Tag Archives: lasers

Russian billionaire backs interstellar project

The competition heats up: A Russian billionaire has announced a $100 million investment in an effort to use lasers to propel cellphone-sized spacecraft on an interstellar voyage to Alpha Centauri.

Called Breakthrough Starshot, the programme is based on an idea that has been around for decades: the solar sail. The theory is that a lightweight space sail could harness the momentum carried by photons in order to travel without fuel.

The Breakthrough Starshot team is betting that a burst of concentrated lasers, fired from the ground, could rapidly accelerate a mobile-phone-sized device equipped with microelectronics and a tiny sail — providing much more energy than could be harnessed from the Sun. Whereas NASA’s plutonium-powered New Horizons spacecraft took nine years to reach Pluto, the “nanocraft” envisioned by Breakthrough Starshot would pass by the dwarf planet and exit the Solar System in three days.

The project’s initial US$100-million budget covers only research and development of such a spacecraft. But Breakthrough Starshot’s ultimate goal is to demonstrate proof of concept for an international programme that would send a fleet of nanocraft into space. Doing so would require the group to surmount enormous scientific and engineering challenges in developing the necessary laser technology, materials and communications systems.

This technology is related though not identical to an earlier story about using lasers to power spacecraft.

Using lasers to travel to the stars

The competition really heats up! A research team at the University of California, Santa Barbara (UCSB) has proposed that an array of space-based lasers can be used to accelerate a solar sail to speeds as much as 26% the speed of light, thus making interstellar travel possible.

[The] key breakthrough was the development of modular arrays of synchronized high-power lasers, fed by a common “seed laser.” The modularity removes the need for building powerful lasers as a single device, splitting them instead into manageable parts and powering the seed laser with relatively little energy. Lockheed Martin has recently exploited this advance to manufacture powerful new weapons for the US Army. In March last year, the aerospace and defense giant demonstrated a 30 kW laser weapon (and its devastating effect on a truck). By October, the laser’s power had already doubled to 60 kW and offered the option to reach 120 kW by linking two modules using off-the-shelf components.

The UCSB researchers refer to their own planned arrays as DE-STAR (Directed Energy System for Targeting of Asteroids and ExploRation), with a trailing number to denote their size. A DE-STAR-1 would be a square array 10 meters (33 ft) per side and about as powerful as Lockheed’s latest; at the other end of the spectrum, a DE-STAR-4 would be a 70 GW array covering a massive area of 100 square kilometers (39 square miles).

…Lubin stresses that even a relatively modest orbital array could offer interesting propulsion capabilities to CubeSats and nanosatellites headed beyond Earth orbit, and that useful initial tests would still be conducted on the ground first on one-meter (3-ft) arrays, gradually ramping up toward assembling small arrays in orbit. While even a small laser array could accelerate probes of all sizes, the larger 70-GW system would of course be the most powerful, capable of generating enough thrust to send a CubeSat probe to Mars in eight hours – or a much larger 10,000-kg (22,000-lb) craft to the same destination in a single month, down from a typical six to eight.

Further upgrades would make it possible to send a cubesate and its lightsail to Alpha Centuri in about fifteen years.

The important point here is that it appears that all the technology for building this already exists, or is relatively straightforward to develop.