Starshot
Space Technology

Breakthrough Starshot Interstellar Probe Likely to be Damaged by Gas and Dust

The Breakthrough Starshot team are working on solving 20 challenges that would have to be overcome before a probe could successfully be sent to the Alpha Centauri star system. As part of this initiative, a small team of researchers at Harvard University has been focusing on the likely damage an interstellar spacecraft might suffer when traveling at approximately one-fifth the speed of light. Although such damage may be catastrophic, the team believes they have a solution.

It all started when Russian billionaire Yuri Milner put up $100 million of his own money to get the ball rolling on a venture to send a probe to Alpha Centauri. The total effort is expected to cost multiple billions of dollars. Milner’s advisors identified the 20 challenges that researchers are now working on solving one at a time. The Harvard team is evaluating the likely damage to the craft due to space dust and gases.

The initial working design of a space probe able to travel one-fifth the speed of light is little more than a circuit board. It is known as a wafersat and will be attached to a light sail that is targeted by a laser sent from Earth to push it during the initial part of the trip. Graphite and quartz are likely to be the main materials that will be used for the wafersat’s construction and the researchers are therefore concentrating on these.

Research results show that objects colliding with the craft would likely be collections of heavy atoms rather than space dust in the form of particles. These collisions would create pits of the craft’s surface resulting in loss of material. It is estimated that up to 30 percent of the entire craft could be lost in this way.

An additional problem is melting. If it should happen that the craft runs into something bigger, it is likely that it would be destroyed partially or even completely. The odds of this happening are however so minute that the team feels the project is viable. Excluding such a collision, coating the front of the craft with a buffer should be enough to safeguard it sufficiently to guarantee safe arrival to the Alpha Centauri star system. The journey from Earth is expected to take about 20 years.

Research ‘The interaction of relativistic spacecrafts with the interstellar medium’ has been published in the Arxiv.