M-Drives

Discuss the Traveller RPG and its many settings
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

M-Drives

Postby barnest2 » Mon Mar 07, 2011 5:27 pm

Quick question, cos I cant find it
What TL do the different types of manoeuvre drive come in?
I mean Grav plates, reaction drives, etc
User avatar
alex_greene
Cosmic Mongoose
Posts: 3800
Joined: Sun Dec 21, 2008 11:29 pm
Location: UK
Contact:

Postby alex_greene » Mon Mar 07, 2011 5:44 pm

Reaction drives - rockets - come in as low as TL 6. Ion drives come in at TL 7-8. I think Traveller's impulse drive comes in at TL 9.
Board moderator. Product List [DriveThruRPG]: Blood Path [Legend]; Cosmopolite [Traveller]; Castrobancla [Traveller]
hdan
Lesser Spotted Mongoose
Posts: 772
Joined: Wed Aug 13, 2008 2:11 am
Location: Austin, Texas

Postby hdan » Mon Mar 07, 2011 5:44 pm

From other sources, you get:

TL-10 introduces "grav lifter" drives. Reactionless, but don't work away from a gravity well
TL-11 gets you "thruster plates" - Reactionless drives that can work in deep space.

People still use reaction drives at TL-10 since TL-10 gravitic drives aren't useful beyond orbit.

This site is useful: http://traveller.wikia.com/wiki/Tech_Le ... ison_Chart

Also note: when culling info from the web, GURPS Traveller uses a different Tech Level progression.
/hdan
Jeraa
Lesser Spotted Mongoose
Posts: 552
Joined: Thu Feb 24, 2011 10:01 pm

Postby Jeraa » Mon Mar 07, 2011 5:47 pm

Lets see... reaction drives are late 5/early 6 I believe.

And going back to Classic Traveller:

drives A-D TL9
drives E-H TL 10
drives J-K TL11
drives L-N TL 12
drives P-Q TL 13
drives R-U TL 14
and the rest of the drives TL 15
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 5:59 pm

Oh, damn: SPOILERS FOR MY PBP PLAYERS















Okay, so a TL-8 world will be using reaction rockets for its space ships?
This is going to be hilarious...
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 6:23 pm

barnest2 wrote:Okay, so a TL-8 world will be using reaction rockets for its space ships? This is going to be hilarious...
Yep, AND taking months to get somewhere as far away as Mars...
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 6:29 pm

How come? I mean they make the same thrust as a grav driven ship...
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 6:40 pm

barnest2 wrote:How come? I mean they make the same thrust as a grav driven ship...
Same reason as today (late TL 7). You have to carry reaction mass needed.
It's too bulky (mass) to carry enough to actually sustain thrust for more than an hour or less. Grav is continuous thrust due to fission or fusion PP's. Rockets burn fuel VERY fast for the same thrust.

Here is a simple treatment of the situation: http://www.projectrho.com/rocket/mission.php#Delta-V
Last edited by DFW on Mon Mar 07, 2011 6:45 pm, edited 1 time in total.
AndrewW
Cosmic Mongoose
Posts: 4346
Joined: Fri Dec 19, 2008 11:57 pm

Postby AndrewW » Mon Mar 07, 2011 6:43 pm

DFW wrote:Grav is continuous thrust due to fission or fusion PP's. Rockets burn fuel VERY fast for the same thrust.
Or antimatter PP's as the case may be.
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 6:44 pm

Fair enough... though I just got 6 hours of thrust at 2G's into a 4000 tons hull :D which is awesome.. it also has a full weapons complement :D.
Anyway, thankee kindly.
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 6:47 pm

barnest2 wrote:Fair enough... though I just got 6 hours of thrust at 2G's into a 4000 tons hull :D which is awesome.. it also has a full weapons complement :D.
Anyway, thankee kindly.
Yep, MGT throws out any physics even at current TL science.

Pretty good though. But, you aren't going to really be going to mars in that ship. Not in any reasonable time frame anyway...

4 hours of 2 G accel-decel gets you 63,568 km.
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 7:01 pm

At the acceleration given, with an acceleration time of two hours, and a deceleration time of two hours, I found it would take something like 4 days to get too Mars, that's all ... That seems usable at the very least.
(this is in a 2G reaction drive ship, with a thrust then glide method)
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 7:05 pm

That is best possible time however. Its more likely to take something like 16 days (or two weeks)
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 7:22 pm

barnest2 wrote:That is best possible time however. Its more likely to take something like 16 days (or two weeks)
I got (when Mars/Earth are at their closest ever), 6 days 8 hours.

16 days sounds about right for an average. Should be very interesting as there is no fuel left for anything in between.

Could be a real nail biter type of scenario. Good fun.
User avatar
barnest2
Greater Spotted Mongoose
Posts: 1104
Joined: Thu May 28, 2009 9:38 am
Location: Northern England

Postby barnest2 » Mon Mar 07, 2011 7:35 pm

Well it only takes a month using only one hour of fuel each way. That gives you two hours of fuel (40 G/turns) for manoeuvring etc...
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 10:59 pm

barnest2 wrote:Well it only takes a month using only one hour of fuel each way. That gives you two hours of fuel (40 G/turns) for manoeuvring etc...
Right. However, you need a PP for all other ship power needs and enough fuel for whatever duration...
hdan
Lesser Spotted Mongoose
Posts: 772
Joined: Wed Aug 13, 2008 2:11 am
Location: Austin, Texas

Postby hdan » Mon Mar 07, 2011 11:16 pm

Yeah, but if you use an atomic pile for your PPlant, you don't need fuel.

(Woohoo! Atomic Rockets!)
/hdan
User avatar
DFW
Cosmic Mongoose
Posts: 2956
Joined: Mon Jun 07, 2010 7:24 pm

Postby DFW » Mon Mar 07, 2011 11:31 pm

hdan wrote:Yeah, but if you use an atomic pile for your PPlant, you don't need fuel.

(Woohoo! Atomic Rockets!)
Fissionables ARE fuel. Also, you can't use it for TL rockets so, you need, rocket engines, rocket fuel & a nuke PP.

Who is online

Users browsing this forum: No registered users and 51 guests