[Spaceships] TL10^ multipurpose orbital shuttle

[Agemegos]

Type 64 MkI orbital shuttle (TL10^ limited-superscience)

This is an orbital shuttle designed for landing parties from an exploration vessel on the surface of a habitable planet and returning them to rendezvous with their ship in orbit. Built on a 30-ton streamlined airframe, it is a winged design 45 feet long, with a fusion-powered ram-rocket intended more for atmospheric cruising than for making an important contribution to reaching orbit. The winged design allows the shuttle to fly with the ram-rocket at low throttle, which is reasonably inoffensive near settled areas.

Besides sporting landing wheels, Type 64 MkI shuttles are designed for a water landing. They are fitted with a refining plant for wilderness refuelling. Each will carry ten passengers in acceleration couches and nine tons of cargo. The manufacturer offered "fuselage tanks" that could be fitted in the cargo hold to carry an extra eight tons of water, but in practice these only ever used for conveying cargoes of fuel to the mother ship.

Forward hull

[1] Armour, nanocomposite (dDR 5), $150k, —
[2–6] Passenger seating (10 acceleration couches), $60k, —
[core] Control room (comp 6, com/sen 4, stations 1), $60k, —

Midships hull

[1] Armour, nanocomposite (dDR5), $150k, —
[2–6, core] Cargo hold (9 tons), — , —
[wings] $150k

Aft hull

[1] Armour, nanocomposite armour (dDR5), $150k, —
[2] Refinery (0.5 tons/hour), $30k, —
[3] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[4] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[5] Reaction engine, fusion torch (1.5 g with water), $300k, —
[6] Reaction engine, fusion torch ram-rocket (1.5 g with water), $1.5M, — [note 1]

Basic Stat block

PILOTING/TL10 (HIGH-PERFORMANCE SPACECRAFT)
TL: 10^
Spacecraft: Type 64 Mark I exploration shuttle
dST/HP: 20
Hnd/SR: +4 / 6
HT: 12
Move: 3 g. / 10 mi./sec. (air speed 3,450 mph [note 1])
LWt.: 30 tons
Load: 9 tons
SM: +5
Occ.: 1+10 SV
dDR: 5 / 5 / 5
Range: 0
Cost: $2.57M
Refuel: $60

Notes

1. Air typically has an average molecular weight of about 29 AMU, giving 3.8 times the thrust of hydrogen (and 0.26 times the delta-v) for the same reason that water gives three times the thrust of hydrogen. That means that the Type 64's ram-rocket gives 1.9 gee of acceleration in air and an air speed of 3,450 miles per hour (nearly a mile per second towards orbital velocity). At least in a breathable atmosphere it does. In the hydrogen atmosphere of a gas giant it would produce only 0.5 gee and 1,770 miles per hour.)

[DouglasCole]

Originally Posted by Agemegos

Type 64 MkI orbital shuttle (TL10^ limited-superscience)

This is an orbital shuttle designed for landing parties from an exploration vessel on the surface of a habitable planet and returning them to rendezvous with their ship in orbit. Built on a 30-ton streamlined airframe, it is a winged design 45 feet long, with a fusion-powered ram-rocket intended more for atmospheric cruising than for making an important contribution to reaching orbit. The winged design allows the shuttle to fly with the ram-rocket at low throttle, which is reasonably inoffensive near settled areas.

Besides sporting landing wheels, Type 64 MkI shuttles are designed for a water landing. They are fitted with a refining plant for wilderness refuelling. Each will carry ten passengers in acceleration couches and nine tons of cargo. The manufacturer offered "fuselage tanks" that could be fitted in the cargo hold to carry an extra eight tons of water, but in practice these only ever used for conveying cargoes of fuel to the mother ship.

Forward hull

[1] Armour, nanocomposite (dDR 5), $150k, —
[2–6] Passenger seating (10 acceleration couches), $60k, —
[core] Control room (comp 6, com/sen 4, stations 1), $60k, —

Midships hull

[1] Armour, nanocomposite (dDR5), $150k, —
[2–6, core] Cargo hold (9 tons), — , —
[wings] $150k

Aft hull

[1] Armour, nanocomposite armour (dDR5), $150k, —
[2] Refinery (0.5 tons/hour), $30k, —
[3] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[4] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[5] Reaction engine, fusion torch (1.5 g with water), $300k, —
[6] Reaction engine, fusion torch ram-rocket (1.5 g with water), $1.5M, — [note 1]

Basic Stat block

PILOTING/TL10 (HIGH-PERFORMANCE SPACECRAFT)
TL: 10^
Spacecraft: Type 64 Mark I exploration shuttle
dST/HP: 20
Hnd/SR: +4 / 6
HT: 12
Move: 3 g. / 10 mi./sec. (air speed 3,450 mph [note 1])
LWt.: 30 tons
Load: 9 tons
SM: +3
Occ.: 1+10 SV
dDR: 5 / 5 / 5
Range: 0
Cost: $2.57M
Refuel: $60

Notes

1. Air typically has an average molecular weight of about 29 AMU, giving 3.8 times the thrust of hydrogen (and 0.26 times the delta-v) for the same reason that water gives three times the thrust of hydrogen. That means that the Type 64's ram-rocket gives 1.9 gee of acceleration in air and an air speed of 3,450 miles per hour (nearly a mile per second towards orbital velocity). At least in a breathable atmosphere it does. In the hydrogen atmosphere of a gas giant it would produce only 0.5 gee and 1,770 miles per hour.)

