Space Science Board, National Academy of Sciences
TEN YEAR PROGRAM IN SPACE SCIENCE

(Submitted by J. Lederberg 10/10/59)
Suggestions for planetary biology.

The detection and characterization of life beyond the earth is one of the
principal aims of spaceflight research. To a greater extent than in the physical
sciences, it is difficult to plan in detail beyond the initial steps, the in-
formation from which would be crucial for subsequent plans. The conclusions
of planetary chemistry are especially important as a foundation for biological
work. On the other hand pioneering studies must be conducted so as not to pre-
judice later efforts. Explicit recognition of aims in planetary biology is
therefore needed, even in advance of detailed experimental planning.

The following outline Is predicated on the following possibilities for
vehicular and communications development:

The satellite telescope (fn orbit around earth)

Planetary probes:

vicinal approaches Mars, Venus, Jupiter, Moon
orbiters Moon; Mars-Venus?
controlled landings Moon, Mars, Venus

landing and return (unmanned) Moon
Program (in rough sequence only)

1. Telescopic observations of Mars and Venus for organic substances in
atmospheres or surface material.

2. Ditto, by vicinal approach (this competes with <I> if closer approaches,
and consequent advantages in energy collection and afgular orientation (i.e. size
of collecting lens and its stabilization), compensate for costs of propulsion and
guidance.

3. Orbiters: high resolution optical. (including IR) surveys; vidicon
photography with resolution of order of .1 to I meter might give evidence
of vegetation. Applied to Moon, this would be important in choosing advan-
tageous sites for chemical analysis, e.g. plutonic emissions.

4. Controlled landings. For the first time, these will permit explicit
biological searches. In general, chemical analysis would precede any compre-
hensive biological survey.

Moon: Chemical and physical studies should take full precedence. Very large
scale surveys would be necessary to detect the remotest possibility of dormant
life at any point near the surface. Singularities in surface composition would
be possible teads for biological followup in ultimate experimentation.

Mars and Venus: Larger organisms might be detected by their form or
movement by vidicon surveys. More likely, a microscope input to the vidicon
«ould detect microorganisms in the ‘soil’ and air-borne dust, either as such,
or after nutrition with water and other substances. The same instrument could
be used for simple cytochemical procedures to identify DNA and other Important
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components of terrestrial life. These biological surveys should be concurrent with
chemical analysis, which should include tests for organic molecules. The spectro-
photometer and mass spectrometer would be useful as terminal sensors for systems of
biochemical analysis. Automatic culturing devices could increase the availability

of particular kinds of microorganisms, e.g., phototrophs, for cytochemical analysis.

5. Return samples (Moon). For any scientific purposes, these should be
hermetically sealed to avoid exposure to Earth's atmosphere upon re-entry.
Fortunately, this precaution will also protect the samples for biological
analysis. One can suggest some. far-fetched possibilities -- e.g. search
for spores or traces of DNA -~ but probably it would be more reasonable to
complete preliminary chemical studies before programming the blological work.

Even when it becomes technically possible, samples should not be returned
from other planets until the consequences of possible biological contamination
of the Earth have been exhaustively studied with the help of remote, telemetric
instrumentation. ,

it is doubtful whether the question of return of manned flights to the
planets will arise during the 10 year interval.

The interplanetary medium. Samples of interplanetary particles
(collected from f¥ee space as well as on the Junar surfaces) will certainly
be sought for chemical analysis. These should be collected in such a way as
to conserve carbonaceous molecules that would be of biochemical interest. This
qualification will make it necessary to develop new collecting devices avoiding
the use of grease, paper, millipore filter membranes, and similar articles in
current practice.