[Spaceships] Reactionless STL ships

[DataPacRat]

I've started nailing down some stats for some of the other ships in this setting. (Which is roughly THS-level tech, plus what SS1 calls a rotary reactionless drive and SS7 a perpetual-motion generator.)

Anyone up to poking some holes?


* Adapting THS ships:
Any ship with less than 0.1G accel, and at least two spaces dedicated to drive and fuel, gets upgraded to one space of "Horizon Drive" and a generator. To avoid recalculating cargo space and such, I'm thinking of counting up the original designs' spaces for drive and fuel, replacing them with the new tech, and recalculating accel from that. The Solar System is a much smaller place than in baseline THS.

For example, the Sunlance is supposed to have some of the best legs around. It's got 17 spaces dedicated to transport; if I give it 11 spaces of Horizon Drive, and 5.5 spaces of Fusion Plant (and throw the other .5 space to cargo), then it'll have an accel of 1.1G, which is probably as high as this Drive can be pushed. (Well, maybe another .2 or so if I replace Fusion with Antimatter, but volatile systems can be a real pain for day-to-day work.)

* Earth to Orbit:
The most fundamental piece of tech, which is going to be heavily optimized to reduce costs. I tried statting up some 1.1G Horizon-Drive ships that could go up and down at will, but they were pretty expensive; spaceplane versions were a /lot/ cheaper. So here's my drafts to replace THS's medium-lift Pegasus and heavy-lift Mercury:

* SM+6 Spaceplane: (equivalent to Pegasus TAV)
- Streamlined
- Winged: $500k
- 1spc Armor, Steel [dDR 1/0/0]: $20k
- 1/3spc Control Room: $60k
- 2spc Power Plant, Fuel Cell (24h, 19 trips up plus aerobraking down, $1k to refuel): $100k
- 2spc "Horizon Drive": $100k
- 14 2/3spc: Cargo (73 tons)
- total: $810k, 0.2G, aispeed 1,100 mph, time to orbit 1h14m, ~9 trips/day

* SM+8 Spaceplane: (equivalent to Mercury HLV)
- Streamlined
- Winged: $5M
- 3spc Armor, Light Alloy [dDR 5/5/5]: $1.5M
- 1/3spc Control Room: $600k
- 2spc Power Plant, fission (75y), $6M
- 2spc "Horizon Drive": $1M
- 12 2/3spc: Cargo (630 tons)
- total: $14.1M, 0.2G, airspeed 1,100 mph, time to orbit 1h14m, ~9 trips/day

Some of my back-of-the-envelope estimates suggest costs-per-pound a lot lower than SS2p40 suggests for shipping rates, so I'm probably going to go with SS's listed prices, with the extra going to depreciation, profit, and the like.


* STL
The last design I've already got a statblock for is kind of ridiculous, in a good way. Starting with the interstellar ablation rates from SS5p40 to figure out how much armor I need, and then reducing costs as far as I could think to, I've ended up with a ship that can get to Alpha Centauri in under 20 years, at a cost of $5.3M - which works out to $4.57/lb of cargo moved. SS2p40 suggests a freight rate of $7.83/lb, so I seem to be on the right track.

* Cheap Interstellar Cargo Ship:
- SM+8, USL, 1,000 tons
- 6 spc: Armor, steel (dDR 30/0/0), $1.2M
- 1 spc: Horizon Drive, $0.5M
- 1 spc: Power, Fission (75y), $3M
- 1/3 spc: SM+7 Control Room, $0.6M
- 11 2/3 spc: Cargo (580 tons)
- Total $5.3M ($4.57/lb cargo), 0.1G.

