[Spaceships] Lockheed Phoenix-class rocket transport

[tratclif]

Another for your consideration.

Lockheed Phoenix-Class Rocket Transport (TL7)

Beat The Clock with Transcontinent Rocket Lines! 40 minutes between New York and Los Angeles!
-- Ad, New York Times, Jan 30 1981

Loosely based on this article , this is a delta-winged transcontinental or transoceanic rocket passenger transport for a TL(6+1) retrotech campaign. Launched vertically, the rocket travels ballistically until reentering the atmosphere, then glides hypersonically to its destination. The jet engine provides thrust for landing maneuvers or short-range ferry flights, and has one fuel tank reserved for its use.

Systems Table.

Front Hull System
[1] Armor, Light Alloy (dDR 3)
[2] Control Room (C7 computers, Com/
Sensor 3, Control Stations 3)
[3-4] Passenger Seating, 40 seats
[5-6] Fuel Tank (15 tons LOX/Kerosene and 0.21 mps each)

Central Hull
[1] Armor, Light Alloy (dDr3)
[2-6, core] Fuel Tank (15 tons LOX/Kerosene and .21 mps each)

Rear Hull
[1] Armor, Light Alloy (dDR3)
[2] Jet Engine (1 G acceleration)
[3] Reaction Engine, Chemical (3G accceleration)
[4-6, core] Fuel Tank (15 tons LOX/Kerosene and .21mps each)


Spacecraft Table

PILOTING/TL7 (AEROSPACE)

TL	Spacecraft	dST/HP	Hnd/SR	HT	Move	
7	Phoenix          50	-2/4	12	3/2.3mps

SM	LWt	dDR	Occ	Load	Cost
+7	300	3	43	4.3	7550K

Notes: Air performance(Speed 2500 MPH, Acc 10, Top Speed1250 yds/s, Hnd 2, SR 5). Rocket delta v uses only 11 of the 12 fuel tanks, one tank is reserved for emergency or jet use.

[Agemegos]

I really don't think that what amounts to an airliner needs to be so heavily armoured. And on the other hand it isn't actually heavily armoured enough to make any important difference.

The rules require that a streamlined spaceship have an armour system in either front or centre. You could strip out the other two armour systems, replace them with passenger seating, and double capacity, allowing you to halve the price of a ticket.

[Peter Knutsen]

This isn't so much directed at you, but is a more general commentary: I think it would be very useful if, when people post GURPS Spaceships designs, they always include the TL of the design.

Also, ideally, the subject should state whether the design is realistic, or superscience, or limited superscience, although I myself have not done this.

[tratclif]

Originally Posted by Agemegos

The rules require that a streamlined spaceship have an armour system in either front or centre. You could strip out the other two armour systems, replace them with passenger seating, and double capacity, allowing you to halve the price of a ticket.

Realistically, a semiballistic transport should pay a heavy weight penalty for thermal protection, and the rocket should be less efficient than the one listed in Spaceships. I guesstimated the passenger load by counting the windows the artist chose to put in the illustrations and assuming 4 across seating. I'd expect an early aircraft like this to have uneconomically-low passenger capacity. I'll think about replacing armor with additional fuel tanks, the article says that "two thirds" of the weight of the craft is fuel.

[thtraveller]

Originally Posted by tratclif

TL	Spacecraft	dST/HP	Hnd/SR	HT	Move	
7	Phoenix          50	-2/4	12	3/2.3mps

SM	LWt	dDR	Occ	Load	Cost
+7	300	20	43	4.3	7550M

Shouldn't Hnd/SR be 3/6 as presumably it is winged - at least according to the cost.

(And typos on the dDR and cost)

Realistically, a semiballistic transport should pay a heavy weight penalty for thermal protection, and the rocket should be less efficient than the one listed in Spaceships.

Why? It isn't doing reentry at orbital speed and I didn't think you got much choice about how efficiently H and O mix?

Possibly the jet engine is too efficient for what you want. If you were to put 4 1G Jet engines on it, then you have an airspeed of 5000 mph and you can do the 40 minutes trip without rockets.

[tratclif]

Originally Posted by thtraveller

Shouldn't Hnd/SR be 3/6 as presumably it is winged - at least according to the cost.

As I read it, I take the Hnd/SR from the hull table (p. 9), adjust down for TL7 (p. 35) then adjust back up for winged (p. 35) to get 2/5.

Originally Posted by thtraveller

Why? It isn't doing reentry at orbital speed and I didn't think you got much choice about how efficiently H and O mix?

I can't provide a citation, it's just I've kibbitzed on discussions before about how hypersonic glides can be worse for weighty thermal protection than reentry. Reentry is high heat but short duration, hypersonic travel is somewhat lower peak heat but much longer duration.

The Reaction Engine, Chemical in Spaceships is apparently an optimized LOX/Hydrogen rocket, while the design I'm trying to simulated is an early LOX/Kerosene design, which would probably give less than 3/4 of the Spaceships delta-v.

Originally Posted by thtraveller

Possibly the jet engine is too efficient for what you want. If you were to put 4 1G Jet engines on it, then you have an airspeed of 5000 mph and you can do the 40 minutes trip without rockets.

I always end up making strange vehicles, a jet transport is just to mundane to catch my interest.