GURPS Spaceships for THS conversions?

[The Wrathchild]

Hmm yeah, maybe that was it ... in which case I'm remembering wrong AGAIN (that does happen a bit much these days, mayhap I should test the stress levels ;-)

Back to the drawing board :-)

[thtraveller]

Areon News - Islandia Express Launched

Today sees the launch of the “Islandia Express” passenger service using the first production model of Vosper-Babbage’s “Void Skimmer” passenger shuttle. Capable of making the Earth-Islandia run in 9 hours it is hailed as a major speed breakthrough that makes Earth-L4 travel as fast as intercontinental travel on Earth. Twice as fast as existing Earth-Lunar shuttles the service caters for the premium end of the burgeoning mass transit market between Earth orbit, Lunar orbit and L4.

Our reporter joined the chairman of both Vosper Babbage and Islandia Space Lines on its maiden voyage from Islandia in L4 to Von Braun station in low-Earth-orbit.

Islandia Space Lines: “With the Olympus project well underway the expected growth in demand for rapid transit between Earth, Lunar and L4 is huge. Providing our customers with what they want before anyone else reinforces our position as the premier passenger carrier in Trans-Lunar space. We also take the comfort and safety of our passengers very seriously indeed as you can see from the generously appointed interior.”

Vosper Babbage: “The Void Skimmer was a concept craft we had on the drawing board for the military market. When we were approached by ISL about an express passenger shuttle the synergy was obvious. Our close location to Islandia meant that we could closely collaborate in person at all stages of development leading to a much better final product. We are already working together to design the second generation of rapid transit shuttles.”

The voyage itself is something of an eye-opener. On existing shuttles there is the gentle pull of micro-gravity. On the Islandia Express you are pinned to your seat! Acceleration is close to Lunar standard gravity during the trip and it goes on for the entire journey which takes some getting used to.

Time is money, and this is reflected in the ticket prices. A first class seat costs $1000 and a standard seat costs $500, many times as much as existing shuttles. Industry watchers say prices will drop sharply once competitors enter the market.

Detractors point to the high running costs & the infrastructure required compared to existing shuttles. One shuttle operator commented that “This is a charter for the big carriers to edge out the smaller independent carriers.”

Design

From the drive bell dominating the rear of the craft and with every spare inch of hull covered in radiator panels it is obvious to look at that this craft means business. The hull material also says speed as it is made of Nanocomposite which is more commonly seen on military vessels. Other than that the dimensions are similar in dimensions to standard passenger shuttles. A standard cylindrical design, approximately 45 feet long by 15 feet in diameter.

Inside the craft says luxury, with a large first class section and a high standard of fittings throughout. With twin airlocks and generous backup power the craft significantly exceeds the latest safety standards.

Front
1 Armor (Nanocomposite) dDR 7
2-6 Passenger Seating (10 seats)
C Control Room

Central
1 Armor (Nanocomposite) dDR 7
2-4 Cargo (4.5 tons)
5-C Fuel Tank

Rear
1 Armor (Nanocomposite) dDR 7
2-6 Fusion Rocket (High Thrust Water) 0.15G

TL 10, dST/HP 20, Hnd/SR 0/4, HT 12, Move 0.15G (30 mps), LWt.30, Load 4.5, SM 5, Occ 16 SV, dDR 7, M$ 2.1

Earth-Lunar/L4/L5 Travel Time: 9 hours

Economics: Assumes 2 trips per day, 700 trips per year. Breakeven with 90% passenger load approximately $80 per ton of cargo, $60 per standard passenger and double that for first class passengers. Suggested ticket price $300 per standard passenger and $600 per first class passenger.

* first class seating is simply half the number of seats in the same space as two normal seats.

(Those with long memories may recall the color text from the old TS version I did in 2004 - and my website)

[thtraveller]

Branson Class Conventional Orbital Lighter (Lifter and Spaceplane)

Branson class space planes are cheap reusable two part orbital lighters that can take off and land at a normal landing strip. It can easily make the return journey to and from low-Earth-orbit once for every four orbits of the LEO space station or every 360 minutes.

