[Spaceships] TL10 Space RV
 

I want to throw together a relatively low-cost craft, for a wealthy biont to get from Earth to orbiting the other planets, as they see fit. (And to land on Titan, and anywhere under 0.1G surface gravity.) I'm a little nervous about pushing at the edges of Spaceships' simplifying assumptions, since I don't know where they start breaking; has anyone got any details on that? For example, is it really feasible to launch a craft with wings and a 0.1G drive from Earth's surface? (SS1 p39 says that it would take 2 hours 36 minutes.)

The setting is approximately THS, roughly TL10 with only a couple of pieces of superscience: a low-thrust reactionless drive (call it around the stats of Spaceships' Rotary Reactionless Drive, 0.1G per space) and as a spinoff of that tech, what's effectively a vacuum-energy power plant (though it uses completely different technobabble; call it SS7's Perpetual Motion Machine, 1 PP per space). Though if any non-superscience doodads get the job done for less investment, I'm open to using them instead.

(By the way, does anyone know how those two Spaceships systems compare to 3e Vehicles' "TL9 reactionless drive" and "TL10 zero-point energy generator" (the latter described as an NPU with +25% cost and unlimited lifespan)?)

Quickie design sketch: SM+4, streamlined, TL10 (mostly non-superscience).
- Design switches: Advanced Computers (as TL11), Exposed Radiators, Slower Industrial Systems
- Winged: $50k
- 1 spc: Armor, nanocomposite, dDR 3 (1 per facing), $50k
- 4 spcs: Cargo Holds, 2 tons
- 1 spc: Control Room, $20k
- 1 spc: External Clamp, $1k
- 10 spcs: Habitat: 1 SM+6 space: bunkroom for 2, total life support: $100k
- 1 spc: Power Plant, Fission Reactor, 1 PP, 75 years: $30k
- 1 spc: Reactionless Drive, rotary, accel 0.1 G, req 1 PP, $50k
- 1 spc: Weapon, central turret, improved laser, rapid fire: Major SM+4 battery (300 kJ, dDmg 1d+2, RoF 20/20s, rng C/S or 300/1000 mi), req 1 PP: $100k
-- Total cost: $401k
-- LMass 10 tons, length 10 yards, dST/HP 15, HT 12, Hnd/SR -1/4, dDR 1, Occ 2ASV.
-- Air performance: 800 mph. Hnd/SR 3/5.

? Self-Healing: +$200k, regenerate 1 dHP per 6.66 days?
? replace external clamp: Robot Arm, +$99k?
- Power Plant refueling: $3k every 75 years

How many cost-cutting corners can you think of, or other improvements that seem reasonable? (I'm open to using any of the SS books, or Pyramid articles offering more options.)



(In case you're wondering: Yes, I'm biting the bullet that such drives can be used to accelerate to high fractions of light-speed and impact a planet with devastating effects. I'm postulating a large-scale mutual-defense treaty that runs large numbers of UltraTech's non-superscience gravscanners as a detection net, and just one of the layers of interceptors being around 15,000 32cm missiles around a third of an AU from Earth. I currently plan on mentioning the existence of these two platforms as being public knowledge, and that there are further defenses that either aren't relevant to the game or are not-widely-known military secrets.)

Re: [Spaceships] TL10 Space RV
 

This won't let you take off from Titan—Titan's surface gravity is 0.14G. The "extra large" habitat seems fine and I don't think it breaks anything even if it isn't RAW. I might consider more armor, even just for purposes of dealing with micrometeor impacts (IIRC Spaceships 5 has them doing 1d dDamage per 10 mps of velocity). If the laser is solely for micrometeor / missile defense you might make it very rapid fire—point defense is a major area where Spaceships can give odd or at least-counter intuitive results.

Re: [Spaceships] TL10 Space RV
 

If you've got a reaction-less drive, a power source that doesn't run out, and you can make it to the extreme upper atmosphere? you probably can get into orbit, and once in orbit the size of the acceleration doesn't matter.


I think your bird can fly, but not strongly. The power to weight ratio on a jet liner is about 0.3, and you've got a third of that.



I've got some concerns about the play between air resistance, lift, velocity, and heating. You need to be in atmosphere to generate lift until you reach orbital velocity. atmosphere is going to slow you down as long as you're in it, and eventually create massive heating around your ship, not to mention drag. You can reduce drag by flying higher, but that also reduces your lift.

Re: [Spaceships] TL10 Space RV
 

Yeah, I don't think there's any way you can make it to orbit with 0.1G thrust. Even doing it with 1G would be tricky. If you want a rigorous answer though you'd need to play around with a program like Orbiter or perhaps a heavily modded Kerbal Space Program.

Re: [Spaceships] TL10 Space RV
 

Yes, but it also has an atmosphere denser than Earth's; if the RV can fly into orbit from Earth, it should be able to fly up from Titan.


We're a bit squeezed for space; even upgrading to best-in-setting diamondoid armor, 2 spaces provides a total of 10 dDR to spread across 3 hull sections. ... Probably still a good idea.

I looked at that, and the trouble with a VRF beam seems to be that its kJ goes down so far it only does 1d-2 dDamage, which runs a 1-in-3 risk of not being able to vaporize a micrometeor even if it hits.

Hm... re-reading attack rolls, though, it looks like going from RF to VRF adds +5 to the attack roll, so any attack that would hit with a RF shot would like hit with at least 5 VRF shots, and there's more than a 99% chance of getting at least 1 damage with at least 1 of 5 shots. Looks like another change worth making.


By SS's RAW, the RV should be able to hit 790 mph, rounded up; I'm not worried about relatively poor in-atmosphere performance, as long as it's got at least some.


I suppose another reality check might be to try to recreate the RV in 3e's Vehicles, and see it it still works. Let's see, that's Vp164's sidebar; if the craft's aerial top speed is below orbital velocity, it should be able to reach Earth orbit, though the sAccel is reduced by whatever portion is required to keep the craft aloft. However, SS doesn't get fine-grained enough to describe stall speeds; that's in VXii p30, and if I guesstimate a lift area of 70 sf and "good" streamlining, that's a stall speed of 250 mph. With SS's airspeed of 800 mph, then less than half of the craft's thrust is needed to keep it airborne, so the other half can still be applied as sAccel to get into orbit.

Though I've probably made all sorts of math errors in that paragraph, so somebody with more experience with GURPS vehicle-building should feel free to correct me. :)

Re: [Spaceships] TL10 Space RV
 

By that particular equation, a boeing 747 can hit 1300 mph (about double the true number) and sixth generation fighter jets can hit 2500 mph (about 1000 mph high). The equation performs best for needle-like rocket shapes with 1G or more of acceleration. It also claims that 10 cm per second squared acceleration can get you to 250 mph in atmosphere, and that's even more obviously wrong.


I would not use that acceleration equation for anything under 1G. I do have an alternate equation, which is to remove the square root, and replace the 2,500 mph with 1,500 mph if its plane like rather than rocket like (and with that kind of thrust, it needs to be to take off). So I've got the top speed for the plane at 150 mph for sea level air pressure.

Re: [Spaceships] TL10 Space RV
 

If we're going to get rid of SS's formula here, we might as well fall back to Vehicles'. The craft is SM+4, implying a volume of 301 to 1,000 cf, thus a surface area of 300 to 600 sf, which feeds into the drag formula. Given 2,000 lbs of thrust, then top aerial speed depends on the level of streamlining (for which I'll assume at least "good", since the frame is Spaceships "streamlined"): "good" streamlining, max aSpeed 275 to 385 mph; "very good" 355 to 500 mph; "superior" 500 to 705 mph; "excellent" 705 to 1000 mph; "radical" 1000 to 1415 mph.

I'm not really sure how best to estimate stall speed, since it depends mainly on wing area... and which is relevant here because, according to VXii, an aircraft's ceiling is 8,000 yards * ln (TopAirSpeed/StallSpeed). I'm also not sure how this ceiling figure meshes with Vehicles p164's ground-to-space equations.

Re: [Spaceships] TL10 Space RV
 

Are you sure you've taken Wing surface area into account in those numbers? they feel rather high to me.


EDIT: you know what? never mind. I think we've established that the thing can get off the ground, and that it will take some really high-end streamlining to get it going at decent speeds. I'm not sure if living quarters at SM+4 can be streamlined that much and remain usable, but this thing can get into the atmosphere, and I'll bet you can get it into the upper atmosphere.


Vehicles 133 has a stall speed equation.

