The human presence on Mars is supposed to be possible by overcoming a myriad of great challenges, and many of these challenges depend on only one basic prerequisite: electricity. Whether we’re talking about making oxygen and moving vehicles, or providing heat and light and communicating with Earth, the future inhabitants of Mars need a steady stream of electricity to stay safe and carry out their missions as planned. .
But obviously no power grid can be found on Mars, and current solutions will only remove obstacles for a short time. So the question is, what will our first non-terrestrial power plant look like? To prepare this article, Digital Trends spoke with two experts working on the most advanced space power supply systems in two different agencies.
Nuclear reactors in space
NASA’s plans for the future of power generation include the use of nuclear shoe systems, in which uranium atoms are split into two reactors to generate heat. Compared to radioisotope systems that power NASA’s endurance rover, for example, shoe systems can be built in a variety of dimensions in addition to generating more electricity.
In 2018, NASA’s Kilopower Project demonstrated an experiment with a shoe system capable of generating 1 kilowatt of electricity that could be used to power future space reactors in a test called KRUSTY (short for Kilopower Reactor Using Known as Stirling TechnologY, we saw the use of uranium-235 kernels, which NASA describes as “about the size of a roll of tissue paper.” This system generated heat, which was then converted into electricity by a mechanism called a Stirling engine.
A shoe-based surface power generation system can be very small and lightweight, and at the same time will generate electricity for at least 10 years. This makes NASA’s concept ideal for future missions to the moon and then to Mars.
Over the past year, NASA, in conjunction with the US Department of Energy, has called for the development of a system that can reach 10 kWh. Four or five such systems could operate a Martian habitat with all of its equipment – such as oxygen generators for rocket fuel, as well as meeting the general needs of the three or four astronauts on the Red Planet, all of which are expected to require about 40 kilowatts of energy. .
Diane Hernandez Logo was the director of the Kilopwer project and now manages the NASA shoe electricity project. In an interview with Digital Trends, he said that the space agency plans to test the system on the moon for the first time in a decade.
He says the idea is to test the system first on the moon as part of NASA’s Artemis program. “Our project seeks to develop a 10 kW system, and the first test will be performed on the moon. “In this way, we can have a better understanding of how the system works.” After that, you can make all the necessary design changes and be better prepared for the next missions to be performed on Mars.
NASA is planning for the first experiments on the moon because it wants the power plant to remain inside its lunar lander. Keeping the power unit inside the lander “makes system operations easier and no extra steps are taken to remove it.” The Hernandez logo team is doing just that.
But at the same time, they hope to see new ideas from activists in the field and see what new solutions can be put in place. “Right now, within our group, the idea is to keep the system inside the lander,” he says. “But there are a lot of innovations in the world, and this time we are looking for innovations from industry activists to see what other options we have.”
A NASA internal study estimated that each 10-kilowatt unit could be six meters high and two meters wide, but more detailed details will depend on the final design of these units. A concept image provided by NASA, shown above, shows four different units connected to each other on the surface of Mars to supply energy to the habitat. So you can imagine what a Martian power plant would look like.
Nuclear energy security
When using nuclear energy on Earth, one of the factors that always worries people is security, and the same is true of space missions. The radioactive elements used in nuclear reactors – such as the uranium used in the Kilopower show – have radiation that endangers human lives and even disrupts the performance of nearby electronic equipment.
To protect humans and electronics, electric shoe systems are covered with thick layers of metal that trap radiation. Any new power generation system used for the Mars mission must have already undergone extensive and rigorous tests on Earth to ensure that it remains safe even in the worst possible conditions. These tests include operational testing, suction testing and vibration testing.
“The NASA has more than 20 missions in the past that use a wide range of nuclear power systems,” he said. “So NASA has the expertise and background to send nuclear power systems to both the moon and Mars.”
Then it comes to worrying about the use of highly enriched uranium in the electrical systems used in the Kilopower show. It could also be used to make nuclear weapons, so some political leaders have worried that using it in space projects could lead to more land use.
To address these concerns, future shoe systems may instead use less enriched uranium, which is commonly used in ground-based reactors and is not up to standard weapons. “The design of low-enriched uranium is more attractive in terms of reducing legislation and complying with the laws of the space core,” Hernandez Lugo wrote in an email. “Of course, if the mission has special needs, there is still the possibility of using richer uranium.”
