Solar Sail powered spacecraft visible over London – if weather permits

If the weather gods are favourable, you can see a novel new spacecraft flying over London several times this week.
An artist’s concept of NASA’s ACS3 solar sail spacecraft in Earth orbit. Image: NASA
What is known as the Advanced Composite Solar Sail System (ACS3) is a satellite that was launched in April to test the idea of using a huge solar sail to propel spacecraft through space.
Just like the sailing boats of the past, the solar sail uses the gentle but persistant pressure of th