"NASA Should Shoot for the Moons of Mars"

By: S. Fred Singer, chief scientist, Department of Transportation.

    Mr. Singer served as the first director of the U.S.
    operational weather satellite program.

from: The Wall Street Journal, Wednesday, December 7, 1988

     George Bush will have the challenge of choosing a national space goal, a
task that can be be viewed in a bipartisan spirit.  Presidents Kennedy and
Reagan were both strong advocates of the space program.  But while Kennedy
initiated Project Apollo, a manned landing on the moon, Ronald Reagan never
spelled out a similar overarching goal.  Though Mr. Reagan's National
Commission on Space developed a wide range of choices, neither NASA nor the
White House settled on a single, long-range project to fire the imagination of
the public and the world, and gain support of various constituencies in the
science community, industry and Congress.  Yet defining this elusive goal is
not so difficult once we determine the purpose of the federal portion of the
space program.  In order to set out what NASA should do, we must be aware of
what it shouldn't be doing.  By process of elimination we will end up with the
goal of a manned mission to the moons of Mars (M-4) as the most effective way
to advance space exploration and planetary science.

     Commercial applications of space should be left mainly to the private
sector. For example, communications satellites essentially provide the role of
commercial long-distance telephone cables and microwave links - often at much
lower cost than for cables.  Surveillance satellites, whether for meteorology
or for mapping of Earth resources, can perform services many organizations and
individuals are willing to pay for.  The promise of manufacturing in space
supposedly is a major justification for a permanent manned space station.
Actually, even the initial experiments do not require a continuous manned
presence - only occasional visits to set up operations or retrieve materials.
Again, the purpose would be commercial; space manufacturing may involve
reimbursable use of government facilities and purchase of Shuttle launch
services, but should not become a federal operation.

     NASA's primary task should be non-commercial: space science and manned
exploration of space, plus the advanced technology to support them.  The
challenge is to find a goal that does both, a manned exploration program that
advances science in a way that cannot be achieved or easily duplicated by
generally lower-cost unmanned means.  The best candidate is a project focused
on Mars.  None of the other planets is in any way comparable.  They are either
too distant, requiring more propulsion and imposing longer travel times; or
they are inhospitable for direct exploration.  The moon's scientific
potential, compared with that of Mars, is limited.  It is not a planet, and
cannot tell us as much about the evolution of Earth.  It doesn't have an
atmosphere and cannot teach us about meteorology or climate change.  From a
public-relations point of view, the moon is no longer exciting.  We have been
there and don't anticipate any startling discoveries.  Further, the moon as a
space goal implies we can do without the space station.  Since the moon has
gravity, about one-sixth that of Earth, astronauts do not need the gravity-
free environment of the space station for training.

     Another reason for choosing Mars may be that a moon landing (and takeoff)
requires more propulsion energy than visiting one of the tiny moons of Mars
such as Phobos or Deimos.  They are not very deep in Mars's gravity field and
are small enough to be practically gravity-free.  The M-4 project from Earth
would involve transfer of a spacecraft from Earth orbit to Mars orbit.  While
it might take a year to get there, most of the time would be spent coasting,
without need for propulsion.  The rocket power necessary is less than that for
the moon project, hence less fuel, less weight and much less cost are
required.  In fact, an M-4 mission would cost less than the Apollo program.

     The cost consists of two major items: (1) designing and building the
space habitat and all the experimental equipment, essentially a specialized
space station - plus the rocket propulsion there and back; and (2) lifting all
of it into Earth orbit.  The best estimate is $25-35 billion over 15 to 20
years - less than 20% of NASA's current budget.  Substantial savings can be
achieved if a heavy-lift booster rocket is developed.  And if the current
space-station effort were oriented toward, and formed part of, the Mars
project, NASA's annual budgets might not grow at all.  Studies suggest the M-4
mission could be optimized by dividing it into two parts: a "slow freight" and
a "manned express."  Most of the spacecraft and weight, consisting of rocket
propellants and experimental gear, could be sent on a slow (typically one
year), low-thrust trajectory.  The manned habitat capsule would then be
launched from Earth orbit on a fast trajectory, travelling only a few months
but requiring more propulsion.