Re: [Spaceships] TL10 Space RV
 

By that equation, then assuming wings of 0.1 times the body's volume (as suggested in pV17), depending on the exact size of the ship and level of streamlining, I get stall speeds between 144 and 288 mph.

Re: [Spaceships] TL10 Space RV
 

Unless you are using the Gravitic Focus design switch (Spaceships p. 30), you will never use the 3kJ or 10kJ entries in the beam weapons table. The weakest beam weapon will be 30kJ (3MJ / 100), which does 1d+1 dDamage. Furthermore, according to Spaceships p. 60, "If firing in point defense against incoming missiles or shells, don’t bother rolling damage – each weapon hit (including tractor beams) kills one missile or shell." I think this is totally plausible—that 1d-2 damage on the d-scale should be thought of as more like 6d damage on a regular damage scale. If you think about it in those terms, the attack is never literally doing zero damage, and should always be enough to vaporize a micrometeor or puncture the fuel tank (or ruin the guidance system, etc.) of an incoming missile.

That's only slightly more than 0.2 mps. It's the sort of thing that matters for building a near-future spaceplane when every bit of delta-V counts, but won't really help you with the thing you're trying to do.

The Vehicles sidebar ignores the fact that the earth's atmosphere isn't like an ocean, with a well-defined "top". Atmospheric pressure gradually decreases as you get higher and higher. This means that aircraft generally have a flight ceiling well below the altitude where it's possible to orbit for any length of time before de-orbiting (or even burning up) due to drag. The altitude record for an air-breathing aircraft is ~37 kilometers, less than half the commonly quoted "edge of space" of 100 km.

If you want launching from Earth's surface to be easy, I would recommend allowing fusion torches, standard/hot reactionless engines, and/or contragravity lifters. If you want space travel to be super-duper cheap I guess you could also arbitrarily declare that in your setting, those systems cost less than they do in RAW.

Re: [Spaceships] TL10 Space RV
 

An option to reduce cost, and perhaps make streamlining more feasible, would be to cut the habitat in half (5 systems), giving it the same amount of living space but removing the total life support. That drops price by $50k, and you can stock the additional 5 systems (which you can set as cargo holds) with enough food to last the pilot over 3 years. Indeed, the $50k you save is enough to keep you stocked with food for somewhere around 68 years (more if you invest it somewhere with a decent rate of return), so long as you're able to stop at a store every couple of years or so.

I considered an option to replace the reactor with a fuel cell and sacrifice some of those cargo holds for fuel tanks to power it, but that doesn't make for much savings at the start, and you only get a few months of use out of it before fuel replacement makes it cost more than the fission reactor did.

Is it strictly necessary that the ship be capable of interfacing? A pure spaceship would be a lot easier, and at least a bit cheaper, to design, although at SM+4 it's not got any space for an interface craft (it would need to dock with an orbital station so the owner could rent/hire a shuttle to go planetside).

Re: [Spaceships] TL10 Space RV
 

I'm a little curious why you're so set on having cheap spaceships in your setting. If you're trying to do the Han Solo / Mal Reynolds thing of having lots of people who somehow own spaceships in spite of being hard up for cash, my first suggestion is not thinking about it too hard. If the PCs want to be that sort of person, you can represent that as Wealth with a -20% limitation for Conditional Ownership meaning you "cannot or will not resell" the asset (see Spaceships 2, p. 27). Alternatively, there was an article in Pyramid #3/71 that suggested treating the ship itself as a Patron. The article has a fair amount of detail but the basic idea is to replace "patron's net worth" with "value of the ship" in the Patron rules. So for example, a constantly available patron with resources of 1000x campaign starting wealth is 40 points, there owning a spaceship worth 1000x campaign starting wealth while inexplicably being hard up for cash otherwise is also worth 40 points.

If you want to justify this sort of thing in-setting somehow, maybe there are legal restrictions on buying and selling of spaceships that make it difficult to convert spaceship ownership into cash. This could be as simple as exorbitant taxes on the buying and selling of spaceships, or something bizarre like early 19th century entailment laws applied to spaceships, or prohibitions on a certain class of people owning non-spaceship capital. But it's not necessarily wrong to just have that as an area where suspension of disbelief is called for.

Re: [Spaceships] TL10 Space RV
 

This is true, but it's eliding a key difference between air-breathing aircraft and this vessel:

The reactionless thruster produces the same 0.1g at all speeds and altitudes. That's the main limiter on real high-altitude airplane operation. Air-breathing engines lose performance (or outright stop working) in thin, fast airstreams. (Even if you're using a non-combustion air-breather like a nuclear ramjet.) No problem with that here.

Without that problem, I think things look good. Drag and lift both tend to scale with air density and the square of airspeed, AFAICT, so if you can get above the surface effect at sea level with 0.1g you should be able to sustain flight an any altitude with 0.1g, and that means you can insert into low orbit for sure.

Re: [Spaceships] TL10 Space RV
 

A spaceship as a Patron is also not a bad idea for something like Rogue Trader, where the spaceship belong to your family (and small starships are SM+15).

Re: [Spaceships] TL10 Space RV
 

<Does algebra>

Oh huh, you're right. At higher altitudes, you can cancel out having less lift due to lower pressure by going faster, which you can do because the lower pressure means less drag. So it al works out.

EDIT: This actually upends a lot of assumptions I and other seem to have historically made about world-building futuristic settings. Kinda wanna test out a low-thrust spaceplane concept in a simulator like Orbiter. But I'm going to resist the urge to get too deep into this in the near-future.

Re: [Spaceships] TL10 Space RV
 

Wouldn't gravity drag be an issue with only 0.1g acceleration? For a 3g acceleration, you end up losing around 0.5 km/s when attempting to reach orbital velocity (meaning gravity drag is around 0.15g). In effect, the spaceship should not be able to fly, much less leave the atmosphere, as gravity drag would negate its acceleration.

Re: [Spaceships] TL10 Space RV
 

Note that at 0.1g, this implies a takeoff run of 7,000 to 28,000 feet, assuming your ship can even manage those speeds as a ground vehicle. I echo ericthered's comment and recommend you increase this to 0.3g, despite the added cost.

Re: [Spaceships] TL10 Space RV
 

'Gravity drag' only exists when you're thrusting against gravity. You basically don't ever do that at all with this type of craft.

Gravity drag is also a somewhat misleading name, and describing it as an acceleration suggests you have in fact been mislead...

Re: [Spaceships] TL10 Space RV
 

Maybe a small rocket for take-off assist? You could probably get that into just a few smaller systems. A water NTR would be pretty easy to refuel on most bodies that you'd have any chance of leaving...

Re: [Spaceships] TL10 Space RV
 

Al/right/y, then. That nicely solves the bit of math that I hadn't been able to figure out; thank you kindly. :)


A fair point; I can work with that.


I'm already invested in the particular technobabble in play, but I'm still doing a bit of setting-creation, working out further consequences of the basic setting assumptions (ie, the existence of the superscience drive and power plant). The fact that, for the price of a good-sized house, somebody can buy a two-person craft capable of booting around the whole Solar system while going for a couple of years without resupply, leads to a variety of knock-on effects compared to the original THS setting. It would have been easier to move the mass from Luna into L4 and L5 to create O'Neill Cylinder colonies; there's much less incentive to save launch costs by building a beanstalk; there's no need for He3 mining in gas giants; it's that much easier to found an asteroid settlement; and so on. As long as I keep the consistent world-building at least one step further than the freelance Vacuum Cleaner PCs, I should be good. :)

(Next on my to-do list: check SS5's table of near-c ablation damage, to check for the feasibility of sub-trillion-dollar STL colonization attempts.)


I've just finished back-engineering a few numbers to get a full set of 3e Vehicles stats:

. SM+4: excellent streamlining, external volume 540 cf (internal volume 400 cf), area 400 sf; wings 8.4+8.4 cf, area (25+25)*1.5=75 sf; wing hp 38 ea.
. gSpeed: 250 mph, gAccel 10 mph/s, gDecel 10 mph/s, gMR 0.25, gSR 4.
. aDrag = 24, aSpeed = 790 mph, aAccel 2 mph/s, aMR 1.5, aSR 5, aDecel 6 mph/s, aStall = 220 mph, ceiling 9.4 km; terminal speed 2500 mph, top glide speed 1,000 mph, glide ratio 20:1; takeoff/landing run 1,210 yards (0.7 miles)
. floatation rating 34,800 lbs (17.4 tons), draft 22 inches, wDrag 737, wSpeed 8 mph, wAccel 2 mph/s, wMR 0.75, wSR 6, wDecel 10 mph/s.

