That's roughly six months faster than it would take to reach the red planet with current technologies.
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A concept image of a NASA nuclear rocket. |
NASA selected a nuclear propulsion concept for Phase I development as part of its Innovative Advanced Concepts (NIAC) program for 2023.
The Nuclear Thermal and Nuclear Electric Propulsion
(NTP/NEP) concept is a new class of bimodal nuclear propulsion system that uses
a "wave rotor topping cycle," as per a NASA blog post.
The scientist behind the proposal, Prof. Ryan Gosse from the
University of Florida, believes it could reduce travel time to Mars to a mere
45 days. If the technology does work as planned, it could drastically reduce
travel times to Mars and make missions to the red planet innumerably safer for
humans.
Is nuclear propulsion the future of human spaceflight?
The new proposal, titled "Bimodal NTP/NEP with a Wave
Rotor Topping Cycle," is one of 14 selected by the NIAC for Phase I
development. It received a grant to the tune of $12,500 to research and develop
the technology required.
NASA has a long history of considering nuclear propulsion
for spacecraft, according to Universe Today. This includes the Nuclear Engine
for Rocket Vehicle Application (NERVA) concept, which was successfully tested
but then defunded around the same time the Apollo Era came to a close in 1973.
More recently, NASA also tested nuclear propulsion concept
technologies with Project Prometheus in the early 2000s. Private firm Ad Astra,
meanwhile, which is run by former NASA astronaut Franklin R. Chang DÃaz,
completed a record 88-hour high-power endurance test of its Vasimr VX-200SS
plasma rocket at 80 kW in 2021. Ad Astra claims its nuclear rocket technology
could eventually take humans to Mars at speeds of 123,000 mph (197,950 km/h).
NASA's new nuclear propulsion concept
NASA's new NIAC grant recipient leverages two of the key
concepts behind nuclear propulsion. Nuclear-Thermal Propulsion (NTP) utilizes a
nuclear reactor to heat liquid hydrogen propellant so that it is converted into
plasma and channeled through a nozzle to generate thrust.
Nuclear-Electric Propulsion (NEP), meanwhile, uses a nuclear
reactor to power a Hall-Effect thruster (ion engine) with electricity. This, in
turn, generates an electromagnetic field that ionizes and accelerates an inert
gas to create thrust.
Gosse, who serves as the Hypersonics Program Area Lead at
the University of Florida, combines the advantages of both NTP and NEP with his
new concept. The engineer proposes a bimodal design based on a solid-core NERVA
reactor that would provide a specific impulse (lsp) of 900 seconds. That is
twice the performance of existing chemical rockets.
On top of that, Gosse also proposes using a Wave Rotor (WR)
to further compress the reaction mass using pressure generated by the reactor's
heating of the liquid hydrogen fuel. According to the engineer, this has the
potential to deliver thrust levels comparable to that of a NERVA-class NTP
concept but with a higher Isp of 1400-2000 seconds. Combining this with an NEP
cycle would produce even higher thrust levels.
Shorter travel times are vital for the well-being of astronauts
What all of that means is that Gosse's concept could drastically reduce the travel time to Mars for future astronauts. Using existing technologies, a crewed voyage to Mars could take about six to nine months to reach the red planet. So, reducing the travel time to about 45 days would mean Mars missions could last months instead of years.
This is vitally important as long missions to Mars would
expose astronauts to high levels of radiation that could prove deadly. Not only
that, the effects of microgravity on humans for such a long time period would
also have negative health implications, meaning there is a strong incentive to
reduce Mars mission times.
Other concepts awarded a grant by NASA's NIAC program
include a hybrid aircraft concept called TitanAir that could collect samples
from the seas of Saturn's moon Titan. A concept for a lunar pipeline could also
improve the efficiency of oxygen delivery for NASA's upcoming Artemis moon
missions. The space agency has posted a full list of the impressive space
concepts it is considering as potential game-changers for astronomy, Earth
science, and human space exploration.