     A mission to Phobos and Deimos (Ph-D) is not only easier and cheaper by
far, but scientifically more valuable than landing people on Mars itself.
Astronauts on the mountainous Martian surface would be quite limited in their
exploration, with safety being the main consideration.  Landing and takeoff in
the presence of Martian gravity would require a great deal of rocket
propulsion, at least doubling the cost compared with a Ph-D mission.

     After establishing a laboratory on Deimos (or perhaps Phobos), astronauts
could direct robotic rover vehicles to the Martian surface to explore, take
data, pick up samples and send them back to Deimos.  The analysis then
provides an immediate feedback for directing another rover to an exciting
Martian location.  Because of this feedback, the scientific return from such a
mission would be enormous.  By contrast, if exploration was remotely
controlled from Houston Space Center instead of Deimos, each command and
return signal to and from the rover would take up to an hour instead of a
fraction of a second.  A dozen or so unmanned rover missions would stretch
over decades, be more costly, and still not accomplish the same scientific
results as one Ph-D mission.  Many sample-collecting rovers would be needed,
especially in moist regions near Mars's polar ice caps, with new instructions
issued to the rovers as samples were analyzed in the Deimos laboratory and new
results discovered.  Transporting Martian soil and rock samples from the
surface to Deimos would only take a few hours, instead of a year or more to
Earth; and fresh samples would not have to be quarantined to protect Earth.

     A Ph-D mission would touch on many areas of science.  The most
challenging is the origin of life.  Is life unique to Earth, or could it have
developed on another planet, assuming evironmental conditions were similar to
those of the early Earth?  The preponderance of scientific opinion favors the
latter.  Mars once had a warm, wet climate with flowing water and oceans, so
it would be surprising if life forms hadn't developed.  That does not mean
life still exists on Mars, but that "fossils" may be found.  There is no
guarantee, however, that possible Martian life forms were similar to Earth's -
leading to one of the most fascinating questions of all: Would life evolve in
the same way?

     Physical scientists would want to learn how planets formed and why Mars
evolved differently from Earth in terms of internal structure, volcanism and
mountain building.  Even the moons of Mars hold special fascination.  They may
be captured asteroids or pieces of original planetesimals that formed Mars 4.5
billion years ago.

     For atmospheric scientists, Mars would be a gold mine of information.
Its weather patterns resemble Earth's, but with important differences,
providing clues about what determines weather changes on a planet without
oceans.  For climate-change studies, Mars represents a veritable Rosetta
stone.  It is now a cold and dry planet, with ice caps and no flowing water.
Yet the Martian sediments may hold answers to why the climate changed so
drastically - and apparently irreversibly - billions of years ago.  Sediment
data about climate fluctuations, when compared with Earth's history, should
clarify whether such fluctuations were due to outside influences, such as
changes in the sun's radiation - or to internal causes, such as changes in the
planet's orbit or in atmospheric composition (that led to the disappearance of
the ancient greenhouse effect on Mars). Comparative planetology, the study of
climate change on Mars, ties directly to studies of global change on Earth due
to the ehnanced greenhouse effect from atmospheric pollution.

     In defining the national space goal we must resist the temptation to step
out too far into the future.  Setting up a permanent habitation on Mars or
using the material resources of extraterrestrial bodies such as Phobos and
Deimos are promising projects but can be left till later.  The first goal
should be scientific exploration - and that's a big enough challenge if done
properly.

     Once we have chosen a goal - the manned mission to the moons of Mars, it
is to be hoped - the steps to get there fall into place.  A space station is
necessary, but with the focus of testing humans' ability to survive in a
gravity-free environment for two to three years, the estimated time for a
mission to Mars.  Space-station experiments can determine whether artificial
gravity is required, how people can live together for long periods of time,
how life-support systems can operate reliably.

     International cooperation can best be achieved in this phase of the
project, sharing the experience of human physiology under zero gravity.
Additional cooperation can be achieved in boosting the spacecraft and rocket
propellants into Earth orbit, using the large, low-cost boosters now becoming
available throughout the world.

     Once we set the long-term goal, we will have a rational purpose for the
space station.  And once we define the station's design and parameters, we
will know what kind of manned launch program is necessary to support it.  With
a clear road map drawn, cooperation with other nations, including the Soviet
Union, can be pursued with greater certainty.  Such a program should have no
problem in gaining popular and congressional support.