... which is a takeoff run of only 3,630 feet, which seems reasonably reasonable.

Re: [Spaceships] TL10 Space RV
 

That number does not seem right. 10 mph/s would be almost 4.5 m/s^2, meaning about .45g...

Re: [Spaceships] TL10 Space RV
 

The takeoff run is reasonable for 10 mph/s = 0.46g. Did you add the JATO unit you were talking about?

Re: [Spaceships] TL10 Space RV
 

Alright, lemme give that another go
Vp128, wheeled gSpeed = (0.25 * ReactionlessThrust / LoadedMassInTons)^0.5 * WheeledSpeedFactor * StreamliningFactor = (0.25 * 2000 / 10)^0.5 * 18 * 1.1 = 140 mph. gAccel = 0.8 * gSpeed / SpeedFactor = 6.2 mph/s

... Hunh. Ah, I see; I neglected the quartering of the thrust number the first time around.

Okay, I seem to recall that a Pyramid article mentioned something about attaching add-on packs to a spacecraft and/or mecha, so I'll see if I can dig that up to try applying as a booster.

Re: [Spaceships] TL10 Space RV
 

I can't follow the equations without a lot of digging into the book, but it looks like you're still getting a ground acceleration of more than double your vessel's actual thrust.

Re: [Spaceships] TL10 Space RV
 

Do you have Transhuman Space's DNA Repair nano? They get it 1 TL earlier (at the cost of the Extended lifespan) than the same-named item from Bio-tech. This is absolutely esential to keep people from getting lethal doses of cosmic radiation in small, thin-hulled spacecraft.

Thrash is right about the take-off run and that applies to climbing to altitude and even breaking loose rom Earth Orbit. You won't be able to jsut point your nose where you want to go. Any time you're ina gravity well you're going to have to spiral outward while you build up speed.

I'd go to at least .2 Gs so I could land on the moon and get closer to commercial aircraft rates of speed and acceleration.

If you stay at 0,1G a rule of thumb is that after you reach escape velocity it will take you 9 days of accel/decel to go 1 AU. The good news is that longer distances get multiplied by the square root of the increase factor. So if you've got a 9 AU trip to Saturn(Titan) that's 27 days plus orbital maneuvering and takeoff/landing. Put a hibernation pod in the thing and sleep the trip away. That cuts way down on your habitat requirements.

Re: [Spaceships] TL10 Space RV
 

I've triple-checked Vehicles' formulas, and I think I'm following them properly now. I don't know what to say, other than that it seems like Vehicles thinks that applying thrusters to a wheeled vehicle on the ground has different effects than applying them when it's in the air.


Yes, definitely; I'd even forgotten the BioTech version was at a higher TL.

Just taking an orbital speed of 17,800 mph, and an acceleration of 0.1G, it takes around 2.25 hours to get up to speed, and travelling 32,300 km. That's over three-quarters of the way around the Earth, which I'd say is a fairly good spiral.


With the bunks dropped from 10 spaces to 5, there's actually enough room for that, now.


Since there's been a few changes, here's the latest draft of the Space RV. (For the takeoff run, it seems that the craft would accelerate up to 200 mph with the reactionless thruster, then kick in the booster for just under a second for the other 20 mph needed to get up to stall speed.)

Quickie design sketch: SM+4, streamlined, TL10 (mostly non-superscience).
- Design switches: Advanced Computers (as TL11), Exposed Radiators, Slower Industrial Systems
- Winged: $50k
- 2 spc: Armor, diamondoid, dDR 10 (4/3/3), $200k
- 5 1/3 spcs: Cargo Holds, 2.666 tons
. Food, 1 ton: 500 man-days, $1k
- 1 spc: Control Room, $20k
- 1 spc: External Clamp, $1k
- 1/3 spc: SM+3 Fuel Tank in SM+4 craft, 0.05 mps delta-v (8.2 seconds, +180 mph, good for 9 takeoffs), $1k. 0.15 tons fuel, $120 for fuel.
- 5 spcs: Habitat: 0.5 SM+6 spaces: bunkroom for 2: $50k
- 2 spcs: Power Plant, Fission Reactor, 2 PP, 75 years: $60k
- 1/3 spc: SM+3 Reaction Engine in SM+4 craft, Chemical Rocket: 1G accel, $6k.
- 2 spcs: Reactionless Drive, rotary, accel 0.2 G, req 2 PPs, $100k
- 1 spc: Weapon, central turret, improved laser, very rapid fire: Major SM+4 battery (30 kJ, dDmg 1d-2, RoF 200/20s, rng C or 150/500 mi), req 1 PP: $100k
-- Total cost: $588k
-- LMass 10 tons, length 10 yards, dST/HP 15, HT 12, Hnd/SR -1/4, dDR 4/3/3, Occ 2ASV.
-- Air performance: 1,120 mph. Hnd/SR 3/5.

. SM+4: excellent streamlining, external volume 540 cf (internal volume 400 cf), area 400 sf; wings 8.4+8.4 cf, area (25+25)*1.5=75 sf; wing hp 38 ea.
. aDrag = 24, aSpeed = 1,120 mph, aAccel 4 mph/s, aMR 1.5, aSR 5, aDecel 6 mph/s, aStall = 220 mph, ceiling 9.4 km; terminal speed 2500 mph, top glide speed 1,000 mph, glide ratio 20:1; takeoff/landing run 1,136 yards + 6 yards (0.65 miles)
. floatation rating 34,800 lbs (17.4 tons), draft 22 inches, wDrag 737, wSpeed 11 mph, wAccel 4 mph/s, wMR 0.75, wSR 6, wDecel 10 mph/s.
. gSpeed: 200 mph, gAccel 8.8 mph/s, gDecel 10 mph/s, gMR 0.25, gSR 4.

Re: [Spaceships] TL10 Space RV
 

I suspect it's that thrusters are bolted on to the calculation and thruster-only builds interface poorly with the expectation that ground acceleration is a factor of the square root of drive train power/weight.

Re: [Spaceships] TL10 Space RV
 

Well, if I cap gAccel at sAccel, that'd be 2.2 mph/s for just the thruster, and 24.1 mph/s with the booster. So that'd be a takeoff run of 4,545 yards to get up to 200 mph, then another 5 yards for the final boosted push to stall speed (total 2.6 miles). Or, 182 yards to get up to 40 mph, plus 336 yards to use up all the booster's fuel for the remaining 180 mph (total 0.3 miles).

Re: [Spaceships] TL10 Space RV
 

An alternative version that I think would work better at TL10^ would be a SM+6 spaceship with the following: 1 control room, 1 engine room, 1 fusion reactor, 2 external clamps, 2 hot reactionless engines, 3 steel armor, 4 habitats, 6 hanger bays. The spacecraft would possess four double occupancy cabins (two crew and two passenger), allowing for a total of eight people. The 6 hanger bays would allow for unloaded cargo without decompressing the entire ship and would allow for 18 tons of cargo. The two external clamps would allow for additional cargo transfer, as the 2g acceleration of the spacecraft would allow it to take two SM+5 cargo barges into orbit at 1.25g. With artificial gravity and winged, it would cost $2.97M.

Now, this is not as cheap as the SM+4, but it is a mighty workhorse due to its high acceleration. While towing two SM+5 barges, it is capable of making Earth to Saturn in 8 days (maximum velocity a hair over 1.4% c). Of course, it would likely cater to clientele who did not want to go with the regularly scheduled cargo ships (usually smugglers), but that would be part of the excitement. It would tow SM+5 barges for legitimate purposes while the illicit cargo (and passengers) would be hidden within the hanger bays and cabins.

Re: [Spaceships] TL10 Space RV
 

Of course the OP explicitly did not include hot reactionless (or even 'standard' reactionless) drives in the setting.

Re: [Spaceships] TL10 Space RV
 

In for a penny, in for a pound. A 0.1g reactionless engine allows a SM+4 spacecraft to reach 370 mps after a week of acceleration, meaning that it is a potent kinetic energy weapon. No rational society allows random civilians to have vehicles that are the equivalent to 350 ktons of TNT (the drives may exist in a rational setting, but they will likely be reserved for military use).

