The Interaction of Relativistic Spacecraft With The Interstellar Medium

©Project Starshot

Project Starshot

The Breakthrough Starshot initiative aims to launch a gram-scale spacecraft to a speed of v∼0.2c, capable of reaching the nearest star system, α Centauri, in about 20 years.

However, a critical challenge for the initiative is the damage to the spacecraft by interstellar gas and dust during the journey. In this paper, we quantify the interaction of a relativistic spacecraft with gas and dust in the interstellar medium. For gas bombardment, we find that damage by track formation due to heavy elements is an important effect. We find that gas bombardment can potentially damage the surface of the spacecraft to a depth of ∼0.1 mm for quartz material after traversing a gas column of NH∼2×1018cm−2 along the path to α Centauri, whereas the effect is much weaker for graphite material.

The effect of dust bombardment erodes the spacecraft surface and produces numerous craters due to explosive evaporation of surface atoms. For a spacecraft speed v=0.2c, we find that dust bombardment can erode a surface layer of ∼0.5 mm thickness after the spacecraft has swept a column density of NH∼3×1017cm−2, assuming the standard gas-to-dust ratio of the interstellar medium. Dust bombardment also damages the spacecraft surface by modifying the material structure through melting. We calculate the equilibrium surface temperature due to collisional heating by gas atoms as well as the temperature profile as a function of depth into the spacecraft.

Our quantitative results suggest methods for damage control, and we highlight possibilities for shielding strategies and protection of the spacecraft.

Thiem Hoang, A. Lazarian, Blakesley Burkhart, Abraham Loeb
(Submitted on 18 Aug 2016)

Comments: 15 pages, 16 figures, submitted
Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
Cite as: arXiv:1608.05284 [astro-ph.GA] (or arXiv:1608.05284v1 [astro-ph.GA] for this version)
Submission history
From: Chi-Thiem Hoang [view email]
[v1] Thu, 18 Aug 2016 14:54:04 GMT (935kb)
http://arxiv.org/abs/1608.05284

Please follow SpaceRef on Twitter and Like us on Facebook.