Exploring Europa. Artwork of a hydrobot submarine (centre) after being deployed from a cryobot penetrator spacecraft (upper left) into the water beneath the icy surface of Jupiter's moon Europa. The robotic hydrobot is seen with hydrothermal vents formed by warm water rising from the moon's interior. Water in these vents may carry chemicals that can support life. During this proposed mission the cryobot would land on Europa's surface & melt its way through the ice. The self-propelled hydrobot would then analyse the water's chemical composition to check for signs of Europan life. This system may first be tested on Lake Vostock, a body of water under Earth's Antarctic ice cap.