Breakthrough Starshot brings the Silicon Valley approach to space travel, capitalizing on exponential advances in key areas of technology since the beginning of the 21st century.
Nanocrafts are gram-scale robotic spacecrafts comprising two main parts:
- StarChip: Moore’s law has allowed a dramatic decrease in the size of microelectronic components. This creates the possibility of a gram-scale wafer, carrying cameras, photon thrusters, power supply, navigation and communication equipment, and constituting a fully functional space probe.
- Lightsail: Advances in nanotechnology are producing increasingly thin and light-weight metamaterials, promising to enable the fabrication of meter-scale sails no more than a few hundred atoms thick and at gram-scale mass.
The rising power and falling cost of lasers, consistent with Moore’s law, lead to significant advances in light beaming technology. Meanwhile, phased arrays of lasers (the ‘light beamer’) could potentially be scaled up to the 100 gigawatt level.
Breakthrough Starshot aims to bring economies of scale to the astronomical scale. The StarChip can be mass-produced at the cost of an iPhone and sent on missions in large numbers to provide redundancy and coverage. The light beamer is modular and scalable.
Path to the stars
The research and engineering phase is expected to last a number of years. Following that, development of the ultimate mission to Alpha Centauri would require a budget comparable to the largest current scientific experiments. Once it is assembled and the technology matures, the cost of each launch is projected to fall to a few hundred thousand dollars.
The program will require:
- Building a ground-based kilometer-scale light beamer at high altitude in dry conditions.
- Generating and storing a few gigawatt hours of energy per launch.
- Launching a ‘mothership’ carrying thousands of nanocrafts to a high-altitude orbit.
- Taking advantage of adaptive optics technology in real time to compensate for atmospheric effects.
- Focusing the light beam on the lightsail to accelerate individual nanocrafts to the target speed within minutes.
- Accounting for interstellar dust collisions en route to the target.
- Capturing images of a planet, and other scientific data, and transmitting them back to Earth using a compact on-board laser communications system.
- Using the same light beamer to receive data from nanocrafts over 4 years later.
Some of these requirements represent significant engineering challenges, which the Breakthrough Starship team have begun the process of addressing. The proposed light propulsion system is on a scale significantly exceeding any currently operational analog. The very nature of the project calls for global co-operation and support.
Clearance for launches would be required from all the appropriate government and international organizations.