SPACE RESOURCES

Asteroid
Mining

Near-Earth asteroids contain water ice, metals, and minerals. No commercial operation has yet extracted resources from one. Here is what the proposition actually involves, who is attempting it, and why it remains hard.

Learn about asteroid types →

What asteroid mining actually means

Asteroid mining is the proposed extraction of materials from asteroids, either for use in space or for return to Earth. The idea has existed in theoretical form since the 1970s, but serious private-sector investment only began in the 2010s. As of 2024, no commercial mining operation has extracted a single kilogram of material from an asteroid.

The two very different resource targets have very different economic cases. Water ice, processed into hydrogen and oxygen for rocket propellant, could underpin an in-space economy by allowing spacecraft to refuel away from Earth. Precious metals, by contrast, would need to be physically returned to Earth to have market value, which is where the economics break down quickly.

Resources found in asteroids

Resource	Found In	Proposed Use	Economic Case
Water ice	C-type asteroids	Electrolysis into H2 and O2 for rocket propellant; in-space refuelling depots	Strongest case; avoids launching propellant from Earth
Iron and nickel	M-type asteroids	Structural metals for in-space construction	Weak for Earth return due to transport cost; better for in-space use
Platinum-group metals	S-type and M-type asteroids	Industrial and electronic applications on Earth	High Earth value but transport costs dominate; speculative
Silicates	Most asteroid types	Construction and shielding material in space	Low intrinsic value but abundant; useful for bulk construction

The key economic question: The economics of asteroid mining depend almost entirely on whether resources are used in space or returned to Earth. Water for rocket propellant makes sense. Hauling iron back does not.

The Psyche asteroid and NASA's mission

16 Psyche is one of the most metal-rich objects in the solar system. Scientists believe it may be the exposed iron-nickel core of a protoplanet that lost its rocky outer layers in ancient collisions. Early media coverage described its metal content as worth "quadrillions of dollars", a figure that means nothing in practical terms: extracting and returning that material would cost far more than any commodity market could absorb.

NASA's Psyche spacecraft launched in October 2023 and will arrive at the asteroid in 2029. It carries no mining equipment. The mission is entirely scientific: mapping the surface, measuring the magnetic field, and determining whether 16 Psyche is genuinely a planetary core or something more compositionally complex. The data will inform both planetary science and any future resource assessment.

Why it is difficult

The challenges of asteroid mining extend well beyond the obvious engineering problems of operating in microgravity. Delta-v budget is the first constraint: reaching a target asteroid and returning extracted material requires enormous quantities of propellant, which itself has mass. The closer a near-Earth asteroid is in delta-v terms, the more attractive it becomes, and a handful of NEAs actually require less energy to reach than the Moon's surface.

Composition uncertainty is the second problem. Ground-based spectroscopy gives broad mineralogical classifications, but the actual distribution of resources within an asteroid is unknown until a spacecraft arrives. Itokawa's rubble-pile structure, confirmed by Hayabusa 1, shows how different reality can be from initial estimates. An M-type classification does not guarantee a mine-able concentration of metals.

Asteroid spin adds a further complication. Some asteroids rotate rapidly, making anchoring equipment physically challenging. Others are tumbling rather than rotating around a stable axis. Proximity operations near an asteroid's surface require precise navigation against a very weak gravitational field.

Finally, the legal framework remains unresolved. The 1967 Outer Space Treaty prohibits national appropriation of celestial bodies but is silent on resource extraction. National laws in the United States and Luxembourg grant rights to extracted materials, but no international agreement exists. Any large-scale mining operation would operate in legally contested territory.

Companies that have attempted it

Planetary Resources

Founded in 2010, Planetary Resources attracted investment from Google executives and raised over $50 million. It launched a series of small technology demonstration satellites but failed to secure the capital needed for actual asteroid prospecting. The company was acquired by ConsenSys in 2018 and subsequently dissolved.

Deep Space Industries

DSI was founded in 2013 with a focus on smaller prospecting spacecraft and in-space manufacturing. It developed propulsion technology and conducted some hardware testing before being acquired by Bradford Space in 2019. The asteroid mining programme did not continue under the new ownership.

AstroForge

AstroForge, founded in 2022, is the most active asteroid mining company as of 2024. It launched a technology demonstration mission in 2023 to test refining processes in orbit. The company plans a prospecting mission to a specific near-Earth asteroid and is focused on platinum-group metal extraction. Whether the business model will prove viable at scale remains to be seen.

Near-Earth asteroids versus the main belt

Popular coverage often focuses on main-belt objects like Ceres or 16 Psyche because of their size, but they are not the most accessible targets. The delta-v required to reach a main-belt asteroid and return is substantially higher than for many near-Earth asteroids. Several NEAs, in the right orbital configuration, require less total propellant to reach than a lunar landing. This makes them more practical targets despite being smaller. Resource prospecting missions would almost certainly focus on NEAs rather than belt objects for this reason.

Asteroid Types

C-type, S-type, M-type and their mineral compositions.

Near-Earth Objects

Which asteroids come close to Earth and why they matter.

Planetary Defence

How deflection missions relate to our knowledge of asteroid structure.

Famous Asteroids

The most well-known asteroids and what makes each significant.

How Are Asteroids Discovered

Survey telescopes and the discovery pipeline.

Asteroid vs Comet

How comets and asteroids differ in composition and behaviour.

Common questions

Is asteroid mining profitable?

No commercial asteroid mining operation has yet extracted a single kilogram of resources from space. Profitability depends almost entirely on what the resources are used for and where they are used. Water extracted in space for rocket propellant could become economically viable, because launching propellant from Earth is expensive. Returning metals to Earth is far less likely to be profitable, given the enormous cost of getting mass back down a gravity well. The most credible near-term business case is propellant production in cislunar space.

What resources do asteroids contain?

Asteroids contain a range of materials depending on their type. C-type asteroids are rich in carbon compounds and, critically, water ice locked in hydrated minerals. S-type and M-type asteroids contain iron, nickel, cobalt, and platinum-group metals. Silicate minerals are found across most types. The platinum-group metals are particularly interesting because they are extremely rare on Earth's surface, having sunk to the core during planetary formation. Asteroids, which never differentiated fully, still carry them in accessible layers.

What is the Psyche mission?

NASA's Psyche mission, launched in October 2023, is a science mission to study the asteroid 16 Psyche, a large metal-rich body believed to be the exposed iron-nickel core of a protoplanet that lost its rocky mantle through ancient collisions. The spacecraft will arrive in 2029. Psyche is not a mining mission: it carries no extraction equipment. Its goal is to understand how planetary cores form and whether metal-rich asteroids differ structurally from rocky ones.

Which asteroids are best for mining?

From a practical standpoint, the best candidates are near-Earth asteroids with low delta-v requirements, meaning they are relatively easy to reach and return from without huge fuel expenditure. A handful of near-Earth asteroids actually require less energy to reach than the lunar surface. C-type NEAs are particularly attractive for water extraction. M-type objects are interesting for metals but tend to be rarer among NEAs. The asteroid database maintained by NASA's CNEOS includes orbital data that allows delta-v calculations for any known object.

Is asteroid mining legal?

The 1967 Outer Space Treaty prohibits national appropriation of celestial bodies, but does not explicitly address resource extraction. Several countries have since passed national space resource laws. The United States Space Act of 2015 grants American companies the right to own resources they extract from space. Luxembourg passed similar legislation in 2017. However, no binding international framework governs space resource extraction, and the legal status of commercial mining operations remains a subject of ongoing debate among space law scholars.