- STL flight plans:
. 5 ly at 0.5c (10y), eg Alpha Centauri. (0.1G accel: 2.99 ly to accel to 0.5c, 11.2y Earth-time)
.. Actual flight-plan to Alpha Centauri, 4.3ly: Accel for 2.15ly, decel for 2.15ly, total time 18.76y Earth-time (18.09y ship-time), max speed 0.435c.
. 7.9 ly at 0.4c (20y) (0.1G accel: 1.76 ly to accel to 0.4c, 8.5y Earth-time)
. 18ly at 0.3c (60y), eg Sirius, Epsilon Eridani, 61 Cygni, Procyon, Tau Ceti. (0.1G accel: 0.936 ly to 0.3c, 6.1y Earth-time)

If the builder spends +$3M to upgrade power-plant to a "Horizon Generator" ($7.16/lb), then it can last long enough for some longer trips:
. 35 ly at 0.2c (175y) (0.1G accel: 0.4 ly to accel to 0.2c, 4y Earth-time)
. 143 ly at 0.1c (1,430y) (0.1G accel to 0.1c: 0.1 ly to accel to 0.1c, 1.95y Earth-time)

- Some possible cargos:
> 1,000 Industrial Robofacs (UTp90, 500 tons, $1B, produce $1M/hr) + 80 tons rare-element feedstock ($1.6M+)
> 280 hibernation chambers (11 2/3 SM+8 habitats, SS1p17), $11.6M
> 64 cabins (10 2/3 SM+8 habitats, SS1p17), $11.6M + 1 Open Space Garden for food (SS1p19, $0.1M) + 0.1G spin gravity (SS1p30, $0.1M)
> 2,320 nanostasis pods (UTp201, 580 tons, $1.16B)
> 1,160 adult biofabs (UTp204, 580 tons, $4.64B)


If you've read this far, anything else come to your mind? :)

[ericthered]

Originally Posted by DataPacRat

- Some possible cargos:
> 1,000 Industrial Robofacs (UTp90, 500 tons, $1B, produce $1M/hr) + 80 tons rare-element feedstock ($1.6M+)
> 280 hibernation chambers (11 2/3 SM+8 habitats, SS1p17), $11.6M
> 64 cabins (10 2/3 SM+8 habitats, SS1p17), $11.6M + 1 Open Space Garden for food (SS1p19, $0.1M) + 0.1G spin gravity (SS1p30, $0.1M)
> 2,320 nanostasis pods (UTp201, 580 tons, $1.16B)
> 1,160 adult biofabs (UTp204, 580 tons, $4.64B)


If you've read this far, anything else come to your mind? :)

The robofacs by themselves don't make a von neuman machine. You want some shuttles to drop them off on asteroids or land them on planets, and you need some starter excavators for resource extraction. You also need outside power.



If you've got full THS tech, I'd send some AI's along as well, to handle kinks in the process and dumb robots being dumb robots. See page 92 of Ultratech.

[DataPacRat]

Originally Posted by ericthered

The robofacs by themselves don't make a von neuman machine. You want some shuttles to drop them off on asteroids or land them on planets, and you need some starter excavators for resource extraction. You also need outside power.



If you've got full THS tech, I'd send some AI's along as well, to handle kinks in the process and dumb robots being dumb robots. See page 92 of Ultratech.

I expect a serious colonization attempt would have a little from column A, a little from column B, and so on; that initial cargo-list was mostly to get a feel of how much would fit in the hold.

(I'm still thinking through the implications for interstellar civilization when reasonably-priced trips take at least 20 years, but comms are available at lightspeed via 550-AU-distance relays.)

[AlexanderHowl]

Any society that does not nuke Von Neuman machines as soon as they appear is just asking for extinction. Of course, you could technically have a managed expansion by just having a SM+12 mining facility with a crew of fifty humans. If they used fusion for power, they could have four fusion reactors, four factories, four mining, three hanger bays, three steel armor, one control room, and one habitat. The facility would be immobile and have high automation. A solar version would have six solar panels, three mining, and three factories, but it would also have much less production unless on a tide-locked barren world on the sunny side.

