Solar shield concept would tether asteroid to reduce launch weight

The idea of using a solar shield to deflect a portion of the Sun’s energy away from Earth has been around for many years, generally tabled as a method for mitigating global heating. Gravitational forces dictate that a huge amount of mass would be required to counterbalance the shield and keep it in position, preventing solar radiation pressure from blowing it away.  However, this scale would make launching the device impossible with current technology.

István Szapudi, from the University of Hawaiʻi’s Institute for Astronomy, has proposed using captured space material – either Moon dust or an asteroid – to act as the counterweight for a solar shield. According to Szapudi, this would enable scientists to use much lighter material for the shield itself, reducing launch weight by a factor of 100. His paper, “Solar radiation management with a tethered sun shield,” is published in Proceedings of the National Academy of Sciences.