Imagine transforming night-time heliostat fields, traditionally used for solar power, into cosmic detectors. That’s the innovative idea proposed by Dr. John V. Sandusky of Sandia National Laboratories. He suggests that these arrays of mirrors could play a pivotal role in tracking near-Earth asteroids and lost spacecraft.
Unlike traditional methods that rely on imaging, Sandusky’s technique involves observing frequency shifts in reflected starlight. As these heliostats follow star paths, they can detect slight changes when an object, such as an asteroid, moves relative to the stars. Impressively, even the tiniest shifts, as minute as one-one-millionth of a cycle per second, can be measured.
A practical test at the National Solar Thermal Test Facility demonstrated the feasibility of this approach. While an asteroid wasn’t detected during the experiment, the precision of the control system and methodology was successfully validated.
This novel application could give idle heliostat arrays a productive “night job,” complementing existing systems like NASA’s Atlas telescope network, which focuses on identifying near-Earth asteroids. Sandusky also envisions this method being useful for monitoring spacecraft in the challenging space between Earth and the Moon.
Heliostats are cost-effective compared to telescopes and are already being deployed on a large scale, making them ideal for continuous sky scanning. As Sandusky puts it, these solar thermal mirrors are unoccupied at night, so why not put them to good use? This forward-thinking approach could redefine how we utilize existing technology to keep an eye on our cosmic neighborhood.