10 passengers, more than 6 tons of cargo, and 45 feet long? That's cool. An F-14 is like 60 feet long and 64 feet wide. I'd be interested to see what the deck plans of a ship like this would be.

[Peter Knutsen]

At a quick glance, the major expenses seems to be the ram-rocket engine, the ram-rocket engine, the ram-rocket engine, and secondarily the armour.

The ram-rocket engine has to be there, of course, but the cost could be reduced somewhat if the armour is downgraded from TL10 to TL8. You'd lose a bunch of dDR doing that (going from dDR 5 to dDR 2), but it would save you 360k$.


Thinking more, might it be possible to replace the ram rocket engine with a jet engine? You'd have to install a jet fuel tank, and then the mother ship would have to carry jet fuel in a separate tank (even if only a half-module is devoted to it, you'd still have enough fuel to fill up one shuttle 50 times).

That quite nerfs the shuttle's performance, but it lowers the cost significantly.


As for having just one shuttle, as we discussed in the other thread, I can see why you'd want redundancy in the design, and that's why I'm suggesting ways to make the shuttle cheaper, so that it becomes feasible to carry 3 of them.

[thtraveller]

Originally Posted by Agemegos

Type 64 MkI orbital shuttle (TL10^ limited-superscience)

Note that fusion torch drives are double price from the table footnote, so it is even more expensive than you thought it was. I get $4.36M total.

Perhaps consider a cheaper NTR air-ram as the second drive? - just for fuel-less atmo flight - but I suspect it doesn't really fit the theme.

The refinery is a powered system and there is no power, unless this is only used when hooked up to the mother ship?

I think I see minor discrepancies or typos on the passenger seating price, SR and SM.

[thtraveller]

Originally Posted by DouglasCole

10 passengers, more than 6 tons of cargo, and 45 feet long? That's cool. An F-14 is like 60 feet long and 64 feet wide. I'd be interested to see what the deck plans of a ship like this would be.

I guess it wouldn't look much different from the Babylon 5 atmospheric shuttle.

Or just take any small Hotol space plane design and strip out most of the fuel tanks. I can't immediately find one but there must be a space plane plan view somewhere on the web we can adjust to fit?

[Agemegos]

Originally Posted by DouglasCole

10 passengers, more than 6 tons of cargo, and 45 feet long? That's cool.

It's what the design system tells me.

An F-14 is like 60 feet long and 64 feet wide.

Presumably this vessel is somewhat wider-bodied than an F-14. How long is, say, an EMB-110 Bandeirante? Fifty feet or thereabouts? And a Bandeirante carries 18–20 passengers plus luggage, depending on configuration of the seats.

Mind you, a Bandeirante has a maximum takeoff weight of 12.5 tons, so this 30-ton shuttle would need to be about half again as stubby as a Bandeirante and would require a large wing surface.

[Agemegos]

Originally Posted by Peter Knutsen

At a quick glance, the major expenses seems to be the ram-rocket engine, the ram-rocket engine, the ram-rocket engine, and secondarily the armour.

Indeed. The price for ram-rockets seems excessive. You can get an air intake and compressor, bypass conduit &c. as part of jet engine that costs $300k. But add them to a fusion torch and they cost $2.4M: eight times the cost of the entire jet engine. The really galling thing is that I reckon the capability ought to be nearly free with an air-entraining aerospike engine.

The ram-rocket engine has to be there, of course, but the cost could be reduced somewhat if the armour is downgraded from TL10 to TL8. You'd lose a bunch of dDR doing that (going from dDR 5 to dDR 2), but it would save you 360k$.

Yeah, and I could save another $45k by going down to light alloy, or $72k by going to steel. That wouldn't give any actual DR, of course, but there isn't a lot of practical difference between dDR2 and dDR0, even against smallarms at TL10.

Thinking more, might it be possible to replace the ram rocket engine with a jet engine? You'd have to install a jet fuel tank, and then the mother ship would have to carry jet fuel in a separate tank (even if only a half-module is devoted to it, you'd still have enough fuel to fill up one shuttle 50 times)..

That quite nerfs the shuttle's performance, but it lowers the cost significantly.

It does indeed. It cuts air endurance from years to 1 hour, at a cost of two modules. In my opinion that leaves the air cruise capability so slight as to be useless. And carrying jet fuel on the mother ship means that you have to go to orbit to refuel (unless you are on an ice world with lakes and oceans of liquid hydrocarbons. Might as well scrub the capability.