That being said, you can make the same SM+6 design with 0.2g base acceleration, it is just slower. It costs around $2.5M when you replace the 2g engines with 0.2g engines, and requires around $50,000 a month in income to keep going. It takes a little less than 1 month to go from the Earth to Saturn (and back), meaning a maximum velocity of over 700 mps.

Re: [Spaceships] TL10 Space RV
 

No, The OP has been working with these numbers pretty carefully. Telling him he should multiply both his power ratio and weight by x10 without showing that the original version doesn't work is a touch pushy.



I am somewhat amazed that the .1G version seems to be capable of doing what its asked to. Its a ridiculous contraption that will take some odd infrastructure and lots of time, but it does seem doable, against my expectations.


I do think a .2G version will perform much better, and it adds landings to the moon, Io, Ganymede, Europa, and Callisto. You add 20% to the cost of the vehicle, which isn't too bad.

Re: [Spaceships] TL10 Space RV
 

Silly phrasing of a setting detail: "The traffic cops have nukes, and aren't afraid to use them." (See last paragraph of thread's initial post.)


That sounds like an entirely reasonable craft. (Though it probably only needs 1 external clamp system; SS8 suggests that one system covers all of a ship's external cradles. Or maybe even 0 systems, taking a telescoping robotic arm from SS8p9 instead.)

I expect that there are a lot of different designs that take advantage of the available tech, at least as many as in baseline THS, for just as wide a variety of purposes.


Amusing detail: It looks like the draft of the Space RV in post 26 could push itself up to 0.2c, and make it to Alpha Centauri in under 22 years, without completely ablating its armour. Surprisingly cheap STL colonization compared to a lot of settings - it wouldn't take much larger of a craft to carry enough armour to get a better coasting speed, and enough robofacs and gene-banks to start Von Neumanning.


Next on my to-do list: Dig up my old copy of GURPS Mars, to figure out how far along in the terraforming process the planet would have to be in order for the Space RV's wings to provide enough lift to allow for landing and takeoff. (I'd like to go with a slightly more realistic terraforming timescale than in baseline THS; probably lots of domes, the reactionless thruster tech has probably made it easier to divert some comets to impact into the Hellas basin...) I found one RAW implying that as long as the pressure's at least 0.01 Earth's, the craft can fly; which would only need to double Mars' atmospheric mass, which could be done with a single, fairly modest comet.

(I've also made notes from THS:In the Well and THS:Deep Beyond that the craft would melt if it got to Mercury's orbit or inside Venus's atmosphere; and that it could dive into a gas giant down to 339 bars of pressure, which is below Jupiter's cloud layers; which still leaves a pretty wide range of places to go.)


The current draft, on post 26, is 0.2G. :)

Re: [Spaceships] TL10 Space RV
 

Got another optimization question to ask the hive-mind;

For civilian meteor-defense, should I stick with Spaceships' very-rapid-fire improved laser, in a central turret (30 kJ, dDmg 1d-2(2) burn/dmg 6d(2), RoF 200/20s, rng C or 150/500 mi, $100k, 0.5 tons/1 space); or should I hit the THS vehicle design system, and replace it with a couple of 2.5 kJ lasers in pop turrets (dmg 3d Imp, 1/2D range in space 15.8 miles, Max range in space 22.7 miles, RoF 8 per second) (each turret also holds two E-cells, enough for 2,880 shots; and each pop-turret and its contents takes up 6 cf, 0.061 tons, and costs $11,050)?

Two such pop-turrets only take up about a quarter-space of mass, and the remaining saved space could be used to squeeze in a bit more cargo or built-in equipment. But I'm not really sure whether the lower damage and shorter range is good enough to handle the occasional micrometeor.

Any opinions?

Re: [Spaceships] TL10 Space RV
 

I think you may have misread the THS laser stats. A "light laser" in THS is 2.5MJ and weighs 5 tons. Unless you mean the 20kJ tactical lasers from Deep Beyond—in which case I would use the stats from Transhuman Space: Changing Times and basically treat them as cargo.

Re: [Spaceships] TL10 Space RV
 

Actually, I'm looking at In the Well, pages 130 and 108, for the 2.5 kJ laser's stats. (And meshing the THS build system with Vehicles, to turn the former's turrets into pop-turrets.)

Re: [Spaceships] TL10 Space RV
 

While not quite RAW, an old UT vs SS analysis I did implies that the full-power SS beam weapons could be used at RoF 10 instead of their current RoF 0.05 (thus RF would be RoF 100, VRF would be RoF 1000); I took this to mean the low RoF of SS lasers was due to power constraints - that is, 1 PP can only provide enough power for 1 shot every 20 seconds for a full power Major Battery. This was based largely on the blaster rifle, which has an appropriate weight and damage for a full-power SM+0 Major Battery, but has RoF 10 rather than the predicted RoF 0.05 of SS (other beam weapons of equal damage have roughly comparable weights, it's just the blaster rifle that hit it dead-on).

If that doesn't sound too reaching to you, you could boost your RoF by 200x without any loss of damage by giving up some cargo space for an array of rechargeable power cells. A 3 MJ laser (30d(2) burn damage, or 3d(2) burn dDmg) would get roughly 5 shots out of a 20 lb E cell at TL 10 (based on the 1/100th power blaster rifle getting 5 shots out of a C cell, which is conveniently 1/100th the power of an E cell), implying around 4 lb per shot. Sacrificing 1 cargo bay for 0.5 tons of energy bank would cost $20k, but would get you 250 shots (enough to continually fire at RoF 10 for 25 seconds), and shots would replenish at a rate of 1 shot every 20 seconds* for each PP you allocate to recharging the energy bank. If you'd prefer RoF 100 (or a Secondary Battery of 10 RoF 10 lasers), you could drop to 300 kJ (12d(2) burn damage, or 1d+2(2) burn dDmg), in which case that same energy bank would get you 2,500 shots, and shots would replenish at a rate of 1 shot every 2 seconds for each PP. In an emergency, the full energy bank can provide power to one rotary drive for up to 5000 seconds (a bit over 83 minutes), or to both of them for up to 2500 seconds (a bit under 42 seconds). Note you might be able to exploit this to avoid needing two fission reactors if you only have the second rotary drive for purposes of reaching orbit - you could power the second drive with the energy bank, then once you reach orbit spend some time (roughly as long as it took you to reach orbit) drifting to recharge your energy bank, then go on your way at 0.1G. That's only possible if you can reach orbit from the ground within 80 minutes (or at least can get to a point within 80 minutes that lets you use 0.1G to get the rest of the way); unfortunately, I don't know how long 0.2G takes to get you to orbit, as the equation from SS1:38 gives a negative number (?) if acceleration is less than the force of gravity and air speed is less than 80% of escape velocity.

As for how much of a punch you'd want from your lasers, SS5:39 implies most meteoroids that would be problematic have dHP around 0.006 (or HP around 0.06) - anything larger would likely be detected far enough away you could either alter course to avoid it or use your lasers from a distance to nudge it out of the way. Keeping in mind they're so small (SM -10), and even a personal holdout laser would vaporize them, the higher the RoF, the better. If you anticipate needing to deal with larger meteors or debris for whatever reason, going off the table from SS4:36 the 3 MJ laser requires roughly (going off average damage, and rounding hits up) 4 hits to stop (reduce to -5xdHP) a SM+0 chunk, 6 to stop an SM+1 chunk, 8 to stop an SM+2 chunk, 12 to stop an SM+3 chunk, and so on. A 300 kJ laser requires about twice as many hits, while a 30 kJ requires about 5x as many hits. You may want to base your damage off of the sort of chunks you anticipate encountering, but honestly 30 kJ (with up to RoF 1000) should be more than sufficient.

*Optionally, because TL 10 sees a x2 RoF for visible-light lasers in SS, you could argue for this being a recharge rate of 1 every 10 seconds, or one every second for the 300 kJ laser(s).

Re: [Spaceships] TL10 Space RV
 

Speaking of; I'm now pretending that SS4 lets me buy a secondary battery for a SM+4 ship; for a retractable, turret, very-rapid-fire, improved laser, that's all the way down to 3 kJ, which is close enough to the THS laser I was thinking of. Sell back eight of the ten, and I've got the lower-cost defense I was thinking of above.


It feels odd that not one of the Spaceships books included power cells, capacitors, or battery tech. I have to wonder if that was a deliberate choice, to direct ship-designers interested in chemical power-storage to use fuel cells or MHDs for the stats.


It didn't give me a negative number...

... Oh, are you treating that dash on the end of the line as a minus-sign? It's not really supposed to be there; just compare the equation to the one for escape velocity just below it.

