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Mission to Alpha Centauri

The next step for civilisation is exploration beyond our Solar System
Travel to another star sounds futuristic, but it is becoming possible. Staff in the School of Physics are tackling fundamental challenges posed by Breakthrough Starshot, a $100M initiative to send small spacecraft to Alpha Centauri.

Starshot Grand Challenge

Our aims

The ultimate aim is to send small probes to α-Centauri, the closest star system to Earth. The spacecraft will be propelled by radiation pressure due to an external, high-power ground-based laser array reflecting off a sail on the spacecraft. The ultralight spacecraft will experience extreme acceleration (50,000 g) and will reach a cruising speed of one-fifth the speed of light, within about ten minutes. At this speed, the spacecraft will reach α-Centauri in about 20 years.

Our research

This is a Grand Challenge project within the School of Physics, funded for 2020-2021. Our team will tackle fundamental problems needing to be overcome to realise the Breakthrough Starshot aim of reaching Alpha Centauri.

We will focus on key physical challenges:

  • ensuring the stability of the spacecraft sail in 3-D under acceleration
  • understanding the internal dynamics of the sail, i.e. its bending and flexing
  • modeling the interaction of the sail with the laser beam
  • modeling the thermal response of the sail
  • design and fabrication of material for the sail
  • providing an experimental proof-of-principle of the thrust mechanism.

Our research will exploit expertise distributed in different groups within the School, spanning photonics, astronomy, astronomical instrumentation, solar physics, materials physics and applied physics. The project will encompass theoretical calculations, numerical computation, laboratory experimentation, and materials prototyping.

We are looking to appoint a Research Fellow to help us with this exciting endeavour. 

Current Projects

Mission to α-Centauri—sail stability

This project is part of a School of Physics “Grand Challenge” that aims to propel an object to the stars closest to Earth. It is based on radiation pressure, the phenomenon that causes comet tails to stream away from the Sun. The plan is to use an intense laser beam to exert radiation pressure on a highly-reflective “sail”. The aim of this part of the project is to study the motion of the sail in an inevitably non-uniform laser beam, and to investigate how stability can be achieved. It has been suggested that including a grating on the bottom of the sail, which reflects some of the light in a sideway direction, would help achieve this. This project, which uses the techniques developed in theoretical mechanics, consists of a combination of pen-and-paper calculations and numerical modelling.

Mission to α-Centauri—materials

This project is part of a School of Physics “Grand Challenge” that aims to propel an object to the stars closest to Earth. It is based on radiation pressure, the phenomenon that causes comet tails to stream away from the Sun. The plan is to use an intense laser beam to exert radiation pressure on a highly-reflective “sail”. As a precursor study to an experimental program, we will identify the critical challenges of finding strong refractory materials from which to construct a sail of the highest possible reflectance, tuned to the laser frequency with allowance for the Doppler effect. The forces arising from differential temperature distributions will be studied together with the forces of interaction with a Gaussian laser beam. This will require simulation of the fields in and around a multilayer construct of high and low refractive indices and its net force of interaction with the field. Student will gain skills in thermal physics, in electromagnetic wave simulation and in the design of optical multilayer devices.