First generation Nuclear Thermal Propulsion,
or “NTP,” could enable both faster transit
between the earth and Mars, and a series of
advanced space missions.
Nuclear Thermal Propulsion is powered by nuclear
fission, which has been used on earth for
more than seventy years.
How it works is conceptually simple – energy
from fission is used to heat hydrogen to ~4400
F.
This hydrogen is then accelerated through
a nozzle resulting in a propellant efficiency
roughly twice that of the best chemical rocket
engines.
Nuclear Thermal Propulsion was considered
for use in the Apollo program, and significant
development and ground testing was accomplished.
Advances in technology since the 1960s may
improve its affordability, viability, and
acceptability.
For example, it may be possible to fuel modern
NTP systems with low-enriched uranium instead
of highly enriched uranium.
In addition, it may now be possible to ground
test NTP systems at established safe, self-contained
rocket engine test facilities.
For human Mars missions, the physical size
of an NTP engine is largely determined by
the rate at which fission energy can be transferred
to the hydrogen propellant.
However, the equivalent volume of the uranium
that would be split is actually quite small,
roughly that of a toy marble.
That energy is used to get astronauts to Mars
faster, NTP can take months off the trip compared
to using traditional chemical systems, reducing
risks associated with exposure to galactic
cosmic radiation, microgravity, and other
hazards of deep space travel.
The maturation of Nuclear Thermal Propulsion
will also facilitate the development of fission
surface power systems, enabling a power-rich
environment at any exploration location.
Abundant power could also be used for In-Situ
Resource Utilization, life support, communication,
and other diverse applications.
First generation NTP systems are a first step
towards advanced nuclear propulsion systems
capable of travel throughout the solar system.