... or maybe you didn't apply the text that a winged vehicle treats the planet's gravity as 0?

There's so many ways I've made mistakes with GURPS equations over the years. :)


I found some old notes of mine, for a ship with worse sensors, worse acceleration, and less damage per second; and was able to work out that for micrometeors moving at average orbital speeds, they were either too small to get through the armour, or were small enough to get shot down between when they were detected and when they impacted, or were big enough to get detected far enough out that the ship could move out of its way.



On a related note; for Ultra-Tech's fabricators, are there any costs or weights listed anywhere for printer cartridges? (I'm planning on throwing in a suitcase minifac for spare parts, and am trying to figure out how much weight to allot to its raw materials.)

Re: [Spaceships] TL10 Space RV
 

Roughly speaking, one system of UT power cells will, by my calculation, provide 1 power point for all of 80 minutes, which is pretty much nothing in Spaceships terms. Of course, there's also the issue that UT has vastly different assumptions - most SS power plants gain roughly x2 endurance 1 TL after introduction, while UT power cells gain x10 per +1 TL (additionally, at TL 12 UT Grasers use 10x as much power as an equal-output TL 11 X-ray laser or blaster, which use 10x as much power as an equal-output TL 10 laser; in SS, all beam weapons use roughly the same amount of energy, with those that have been out for over 1 TL being twice as efficient). Indeed, there are a lot of things that UT assumes is x10 that SS does as x2, like beam weapons 1 TL after introduction. Not having UT power cells may well have been a way to sidestep that particular issue.

That's the one. That in mind, it looks like, again assuming 200 mph, 0.2G will get you from the surface to orbit in ~76.9 minutes; seeing as the energy bank lasts 80 minutes, that leaves you with only 4 minutes, 52 seconds to spare. So, doable, but perhaps a bit risky.

Re: [Spaceships] TL10 Space RV
 

Where does it say that UT power cells gain x10 capacity every TL?

Re: [Spaceships] TL10 Space RV
 

Nowhere that I know.

The numbers seem to be different based on what you use...

Exploding power cells rule UT:
TL9->10 REF increases by *4->*4 explosive energy
TL10->11 REF increases by *4->*4 explosive energy
TL11->12 REF increases by *2->*2 explosive energy

Plasma explosives UT(described as being powercells)
TL11->12 REF increases by *2->*2 explosive energy

Blaster and laser design in pyramid seems to use a fixed *4 increase/TL for TL 9-12.

So there is a discrepancy..


But as for the other differences between power:
Spaceships has an TL increase in power generation of only *5 total for the same mass. But UT has 200 for super science tech and 100 for non super science.

There is also some wonkiness when it comes to damage..
As example take the UT Area Defense Laser and Laser Cannon. They seem to be the different TL versions of the same weapon.

The TL 10 version does double damage(That is *8 energy to target) in UT but same Rof, but in Spaceships it does same damage but gets *2 shots. Thus in effect gaining *2 energy output over same time.

Then comparing the TL10 Strike Laser to the TL9 Area Defense Laser, the TL 10 weapon gets same damage output but has 1/8th the mass, thus almost -2 SM system in spaceship terms. The TL 10 laser also requires 1/8th the energy cells to get the same damage. But the needed cells actually make sense if using the blaster and laser design *4 energy and *2 better efficiency.

So both the weapons and energy generation seem to scale much faster/mass unit in UT compared to SS.

Re: [Spaceships] TL10 Space RV
 

REF is inside the square root in the explosives damage formula, so it's a direct multiplier of energy. Thus the progression is x4, x4, x2.
That's actually TL10-TL11, and the various weapons' stats suggest anywhere from x2.37 to x3.375 going from TL10 to TL11.

Re: [Spaceships] TL10 Space RV
 

You are correct, fixed above.

The two ref numbers we have for Plasma Explosive are REF 10 at TL11, and REF 20 at TL12. Thus doubling energy in that TL increase from 11 to 12.

Re: [Spaceships] TL10 Space RV
 

I thought there was a rule in UT that using a higher TL power cell got you x10 endurance, but now that I look at it, it just says "increased operating time." I may have been conflating the size progression in with that, and there's also the issue of beam weapon cannons that tend to get x2 damage (x10 output by Spaceships, x8 using cube root) at +1 TL.

Re: [Spaceships] TL10 Space RV
 

Ah, my mistake - I misunderstood that as talking about plasma/fusion guns, which are described as having one-use plasma power cartridges (in magazines that are listed in the tables as power cells).

Re: [Spaceships] TL10 Space RV
 

For the moment sticking to SS's rules, but abusing the size-scaling thing... a SM+4 secondary weapon-battery's individual weapons could, in theory, be treated as being a SM+2 major weapon-battery; that is, each SM+4 secondary weapon should be able to be powered by a SM+2 power plant's Power Points. A SM+2 system should weigh 100 lbs (which I'd just subtract from cargo space; I've already got a whole section of "built-in gear" from various sourcebooks); a SM+2 fuel cell would provide 1 SM+2 PP for 24h and cost $500, a SM+2 MHD provide 2 SM+2 PPs for 12h and cost $1k, and this setting's SM+2 superscience infinite-duration power-plant would provide 1 SM+2 PP for $6k.

And that 12-or-more hours of ammo is without even getting into turning the main drive down a notch, and funnelling some of the main fusion reactor's surplus power through an electrolysis (or whatever) gizmo built with the minifac, to recombine the fuel cell or MHD's expended chemicals back into usable stored chemical energy again. :)


I've found some of my old notes on SS's power scaling, implying that a SM+4 Power-Point is somewhere in the vicinity of 500 to 1,000 kW; does that match up with anyone else's estimates?

Re: [Spaceships] TL10 Space RV
 

I have come around to the idea that a SM+10 power point is 600 MW (calculated from assuming a beam weapon system efficiency of 25% at TL and 50% at TL+1), so a SM+4 would be 600 kW. You could get a different number with different assumptions about efficiency, but it seems to work for the beam weapon energies.

Re: [Spaceships] TL10 Space RV
 

Works for me. :)


Speaking of, here's the current draft of what I'm stuffing into the Space RV's cargo space, with a capacity of 3.5666 tons (7,133.33 lbs). (This list doesn't include the cybershells like the cyberdoc, or tools specific to a Vacuum Cleaner's job; it's more about the built-in stuff, and consumables for the same.) Anyone see anything problematic, or important but missing?

- Fixed gear (total 1,651.5 lbs):
- Magnetic field generator, around pilot's bunk (VX1p21), PF 100, radius 3 feet, field 115 cf: 172.5 lbs, 3.45 cf, $17,250, 11.5 kJ to activate
- Luxury Interior, for 2 bunks + 1 seat (VLp29): 75 lbs, 1.5 cf, $15k
? (Possible luxury interior items: Responsive Beds (UTp69), Sonic Shower Head (UTp70), 3D Video Walls (THSp147))?
- Surgery (THSp184): 280 lbs, $50k, 0.5 kW
- Medkit, Vehicle (THSp162): $5k, 50 lbs
- Diagnostic toilet (THSp147): $200
- Self-sealing hull (VX2p29), 400 sf: $4k, 20 lbs
- Basic Tool Kits (Armoury, Electronics, Engineer & Mechanic, THS p153): $4k, 800 lbs
- Minifac (UTp90): 100 lbs, $50/hr->day, $50k
- 5 Pocket Analyzers (Bio, Chem, Forensic, Geo, Metallurgy, UTp66): $2500, 3 lbs
- Wall Safe (UTp102, DR150, HP25, 1cf): $100, 50 lbs
. Scanlock biometric scanner (THSp151, UTp104): $1k, 1 lb
- SM+2 power plant (for lasers), MHD: 2 SM+2 PP (2*60 kW) for 12 hours, 100 lbs, $1k (refill of power plant fuel: 25 lbs, $10)

- Misc Cargo (5,481.8333 lbs):
. Food, 2/3 ton (1,333.33 lbs): 333.3 man-days, $666.67
. Fabricator feedstock (UTp90,93), 500 lbs, $5k
. Other cargo, 3,648.5 lbs

Re: [Spaceships] TL10 Space RV
 

I have the same values. My chart for the power points at different SMs can be found in: https://gsuc.roto.nu/doku.php?id=power_plant_energy

Re: [Spaceships] TL10 Space RV
 

I found something in 3e Covert Ops that I'm debating whether to throw in. For $25 or $50 per square foot, a room - or presumably a spaceship - can provide its inhabitants -5 or -10 against electronic eavesdropping ("transmitters, TEMPEST gear, thermographs, millimeter-wave radar... laser mikes... visual surveillance... contact mikes, long-distance mikes, and ears at the door... bugs and wiretaps"). I already figured that the Space RV has around 400 cf internally, implying a cost of $10k or $20k...