The lifter craft and the orbiter craft are both capable of independent operation and flight. The orbiter rides underneath the lifter until separation above the atmosphere. Both use standard chemical rocket fuel. The lifter also has a large jet engine.

Using Jet engines the lifter takes off and clears local population centers before going supersonic and accelerating to maximum air speed in an easterly direction. It then ignites its rocket drive and boosts towards orbit until it runs out of fuel. At this point the orbiter detaches, engages its rockets and completes the climb into orbit. The lifter drops back into atmosphere and flies back to its base using its jet engines where it refuels and picks up the second orbiter.

Having docked with the orbiting space station and exchanged passengers the orbiter makes a re-entry burn to enter atmosphere and then makes a slow glide descent back to Earth. It lands on its airstrip a couple of hours after it took off.

The Lifter cycles every 180 minutes and each orbiter every 360 minutes.

To take advantage of the Earth's spin they typically take off from airports close to the equator.

Branson Lifter "Big Richard":
Front
1-6 Upper Stage (Orbiter)

Central
1 Armor (Light Alloy)
2-6 Fuel Tank (HO)
C Control Room

Rear
1 Armor (Light Alloy)
2 Fuel Tank (HO)
3 Chemical Rocket (3G, 1.08 mps)
4-5 Jet Engine (2G, 0.97 mps)
6-C Fuel Tank (Jet fuel, 1 hour)

dST/dHP 50, Hnd/SR 3/6, HT 12, Move Flight 2G/3500 mph/0.97 mps, Move Boost 3G/1.08 mps, LWt 300, Load 2.5, SM +7, Occ 3 SV, dDR 3, Cost M$ 9.6., TL7, Streamlined, Winged, Length 40 yards

Total DeltaV 2.05 mps

Jet Engine 3500mph = 0.97 mps
6 Chemical Fuel Tanks 6*0.15*1.2 (6 tank adjustment) = 1.08 mps

Branson Orbiters "Little One" and "Little Two":
Front
1 Armor (Light Alloy)
2-5 Passenger Seating (24 seats)
6 Fuel tank (HO)
C Control Room

Central
1-C Fuel Tank (HO)

Rear
1 Chemical Rocket (HO, 3G, 3.12 mps)
2-6 Fuel Tank (HO)

dST/dHP 30, Hnd/SR 4/5, HT 12, Move Boost 3G/3.12 mps, LWt 100, Load 2.6, SM +6, Occ 26 SV, dDR 2, Cost M$ 1.46, TL7, Streamlined, Winged, Length 30 yards

DeltaV 3.12 mps - 13 Water Fuel Tanks 13*0.15*1.6 (13 tank adjustment)

Combined Effective Delta-V of Lifter and Orbiter = 2.05 + 3.12 = 5.17 mps (only 4.6 mps required to attain orbit)

Advance Return Ticket price = $16000

Designers comment: these craft are all "low tech" TL7 designs, they just bring together technology that is already available.

[wabishtar]

If you are going to use GURPS Spaceships for Transhuman Space, you need to realize that the fuel costs in GURPS Spaceships are WAY too high for the Transhuman Space universe. If you look at the core book, they have fuel cost per space, and then they have the tonnage for that space, so it's fairly easy to figure out fuel cost per ton. Here is the cost for fuel per ton as it should be in the Transhuman Space universe.

Water $20
Coolant $80
Hydrogen-Oxygen $85
Argon $170
Hydrogen $350
Nuclear Pellets $500
Jet Fuel $1,000

Given that in Transhuman Space nuclear pellets are $500 and the price listed in GURPS Spaceships is $50,000, I have to ask. What universe are the prices in GURPS Spaceships intended for? Is this is cost of fuel assuming none of the fuels are being mass produced?

[Crakkerjakk]

However, the fact that a ton of nuclear pellets are cheaper than a ton of jet fuel should also trip your warning sensors about the validity of the THS numbers as well.

