It is, without a doubt, the next goal of the space age: Mars. It is no longer enough to send probes, obtain images in real time or receive samples directly from our neighbor: You have to step on Martian soil. The problem is time.
It takes seven to nine months for a spacecraft to reach Mars. The time depends on the ship and the distance between the two planets, which changes as they continue their orbits around the Sun. NASA’s Perseverance probe (the most recent spacecraft to make the trip) took about seven months.
But sending a manned mission to Mars is much more complicated than sending a robotic explorer like Perseverance. The probe, for example, will stay there after its mission ends, something that is unthinkable with humans. The distance between Earth and Mars can range between 54.6 million kilometers and 401 million kilometersalthough on average it is about 225 million kilometers.
With this in mind, one of the main restrictions is the launch windows, the right time to reduce the trip between both planets. These occur every 26 months when the planets are closest to each other.which makes the trip shorter. In this way, the minimum for a manned mission to Mars could take about four years, taking into account that windows must be taken advantage of to reduce the round trip time.
To solve these obstacles, NASA is developing a more efficient propulsion system that could transport a crew to Mars on a round trip in just two years. Engineers at the Langley Research Center NASA is working on a nuclear electric propulsion system that could bring Mars closer in those time frames.. These systems use a nuclear reactor to generate electricity, which is used to ionize or positively charge the gaseous propellants and create thrust.
But there is a problem: it has to be assembled in space. The system is called Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles (MARVL) and the goal is to launch it in the next decade.
One of the components of the system is its heat dissipation system. The system is an assembly the size of a football field once deployed. The idea is to split the system into separate components that can be assembled robotically in space.
“By doing that, we eliminate the need to try to fit the entire system into a rocket chest,” explains Amanda Stark, heat transfer engineer at NASA Langley and MARVL principal investigator. In turn, that allows us to relax the design a little bit and really optimize it.”
Folding the entire system into a payload small enough to fit inside a rocket chest isn’t really an option. However, making the heat dissipation system modular and assembling it in space with robots opens up new possibilities. The components could be launched into space in any order and in any combination that makes sense.
“Existing vehicles have not previously considered assembly in space during the design process – adds Julia Cline, also part of the project –, so we have the opportunity here to say: We are going to build this vehicle in space. How do we do it? And what does the vehicle look like if we do that? I think it’s going to broaden what we think about when it comes to nuclear propulsion”.
NASA gave the MARVL project team two years to develop the idea. By then, the team hopes to have a small-scale ground demonstration ready. And then come up with the final version.