Low tech starships

Date: Tue, 22 Aug 1995 18:33:37 GMT
From: "Brendan O'Donovan" <Brendan@odonovan.demon.co.uk>
Subject: Low tech starships

(Techy bit follows, skip to bottom for adventure seeds)
I've just tried designing some starships at TL9, I haven't finished the designs 
yet, but lots of interesting things turned up while I was working on it.

- There is an error in the MFD chart, which includes TL9 MFDs with ranges up to 
10 hexes. All very well, but they need a pencil beam active sensor, and TL 9 
radar has a maximum short range of 3 hexes. This means that there is no point in 
fitting a (3hex) MFD, as a 10 hex beam-pointer would be far more effective at 
most ranges.
I would suggest the following chart as a quick fix for this

Radar availability
                        Processor Volume
Short range (km)         TL8    TL9
90,000                   60     30
120,000                  70     35
150,000                  85     45
180,000                  100    52
210,000                  -      57
240,000                  -      62
270,000                  -      75
300,000                  -      85


- It is very hard to design any kind of exploration craft, even once Jump-1 
becomes available at TL9. For proper exploration, refuelling capability is 
important. Fusion rockets are very effective drives, so long as you don't want 
to get anywhere fast, but they 'cannot be used in planetary atmospheres'. I 
assume this is mainly because of the effects of radiation on planetary 
ecologies, so this doesn't apply entirely to gas giants. However, flying a 
fusion rocket powered craft through a gas giant creates another problem, as the 
plasma exhaust will cause secondary fusion reactions in the hydrogen behind the 
craft. This means that any refuelling craft needs to keep up speed inside the 
gas giant so the fusion explosion behind it doesn't catch up. In design terms 
this requires an airframe hull and armouring to 30 to prevent the fuel shuttle 
from burning up, and to allow it to go fast enough in the atmosphere, although 
1G acceleration should be sufficient to allow escape.
:From orbit the sight of fuel shuttles refuelling is truly impressive. On 
entering the atmosphere an initial fireball speads out slowly from the point of 
impact with the atmosphere. From one edge of the expanding fireball a point of 
fire reaches out, an inferno spreading out like the wake of a speedboat from the 
speeding shuttle.
Even with a specifically designed craft the danger of this maneouvre is 
considerable. Refuelling in this way is a Difficult:Pilot Interface/Grav task. 
Failure results in 1h damage to the fuel shuttle, and -1 to the physical 
attributes of the crew for the next week due to slight radiation poisoning (The 
only symptom unless the referee is cruel/realistic. ADVENTURE idea: Optionally 
some or all of the crew develop cancers which may not be treatable at TL9, 
turning their exploration mission into a race against time to find some 
civilisation advanced enough to treat their sickness.)
Catastrophic failure results in the destruction of the craft (crewmembers could 
escape in a specially designed rocket escape pod, but they would definitely 
receive major radiation poisoning)
Low tech pilots tend to be _very_ good for this reason.

-Exploration is also hampered by the available thrusters. All of the lower tech 
thrusters have very large fuel requirements, and cannot be fueled on hydrogen. 
The low thrust of the 'clean' thrusters means that the main exploration vessel 
cannot land on habitable planets using them, so much smaller landers, launched 
from a jump capable fusion rocket propelled craft would need to be used. Because 
none of the clean thrusters can be fuelled with hydrogen, the mothership would 
need to carry enough fuel for the whole mission.

I suggest the following thruster as a TL9 solution for planetary landings

TL Type             Th   MCr    MaxT    FC     FT     Airframe
9  HeatJet          8    0.5    -       2.00   Lhyd   Hyper

The heat jet passes liquid hydrogen around a fusion reactor, heating it and 
boiling it, expelling it as a gas. This is a precursor to the HEPlaR drive, but 
the hydrogen does not reach a plasma state. Although considerably inferior to 
the fusion rocket which becomes available at the same time, it is a cleaner 
alternative, and can be used within planetary atmospheres.
Alternatively stick with the FFS rules, it produces interesting results and 
makes design challenging, if not impossible.

Adventure idea:
Under normal conditions the fusion wake in gas giant atmospheres will die down, 
as the atmosphere is not dense enough to support the fusion reaction. However, a 
brown dwarf, a gas giant which is almost a star, could possibly be triggered by 
a fusion rocket into igniting into a full star, making the vicinity decidedly 
uncomfortable for any lifeforms.
This could cause all sorts of problems for the players:
1. Get out of here! Now! - The players' ship should be capable of taking them 
out of danger, of course now would be a particularly unfortunate time for 
saboteurs/vermin/old age to strike at the maneuver drive, resulting in a race to 
repair it before the the characters become Kentucky Fried Travellers.  
Alternatively, insufficient fuel to escape had been taken from the star, so the 
fuel shuttles are forced to make a few last runs into an igniting star to get 
enough fuel to escape

2. Guilt trips - Even if the players can get away, it doesn't meant that 
everyone else nearby can. If the players' actions have accidentally caused the 
impending doom of someone nearby, then they should probably have a go at 
rescuing the victims, who could be:
1/A settlement on a nearby agricultural moon.
2/Sentient aliens encountered living within the atmosphere of the gas giant.
3/A nearby free trader who is experiencing problems similar to those outlined 
above for the players.
4/An old imperial research station, complete with signal beacon and remnants in 
low berths. 
5/For mercenary players, a cache of relic technology could be discovered on 
one of the moons just as the gas giant ignites - how much can they grab before 
the lot goes up in flames?

-- 
Brendan