If you want to build a functioning starship along the lines of Icarus by the year 2100, there is a lot of basic science that has to be done. It is very difficult to predict the course of basic science, because you don't know what you don't know, and it is therefore hard to anticipate how far away the frontiers might be.
The main problem with Icarus is that it aims to create a ship that can do the trip on the scale of a human lifetime. With space travel, the amount of energy required, and therefore the difficulty of the project, is related almost exclusively to how fast you want to get there, the delta-v, if you will.
Therefore, it is unreasonable for Icarus to set a timetable.
If you really want to set a timetable, there is an easier way: stop worrying about how long it takes. Concentrate all of your effort into curing death, and then build a starship with a solar-sail, or some other sort of environmentally-friendly, but slow, technology.
The advantages to this approach are many: easier to get funding, direct economic payoff, no difficulty convincing people that your effort is worthwhile, and, oh yes, you get to cure death.
Then, while you are aboard your starship, you can spend the hundreds of years (say) that it takes you to get to Alpha Centauri further advancing science. If you are adequately equipped, as a nuclear-pulse propulsion vessel would likely be, you can invent better propulsion technology as you go along.
In a sense, the problem of human senescence and its attendant illnesses and the problem of interstellar travel are one and the same. If someone asked me to solve the latter as quickly as possible, I would begin by solving the former.
The main problem with Icarus is that it aims to create a ship that can do the trip on the scale of a human lifetime. With space travel, the amount of energy required, and therefore the difficulty of the project, is related almost exclusively to how fast you want to get there, the delta-v, if you will.
Therefore, it is unreasonable for Icarus to set a timetable.
If you really want to set a timetable, there is an easier way: stop worrying about how long it takes. Concentrate all of your effort into curing death, and then build a starship with a solar-sail, or some other sort of environmentally-friendly, but slow, technology.
The advantages to this approach are many: easier to get funding, direct economic payoff, no difficulty convincing people that your effort is worthwhile, and, oh yes, you get to cure death.
Then, while you are aboard your starship, you can spend the hundreds of years (say) that it takes you to get to Alpha Centauri further advancing science. If you are adequately equipped, as a nuclear-pulse propulsion vessel would likely be, you can invent better propulsion technology as you go along.
In a sense, the problem of human senescence and its attendant illnesses and the problem of interstellar travel are one and the same. If someone asked me to solve the latter as quickly as possible, I would begin by solving the former.