It would produce $40M of product every hour ($40M every ten days if building a copy of the facility. It would cost ~$45B, meaning that it would take over 30 years to produce a copy of itself (assuming that it built its own robot workforce). After 300 years though, you would have ~1,000 of them, which would give a world an amazing industrial capacity (~$354T worth of consumer goods per year). Solar would take much longer, three times as long, and would produce 75% as much. Putting it in orbit would be counter productive because it would need another facility to send it materials.

[Ulzgoroth]

Originally Posted by AlexanderHowl

Any society that does not nuke Von Neuman machines as soon as they appear is just asking for extinction.

Any society that does nuke Von Neuman machines as soon as they appear has already deleted itself.

[DataPacRat]

Originally Posted by DataPacRat

(I'm still thinking through the implications for interstellar civilization when reasonably-priced trips take at least 20 years, but comms are available at lightspeed via 550-AU-distance relays.)

Anyone want to guesstimate what sort of bandwidth a relay satellite like this might be able to provide, given how much amplification that using the sun's gravitational lens provides?

FOCAL Relay satellite:
SM+4 (10 tons), USL
- 6 spc: Armor, light alloy (dDR 2/2/2): $30k
- 1 spc: Control Room, no control stations (C7 comp, level 3): $10k
- 10spc: SM+6 Enhanced Comm Array (level 7): $200k
- 1 spc: Horizon Drive, 0.1 G: $15k
- 1 spc: Horizon Generator: $60k
- 1/3 spc: backup SM+3 Horizon Drive, 0.03G: $5k
- 1/3 spc: backup SM+3 Horizon Generator: $20k
- 1/3 spc: backup SM+3 Control Room, no control stations (C6 comp, level 2): $10k
- total: $350k
0.1g to 275 AU: 106.05 days; accel decel to 550 AU, 212.1 days

(Edit: The actual paper is here, and it mentions that with a relay satellite at both stars, communications between Sol and Alpha Centauri could be done with a transmitter of 0.1 milliwatts.)

Originally Posted by AlexanderHowl

Any society that does not nuke Von Neuman machines as soon as they appear is just asking for extinction.

Given that one of the most obvious anti-extinction measures a society can accomplish is to create daughter interstellar colonies that can themselves create granddaughter interstellar colonies, I'd be willing to argue that giving up on Von Neumann tech is what's most likely to doom a society.

Of course, you could technically have a managed expansion by just having a SM+12 mining facility with a crew of fifty humans. If they used fusion for power, they could have four fusion reactors, four factories, four mining, three hanger bays, three steel armor, one control room, and one habitat. The facility would be immobile and have high automation. A solar version would have six solar panels, three mining, and three factories, but it would also have much less production unless on a tide-locked barren world on the sunny side.

It would produce $40M of product every hour ($40M every ten days if building a copy of the facility.

Where do you get that figure, of slower production, from? It doesn't seem to match the x100 slowdown UT suggests for megascale projects, or the x10 slowdown for using scrap instead of prepackaged parts.

It would cost ~$45B, meaning that it would take over 30 years to produce a copy of itself (assuming that it built its own robot workforce). After 300 years though, you would have ~1,000 of them, which would give a world an amazing industrial capacity (~$354T worth of consumer goods per year). Solar would take much longer, three times as long, and would produce 75% as much. Putting it in orbit would be counter productive because it would need another facility to send it materials.

This setting is rather closer to a century from the present than a millennium, so I think solar wouldn't be likely to be prominent in any daughter colonies. Hm... I should probably try to work out a minimum viable daughter-colony package, which is capable of ramping up to making granddaughter colonies; and how long an unsupported daughter colony would take to ramp up to sending along the next generation. (And then how much time could be saved by sending along additional supports.)

[AlexanderHowl]

SS6 gives guidelines on using factories to make spaceships. If the spaceship is -6 SM, you replace hours with days. If the spaceship is larger than -6 SM, you also have to increase the effective cost by 10x (there is also a separate assembly time, but that are what robots are for). It might be cheaper to have a SM+18 facility produce four SM+12 factories in nine days (three in eighteen days if using solar).