Sky Lights

This summer's Russian module launch marked a critical milestone toward a permanent human presence on the International Space Station, but many space buffs would rather see expedited plans for more ambitious and distant missions piloted by people. Recent discoveries indicating subterranean water on Mars and oceans below Europa's ice sheets have renewed calls from the Planetary Society and other advocacy groups to reinstate a goal lost after the last Apollo moon landing in 1972: human exploration beyond Earth orbit.