Light years and delta-v

[JMD]

Back when I first started learning the spaceships rules I told my players they were 7 light years from their destination (trying to get back to Earth). It never mattered until now since they have been marooned on a hostile alien planet....but they have since captured a generation ship and are on their way back home shortly.

I picked up a pen and tried to figure it out.

Their delta-v is 60mps since they have an Advanced Nuclear Pulse engine and 3 fuel tanks.

Their being 7 light years away means they are 4.11494987 × 10^13 miles from their destination.

It looks like this will end up being a 21,732 year journey at max speed. Is this correct?

[Bruno]

Sounds about right. A lightyear is VERY VERY big.

[JMD]

Originally Posted by Bruno

Sounds about right. A lightyear is VERY VERY big.

Now I play the game where I make them realize how big a light year is and introduce some plot as to how they got out that far in the first place.

I at another point said it was a 35 year journey from Earth to Terra 5, I suppose they could have shortcuted through a black hole or something I don't fully understand yet. There is no FTL in this game...any suggestions?

[Anders]

Remember, it will not take that long for the people on the ship. I don't know how much time dilation would 'shorten' the trip, but they would not age as much.

[Kuroshima]

Originally Posted by JMD

Now I play the game where I make them realize how big a light year is and introduce some plot as to how they got out that far in the first place.

I at another point said it was a 35 year journey from Earth to Terra 5, I suppose they could have shortcuted through a black hole or something I don't fully understand yet. There is no FTL in this game...any suggestions?

Give them reactionless engines that allow them to accelerate for half the trip, and decelerate for the other half. With reaction engines, remember, you need to brake somehow, when you get there, so using all your delta-v isn't wise...

[Than]

Reactionless drive.

Even relatively (pun intended) modest constant accelerations can get a spacecraft up to a good fraction of lightspeed. That makes journey times years rather than millennia, and time dilation improves things even further for those on board.

Edit: Scooped.

[Dammann]

If you're resistant to reactionless, consider laser propelled solar sails for journeys away from a star, and only using reaction mass for slowing down. I am not a big fan of the movie Avatar, but the interstellar ship they use is regarded by some (well at least Winchell Chung) as a reasonable way to use this sort of scheme to get between close stars in decent spans of time.

[Kuroshima]

Well, using this page, I get that with a constant acceleration of 0.023g, you can travel to your Terra 5 in 35.07143634455902 earth years (the crew will experience only 34.131142192432755 years though)

[Diomedes]

Originally Posted by Asta Kask

Remember, it will not take that long for the people on the ship. I don't know how much time dilation would 'shorten' the trip, but they would not age as much.

Not by much; to get even 1% time dilation requires about 15% of c (about 28,000 mps).

[JMD]

Originally Posted by Asta Kask

Remember, it will not take that long for the people on the ship. I don't know how much time dilation would 'shorten' the trip, but they would not age as much.

Interesting, how much would time slow down going 60 mps? Edit:Looks like someone answered this as I was typing!

Also, I was thinking of a wormhole or some similar logic...I'm trying to stick with hard science as much as I can so suggestions are welcome. We are at TL9 with some TL10 available on the ship they are on.