![Terran Trade Authority [Spaceships]](https://preview.redd.it/tu9r4qz929fh1.png?width=140&height=140&crop=1:1,smart&auto=webp&s=bc0d9f2c16d0a7a12c3cc6dd66f33da455f8515a)
Terran Trade Authority [Spaceships]
I've recently saw a video about the Terran Trade Authority books (late 70s). This is just the sort of book that would've captivated me as a young child. I loved this era of sci-fi spaceship art: Usborne's "Computer Spacegames" was a treasured book, and I liked the covers of the Maplin catalogues here in the UK.
The TTA books have a delightfully anachronistic timeline in retrospect. There is an an official TTA RPG that Stewart Cowley co-wrote, but I was disappointed with the forward shift in timeline, and the replacement of some technologies with more "fashionable" ideas of the 2000s - for example the Dune-inspired space folding warp drive became an Alcubierre drive.
I love converting things to GURPS Spaceships, so here's my attempt at the SSF 21D Cutlass.
Technology notes
TL9 up to the 2040s. TL10 with the introduction of force screens and contragravity.
McKinley Ion Ultradrive - treat as a VASIMR drive in low thrust mode.
deVass Warp Generator - treat as a Jump Drive, limited to safe jump points outside of gravity wells, and requires a charge-up time of one day per light year of jump. The jump itself takes one day per light year. Maximum jump distance of 5 light years.
Defense Shield - treat as a Force Screen, with a dDR of one SM smaller than that of TL 11, and must have the energy switch.
Gravity Resist Projector - treat as contragravity.
Synthetic Steel - treat as metallic laminate
Plastisteel - treat as advanced metallic laminate. High-density plastisteel is hardened AML.
Various advanced Plastisteel variants such as flexible, articulated or layered are treated as nanocomposite.
SSF 21D Cutlass (TL10)
Manufacturer: Various
User: Terran Defense Authority
Year: 2050
Role: Local Defense Interceptor
Crew: Pilot, Gunner, Astrogator
Armaments: 1 OPA-8 Particle Accelerator; 2 Laserlances; Missile Launcher (4 Mk II missiles)
The SSF 21D Cutlass was produced for the Mars War, a military variant of the 2023 Law Enforcement Cutlass.
The Cutlass has a robust 300-ton streamlined hull, 45 yards long. As the hull was designed prior to the introduction of gravity-resist generators, it has wings for aerospace operations. The hull is 14mm high-density plastisteel at the front and center, 7mm in the rear.
Two propulsion systems are installed. Two Avery nuclear thermal ram-rockets provide 300 tons of thrust for combat maneuvering and aerospace operations; or 750 tons when the variable choke venturi tubes are employed. An ion ultradrive is used for interplanetary travel.
At a cruising speed of 10 mps, the Cutlass can travel 1 AU in 29 weeks (13.5 weeks acceleration, 2 weeks cruising, 13.5 weeks deceleration).
Statistics
dST/HP: 50/70
HT: 12
Space Move: 1G/1.8 mps
Space Hnd/SR: -1/5
Air Move: 10/1,250 (2,500 mph)
Air Hnd/SR: 3/6
LWt.: 300
Load: 0.4
SM: +7
Occ: 4ASV
dDR: 16/16/8 (Hardened); 15 (energy force screen)
Range: -
Cost: $49.54M.
Special rules
Pulsed Thrust. The thrust of the nuclear thermal rockets can be doubled. For every one minute of pulsed thrust (in space, this is one fuel tank of fuel, 0.45 mps), make a HT check for the ship. On a failure, the rockets become disabled.
Semi-Rapid Fire beams have a RoF of 3 (20-second), 10 (1-minute), 30 (3-minute), or 100 (10-minute).
Structural Reinforcement is an optional rule from Eric B. Smith’s spreadsheet.
Armour and Volume rules from Pyramid 3/34.
Systems
Front Hull
[1-2] Armor, Advanced Metallic Laminate (total dDR 16; hardened)
[3!] Weapon Battery (one fixed mount 10MJ semi-rapid fire particle beam; two fixed mount 10MJ semi-rapid fire improved lasers)
[4] Control Room (C7 computer; comm/sensor 6; three control stations; Emergency Ejection (Lifepod))
[5] Smaller Systems (three at SM+6): Habitat (1 bunkroom); Weapon Battery (one fixed mount 20cm missile launcher); Tactical Comm/Sensor Array (comm/sensor 7)
[6!] Half-size Systems: Force Screen, Early (dDR 15; Energy); Structural Reinforcement
[core] -
Central Hull
[1-2] Armor, Advanced Metallic Laminate (total dDR 16; hardened)
[3-6] Fuel Tanks (15 tons hydrogen each for Nuclear Thermal Rocket (ram-rocket); 1.8 mps total delta-V)
[core] Power Plant, Fusion Reactor (2 Power Points)
Rear Hull
[1] Armor, Advanced Metallic Laminate (dDR 8; hardened)
[2-3] Nuclear Thermal Rockets (0.5G acceleration each; ram-rocket)
[4!] Ion Ultradrive (0.0002G acceleration)
[5-6, core] Fuel Tanks (15 tons hydrogen each for Ion Ultradrive; 30 mps total delta-V)
Design Notes: The source material states the Cutlass has a thrust of 1,500,000 lb - this is 750 tons. The Cutlass is implied to be able to launch from the surface of Mars, so it needs an acceleration greater than 0.38G. Using NTR drives, this means the Cutlass cannot be greater than SM +8 (1,000 tons); or SM+7 if we also want it to operate in Earth’s atmosphere.
I don't know why Cowley decided on two high thrust rockets when the painting clearly has three.
The stated armour thickness of 14 cm is a problem if plastisteel has the same density as steel: it would mean the ship would have to be almost entirely comprised of armour. I decided to treat this as a “typo” and make this 14 mm thickness.
The illustration depicts the Cutlass as having a streamlined, winged hull - which ties in with the original hull being designed prior to the invention of contragravity. I added the ram-rocket feature to the NTRs on the basis of what appears to be air intakes.