[Agemegos]

Originally Posted by thtraveller

Note that fusion torch drives are double price from the table footnote, so it is even more expensive than you thought it was. I get $4.36M total.

Drat! I had overlooked that. I made the same mistake on the Necho-class frigate.

Perhaps consider a cheaper NTR air-ram as the second drive? - but I suspect it doesn't really fit the theme.

It doesn't work. It gives the desired thrust, but at the cost of 3.5 mi./sec. of delta-v. Or if you use it for air cruising only, acceleration in vacuum or trace atmosphere is cut to 1.5g, which means 25% of delta-v is lost to gravity drag taking off from even a 1-gee planet.

According to Space large garden world can be technically habitable with a surface gravity of 1.7 gee and an escape velocity of 11 mi./sec. (LEO velocity of 7.8 mi./sec., requiring 8.8 mi./sec. for takeoff according to Spaceships)—or even higher if you concede that a 'very hot' climate is inhabitable at all. Now admittedly you might look at a monster like that and note it for followup with specialised equipment. Still, I consider 3 gee and 10 mi./sec. somewhere near minimum spec for an exploration shuttle.

The refinery is a powered system and there is no power, unless this is only used when hooked up to the mother ship?

Dammit! Another oversight on my part. The refinery wouldn't be any use for surface refuelling if it only worked when hooked up to the orbiting mother ship. I will need another module for a down-rated power plant.

Let's see. A power point at SM +5 will fire a 10MJ improved laser twice in 20 seconds, so produces at least one megawatt. A refinery at SM +5 will process 0.5 tons of fuel per hour, or 0.14 kg per second. That's 7.2 MJ/kg. Desalination by reverse osmosis takes about 17 kJ/kg, or one-four-hundredth of that power (now, at TL8).

I am tempted to make up a limited refinery that will produce water by reverse-osmosis but not hydrogen (which would require electrolysis), and which runs on auxiliary power.

I think I see minor discrepancies or typos on the passenger seating price, SR and SM.

I'll check 'em again.

[Agemegos]

Type 64 MkI orbital shuttle (TL10^ limited-superscience)

This is an orbital shuttle designed for landing parties from an exploration vessel on the surface of a habitable planet and returning them to rendezvous with their ship in orbit. Built on a 30-ton streamlined airframe, it is a winged design 45 feet long, with a fusion-powered ram-rocket intended more for atmospheric cruising than for making an important contribution to reaching orbit. The winged design allows the shuttle to fly with the ram-rocket at low throttle, which is reasonably inoffensive near settled areas.

Besides sporting landing wheels, Type 64 MkI shuttles are designed for a water landing. They are fitted with a desalination plant that runs off auxiliary power for wilderness refuelling. Each will carry ten passengers in acceleration couches and nine tons of cargo. The manufacturer offered "fuselage tanks" that could be fitted in the cargo hold to carry an extra eight tons of water, but in practice these only ever used for conveying cargoes of fuel to the mother ship.

Forward hull

[1] Armour, nanocomposite (dDR 5), $150k, —
[2–6] Passenger seating (10 acceleration couches), $50k, —
[core] Control room (comp 6, com/sen 4, stations 1), $60k, —

Midships hull

[1] Armour, nanocomposite (dDR5), $150k, —
[2–6, core] Cargo hold (9 tons), — , —
[wings] $150k

Aft hull

[1] Armour, nanocomposite armour (dDR5), $150k, —
[2] Desalination plant (0.5 tons/hour), $30k, —
[3] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[4] Fuel tank (1.5 tons water, 5 mi./sec. @ 3 g), $10k, —
[5] Reaction engine, fusion torch (1.5 g with water), $600k, —
[6] Reaction engine, fusion torch ram-rocket (1.5 g with water), $3M, — [note 1]

Basic Stat block

PILOTING/TL10 (HIGH-PERFORMANCE SPACECRAFT)
TL: 10^
Spacecraft: Type 64 Mark I exploration shuttle
dST/HP: 20
Hnd/SR: +0 / 4 (air Hnd/SR: +4 / 5)
HT: 12
Move: 3 g. / 10 mi./sec. (air speed: 3,450 mph [note 1])
LWt.: 30 tons
Load: 9 tons
SM: +5
Occ.: 1+10 SV
dDR: 5 / 5 / 5
Range: 0
Cost: $4.36M
Refuel: $60

Notes

1. Air typically has an average molecular weight of about 29 AMU, giving 3.8 times the thrust of hydrogen (and 0.26 times the delta-v) for the same reason that water gives three times the thrust of hydrogen. That means that the Type 64's ram-rocket gives 1.9 gee of acceleration in air and an air speed of 3,450 miles per hour (nearly a mile per second towards orbital velocity). At least in a breathable atmosphere it does. In the hydrogen atmosphere of a gas giant it would produce only 0.5 gee and 1,770 miles per hour.)

[thtraveller]

Originally Posted by Agemegos

Cost: $4.21M

I still get 4.36. Wings?