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View Full Version : 100 Year Starship Project Has a New Leader



Fraser
2012-Jan-11, 06:50 PM
You may have heard by now about the 100 Year Starship project, a new research initiative to develop the technology required to send a manned mission to another star. The project is jointly sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It will take that long just to make such a trip [...]

More... (http://www.universetoday.com/92528/100-year-starship-project-has-a-new-leader/)

neilzero
2012-Jan-13, 04:13 AM
My guess is too soon to start a billion dollar per year effort, but a few million per year may be reasonable. Partical impact may be a show stopper. Apolo traveled about 5 million kilometers without serious damage from microscopic dust, typically about one microgram each. Was that luck, or typical? Let's assume typical, but the starship will have perhaps 100 times the likely surface area of probable impact = 50,000 kilometers between distructive impacts. 100 kilometers per second, instead of 10 kilometers per second, may reduce that to 20,000 kilometers between impacts, depending somewhat on the direction of flight. At higher speeds the kilometers between impacts is about inversely proportional to speed. Worse the damage done by a one microgram partical increases as the square of the speed difference vector. This is reduced some by a reduced area surface likely to be hit. If the space craft survives the month or so that it takes to reach 3000 kilometers per second = 1% of c, a fairly small area protected by several layers of aluminum foil, spaced a meter or more apart will convert the micro gram particles to x rays and gamma rays, which will likely be dangerous only to persons in the bow room of the star ship. Likely most everyone in the star ship will get a bit higher dose of radiation than on Earth at sea level. The propulsion system will likely dose the people with radiation as a result of accerating the reaction mass to several percent of c. Possibly a show stopper as travel time to Centari A is about 430 years. Likely we will not accelerate further, until we are a year from Centarii A when we need about the same amount of ejection mass to decelerate to perhaps 20 kilometers per second while we explore the Centarii A planets, if any. The energy to go faster than 1% of c also seems improbable in this century, but a major break though is possible. After 400 plus years, most of the star ship systems will be beyond repair, so this is a likely show stopper. At very least we need a back up deceleration system = mag sail perhaps. The foil and/or plasma cloud is likely near worthless against one gram collision bodies, so that may be a show stopper. There are of course ethical issues about 12 generations of people who will live their entire lives on the star ship, much longer, if suitable habitats cannot be constructed in the Centari threesome = A, B and C. Human hybernation cannot be proved viable in this century, and may be impossible long term = no one frozen more than a day has been revived even briefly. If 100 people are revived by 2070 and 50 of the revived people are still alive in 2080, that does not leave time to design the generation ship that will be enroute in 2099, even if most people consider that viable = I don't. Neil