It's being marketed as Sunlight On-Demand. American startup Reflect Orbital is proposing a 2026 launch date for it's test satellite, which will a carry giant mirror into orbit capable of reflecting the sun's rays back to earth. But astronomers aren't convinced that the plan can work, and they have many concerns as to the side effects of these giant satellites if they did.    Guest: Michael Brown, Associate Professor of Astronomy at Monash University.