- Project Longshot
Project Longshot is a design for an interstellar
spacecraft , an unmanned probe intended to fly toAlpha Centauri powered bynuclear pulse propulsion . Developed by theUS Naval Academy andNASA , Longshot was designed to be built at theSpace Station Alpha , the precursor to the existingInternational Space Station . Unlike the somewhat similarProject Daedalus , Longshot was designed solely using existing technology, although some development would be required.Unlike Daedalus' closed-cycle fusion engine, Longshot would use a long-lived
nuclear fission reactor for power. Initially generating 300 kilowatts, the reactor would power a number oflaser s in the engine that would be used to igniteinertial confinement fusion similar to that in Daedalus. The main design difference is that Daedalus would rely on the fusion reaction being able to power the ship as well, whereas in Longshot the external reactor would provide this power.The reactor would also be used to power a laser for communications back to Earth, with a maximum power of 250 kilowatts. For most of the journey this would be used at a much lower power for sending data about the
interstellar medium , but during the flyby the main engine section would be discarded and the entire power capacity dedicated to communications at about 1 kilobit per second.Longshot would mass 396 metric tonnes at the start of the mission, including 264 tonnes of
Helium-3 /Deuterium pellet fuel/propellant. The active mission payload which includes the fission reactor but not the discarded main propulsion section would mass around 30 tonnes.A notable difference in the mission architecture between Longshot and the Daedalus study is that Longshot would go into orbit about the target star while Daedalus would do a one shot fly-by lasting a comparatively short time.
The journey to Alpha Centauri B orbit would take about 100 years and another 4.39 years would be necessary for the data to reach
Earth .References
Beals, K. A., M. Beaulieu, F. J. Dembia, J. Kerstiens, D. L. Kramer, J. R. West and J. A. Zito. "Project Longshot: An Unmanned Probe To Alpha Centauri." U S Naval Academy. NASA-CR-184718. 1988.
External links
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890007533_1989007533.pdf Project Longshot: An Unmanned Probe To Alpha Centauri] (Please note that the article cited here refers to an Alpha and Beta Centauri as the orbital target of the mission, but the correct nomenclature for these two components of the Alpha Centauri binary star system is Alpha Centauri A and B. Beta Centauri is an entirely different unassociated star.)
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