Path to Mars

On Sep 16, 10:46*pm, "Jorge R. Frank" wrote:
On 09/16/2010 01:36 PM, Anne Onime wrote:

Obama wants to go to Mars in the 2020's.

Incorrect. In his April speech, Obama called for the first beyond-LEO
flights (to NEOs) in the 2020s. Mars orbital flights would not occur
until the 2030s, and a Mars surface landing would be well after that.

You can do both. You fly past mars on a 2 year orbit, and the
apohelion takes you into the asteroid belt - before arriving at
perihelion and Earth - 2 years later.

We could have done this in the 1960s before we went to the moon. So,
its definitely low-hanging fruit.

In 1962, Ford, General Dynamics and the Lockheed Missiles and Space
Company made studies of Mars mission designs as part of NASA Marshall
Spaceflight Center "Project EMPIRE". These studies indicated that a
Mars mission including a Venus fly-by and Mars fly-by could be done
with a launch of Saturn V boosters and assembly in low Earth orbit, or
with a single launch of a hypothetical "post Saturn" heavy-lift
vehicle.

The EMPIRE missions were only studies, and never proposed as funded
projects. Yet, these were the first detailed studies of what it would
take to accomplish a human voyage to Mars using data from the actual
NASA spaceflight. They are the basis for any future planning.
Significant mission planning by TRW, North American, Philco, Lockheed,
Douglas, and General Dynamics, along with several in-house NASA plans
made use of them.

Specifically, the 1962 studies showed a stretched S-IVB stage
equipped with hydrogen propellant and NERVA engine producing 75,000
pounds at 850 sec Isp - also producing 150 kW with a Brayton Cycle
from that nuclear source - and supplies for 2 years - launched to
orbit by a single Saturn V launch and then docking with a S-IVB
modified as a Skylab space station - with crew already on board - with
an Apollo Capsule - we could have sent a Skylab/Nerva combination such
as this past Mars *before* we landed on the moon. In fact, if the
Russians beat us to the moon in 1968, or if the Lunar Lander wasn't
ready in time, we could have sent a mission to fly-by Mars that same
year. The vehicle would fly past mars, into the asteroid belt, and
back to Earth - passing Mars again on the return. A similar flyby of
Venus and Mercury taking only 1 year to complete and journey very
close to the Sun, is also possible.

With the 'wet' station option, where hydrogen occupied the space
astronauts would eventually inhabit during transit, a single Saturn V
launch could implement these fly by missions.

The NERVA program started with studies by Los Alamos in 1952 and
became ROVER in 1955 when a way to reduce reactor weights was found.
Hardware started being built then. Flight hardware was to be ready
for testing in space in 1964 and to become operational in 1965 - 10
years after program start.

NERVA would have been an interplanetary stage that m

The program was on track until it was cut in November 1963 by LBJ. It
was his first act as President three days after the assassination of
JFK.

He cut back funding of the program reorganized it under the SNPO and
put Harry Finger in charge. Finger was not a top notch scientist. He
was a long-time bureaucrat. He set up strict guidelines that NERVA
had to achieve prior to planning a flight into space. These added
requirements and reduced budget eventually delayed the program for a
decade until it was cut by Nixon as being impractical.

The DOE still maintains the nuclear materials for these rockets. We
could have an operational NERVA type rocket in as little as three
years if we really wanted to.