A man in a tie, holding papers, stands in front of a chart showing stages of a process that begins with Mars.

Invasion from Mars? Microbes!

By Gregory Pike

A 'half-moon' view of the rust-colored planet Mars.
Mars as seen by the Viking 1 Orbiter
Courtesy NASA

Since the retirement of the Space Shuttle in 2011, it’s easy to forget there was a time when America’s space program dominated the headlines. Born in the “fires” of the Cold War between the United States and the Soviet Union, the U.S. space program became an exciting chapter in the race between the two superpowers. During the 1960s and 1970s, Americans were dazzled by stories of the program’s courageous astronauts and astonishing technological achievements. One of those achievements occurred almost 30 years ago this month when the lander portion of the unmanned Viking space probe Viking 1 touched down on the surface of the planet Mars on July 20th, 1976. It was the first time a U.S. spacecraft had landed on another planet. Together with the Viking 2 probe launched a month later, the Viking 1 remains part of the most ambitious and costly mission to explore the Red Planet. One of the scientists intimately involved in designing the scientific equipment aboard the probe that analyzed Martian soil samples was Joshua Lederberg (1925–2008), whose life and work are featured on the National Library of Medicine’s Profiles in Science site.

A man in a tie, holding papers, stands in front of a chart showing stages of a process that begins with Mars.
Joshua Lederberg at the Stanford University Medical School’s Instrumentation Research Lab, ca. 1963
Profiles in Science Joshua Lederberg Papers

Lederberg, a geneticist and microbiologist, who won the Nobel Prize in 1958 for his work in bacterial genetics, had been fascinated by the possibilities of using space probes for scientific experiments since the 1957 launch of the Soviet Union’s Sputnik probe. His fascination, though, was matched by his concerns that such a probe might inadvertently contaminate another planet, or worse, bring back a foreign organism that might contaminate Earth. Science fiction novelist Michael Crichton would explore this possibility in his book The Andromeda Strain (1961) and film adaptation (1971). Lederberg urged strict contamination protocols involving sterilization and quarantines—protocols that were adopted by the National Aeronautics and Space Administration (NASA) prior to its flight to the moon in 1969. Lederberg’s concerns were played out not just within the government but also in the public arena, thanks to his long-running “Science and Man” newspaper column in The Washington Post in the 1960s.



Lederberg’s keen interest on the exploration of life beyond the Earth (with all the necessary safety protocols in place) captured the public’s imagination, coined the new term “exobiology” and catapulted biologists into this new scientific endeavor. He was instrumental in helping define the missions of the Mariner program (a precursor to Viking) that launched probes between 1964 and 1971 to orbit and study the atmospheres of Mars, Mercury, and Venus. As part of the Viking program, he directly participated in designing the scientific and engineering equipment that were to be placed aboard the Viking probes. Working in the Instrumentation Research Laboratory at Stanford University, Lederberg, along with engineer Elliott Levinthal, designed a device (originally called “The Multivator”) that used a conveyor belt to scoop soil samples and deposited them into a mass spectrometer. The readings from the spectrometer ultimately could be analyzed by scientists for evidence of organic compounds.

The rocky landscape of Mars with part of the Viking 1 lander in the foreground.
The first panoramleic image of Chryse Planitia taken by camera 1 on the Viking 1 Lander
Courtesy NASA

Although the results of the Viking space probes proved inconclusive, the program demonstrated the usefulness of space probes and robotics for conducting scientific experiments. Despite this and the wealth of knowledge gained from Viking, NASA eventually shifted its emphasis in the late 1970s from unmanned scientific probes to manned ships like the Space Shuttle. Lederberg left NASA as a consultant in 1977.

Joshua Lederberg stands with models of the Viking 1 and it's rocket.
Lederberg with a model of the Viking 1 orbiter which remained in Martian orbit after the lander detached. The orbiter had its power shut down in 1980 after its altitude control fuel was depleted. The Viking 1 lander operated until November 1982 when contact was lost.
Profiles in Science Joshua Lederberg Papers


We invite you to learn more about Joshua Lederberg and his role in the early space program on NLM’s Profiles in Science.

Gregory Pike, MLS, is a Contract Digital Archivist for the Digital Manuscripts Program in the History of Medicine Division at the National Library of Medicine. He works for History Associates Inc.

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