... For a sub-million-dollar spacecraft, cheap enough to be owned by an individual (especially if they're willing to take out a mortgage with only a 10% down payment), how standard do you think this option would be? That is, would it be particularly unusual to discover someone's Space RV was so shielded?

How do you think its stats might change for a better-than-modern TL?

Re: [Spaceships] TL10 Space RV
 

Mostly things like this don't change stats by TL. They just become effective against the current TL )and last TL's stuff isn't).

Re: [Spaceships] TL10 Space RV
 

Some random thoughts that have cropped up...

If a civilian spaceship with dDR 3 on all facings can already almost-certainly dodge or shoot down any micrometeors, how much added value would there be in abusing 3e's VEx1 and adding dDR 1 to 1.5 of electromagnetic dDR, which offers protection against shaped-charges (including negating their armour divisors), kinetic impacts, and plasma and fusion weapons?

VEx1 also offers some smallish 'craft shops', for skills that don't need the heavy tools of Armoury or Mechanical workshops; 300 lbs and $1k for one skill's set of gear, such as sewing or photography. This leads to some questions when dealing with a craft that might be spending weeks or months out alone in the dark... with that much gear per shop, would you really need separate shops for Jewelry and Artist (body art), or for Professional Skill (bartender) and Carousing? Or for every individual skill under Games? Is it best to just draw a curtain over the 300-lb toybox for Erotic Art? Could there be such a shop for Teaching, possibly based on 4e's SE:BtS's equipment and facilities section (and what could it offer that's an improvement over full-sensory VR)?

GURPS Horror has rules about insanity that can arise from sudden, sharp shocks; are there any GURPS rules I haven't found about slower, longer-term insanity-inducing stresses, such as spending long periods all by oneself?

Re: [Spaceships] TL10 Space RV
 

I grabbed Pyramid3 #103 today, and am very happy with Pulver's "Spaceship Malfunctions" article. As it happens, the current draft of the Space RV's stats already includes an unholy mishmash of Spaceships and 3e Vehicles components, including a few small-but-ruggedized backups: a 0.001G backup reactionless drive, a backup power-plant that can run the main drive at 10% (0.02G), a secondary backup power-plant just for life-support and the backup drive, and a tertiary backup battery that can run life-support for half-an-hour.

But looking through the possible malfunctions, I noticed I don't have anything in place for if the control room goes poof, and we lose the steering jets, sensors, comms, and/or cockpit station. The article mentions the possibility of a "second (auxiliary) control station", but we're already down to using SM+4 systems, and the place is kind of crowded. Pyramid 40 goes down to a SM+3 control station (which, according to SS's rules on smaller systems, imposes a -1 penalty on handling)... but I'm thinking of going all the way down to SM+2; 1/10th the mass of a SM+4 station, probably statting it out at $2k, C5 computer (THS's advanced computer switch), comm/sensor 1, 0 control stations, and -2 to Handling.

Sound reasonable enough to anyone else here?

Re: [Spaceships] TL10 Space RV
 

SM+2 would be 1 ts, 1/20 of that is 100 lb. Can you really call that a Control Station?

Re: [Spaceships] TL10 Space RV
 

If this is a workable approach, then the SM+2 "control room" wouldn't be a seat with controls; presumably, if it was needed, the ship would by run by the pilot using a Space iPad from their bunk, or by whatever backup AI pilot was stored in the backup computer. But 100 lbs for some "wouldn't want to use them if it weren't an emergency" gear doesn't seem entirely out of line. Maybe some low-mass flywheels instead of reaction-control thrusters for basic steering, backup comms with half the range of the main systems, and sensors that probably amount to the radar/lidar equivalents of "cell-phone cameras with lots of signal processing to extract every last scrap of data". The electronics part of the gear for "if we can't fix it, we can at least limp to the nearest safe port, if we're very careful and keep anything else from breaking".



Oh, just had another thought. High Tech mentions that radios can trade range for bandwidth; you can extend your radio's range by x10 if you divide how much data it sends per second by /100, or x100 range for /10,000 data. Anyone want to guesstimate how much data a standard Spaceships comm can send, within its listed range? (This is somewhat more relevant than obvious for this setting, in which a reactionless-drive craft deviating from its announced flight-plan runs a certain risk of getting nuked by the systems' traffic-cops, especially if it changes course to accelerate towards an inhabited target and has stopped communicating.)

Re: [Spaceships] TL10 Space RV
 

In case anyone's interested, here's the final statblock for the Space RV. Primarily based on 4e Spaceships rules, plus piles of gear from THS, Ultra-Tech, and 3e Vehicles. (I converted everything from 'spaces' into 'pounds' for my own convenience.)

About the only thing that's not finalized is the list of removable gear, that the pilot would have decided to bring along for their usual Vacuum Cleaner jobs. Anything seem missing to you?

-----8<-----

** Space RV
. SM+4, streamlined, TL10 (mostly non-superscience). Design switches: Advanced Computers, Exposed Radiators, Slower Industrial Systems
* Surface/Exterior:
- Winged: $50k
- 2,000 lbs: Armor, diamondoid, dDR 10 (4/3/3, or DR 40/30/30), $200k (5 lbs/sf, maybe 7mm of diamond-density material; $500/sf, 13 mm^3 per $1)
- 20 lbs: Self-sealing hull (VX2p29), 400 sf: $4k
- Anti-surveillance shielding, -10 to bugging attempts (3e Covert Ops p99): $10k
- Heat radiator wings, retractable
* Nose:
- 1,000 lbs: External Clamp, $1k
* Near front:
- 1,000 lbs: Control Systems, $20k
- 100 lbs: Backup control systems: $2k
- 50 lbs: Searchlight, range 5 miles (10-yard radius); with Shutters (acts as signal lamp, 100-mile range): 1 cf, $2550, 5 kW
- High-security burglar alarm: $3k
* Habitable space:
-- Living area
- 5,000 lbs: Habitat: bunkroom for 2: $50k
. Diagnostic toilet (THSp147): $200
- 300 lbs: Exercise equipment (Craft Shop: Teaching; room for 1 learner): 135 cf, $1k, 0.5 kW
- 300 lbs: Relaxation Equipment (Craft Shop: Games, Erotic Art, whatever was loaded up at port; room for 1 relaxer; see Pyramid3 103 p7 for relaxing to regain mental stability): 135 cf, $1k, 0.5 kW
- 300 lbs: Improved Cooking Gear (Craft Shop: Cooking, room for 1 chef): 135 cf, $1k, 0.5 kW
- 172.5 lbs: Magnetic field generator, around pilot's bunk (VX1p21), PF 100, radius 3 feet, field 115 cf: 3.45 cf, $17,250, 11.5 kJ to activate
- 75 lbs: Luxury Interior, for 2 bunks + 1 seat (VLp29): 75 lbs, 1.5 cf, $15k
-- Medical Bay:
- 280 lbs: Surgery (THSp184): 250 cf, $50k, 0.5 kW
- 50 lbs: Medkit, Vehicle (THSp162): $5k
-- Workshop:
- 800 lbs: Basic Tool Kits (Armoury, Electronics, Engineer & Mechanic, THS p153): $4k
- 333.333 lbs: Biosynthesis Station (Pyr37p32, produces organic materials up to TL8), 1 lb/min: 45 cf, $5k
- 100 lbs: Minifac (UTp90): $50/hr->day ($2.2/hr, x1/5 for objects under 0.1 lb, x1/20 under 0.01 lb, x1/100 under 0.001 lb), $50k
- 3 lbs: Pocket Analyzers, 5 (Bio, Chem, Forensic, Geo, Metallurgy, UTp66): $2500
* Cargo Holds (capacity 3,936 lbs):
- Refrigerated cargo holds ($0.25/lb): $984
- 50 lbs: Wall Safe (UTp102, DR150, HP25, 1cf): $100
- 1 lb: Safe's Scanlock biometric scanner (THSp151, UTp104): $1k
. 1,000 lbs: Food (250 man-days), $500
. 500 lbs: Fabricator feedstock (new packaged parts, printer cartridges, sheet metal, circuit boards, chemicals, liquid plastics, epoxies, metal powders; UTp90,93), $5k
. 150 lbs: Biosynthesis feedstock (produces 90 lbs materials), $1k
. Vacuum Cleaner gear: 422 lbs
. Other cargo, 1,864 lbs
* Power systems:
- 1,000 lbs: Power Plant, Fusion Reactor, 1.2 MW: $100k
- 145 lbs: Primary Backup Zero-Point Energy Generator (VX2p27), TL10, 120 kW: 145 lbs, 1.45 cf, $36,250
- 67.5 lbs: Secondary Backup Zero-Point Energy generator, ruggedized, 20 kW: 0.675 cf, $16,875
- 20 lbs: Battery (VX1p24), 36,000 kJ (life-support for 2 for 30 minutes), $600
* Outside, opposite sides: Meteor defense:
- 200 lbs: 2 Laser turrets, retracting (3 kJ per shot, dDmg 1d-4 (Dmg 3d), RoF 10 per second, range 150/500 mi), req up to 120 kW: $30k
* Near rear: Main Drives:
- 2,000 lbs: "Horizon Drive", 0.2G accel, req 1.2 MW, $100k
- 30 lbs: backup Horizon Drive, ruggedized (Vp38,27), 0.001G accel, 0.6 cf, req 10 kW, $750
* Rear: JATO booster:
- 333 lbs: Chemical Rocket: 1G accel, $6k.
- 333 lbs: Fuel Tank (8.2 seconds, delta-v 80.4 m/s or +180 mph), $1k.
. includes 300 lbs fuel ($120)
** Total cost: $787,059 (+$6,500 in consumables)
** LMass 10 tons, length 10 yards, dST/HP 15, HT 12, Hnd/SR -1/4, dDR 4/3/3, Occ 2ASV.
** Air performance: 1,120 mph. Hnd/SR 3/5.

