about 2 light-days. For comparison, the entire Inner Solar System, from Pluto to the far side of Pluto's orbit, is about 11 light-hours. If they orbit the same star, it must be a monster, and that 10% variation is odd, too.

When I first came up with the idea I wanted at least two habitable planets in the one solar system, but I did want the possiblity of more, and playing fast and lose with the system creation rules I ended up with 6 stars, all rather far from one another. It took some talking to others here on the forums to straighten things out, this resulted in Star B orbiting Star A at 400 AU, the difference accounts for planetary and stellar Eccentricity. I can change the values without major problems, I think.

Originally Posted by Johnny1A.2

I assume you mean aerobraking, lithobraking would be slowing down by slamming into the surface of the planet.

Yes. Will ships need armor to perform it?

Originally Posted by Johnny1A.2

The truth is that none of the above is going to be very useful for 400 AU trips in a short time. Ion drive in theory can give you constant accelation for a long time, but at a very low acceleration. At 1g, in a straight line flight (which is oversimplified) you'd need nearly two months 1 way to cover 400 AU. Ion drive, realistically, isn't 1g.

I think that I can live with longer transit times then two months, I did say I found 4 years workable earlier

Originally Posted by Johnny1A.2

We need to know a little more about the setting, and how close you want to stick to realistic phsysics, you may need to rework your star system.

Can you think of what else you need to know?

[Anthony]

Originally Posted by scc

Yes. Will ships need armor to perform it?

Any meaningful fraction of 300 kps will vaporize any conceivable TL 9 ship, as they basically turn the kinetic energy of your ship into heat, and 300 kps is 45 gigajoules per kilogram, which is likely somewhere upwards of 1,000 times the energy required to turn the ship into an expanding cloud of vapor.

[malloyd]

Originally Posted by Anthony

Any meaningful fraction of 300 kps will vaporize any conceivable TL 9 ship, as they basically turn the kinetic energy of your ship into heat, and 300 kps is 45 gigajoules per kilogram, which is likely somewhere upwards of 1,000 times the energy required to turn the ship into an expanding cloud of vapor.

It's a bit worse than that, since 300 mps is in miles/second - 486 km/s. You hit with 1 kT equivalent per 80 pounds of ship.