According to the latest Space Law Guidelines issued by the White House in December last year, it is only possible to use high-enriched uranium if the various government bodies have given the green light, and this is only to complete a mission. Be.
But nuclear power is not NASA’s only option for generating electricity: One of the most common options for generating electricity on current space missions is to use solar energy. The European Space Agency (ESA) basically uses solar energy for all of its missions, and its next rover, Rosalind Franklin, will be powered by the sun.
“Solar energy has a big advantage over nuclear energy, and that is that there is no need for additional security measures,” Leopold Summer, director of ESA’s Advanced Concepts team, which studies emerging technologies for space missions, told Digital Trends. He also points out that the increasing use of solar-related technologies means that we have achieved more in this area and are able to use the same achievements in space missions: “Solar-related technologies are evolving rapidly and “Easy to use and access, as well as more maturity and completely renewable, bring their garden.
This rapid rate of development means that engineers are designing panels that generate more and more electricity in return for the same amount of sunlight, and Somer expects future solar systems to just get more and more efficient.
“In space, optimality is even more important than on the ground, and we are constantly pushing for what is technically possible,” he said. A relatively small increase in the efficiency of solar cells can make a big difference in terms of the cost of entire solar systems, especially for smaller devices such as satellites.
But like all technologies, solar energy has its limitations. “The downside is that solar energy relies on an external source – the sun – and that in itself causes problems.” In many different conditions, the energy from the sun is alternating. On a planet with a day-night cycle, batteries can store extra energy during the day and power equipment at night. But the same extra energy storage space makes the design of electrical systems take on a larger shape and the complexity of development increases.
Sunlight on Mars
But when it comes to Mars in particular, using solar energy also has its challenges. Due to the fact that Mars is less than the distance from the Sun to the Sun, less light reaches the surface of the Red Planet. This means that astronauts going to Mars will have access to about half of the sun’s radiation on Earth.
Of course, this does not mean that it will be impossible to use solar energy on Mars, but it simply means that astronauts and mission managers must be very careful about how much energy they consume. The previous generation of NASA, Spirit and Opportunity astronauts used solar energy, and current orbiters such as the Mars Express and Mars Orbiter Mission also draw their energy from the sun.
But this is where an important problem arises on Mars: Earth storms. Mars has a complex climate system that sometimes leads to the formation of massive earth storms all over the planet. These storms temporarily block sunlight and cover almost everything found on the planet with a layer of dust – including solar panels. This is what caused the Opportunity rover, despite its very long life, to finally fail. There was a big earth storm on Mars that finally ended the work of the astronaut during 2018.
Somer thinks that by combining surface energy production facilities as well as facilities that orbit Mars and transmit energy wirelessly, we will eventually be able to provide the energy needed for human habitation. But he also says that by combining solar energy with other energy sources, such as nuclear, we can create new values. “As we have seen in recent astronauts, such as the endurance astronaut who recently landed, sometimes small nuclear energy resources have such great competitive advantages that I expect them to play a role in missions as well.”
Choose the right energy source for the mission
The Hernandez logo acknowledges that different types of power systems each have their own potential values for the Mars mission, including solar, batteries, and nuclear energy. “The power supply system is to be determined depending on each specific mission.” NASA’s Glenn Research Center, where the Hernandez Logo is based, is the center for the development of NASA energy systems and explores a wide range of options such as batteries, solar cells, radioisotope systems, shoe systems and regenerative fuel cells. . The point is, you need to choose the right energy source depending on the needs of the mission as well as the resources available.
Nuclear systems have undeniable benefits for missions involving human habitat. First, when you want to design a power supply system for both the moon and Mars – as NASA does – you have to deal with dark periods of two weeks a month on the moon.
“When you start thinking about how to design a mission architecture that delivers energy continuously, this is where nuclear energy comes into play,” says Hernandez Logo. Because you need a reliable system that continuously supplies power during night operations.
Access to alternating energy flows is also important for Mars, especially for the security of astronauts living on the Red Planet. There is definitely a need for an energy supply system that will continue to operate in all weather conditions and will not fail during dust storms. Nuclear energy can meet these needs.