Date: Tue, 22 Aug 1995 18:33:37 GMT From: "Brendan O'Donovan" 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