HEPLAR Drives

[Gadrin]

I'm mostly familiar with GURPS Traveller, but I was looking into T4's HEPLAR drives to convert Serenity's shuttles into GURPS (which only offers reactionless). Someone on the SJG boards gave me approximations for what the Serenity RPG uses.

I noticed that HEPLAR mentions it takes electricty + fuel to use these drives, would an energy bank be enough to fire up a shuttle, then the drive itself could power some sort of turbine to recharge the energy banks ? or are we talking much, much more power is needed ? (I had thought GURPS provides "power slices" but it's all pretty hazy).

this one uses the "Small Fusion Rocket" not HEPLAR officially.


10-ton Firefly Shuttle "Shuttle One" (TL10)

Crew: 1 Total. 1 Command and Control, 1 Maintenance.

Hull: 10-ton VGSL, non Lifting Body, Light Frame, Standard Materials, Durasteel (Standard) Armored Hull (DR 100), Standard Compartmentalization.

Control Areas: Cockpit/Systems (Complexity 6).

Communicator Range (mi)  Radio  Maser  Laser  Meson  
Cockpit/Systems 5,000,000 0 10,000,000 0 
Sensors Range/Rating (mi)  Passive  Active  Radscanner  
Cockpit/Systems 10,000/35 45,000/39 1,000/29

Engineering: 10 Sm Fusion Rocket (2.94 Gs), 0.5 Cryonic Internal Tank (Fire 0, Loaded with 0.5 stons), Sm Utility.

Accommodations: Sm Passenger Seating (6 Passengers).

Stores: 0.5 Hold (8 dtons free for cargo).

Statistics: EMass 44.47 stons, LMass 84.98 stons, Cost MCr6.75, HP 1,350, Damage Threshold 270, Size Mod 6, HT 12. 12.5 Man-Hours/day Maintenance,

Space Performance: sAcc 2.94 / 5.62 Gs.

Air Performance: aSpeed 740 mph, Skimming aSpeed 9,129 mph, aLift 250 stons.

Underwater Performance: Unable to Submerge.

Sample Times : Orbit 0.08 Hrs, Escape Velocity 0.11 Hrs, 100D 3.72 Hrs, Earth-Mars 63.91 Hrs.

Software Package  Qty  % Utilization  Description  
Datalink 1 0.0000 C1 
Library Data 1 0.0000 C1 
Totals  0.0000

Options
All times are Earth Std, Full Load.
100D and Earth-Mars assume mid-point turnover.
Turrets add to Jump Tonnage for Jump Drive/Fuel calculations

Printed with GTS Version 2.29.07 on 7/11/2007 6:32:00 PM
Copyright © 2000 by Gadrin

 

[Gadrin]

GURPS also offers Light and Heavy Energy banks in Ground Forces

Light = 1350 MWS, 100 lbs
Heavy = 6750 MWS, 500 lbs

which are for Grav vehicles and seem to be enough for a 10-ton shuttle.

 

[Commander Drax]

the problem with your idea, is that the bulk of the energy would have to be in your reaction mass, such as a chemical drive, that uses a battery to start it, though when running generates copious amounts of electrical energy to run the ship and recharge the batteries.

Heplar uses liquid hydrogen as fuel and is heated to plasma state by the vessels main reactor, usually a fusion reactor. Although if some of the heat that is expelled out of the back of the ship in plasma form is converted to electricity via a thermoelectric junction I don't see any problem with recharging the batteries, although to be totally realistic this should result in a tiny reduction in thrust.

When it comes to realism however, Heplar can't really work at the postulated levels of fuel efficiency as presented in TNE unless it coupled with some other postualted scientific advance such as inertia/mass reduction or gravitic enhancements being part of the drive.

 

[Gadrin]

When it comes to realism however, Heplar can't really work at the postulated levels of fuel efficiency as presented in TNE unless it coupled with some other postualted scientific advance such as inertia/mass reduction or gravitic enhancements being part of the drive.

yeah, I can't remember exactly but the "sm utility" (that's listed) used to be similar to a contra-gravity device + internal grav generator, to help reduce the ship's weight, and allow normal gravity in space. I remember the writer of the program mentioning that specifically to me at least once, since the GT setting "owns" gravity

I also noticed I had to use the "SM Fusion Rocket" which waaaaaaaaaay out performed the HEPLAR one in terms of thrust, something like 25 tons of thrust vs 3.75 for the HEPLAR. The guy who wrote the program was pretty good, so I assume he got the nod from the general GURPS gearheads before modeling the drives in their final form for release of his program.

Last night I was going thru GURPS Traveller main book and noticed the basic air/raft they have included an NPU that was about 20-30 lbs, so maybe a single energy bank for backup, a small NPU for electricity and the Utility module and the rest is the Fusion maneuver drive.