It is very useful for landing structures on the Moon, where the combination of low gravity and the razor-sharp rocks thrown up on landing pose a threat to incoming devices.
Landing on the Moon is quite dangerous, and there are a lot of problems to solve if you want to land by any means. This is because the crust of the body is essentially made up of crushed rocks, which, combined with the Moon’s weak gravity, causes the landing craft’s engines to very easily knock over these small, but typically razor-sharp rocks, damaging the craft and other equipment nearby. In fact, the landing can even drill a crater in the lunar crust as deep as the length of the rocket’s nose cone. This was already a problem with the Apollo programme, but it is even more so with the Artemis programme, where the Apollo programme delivered roughly 10 tonnes of payload to the Moon on landing, but Artemis has a payload of 20-60 tonnes. And as the mass increases, stronger rockets are needed to land safely on the surface of the body, but the stronger rockets also hit more rocks. In addition, the rocks that are knocked over can easily damage sensitive scientific instruments.
This serious problem posed by rocket boosters is being addressed in several ways. The simplest solution is to choose a landing site where the surface is more suitable. The other solution is to build a landing platform either from locally found materials (i.e. moon rocks) or from imported solutions. However, such a platform would cost around $120 million to build, and the necessary equipment would take up space from other facilities. Not to mention that, in this case too, the equipment that would start the construction would have to land somehow first.
This is where a private company, Masten Space Systems, which has already been involved in several innovative Artemis projects, such as the Masten Rocket Mining System, which could be used to extract water from the Moon to power the bases. The company’s idea for the problem described above is also very elegant, since it would essentially solve the problem by solving it with the rocket boosters. The Flight Alumina Spray Technique (FAST) means, in a nutshell, that the landing device uses the rocket to create its own landing platform. In the FAST process, the rocket would “spew” ceramic particles on the lunar surface, coating the landing zone and preventing both cratering in loose rock and the rocket from knocking up sharp chunks.
The benefits of this idea are perhaps not worth going into, but let us make a few points: firstly, NASA saves $120 million by not having to build separate platforms. In addition, the lander can land in places where there are already technological equipment and facilities and will not damage them. And the surface conditions would be much less of a factor in determining the landing zone, so that a much larger part of the Moon could be explored, not to mention the possibility of deploying it on Mars if the idea works.
FAST is currently one of the solutions being considered by NASA as part of the Innovative Advanced Concepts (NIAC) programme, and the company is working with several companies and research groups (Honeybee Robotics, Texas A&M University, University of Central Florida), and thanks to NIAC they have already been able to determine some of the numbers needed, such as how thick such a platform would optimally be, what temperature would be needed, and how long it would take for the platform to cool down to the right temperature. So at the moment the concept is very much in its infancy, but who knows, maybe one day this will be the trump technology that will allow us to land on alien bodies without any trouble.
Ad Astra had previously planned to use solar panels to provide the energy needed to heat the gas, a plan that has been sharply criticised by several researchers, who say that it is currently impossible to generate the energy needed to run the engine using solar power. Díaz seems to have realised this in the meantime, as the press release on the July test already describes the Vasimr as a nuclear-electric engine, although it adds that it can be powered by solar energy. The same type of propulsion system is already used, for example, in satellites, which can produce the energy needed for minor orbital changes using solar panels.
For deep space travel, speed is a key issue, as astronauts are exposed to significant levels of cosmic radiation in space, which can cause serious health damage. Since spacecraft, unlike a Mars base, cannot be built to any thickness, astronauts will be exposed to increased levels of particle radiation during space travel, and NASA has recently calculated that a mission to Mars, including the round trip, should not take more than four years.
It is no coincidence that Ad Astra is not the only company that sees nuclear-powered spacecraft as the future of space travel: last October, Seattle-based USNC-Tech delivered plans for a nuclear thermal engine to NASA that could cut the duration of a Mars mission to around three months, while the UK Space Agency is working with Rolls-Royce to create a nuclear engine.
Source: Interesting Engineering