Saturday, April 08, 2023

Traveller: 1G drives and landing/taking off

A rather spirited discussion took place over on COTI about ships with a 1G maneuver drive and if they can or cannot take off from worlds with more than 1G local gravity.

Back in college, we never thought through this: we just assumed if the ship could land on a planet, being streamlined, it could take off again. Going with the classic and pulp-style science fiction, we were not overly concerned with the technical minutia. We only cared about having fun.

Which, as I've mentioned before, fun is relative to the eye of the beholder. For some, arguing about these details is part of the fun. And while I really do enjoy arguing far too much about silly things, in the end it is always your game to be played how you want.

After reading through the discussion, I've decided that now I will take into account the M-Drive of a ship to see if it can or cannot land and take off again. Of course, I usually make ships with 2G drives at a minimum, so not an issue. But if the players get a 1G drive, that will limit them to which planets they can actually land on and take off from.

In reading the discussion, there are some interesting takes that could imply it does not matter. An air/raft can reach orbit of any planet in the planet size x hours. If a starship has grav-lifters like an air/raft, does that mean it too can reach orbit regardless of the M-Drive? The rules, at least in Classic Traveller, are silent about this (and the actual aspect of the M-Drive itself is left to the players. I always assumed the drive was a reactionless magic system like most of my SF reading: takes off gracefully and near silently on some form of thrust that does not destroy the landing pad. Heplar and the M-Drive as a weapon flip that around. And I do not like that idea as then you really can't land ships without a very sturdy infrastructure. As witness the last NASA launch that, due to the very powerful engines, caused quite a bit of damage to the launch system platform!)

One of the takes at least hinted at in the discussion was that the g-drive is proportional to the actual local gravity. That is, the higher the gravity, the more g-drive can push. I'm thinking similar to something in water - deeper down, if it is buoyant, it becomes harder to push deeper. A reaction to the local field that is proportional to the gravity. Sort of like non-Newtonian fluids in a way.

The other argument going on was about lifting surfaces and whether the ship could generate lift. A streamlined ship does not necessarily have wings, it is just designed to be able to enter atmospheres in the Traveller universe. Though a lot of ships as portrayed do have wings, but is it enough? For shuttles and the like, ships less than 100d-tons, as those are specifically designed to be used in atmospheric conditions, certainly. Starships have a higher density than shuttles at a guess so it seems less likely. Though if you are going along at mach 25, it does not take a lot of surface area to give that lift.

Anyways - next Traveller game I play, the ship drive will be affected by local gravity so that a 1G ship cannot take off from a planet with more than 1G.

and not at all related to M-Drive, found this when wandering through project rho site (always a wonderful resource!). I may bet back to figuring out a space station 6-digit USS code (Universal Space Station) code. As Traveller loves its 6-digit codes! This gives us the 1st 3 digits, though I may want to remap them to possibly match the way the UWP works. Or not.


And finally - got laid off yesterday. As always, it is a gut punch to me when this happens. The company has been laying off people left and right so while not exactly expected, it was still a surprise. And job hunting at 59 is not a pleasant thought. There is, of course, a bright side: that is really how this blog started more than 20 years ago. I had a sudden large amount of free time, and I can only clean so much. So I started the Traveller Trade program. Will I restart that again? Maybe - I'm going to try and work on the Avalonia tooling in .Net that is supposed to work for Windows, Macs and Android. Though I am going to go through the tutorials and learn the "proper" way. In between frantically filling out applications! And the other bright side: I learned from the 1st time this happened to have a safety net. So I've a bit of time before I really need to worry. Though I'll worry until I get a job because that is what I do. And if it was not for insurance, I am really close to being able to retire. Unless something catastrophic happens, which is why I want to build up my nest egg more. Sadly, despite my many characters in various games, I can't just go out there and explore space or dungeons!

And finally, finally - I have 22 followers! Thanks for following, though more people do read this and not follow me as was pointed out. All good, and as I've said a lot, this blog is really mostly for me to get some of my creative things out there. Who knows, maybe one of these days I'll try a 'zine on Kickstarter. If I start with a PDF only, see how that goes. Just not sure if I've enough self-confidence for that sort of thing. Also, why I don't work for myself!

2 comments:

NotASnark said...

Technically, a ship with 1G of thrust can't take-off from even a 1G world. It would have just enough thrust to balance the gravity, and would therefore hover. Slightly less than 1G gravity, or slightly more than 1G thrust, would be enough.

In Mongoose Traveller, engineers have the option to 'overload' a drive, providing +1 thrust for a round (6 minutes). This would be enough to launch and get high enough and fast enough that a little bit of aerodynamic lifting body would get you to orbit.

What I assume is that drives have an option to produce an anti-grav effect around the ship - up to 25% of the ship's thrust. That's enough to get to orbit (or to land) on worlds up to 1.25g. It strains the engines and power systems though, so can only be used for a few minutes so isn't on all the time.

Craig Oliver said...

Good point on the 1G worlds. The anti-grav part sounds suspiciously similar to Star Trek's explanation on the impulse drives in that they somehow reduce the mass of the ship in order to accelerate it.

I enjoy the details like that, though not sure my current group of gamers would