* Removable gear (for freelance Vacuum Cleaner pilot):
-- Cybershells:
- Cyberdoc (+microframe), $170k, 150 lbs
- Tenzan THI-200bis spider-bot (PF1p62): $64,200, 40 lbs
- Maintenance snake bot (4eSTp14-5, +tiny comp, +NAI-5): 2 lbs, $2100
- Cybertool (4eSTp5, +tiny comp, +NAI-5): 1.5 lbs, $2400
- Microbots, crawler, cleaning + illumination: $3600, 1 lb
- Pressure Tent (THSp151), 1-man: $500, 15 lbs
- Nanodrug, 1 dose: Very Rapid Healing (+5 HT to recover HT, recover 2 instead of 1 HT), Long-Term (1 day), injection (THSp163): $750/dose
- Drugs, mnemotropins ($100/week), 3 months: $1300
- Autograpnel: $200, 3 lbs. Nanofiber rope, 50 yards: $150, 10 lbs.
- Duct Tape, 200 feet: $5, 2.5 lbs
- RSX-100 "Broomstick": $1,987.50, 35.75 lbs + 120 lbs MOX ($14.30), Thrust 0.35 G (3.5 m/s^2), Burn Endurance 5.5 minutes, delta-v 1.03 km/s
-- Personal gear
- Protective Coveralls: $160, 2 lbs
- Pocket Pack: $20, 0.5 lb
- Vaccsuit (Pyramid 96): TL10, 21.35 sf, Bioplas, DR 15 (vs pierce/cut, DR 5 vs other), flexible, diaphonous, transparent visor, sealed, waste-relief system, extended life-support system, microbot arteries tiny air tank (15 hours), C cell: 5.8 lbs, $7,960
- Thruster Pack: 100 seconds, 50 lbs thrust, $2k, 20 lbs.
. Extra cylinder $30, 10 lb
- IFF Transponder: $100
- Smartboots: $500, 2 lbs
- Smartgloves: $50
- Microbots, paramedical swarm (UTp201): $6k, 1 lb
* Total weight: 422.05 lbs


* Financials (SS2p27)
* Income:
- Vacuum Cleaner job (THS:HFp43): ~$5k/month
* Outgo:
- Bought used: Price * 0.5 = $393,529.50
- Bank loan: 10% down payment = $39,352.95.
- 8% interest for 16 years (half paid for by government subsidies): $3,550/month
- Cost of Living (Islandia, Status -1): $1200/month
- total: $4,750/month

----->8-----

Re: [Spaceships] TL10 Space RV
 

Speaking of; the question has just arisen, "What would it take to be able to survive Mercury?". THS:ITW suggests that a ship with life-support just needs dDR10 over all three facings, so I started thinking in terms of strap-on insulation. For a SM+4 ship, already with dDR 4/3/3, even best-available diamondoid would need another 4 systems, 4,000 lbs, worth of the material. Doable, if kind of awkward.

But I don't need the stuff to protect from damage, just from heat - insulation rather than armor. Going back to 3e Vehicles, that seems like it could be approximated with "fireproof ablative armor". I've previously worked out that in 3e terms the Space RV has a total of 475 sf surface area, and we'd need to add the equivalent of 66.6 DR; with TL10 advanced stuff, that works out to 380 lbs and $6,080. (Or 633 lbs $2,533, or 950 lbs $950, or 1,583 lbs $633.) That's surprisingly reasonable; and there's still enough slack in the Space RV's cargo space that I could throw it in as a permanent feature.


Can anyone think of any flaws - or plot-worthy interesting complications - to this approach?


(The question also arose for Venus, but THS:ITW's numbers seem to imply that a SM+4 ship, even one made of 18 diamondoid armor systems, couldn't hold up to the pressure; dDR 90 vs a needed dDR 267. At least, not without replacing a 'standard' frame with an 'extra-heavy' one, and even then the Space RV would need another 13 spaces dedicated to diamondoid armor, at which point there wouldn't be enough space left for it to be an RV.)

Re: [Spaceships] TL10 Space RV
 

Mercury has extreme differences in temperature, because it has no atmosphere and a very long day. If you land on the far side of mercury, you actually need to heat your craft, not cool it.



If you want to land on the sunny side of mercury, thermal insulation over a very limited contact surface is a good idea. People have also suggested overhead mirrors as an effective cooling mechanism, though that's usually for immobile or quasi-mobile installations.


Using heat armor will always be a merely temporary solution, and you'll need a way to cool off. You also have to get close enough to the sun to land on mercury, which tends to heat up your spacecraft even before you touch down.



Mercury has rather high gravity, all things considered. You need about .4 G to take off.

Re: [Spaceships] TL10 Space RV
 

Any ship that can handle being in vacuum through the solar system should have enough heating for that.


I'm using the 4e SS toggle to enforce heat radiators, so as long as the ship can manoeuvre to keep them edge-on to the sun (and preferably at least one within its own shadow), it should be able to cool itself.

(THS:ITWp64 says that any ship's life-support system can be assumed to have cooling equipment, though 100 DR is also needed to avoid suffering heat damage.)


Ah, an important detail I'd left at the bottom of my notes and had forgotten. Hm... I'm going to have to sketch up some stats for a Mercury-level JATO unit, that can manage something like 3G for 2.5 minutes (or 1.5G for 5, etc). (Though if cooling is managed, the Space RV could at least survive in Mercury orbit.)


Also, can't believe I neglected another setting detail I wanted to include: Aerostats in Venus's atmosphere, floating at around the 1-bar pressure level, around 50 km up. The Space RV already has acid-proof diamondoid armor, and its wings will work in Venusian atmosphere at least as well as Earth's, so it should be able to dip down at least that far, if not all the way down to the surface.

Re: [Spaceships] TL10 Space RV
 

The altitude where Venus is cool enough to support an Earthlike environment is quite safe from acid. The primary concern is the surface, where the combination of acid, heat, and pressure would turn any spacecraft not protected by a silicon armor into a deathtrap. Of course, pure silicon is extraordinarily strong, as strong as carbon fibers, so it might be possible to create an equivalent of diamondiod made from silicon.

Re: [Spaceships] TL10 Space RV
 

Sticking to SS instead of 3e Vehicles, there aren't too many options that can boost a ship by at least 0.18G, provide at least half of Mercury's escape velocity, and not use up too much of the ship's mass. In fact, I've only found two:

- "Mini-Mag Orion": 1 system divvied into 3 smaller systems, one External Pulse Propulsion, one Fuel Tank, and one Magsail. $62k for hardware, $37.5k for fuel, +0.6G, 2.6 mps
- "AM Is Your Friend": 2 systems, one Antimatter Thermal, one Fuel Tank. $56k for hardware, $10k for fuel, +0.2G, 1.8 mps.

