December 17, 1964

To: J. FP. T. Pearman, Executive Director
Exobiclogy Summer Study

Fron: Joshua Lederberg
Profesaor of Genetics

Subj: Recommendations of Plenary Sessions ~ November 6, 1964

As I was not present at the meeting, I can hardly complain about
having to make an exception, but I must record a formal dissent to Item 9%.
Thais may be a highly academic question except in any international discussions,
but these may be crucial in the next few years.

I do not believe we can justify any lander on Mars before we have
had the benefit of comprehensive orbital reconnaissance.

The basis of this position (which I have reached only gradually),
is detailed in other material already submitted. Briefly, we cannot make a
scientifically honest appraisal of the potentially famense risks of contan-
ination, and of the prudence of our response to them, without much more
information sbout Mars than we now have. And the only really safe way to
collect such information {fs from a distance.

It goes without saying that we have to make extensive preparations

for a landing, e.g., the design of an ABL, in advance; otherwise we would
lose 5 to 10 years lead from the time we could decide to land end under what

stringencies.
prea

/ Joshua Lederberg
JL:as

ee: C,. &. Pittendrigh
0. E. Reynolds