Image of the Lunar Roving Vehicle used by astronauts during Apollo 15, 16 and 17

Source: NASA

In situ resource utilisation (ISRU) is the principle of using local resources to supply missions, reducing the requirement to transport large volumes of bulky material through space. ISRU is key to ensuring spacecraft can sustain themselves during their mission in space, using materials that are readily available.

To prepare a spacecraft for this, it is important for equipment and vehicles to be tested in environments and using materials on Earth that are similar to those they may encounter on other planetary surfaces. This allows engineers to ensure any negative interactions between local materials and the terrain on the mechanics or design of the spacecraft are accounted for in its design.

One famous example of the need for ISRU testing resulted from the issues faced by Apollo 15, 16, and 17 astronauts on the Moon; a coating of Lunar dust accumulated on the Lunar roving vehicle's battery, causing it to overheat. Since then, analogue Lunar materials known as simulants have been developed by both NASA and ESA for pre-flight testing; future spacecraft aiming to land on the Moon can be tested to see how this dust could affect its efficiency, allowing engineers to prevent issues in the design of the spacecraft instead.

The practice of efficient in situ resource utilisation will help sustain missions for longer periods of time on extra-terrestrial surfaces, or even allow us to explore further and further bodies from home. NASA aims to carry out extended missions on the Lunar surface during the future Artemis missions, providing an insight into how the processing of these resources could be carried out for future crewed missions to Mars.

Since the launch of Sputnik (the first artificial satellite, by the Soviet Union) in 1957, space exploration has allowed us to explore many other worlds in our Solar System, including moons, planets, asteroids, comets, as well as our own Sun.

The exploration of these bodies can be carried out through fly by missions, where a spacecraft flies in close proximity to another planet or planetary body but cannot return, or orbital missions where a spacecraft is sent to another planetary body and remains in space for at least one orbit.

Both lander and rover missions also play a huge role in space exploration, with space agencies sending spacecraft that remain stationary on surfaces collecting information such as atmosphere, composition, or even topography.

Rovers differ from landers as they roam across planetary surfaces equipped with laboratory instruments that investigate the surface in more detail, including searching for signs of water and past life. There are several active rovers on Mars at present, and even an active rover on the Moon too.

Whether it's a lander, rover, or even equipment used by astronauts during crewed space missions, sending any equipment to explore the surface of a planetary body requires rigorous testing to ensure that missions can sustain themselves in the environments they will be challenged with, and this is where in situ resource utilisation comes in.

Early images from space were grainy & poor resolution, like this NASA image from 1965. The images we are used to seeing today are quite different, thanks to advances in technology.