(A Laser Rocket or HEDM rocket come close, but either one needs at least 3 systems just for enough fuel.)

The current spec's chemical-rocket JATO unit uses 2 smaller systems, which I can get rid of; and I can try doubling the cost of the Fuel Tank to turn it into a reconfigurable system that doubles as a cargo bay. So with the Mini-Mag, I wouldn't lose any cargo space, while with the AM I'd only lose a third of a space of cargo; and the AM costs a lot less per landing or take-off, so that's what I'm leaning towards, despite the inherent coolness factor of any Orion-derived drive design. :)


I don't know what "diamondoid" is made of, but THS:ITWp71 includes the line, "If the device has nanocomposite or diamondoid armor (advanced laminate from TL9 or above, in GURPS Vehicles terms), acid-proofing is free." For strength, p70 has a formula for what's needed, in terms of size, frame-strength and DR. For a SS spaceship, which can be assumed to have a 'medium' frame, the dDR required on every section is (67*SizeMod)-1... kind of hard to manage on anything smaller than SM+12 (with $18B of diamondoid).

Re: [Spaceships] TL10 Space RV
 

In THS:DBp154, there's a formula for figuring out the crush depth of a vehicle, which seems to agree with the one from VX1p30. For a spaceship with DR 30, medium frame, boxy hull, and SM+4, that works out to getting crushed at 30 yards (and a test-depth of 15 yards).

I've just noticed that on the next page of Deep Beyond, the note on translating crush-depth to atmospheres of pressure seems... wildly over-optimistic. It says to multiply the depth by 11.3; that is, from 30 yards to 339 atmospheres, and from 15 yards to 169.5 atmospheres. But if you actually take a craft down 30 yards in an Earthly ocean, it's only experiencing around 4 atmospheres of pressure. If 4 atmospheres of pressure would crush a vehicle underwater, why would 40 atmospheres in a gas giant be more survivable?

Am I misinterpreting something? Should I ignore the 11.3 figure? Should I take the seeming weirdness as written?

Re: [Spaceships] TL10 Space RV
 

Carbon mostly. That's why it's "diamond-like".

I'd have to say that any acid-proofing is some sort of external coating. Carbon is fairly reactive.

Re: [Spaceships] TL10 Space RV
 

There's an alternate equation for crush depth in the alternate spaceship rules from Pyramid 34.

(crush depth in yards) = dDR*150/(hull length in feet)

It also has a different equation for converting from crush depth to atmosphere. It's (depth in feet)/33, which seems to imply that the equation you saw had the right number, just it should have been divided rather than multiplied.

EDIT: I just looked it up, and apparently that equation is off by a factor of 100 and should be 15000, not 150.

Re: [Spaceships] TL10 Space RV
 

There are other, more detailled formula in THS: Under Pressure (as well as detailled formula to calculate crush depth for aquatic vehicle, depending on frame, shape, dr, ...)

It gives
Pressure at x depth (in atmospheres) = Pressure in Atmospheres above liquid + (Depth in feet / K)

With K = 33.2 for Earth sea water, and varies for other worlds. (THS UP p 48)
K is a number equal to 34 / (the gravity of the world in Gs * the density of the liquid relative to fresh water).

So I think the "multiply by 11.3" should be "divide".

edit : the confusion isn't helped by having some equations assume depth in feet, others in yards, with the odd one in miles ... I won't resume a lost battle, but there has been spaceships lost because of that sort of mess ...

Re: [Spaceships] TL10 Space RV
 

Thank you, that clarifies everything. :)

Say, is SJG still accepting errata for In the Well? Who would I submit it to?


(Unrelatedly, I've just realized that with proper design, the Space RV doesn't need a JATO unit to kick its ground-speed up to its stall speed. I've got enough 3e Vehicles stats to work out the numbers to give the craft "variable-sweep wings", which can effectively halve the stall speed down to 110 mph, well within what it can accelerate to within a kicker.)

Re: [Spaceships] TL10 Space RV
 

Latest silliness: Pondering how much coolant tankage it would make sense to throw in as another layer of backup, in case the radiator wings get shot off.

By mixing and somewhat abusing SS's somewhat scant rules on coolant tanks with THS's rules on cooling, it looks like a tank of 100 lbs of coolant would be enough to let the reactor run for an extra 180 seconds as the coolant vents; venting 100 lbs of water instead would get 90 seconds; and melting 100 lbs of ice into water would provide all of 11.25 seconds of reactor time. All of which is after the reactor spends 30 minutes without radiator wings building up heat, and the only thing on the ship requiring full reactor power is the 0.2G main drive, so we're already dealing with a situation where the drive's been running without radiator-wings for at least half-an-hour, which already puts us into at least quaternary-level backup territory. (I've already jotted down the existence of a 20-lb, 36,000 kJ battery, which can power the main drive without the reactor for 30 seconds; and there's a secondary reactor that can push the main drive at 0.02G, and there's a tertiary reactor that can power a backup 0.001G drive.) So it looks like 20 lbs of coolant could keep the ship moving at 0.2G for 6 seconds longer than 20 lbs of battery - and coolant can only be used once, while a battery can be recharged.

The closest I can think of to getting some use out of the idea is that water is often useful for all sorts of things on a spaceship*, so if I throw in a 100-lb tank of ice/water for miscellaneous purposes, then I might as well run a heat-sink into it (plus a valve for venting outside the ship) just on the bizarrely-rare circumstance that a few extra seconds of reactor-power might be useful.

Also related, treating the fusion plant as THS's 'New Fusion', then 1.2 MW of generation requires all of 75 square feet of radiator area. I've already worked out the craft has 475 sf area; checking THS for surface features, I could dedicate 100 sf to the lasers, 224 sf for 14-tons of external-clamp capacity, and still have 151 sf for two separate surface-mounted radiators, either of which would handle the generator's heat all by itself. Meaning I wouldn't need any radiator-wings at all, unless I wanted to spend (by THS's numbers) 750 lbs on 0.075 ksf of folding radiator wing.


(*: Edited to add: Like a hot-tub. :) )


I've also been thinking of micrometeor protection, in hopes of shaving off some of the mass currently dedicated to standard armour. Here in TL8, we use Whipple shields, one or more thin layers held outside a spacecraft's main body, which break up high-velocity impactors into rapidly-dispersing plasma before they touch the craft's real surface. According to table 6 of this paper, it looks like one example of such a shield is 0.230 grams/cm^2, which works out to 224 lbs to cover 475 sf. And the graph here suggests that a simple whipple shield can handle a 3mm micrometer travelling at 3 km/second (0.12 inch, 1.86 mps), and seemingly oddly, larger or smaller projectiles travelling even faster. Up to 0.33" at 4.3 mps, which at average impact speeds, THS:HFp33 suggests would do an average of 145 damage. (I think that would be 14.5 dDmg in 4e SS terms, but I have to re-read a couple of rules to be sure.)

As it happens, 3e Vehicles suggests that over 475 sf, 150 DR of TL10 open-frame advanced ablative armour would weigh 171 lbs and cost $1,368, which seems plausible for a higher-tech version of a couple of thin layers of aluminium. Technically, open-frame armour is supposed to protect against "collisions, falls, rolls, or swinging melee attacks" and only has a 1/3 chance to protect against "thrusting attacks ... bullets, or other small missiles"... but I think I could make a case for an alternative version of open-frame armor, that only protects against objects below 8.5mm/0.33" moving at least 0.5 mps (1800 mph).

Or maybe someone has a better idea; anyone else want to try mathing out a TL10 whipple shield? :)

Re: [Spaceships] TL10 Space RV
 

OMG, 400cf of internal space is tiny!

That’s 7 ft high, ~5.75 ft wide, and 10 ft long (is that even as big as a solitary confinement prison cell?), and has to include 2 fold-away bunks, a combo all-in-one bathroom (probably with fold-away sink and toilet), tiny “efficiency” kitchen (probably just a hot plate and microwave, a pilot station / desk, and all the cargo space tucked into every available nook and cranny.

Better hope that you can get decent exercise with jumping jacks (with everything folded away) and maybe a few resistance pulleys.

There are few UT gear options mentioned down thread that I would not allow in a space that small.

I think at this size, you’re picking and choosing rulesets to get the best of both worlds.
Try working the whole thing up in Vehicles.