Geoffrey Alan Landis (/ˈlændɪs/; born May 28, 1955) is an American aerospace engineer and author, working for the National Aeronautics and Space Administration (NASA) on planetary exploration, interstellar propulsion, solar power and photovoltaics.

[1][2] He holds nine patents, primarily in the field of improvements to solar cells and photovoltaic devices[3] and has given presentations and commentary on the possibilities for interstellar travel and construction of bases on the Moon, Mars,[4] and Venus.

Landis has commented on the practicalities of generating oxygen and creating building materials for a future Moon base in New Scientist,[11] and on the possibilities of using readily available metallic iron to manufacture steel on Mars.

Landis has worked on a number of projects related to developing technology of human and robotic exploration of Mars and scientific analysis of the Martian surface,[16] including studies of the performance of photovoltaic cells in the Mars environment,[17][18][19] the effect of Martian dust on performance,[20] and technologies for dust removal from the arrays.

[32] Landis was a fellow of the NASA Institute for Advanced Concepts ("NIAC"), where he worked on a project investigating the use of laser- and particle-beam pushed sails for propulsion for interstellar flight.

[33] In 2002 Landis addressed the annual convention of the American Association for the Advancement of Science on the possibilities and challenges of interstellar travel in what was described as the "first serious discussion of how mankind will one day set sail to the nearest star".

He went on to describe a star ship with a diamond sail, a few nanometres thick, powered by solar energy, which could achieve "10 per cent of the speed of light".

[40] In 2005–2006, he was named the Ronald E. McNair Visiting Professor of Astronautics at MIT,[41] and won the AIAA Abe M. Zarem Educator Award in 2007.

[46] Landis' first science fiction story, "Elemental", appeared in Analog in December 1984, and was nominated for the 1985 Hugo Award for Best Novella.

[55] He attended the Clarion Workshop in 1985, with other emerging SF writers such as Kristine Kathryn Rusch, Martha Soukup, William Shunn, Resa Nelson, Mary Turzillo and Robert J. Howe.

[52] Writing influences include Arthur C. Clarke, Isaac Asimov, Robert A. Heinlein, Ursula K. Le Guin, Kurt Vonnegut, Larry Niven, and John Varley.