The Breakthrough Starshot system model
Abstract
Breakthrough Starshot is an initiative to prove ultrafast lightdriven nanocrafts, and lay the foundations for a first launch to Alpha Centauri within the next generation. Along the way, the project could generate important supplementary benefits to solar system exploration. A number of hard engineering challenges remain to be solved before these missions can become a reality.
A system model has been formulated as part of the Starshot systems engineering work. This paper presents the model and describes how it computes costoptimal point designs. Three point designs are computed: A 0.2 c mission to Alpha Centauri, a 0.01 c solar system precursor mission, and a groundbased test facility based on a vacuum tunnel. All assume that the photon pressure from a 1.06 μm wavelength beam accelerates a circular dielectric sail. The 0.2 c point design assumes 0.01/W lasers, 500/m^{2} optics, and 50/kWh energy storage to achieve 8.0B capital cost for the groundbased beam director. In contrast, the energy needed to accelerate each sail costs 6M. Beam director capital cost is minimized by a 4.1 m diameter sail that is accelerated for 9 min. The 0.01 c point design assumes 1/W lasers, 10k/m^{2} optics, and 100/kWh energy storage to achieve 517M capital cost for the beam director and 8k energy cost to accelerate each 19 cm diameter sail. The groundbased test facility assumes 100/W lasers, 1M/m^{2} optics, 500/kWh energy storage, and 10k/m vacuum tunnel. To reach 20 km s^{1}, fast enough to escape the solar system from Earth, takes 0.4 km of vacuum tunnel, 22 kW of lasers, and a 0.6 m diameter telescope, all of which costs 5M.
The system model predicts that, ultimately, Starshot can scale to propel probes faster than 0.9 c.
 Publication:

Acta Astronautica
 Pub Date:
 November 2018
 DOI:
 10.1016/j.actaastro.2018.08.035
 arXiv:
 arXiv:1805.01306
 Bibcode:
 2018AcAau.152..370P
 Keywords:

 Breakthrough starshot;
 Beamdriven sail;
 Beamed energy propulsion;
 Modelbased systems engineering;
 Astrophysics  Instrumentation and Methods for Astrophysics;
 Physics  Popular Physics
 EPrint:
 Acta Astronautica, Volume 152, 2018, Pages 370384, ISSN 00945765