STARSHIP DESIGN PROJECT:
This report describes the concepts and summarizes the current results of the Starship design project. In this project we are attempting to come up with a serious, practical, design for a manned interstellar mission; that could be launched in the year 2050. Over the last 18 months we've argued over almost every known concept of interstellar flight. With the only firm ground rule that we limit our technology to what seems plausibly likely for the year 2050. Other than that, we considered everything from multigeneration starships, to anti-matter powered ships. Some concepts were technically easier, but lacked any practical advantage. Others needed radical technologies that seemed implausible. Some were just completely unworkable. Some might work, given certain assumptions.
The sub-documents linked below give a summary of each of the major areas of discussion, and our current progress in them.
Project Assumptions - Briefly describes what we assume will be the background and environment of the assumed starship construction mission in the year 2050. This is the charter for the starship design project.
Flight Types - Here we describe the different types of flights a ship could take to get to the target star system.
Mission Types - Describes what the crew might be expected to do when they get to the starsystem. Different missions from exploration to colonization, and the pluses and minuses of each.
Star drives - Describes the different types of propulsion systems that we are, or were, seriously considering for use by our starship.
Starship Cargo manifest - The equipment we feel the starship will be taking with it to do the mission. Rovers, Shuttle craft, mining equipment, food stores, etc.. Everything a mid 21st century interstellar expedition seems likely to carry.
Future Tech - These are technologies that might be available, but which we assumed weren't available and why. If some or all of these technologies were developed (and many are likely to be sooner or later), the mission could be radically easier, and human society would be radically different.
The rough starship designs we've come up with so far.
The Explorer Class of starships is the oldest and the most detailed of the designs developed by the group. It was my design for a basic fusion powered starship with all the support structures, food consumption, habitation deck, and the rest; worked out in as much detail as we can manage. Its maximum speed is probably only about 1/3rd of light speed, and it can only get to that speed with the equipment to mine millions of tons of fusion isotopes at the destination, and a external fuel launcher system assembled in our solar system. So it wouldn't be fast enough to get to Tau Ceti in an acceptable amount of time. (Thou it would be quite acceptable for a flight to Alpha Centuri or other near by stars.) But it does seem to be a workable starship design, that doesn't require any technologies that don't seem possible within the next 50 years.
The MARS Class (Microwave Augmented Rocket System) by Kevin Houston, assumes similar internal support systems as the Explorer Class, but uses a Microwave Sail to get the ship up to near light speeds. The original idea on how to decelerate the ship, was that the microwaves would be converted to electric power. That electricity would run a high power ion drive that would decelerate the ship. However this is now considered questionable, since some of our equations seem to show that the forward thrust from the microwaves would always match or exceed the reverse thrust from the ion motor. So we don't know if we can a reliably stop the ship at the target system. Assuming we figure a way around that. This classes chief questionable assumption is a microwave emitter system in our starsystem that has millions of time the electrical capacity of late 20 century Earth's power grid. Even worse, an equally fantastic microwave emitter system would have to be constructed in the target system, in order to get the ship and crew home.
The Argosey Class By Brian Mansur, also uses similar internal support systems as the Explorer Class, and Microwave Sails like the MARS class to get the crew to the target starsystem at near light speeds. But it assumes a slower automated craft precedes the manned craft, and assembles a MARS type microwave emitter in the target star system. It uses a beam from this emitter system to slow down the ship. This solves the MARS braking problem, but adds the technically questionable automated construction fight, and adds decades to the mission time.
The Fuel Sail Class is my latest design concept (still in work). It uses the same internal support systems as the Explorer Class. But instead of stored onboard fuel or fuel launched from space based fuel launchers to get itself up to cruise speed. It uses huge Microwave Sails made out of the fusionable metal isotope Lithium-6. The sails themselves are made out of the deceleration fuel and can be scaled up to hundreds of times the weight of the ship itself. The ship would boost out of our starsystem using microwave thrust on the fuel sail (like the M.A.R.S. Class). But it could only go as fast as it can decelerate from with the onboard fuel (like the Explorer Class). However since the microwave sail system could (presumably) work at greater distances than the Explorer Classes fuel launchers. The ship could afford to carry more deceleration fuel. Allowing a higher cruise speed. Possibly as high as 40%-42% of light speed. It would pull in and fuse the sail into a block of Lithium-6, and then burn it to slow down the ship. This solves the MARS braking problem, but isn't capable of the high speeds of a pure microwave sail system.
How far did we get so far? Well we have a couple ideas that might work. The Explorer class or the Fuel Sail class, could get you to the nearer star systems in a usable amount of time. But only if you can mine enough fuel to feed them, and can pay for all the infrastructure they'd need. The relatavistic microwave powered craft (M.A.R.S. and Argosey) have some bugs (and an incredible thirst for power) so they might not be possible, and are very likely to be extremely impractical. In our mission studies we discussed and rejected a lot of the old science fiction standards (multi-generation and hibernation starships, or interstellar colonies for example) as romantic, but having no practical benefit (assuming the sun or human civilization aren't about to collapse).
So we have a couple designs that seem possible; assuming certain technologies, or tremendous budgets. We do not think these are the ships that we will build in 2050, because the people of that time will probably know a lot more than we do. What they will know, and what that knowledge will allow them to do, we really can't guess. But some parts of these designs might prove useful to them.