On the Cover: The last <i>Saturn 5</i>, the largest rocket ever to leave Earth, lifted off December 7, 1972, carrying <i>Apollo 17</i> and the last humans to walk on the Moon. Today dismembered museum relics are all that's left of these colossal rockets. If we are to send human explorers on ambitious missions again to the Moon or on to Mars, we will once more need heavy-lift launch vehicles. With <i>Energia</i>, the Soviet Union is now establishing heavy-lift capability.
4 Earth's a Planet Too: Charlene Anderson shares The Planetary Society's support for Earth Day 1990.
6 Solar System Exploration: Some Thoughts on Techniques and Technologies: Ivan Bekey presents his ideas on launch vehicles and their technological context to our members.
12 Launching Planetary Missions: An International Inventory: Jerry Grey rounds up launch vehicles around the world.
16 Masers from Mira Stars: A Scenario Revealing Jovian Planets? Curtis Struck-Marcell discusses a possible new tool in the search for extrasolar planets.
20 Glaciers and Glasnost: Michael Carroll reports from Iceland on an international art workshop.
3 Members' Dialogue Humans to Mars, SETI, and space exploration priorities.
25 World Watch Upcoming NASA missions; Hungarian space efforts.
26 News & Reviews Poor troubled Galileo.
27 Society Notes Near-Earth asteroids, annual audit, and COSPAR/sister worlds.
28 Q&A Why do some planets have rings while others do not?