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David S F Portree

Science

Mars: A World for Exploration (1959)

May 8, 2012 8:01 PM

Science

Manned Asteroid Flyby Mission (1966)

May 4, 2012 10:11 PM

Science

Talking to the Farside: Apollo S-IVB Stage Relay (1963)

May 3, 2012 12:14 AM

Science

Gemini on the Moon (1962)

May 1, 2012 1:06 AM

Science

Ranger 12? A 1964 Proposal to Extend the Ranger Lunar Program

Apr 28, 2012 10:29 PM

Science

Landing Soyuz Lifeboats in Australia (1992)

Apr 26, 2012 1:04 AM

Science

One-Way Space Man (1962)

Apr 24, 2012 12:36 AM

Science

Apollo Science & Sites (1963)

Apr 20, 2012 12:14 AM

Science

Integrated Program Plan "Maximum Rate" Traffic Model (1970)

Apr 18, 2012 12:57 AM

Science

Robot Rendezvous at Hadley Rille (1968)

Apr 15, 2012 12:16 PM

Science

The LUT, the Shuttle, and the Saturn V S-IC Stage (1969)

Apr 13, 2012 1:19 AM

Science

Ernst's Ions Week Concludes: NERVA-Ion Mars Mission (1966)

Apr 12, 2012 7:41 PM

Science

Ernst's Ions Part 3: Twirling Ion Mars Ships (1962)

Apr 11, 2012 1:39 AM

Science

Ernst's Ions Week Continues: Lunar Ion Freighter (1959)

Apr 10, 2012 12:17 AM

Science

Ernst's Ions Week on Beyond Apollo: The Cosmic Butterfly (1954)

Apr 9, 2012 12:43 AM

Science

Manned Mars Surface Missions (1966)

Apr 6, 2012 10:14 AM

Science

Apollo Space Freighter (1963)

Apr 5, 2012 2:00 AM

Science

Artificial Lunar Atmosphere (1974)

Apr 3, 2012 7:17 PM

Science

Blueprint for 1970s Planetary Exploration (1968)

Apr 3, 2012 1:05 AM

Science

100-Day Mission to Sun-Earth L2 (1999)

Apr 2, 2012 6:38 PM