In this week's live Open Space, people wanted to know if solar sails really work, will we ever get close to the speed of light, what's the best way to get out of Venus' gravity well, and more? 01:46 Do solar sails really work? 02:48 Will we ever get close to the speed of light? 06:22 Best way to get off Venus? 24:08 Why is the speed of light so disproportionate to the size of the Universe?