"Radiation" is supposed to be a problem within an operating drive IIRC but the main reason the engines are mounted on pylons is that if an atomic drive malfunctions or is to damaged you eject the DRIVE not the crew from the ship. The ship has all that nice life support and other functions that keep people alive so you want to stay with the ship and get rid of a drive pod rather than have life pods all over space :)

And actually if radiation WAS a serious problem you don't want to put the drives on pylons because it increases not decreases your exposure angles from stray radiation. Shadow shields are pretty much impossible on a pylon mounted drive so you'd have to heavily shield the whole ship rather than only the "drive" section in that case.

"Fighter" atomic drives are supposed to have radiation issues due to the size of the hull AND mounting a drive right near the pilot without enough space for radiation shielding. Hence the pilot needs to wear a "radiation proof" suit. ("Technically" a lot of the radiation problems can be hand waved away with the use of various "fields" available in SF along with radiation sheilding but Gamma Ray photons are tough to stop)

One of the things I realized about SF is that a "freeze field" works both ways. It can just about stop molecular motion with very little power then it should be able to increase molecular motion to the point where you have "chemical" engines you feed some hydrogen to and turn it into a plasma and then mix it with a heavy, dense, "reaction mass" to produce coupious amounts of thrust in a small rather clean package. I figured "nuclear" and "ion" engines were variations with different fuel sources and reaction mass injection rates.

Randy

(http://jaythurman.deviantart.com/art/Star-Frontiers-Explorer-Ship-with-Lander-Ortho-454952766)

Randy

"Technically" no it should only need some basic sensors (radar) and comms to get from the surface to a desired orbit. Has to have planetary navigaton of some type to assure its on track for the desired inclination and altitude. Once "near" the destination (ship, station, or specific orbit) it would use the radar and ground track information (if available, if the world doesn't have any traffic control more work for the pilot/crew of the ship but still doable) to get close enough to rendezvous with the target. Such a ship could fly between the surface and a nearby moon but interplanetary travel would require some astrogation equipment and computer space.

Randy

Possible, but not necessary. Since any HS:3 ship can be designed for aerodynamic/atmospheric landings, it's an unnecessary and more expensive procedure.

Goingby canon rules I'd say it requires the shuttle astrogation package, the smallest/minimal package available.

And actually if radiation WAS a serious problem you don't want to put the drives on pylons because it increases not decreases your exposure angles from stray radiation. Shadow shields are pretty much impossible on a pylon mounted drive so you'd have to heavily shield the whole ship rather than only the "drive" section in that case.

KH states that 'Atomic engines are mounted on struts that keep them away from the ship's hull. This is because these drives are a source of dangerous radioactivity, and must be isolated from the crew and living quarters of a ship'.

That said, it's not clear if they are dangerous because of potential radiation problems or instead radiation is released at dangerous levels during normal operation.

I agree with you about shadow shields. It also seems more sensible to me to have the engines at the furthest end of the ship, with shields, and not on struts. Maybe the KH designers partly had Star Trek in mind?

I like your idea stemming from freeze fields also. Ion and nuclear drives seem a bit clunky.

We're talking a 50 meter long hull versus a 30 meter long hull, conspicuity really isn't an issue here. Unless your shuttle is HS:1 --- which isn't much of a shuttle, more like a personal transport, at that point you might as well use a launch...which is perfectly within the rules.

The KH designers probably didn't have a clue as to HOW 'radiation' actually worked and were "assuming" that (like many did at the time) ST-TOS mounted the engines at a distance from the hull to substitute "distance" for shielding. That only works over a LARGE distances and a point is trying to reduce the number of angles that the radiation can come from. Putting the engines on pylons helps this not at all as it put the engines AWAY from the hull, but not far enough to help and exposes more of the hull to the "radiation" danger :) More radiation, and more exposure angles means greatly increased shielding mass and cost so its the worst of both worlds unless the reason is more subtle. Given the "self-destruct" for a drive amounts to an unstoppable chain reaction that ends up blowing up the ship I don't see the "radiation" danger holding much water over the far GREATER danger of an engine blowing up while attached to your ship.

None or the drives operate or even resemble their "names" enough for me to see them being "real" drives of that type. Specifically a real "nuclear" engine run-away chain reaction causes a melt down, never an explosion and Ion drives don't have anywhere near the thurst cited, oh there are dozens of reasons to suspect the "names" are not related to what's really going on :)

Randy

Going to bet someone saw articles about the VASMIR plasma drive and wanted to port it over SF. Unfortunatly, a "plasma" is an ionized gas and while most materials they make plasmas out of are NOT what they use in ion drives the basic engine principles are the same. (Hydrogen for plasma for example and Mercury or Zenon for ion thrusters) Ionize a substance (or turn it to a plasma) use electromagnets to accellerate it and toss it out of the ship and the ship goes the other way. Nice, neat, efficent, but really low thrust.

Inject some additional "propellant" into a plasma stream to increase your exhaust mass and it should increase your thrust. In theory :)

"Intermixing" is the main problem with the concept but again, the fact that they can control molecular motion and in a specific area helps a lot. Plasma is a very hot, but very defuse gas that expands (and cools) rapidly once out of the generator/engine. Mixing it into a stream of propellant is tough but if you can do it and continue to heat/expand/accellerate the exhaust steam you've got a dandy reaction drive rocket engine.

Somewhere along the line you'd want to diferentiate between the various "types" or drives so we can assume that "atomic," "ion," and "chemical" came from that need.

And probably not get that deep into it and just say its a game from the start :)

Randy

True, the rules don't spell that out...they're inferred to be space-only vehicles by the opening description although there's really nothing stating they can't make planetfall.

Still, your proposal is basically suggesting a 15 foot boat as a dingy towed behind a 25 foot boat. For what you're spending on construction and operational costs, for a fraction more you might as well make the smaller ship interstellar capable and call it a fleet maneuver. Unless of course you plan on making your shuttle a HS:1 craft, in which case it really is a rowboat that can be used as a dingy behind the 25 footer.

Wasn't the launch bascily "open-topped?" I'd call that a problem with doing reentry :)

Randy