Title (and perhaps the pay-walled article) is misleading. Iodine is the propellant (which is shot out the other way for Newton's Laws propulsion), not the sour

Title (and perhaps the pay-walled article) is misleading. Iodine is the propellant (which is shot out the other way for Newton's Laws propulsion), not the source of energy (which is solar panels). Better discussion at https://news.ycombinator.com/item?id=29276960 https://news.ycombinator.com/item?id=29276960