[wabishtar]

Originally Posted by Crakkerjakk

However, the fact that a ton of nuclear pellets are cheaper than a ton of jet fuel should also trip your warning sensors about the validity of the THS numbers as well.

Not really. Keep in mind, in the world of Transhuman Space, most of the oil has been mined and used up, so I would kind of expect it to be extremely expensive. The only places to get petroleum based products are the few oil wells still running, where as nuclear pellets are made from chemicals found all over the solar system. I would expect them to be cheaper per ton, as the setting seems to indicate that nuclear pellets are significantly more plentiful than jet fuel.

[wabishtar]

Originally Posted by Agemegos

Jet engines need not run on rock oil, they can run on biofuels. And kerosene can be synthesised abiotically if you have an energy source, such as nuclear pellets. In fact, there is so much more energy in nuclear pellets than there is in jet fuel, and the fundamental ingredients of jet fuel (carbon and hydrogen) are so plentiful, that it is very hard to see how the rate of transformation can ever get down to 1:1.

There's also the matter of supply and demand. In the world of Transhuman Space, nuclear pellets are the fuel of choice for virtually all interplanetary spacecraft. Jet fuel, on the other hand, is used by the few transatmospheric vehicles to have not switched over to laser lifters. If I remember Fifth Wave correctly, even most airplanes use ducted fans or some other kind of propeller as the people of Earth seem to avoid polluting as much as possible. That means that there really isn't much of a demand for jet fuel, leading it to not be manufactured in very high numbers, making it more rare, making it more expensive.

Come to think of it, given the environmentalist attitude that most of Earth's government's have taken, I wouldn't be surprised if a big chunk of that fuel cost was taxes meant to discourage use of jet fuel. You can even see that kind of stuff today. The tax rate in the UK on petrol is currently about 188%. Since the governments of Earth in Transhuman Space are very environmentalist, I would assume that similar tax rates would exist, if not become stricter. The prices of petroleum products usually have more to do with political and economic concerns than the actual cost involved in making them.

[wabishtar]

Originally Posted by Agemegos

Congratulations. You seem to have proven that low demand leads to high price, to the defiance of established price theory. Don't hold your breath waiting on the Nobel Prize for Economics.

Your sarcasm aside, you're over simplifying the theory of supply and demand. It's not low demand that leads to low prices, it's low demand in relation to supply. Jet fuel needs to be manufactured, meaning that the supply is artificial. I suppose I wasn't clear enough, but I was saying that the low demand plus the fact that society at large frowns on hydrocarbon fuels plus large taxes on hydrocarbon fuels probably all conspire to make the supply even lower than the already low demand, as there simply isn't much profit in manufacturing jet fuel.

And by the way, was the sarcasm really necessary? Honestly, it feels like I can never have a normal, civil, adult conversation on this message board. What was the purpose of that? Why is it that talking game always seems to make people regress to the age of ten?

[laserdog]

Originally Posted by Phil Masters

No can do. Fusion Torch requires a [rear] location, and [rear] explicitly excludes [core].

Originally Posted by The Wrathchild

I've used the otherwise very exellent online construction system at 101010.org, and that seemed to catch such errors - not that one though.

Yeah, this is my bad. I actually thought that [front] and [rear] just ment they needed to be in those sections, I completely missed the bit on page 9 saying that they can't be core.

I'll try to update the calculator soon for completeness.

[thtraveller]

Originally Posted by wabishtar

Given that in Transhuman Space nuclear pellets are $500 and the price listed in GURPS Spaceships is $50,000, I have to ask. What universe are the prices in GURPS Spaceships intended for?

The 4th edition universe?

The cost of NP in 3rd edition (see Vx1) varied with TL (25k/ton at TL8, 0.5K/ton at TL10) whereas that has gone away in G:Spaceships and presumably 4th edition.

For simplicity I would just say they are third edition figures in TS and fourth edition in Spaceships.