Handbook of Bioastronautics Chapter Author:
Humans and Robots in Space Exploration
Co-author Poster Presentation at the 2020 Fall AGU Meeting:
A Close Encounter with an Interstellar Visitor

To Explore New Worlds and Seek Other Life:

This was why Carl Sagan, Bruce Murray and I formed The Planetary Society.

  • What is our place in the Universe?

  • Are we alone — is life in the Universe iniquitous or unique?

  • Will humankind become a multi-planet species or be limited to Earth?

  • How will Earth and Life evolve:  in cooperative symbiosis or with mutually assured destruction?

I am privileged to have a life seeking answers to these questions and to experience the great adventures and discoveries  of exploring new worlds — metaphorically travelling (with apologies to Isaac Newton)  on the shoulders of giants.


  M  A  R  S 


   is the only world humans can reach with atmosphere and water; on it will be determined how humankind will evolve as a multi-planet species.  Three possible ways (hover over images for description). 

This year (2020) three new missions to Mars were launched from Earth: Mars 2020 from the United States, Tianwen-1 from China,  and Hope from the United Arab Eremites  joining five spacecraft already there.   See a list of all Mars missions; past, present and future.  A fourth mission from  Europe and Russia was planned, but is now delayed to 2022.  Following the launches of the three missions in July 2020, I was asked to give a presentation about them to a general audience -- this is it.  
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Page Publishing, New York

Copyright, 2020



in 2nd Printing by University of Arizona Press, copyright 2015. 


 John Wiley & Sons, copyright 1988. 

The Space Show - Interview


    In 2020 we will celebrate the 40th Anniversary of The Planetary Society – a child I nurtured into maturity.  I owe it, and the great career I had there to two great scientists:  Carl Sagan and Bruce Murray.   Depicted here are the Society’s LightSail-2 mission  (link) which I started, successfully flying in Earth orbit as a solar sail.  Solar sailing is now real.  Among other highlights from my career with the Society are: Our advocacy and testing of Mars Rovers in the 1990s to introduce them into the American planetary program; our creation of a library, Visions of Mars, now on the surface of Mars awaiting the first human explorers; and inventing the Living Interplanetary Flight Experiment (LIFE) intended to be the first test of transpermia – the theory that life can flow between the planets in space. These are depicted below. 



 LIFE (Living Interplan-

etary Flight Experiment)

There have now been four rovers sent to Mars by NASA – Sojourner (named in a Planetary Society contest) in 1997, Spirit and Opportunity in 2004, and Curiosity in 2010. In 2020 NASA and the European Space Agency will launch two more rovers. Mars has a much land area of the Earth to be explored. 

Visions of Mars was developed in cooperation with Time Warner Interactive Media and was intended to fly on the Russian Mars 96 mission. Unfortunately that mission failed to launch from Earth and the spacecraft fell into the Pacific Ocean. Later it was successfully incorporated on NASA’s Phoenix mission to Mars in 2006 which landed in the North polar region of Mars.

Dr. Friedman was the co-inventor of the Living Interplanetary Flight Experiment intended to fly living microorganisms to the Martian moon, Phobos, and back to test the theory of transpermia.  

International Cooperation became a very important objective of The Planetary Society starting in 1983.  Our efforts enhanced the political advocacy for human and robotic space exploration and led the Society to significant influence in American, Soviet, French and Japanese space programs. International cooperation advances science and benefits public interest.  We need that now -- more than ever -- recent American policies have turned away from cooperation.  NGOs, like The Planetary Society, can make a difference.

Current Activities of Interest

The Solar Gravity Lens Focus Mission

To 600+ AU (~ 100 Billion Km from the Sun 
I am working with JPL Scientist Slava Turyshev, Darren Garber of NXTRAC, Prof. Artur Davoyan of UCLA and a team of Aerospace Corporation engineers on a new mission concept to make it possible to image planets around distant stars.
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 A Mission to Find  and Study  Life on  an Exoplanet

See this White Paper presented to the National Academies of Science Space Science Board, connecting to the project above.  

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The solar gravity lens is nature’s telescope — the only one that may permit us to see life on another world.


Article in Aerospace America by Slava Turyshev and I about a mission to the Solar Gravity Lens Focus.  

A fleet of small sat solar sails going out of the solar system at record speed – a project I am studying with colleagues at JPL, the Aerospace Corporation, UCLA and a private company, NXTRAC.

Spinning Toy
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A Low-Cost, Near-Term Technology Demonstration Mission to prove Smallsat-Solar Sail Technology
A Mission to Catch an Interstellar Object as it races through the solar system
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Starting at Earth wtih a low-cost or even free RideShare lauch the sail spirals in toward the Sun, and after a low perihelion pass around the Sun the sailcraft would set a new speed record for fastest spacecraft out of the solar system   
Trajectory and Spacecraft Design from Xplore, Inc. and L'Garde,Inc. - D.Garber