Sample-return mission

Sample-return missions may bring back merely atoms and molecules or a deposit of complex compounds such as loose material and rocks.

These samples may be obtained in a number of ways, such as soil and rock excavation or a collector array used for capturing particles of solar wind or cometary debris.

Samples available on Earth can be analyzed in laboratories, so we can further our understanding and knowledge as part of the discovery and exploration of the Solar System.

While such an investigation of the Solar System is technically easier than a sample-return mission, the scientific tools available on Earth to study such samples are far more advanced and diverse than those that can go on spacecraft.

Samples analyzed on Earth can be matched against findings of remote sensing for more insight into the processes that formed the Solar System.

However, for a more precise inventory of the material on these different bodies, more samples will be collected and returned in the future, to match their compositions with the data gathered through telescopes and astronomical spectroscopy.

One further focus of such investigation—besides the basic composition and geologic history of the various Solar System bodies—is the presence of the building blocks of life on comets, asteroids, Mars or the moons of the gas giants.

Planetary protection aims to prevent biological contamination of both the target celestial body and the Earth in the case of sample-return missions.

Unfortunately, the Genesis capsule failed to open its parachute while re-entering the Earth's atmosphere and crash-landed in the Utah desert.

There were fears of severe contamination or even total mission loss, but scientists managed to save many of the samples.

In November 2010, scientists at the agency confirmed that, despite failure of the sampling device, the probe retrieved micrograms of dust from the asteroid, the first brought back to Earth in pristine condition.

[18] The Russian Fobos-Grunt was a failed sample-return mission designed to return samples from Phobos, one of the moons of Mars.

It was launched on 8 November 2011, but failed to leave Earth orbit and crashed after several weeks into the southern Pacific Ocean.

[27] It reached the proximity of Bennu on 3 December 2018,[28] where it began analyzing its surface for a target sample area over the next several months.

Scientists commented that they "found black dust and debris on the avionics deck of the OSIRIS-REx science canister" on the initial opening.

[37][38] On 13 January 2024, NASA reported finally fully opening, after three months of trying, the recovered container with samples from the Bennu asteroid.

[53] On 22 November 2023, NASA announced that it was cutting back on the Mars sample-return mission due to a shortage of funds.

[citation needed] Sample-return methods include, but are not restricted to the following: A collector array may be used to collect millions or billions of atoms, molecules, and fine particulates by using wafers made of different elements.

Collector arrays, such as those flown on Genesis, are ultra-pure in order to ensure maximal collection efficiency, durability, and analytical distinguishability.

However, due to the high speeds and size of the particles that make up the coma and the area nearby, a dense solid-state collector array was not viable.

[citation needed] Aerogel is a silica-based porous solid with a sponge-like structure, 99.8% of whose volume is empty space.

[56] Since the aerogel is mostly transparent, and the particles leave a carrot-shaped path once they penetrate the surface, scientists can easily find and retrieve them.

[56] Some of the riskiest and most difficult types of sample-return missions are those that require landing on an extraterrestrial body such as an asteroid, moon, or planet.