Because there are so many different people involved, and because everyone has very different ideas about why we should be going to the stars, it has become necessary to give a framework for what we are doing. Not everyone may agree that this framework is the best. But for the sake of our thought experiment, I ask you to accept it for now. You are certainly free to pursue your own designs, and LIT will support you in your independent research with the efforts of our student body. You work will also be gratefully given a place on the LIT World Wide Web pages. However, in order to avoid the usual internet chaos, please stick to this charter when submitting items for the newsletter. In the near future, I would like there to be a FAQ for the design project as well, so that we don't repeat the same questions time and time again. If anyone would like to help with this project, please speak up.
Here is the story. As the years progress, there will be more and more studies of nearby star systems. Most current indications seem to say the planets, on the whole, are fairly common. Most newborn stars in the Trapezium, for instance, seem to be surrounded by accretion disks. There have been many indirect observations of planets (i.e., inferences made from disturbances in the motion of nearby stars). It is likely that as our technology improves, we will eventually obtain direct evidence of planets surrounding nearby stars. Orbiting telescopes and occultation disks could be one way to obtain direct images.
Our assumption is that such an observation has been made. Surrounding many nearby star systems, large jovians and small terrestrial planets are detected. However, spectral analysis gives no sign of interesting molecules (i.e. oxygen, water vapor, etc). However, around Tau Ceti, which is 11.9 light years distant, six planets have been detected. Tau Ceti itself has a mass of 0.82 times that of the sun, 0.44 times the luminosity, and 1.67 times the radius. It is a G8 star (the sun is G2). Out of the six detected planets, five of them are jovians, and one is terrestrial. There may be additional planets we have been unable to detect. The five jovians are:
II: 1.16-1.18 AU, approx. 30 earth masses, orbital period of 1.4 years III: 1.99-2.01 AU, approx. 80 earth masses, orbital period of 3.2 years IV: 2.79-2.81 AU, approx. 1.30-1.34 jupiter masses, period 5.3 years V: 5.60 AU, approx. 0.92-0.96 jupiter masses, orbital period 14.6 years VI: 11.10 AU, approx. 1.05-1.09 jupiter masses, orbital period 41.0 years
The one terrestrial planet, as best as can be determined, is:
I: 0.71-0.73 AU, approx. 0.20-0.22 earth masses, period 8 months
Spectral analysis strongly indicates the presence of oxygen, nitrogen, carbon dioxide and water vapor. However, we cannot give relative amounts. These elements are, however, in large enough amounts to be detected. Tau Ceti's "lifezone" extends from about 0.62 to 0.78 AU, so "I" looks pretty good. There have been no radio signals received from this or any other star.
The public is clamoring for a manned mission, and significant funding is available for this now. It is assumed they are not interested in waiting for results from a probe first. The reason we need to assume this is that we are trying to design this starship back here in the 1990s (remember, LIT takes place in the "future"... more on this later), and we don't have any information about our target (or any target), so we've got to come up with some kind of conditions (no matter how unlikely) that allow us to design a manned mission. A manned mission is inherently more interesting (and, of course, challenging), even if an unmanned mission is more likely and a better choice. Since we're not really building a starship, we should go all the way with our scenario and have some fun while we're at it.
So, our job is to design a manned expedition to this star system. We are fairly sure we'll find something interesting there, but not 100% sure. Are we exploring or colonizing? That depends on the energy available. If we can't get our astronauts back, we need to seriously look at outfitting them for colonization in a number of possible environments. Assume by this time we have some experience with temporary colonies (<50 people) on Mars, and (of course), slightly larger colonies on the Moon. (Speaking of which, the moon's population in the LIT world is near 3000, but quite spread out among a variety of government installations and private enterprises.) Also, because this public funding is coming from the public's keen interest, it is unlikely they will fund a slowship. We should try to focus on fast vessels, but if this turns out to be impossible, then we should go ahead and design a slowship.
What kind of technology are we looking at? No black holes or warp drives, please. I won't say they're impossible, but I would like to stick to the fictional background of LIT, which says that the year is 2055. In other words, what can we do, technologically, with the next 60 years? Who knows, the science of warp drives could even be developed by then, but it's unlikely in the extreme that we could engineer a starship with such technology. Remember, engineering follows science, and even if we have the science, if we don't have the engineering we can't do it. Fusion today is a good example of this. We pretty much know the science, but we don't know all of the engineering. For many many years we've been told fusion is "just around the corner." Well, finally, we'll definitely have fusion in the 2050's. That's one possible power source. So is fission. So are solar sails and laser sails. As for antimatter... well, you'll have to convince everyone else here if you want to go that route. Assuming someone came up with a way to generate copious quantities of antimatter in the next few years, and a rigorous power plant program was followed... it might -just- be possible. But I'll leave that for everyone to decide. What about electromagnetic launching? Or RAIR's? Or even ram-jets for that matter. Do you think we could construct the huge electromagnetic fields required to form the scoop?
Let's see... what else? We probably will have some kind of permanent orbital presence, and a permanent presence on the moon (though likely small). However, we may not have "orbital shipyards". Therefore, if we're building the spaceship in orbit, we have to build the facilities, too. However, by this time, this probably won't be that bad, because we'll have some kind of construction experience in orbit from space stations, etc. Besides, building in orbit or on the moon is cheaper than on the Earth just due to the lifting costs.
Anyway, this should give us a general framework. Let's try to keep the discussions on-topic. If you've got anything you feel should be added to this, please say so, and we'll all consider it.