This talk is organised by The Future of Humanity Institute
Speaker: Dr Simon P. Worden, Chairman for the Breakthrough Prize Foundation
About the Breakthrough Initiatives : On 12 April 2016 – the 55th anniversary of Yuri Gagarin’s historic flight Yuri Milner and Stephen Hawking announced at the One World Observatory in New York Breakthrough StarShot.
The objective of the Breakthrough Starshot Project is to send many lightweight spacecraft to a neighbouring star system. Our initial candidate system is Alpha Centauri, 4.3 light years from Earth, and to return pictures of planets found there. The goal of Starshot is for the flight of the spacecraft to take ~20 years. With the recent discovery of an earth-size planet in the habitable zone of the Sun’s nearest stellar neighbour Proxima Centauri, it too is a target. The average speed of the spacecraft is then approximately 20% the speed of light. The concept is to use radiation pressure from an ultra high power laser installed on the Earth to quickly accelerate the spacecraft consisting of a highly reflective and low absorbing meter class sail attached to the Starchip. After achieving a speed of 0.2 c, the spacecraft is then in a coast mode (except for possibly minor course corrections from a very small on board thruster) for the remainder of its journey.
The star chips less than 1cm square and prototypes have been built on silicon nitride and have a 16-bit processor, 1GB RAM, a one-watt burst mode laser communications downlink to earth, four10 mW laser thrusters for mid-course corrections, four 2 mega pixel cameras, and other housekeeping items. The starchip is powered by a radioactive-decay battery embedded in the 500-micron thick silicon nitride substrate. The vision is to launch hundreds or even thousands of these from a very high orbiting mothership.
Recent technological developments are the genesis of the Starshot Project. The two principal developments are (1) the possibility of building ultra-lightweight sails and spacecraft on a chip and (2) the possibility of building ultra-high power lasers. Even so, the requirements are extremely challenging. To reach 0.2 c with a total spacecraft mass of only 1 gram and a sail optimized for speed, the average irradiance on the sail (just over 4 metres in size) is 6 GW/m2 and must be maintained for 76 seconds out to a range of 2x109 metres (5 times the distance to the Moon) assuming the laser has a 1km aperture has a total power output of 100 GW and is nearly 100% efficient in compensating for atmospheric turbulence. The sail must survive the laser’s incident power density, ride the beam in a stable configuration and live through the journey to serve as an antenna for directing the downlink laser communications signals back to Earth.
The timeline for this project includes 5-10 years of R&D, beginning with $100M of funding. Following a successful research program a prototype system costing between $500M - $1B is planned in the 10-15 year timeframe. Demonstration of the fastest human propelled objects within 6 years and launching interstellar starchips in the 2035-40 timeframe, arrival at Alpha-Centauri and Proxima Centauri around 2060 and getting first data by 2065. This project is targeted for a total cost comparable to the largest international science experiments such as the CERN Large Hadron Collider from both public and private funding sources.