Giant glass spheres blown from Moon dust could one day house astronauts on the lunar surface.

Nasa is funding the development of large-scale glass spheres, which will rise from microwave Moon furnaces like vast bubbles and then harden to form strong, transparent structures.

The concept has been devised by California-based Skyeports, which has already proven it is possible to blow glass balls from lunar dust or "regolith" - a substance of rock, mineral fragments and tiny pieces of abrasive glass.

Although the first spheres are just several inches wide, the goal is to create habitats that are hundreds or thousands of feet in diameter, in which astronauts could live, work, grow food and create water.

The spheres could be built using self-healing glass to seal dents or cracks from micrometeorites or "moonquakes", and have solar panels embedded so they could generate their own energy.

Dr Martin Bermudez, the chief executive of Skyeports, said he hoped that one day there would be cities of glass spheres, linked by sky-bridges, on the lunar surface and beyond.

"Space has always been kind of fascinating for me, and my background was as an architect so I had the chance to start exploring how we can build structures on the Moon or Mars.

"I started to think of the materials that are already on the Moon, and sometimes 60 per cent of the lunar regolith is silicates, so I thought, wait a minute, glass could be what this structure is built from.

"I was originally told 'well glass is too brittle, it's gonna break' so I started reaching out to scientists and realised it can be adapted and become something stronger than steel.

"I contacted Nasa almost two years ago and they really loved the idea from the beginning."

Building anything on the Moon is tricky because materials need to be shipped to the surface, which costs huge amounts of money.

To get around the problem, the company would send a microwave furnace, fed with mined Moon dust before giant pipes of gas blow the melted glass into a sphere.

When the glass has hardened, the pipes will be repurposed as the entrance and the inside fittings will be 3D printed using lunar materials.

Skyeports say the design takes advantage of the structural integrity of a sphere, evenly distributing pressure, while the transparent glass will help the mental health of astronauts.

"The spherical shape happens automatically, because at that temperature it becomes an amorphous liquid, and when it is extruded out of a furnace in low gravity it will form the shape of a sphere," Dr Bermudez said.

"We're going to have to integrate metals into the melt like titanium, magnesium, calcium to help keep the glass strong, and we don't know how big it could get, but possibly in the 300 to 500 metres range."

The project is part of Nasa's Innovative Advanced Concepts (NIAC) programme which funds futuristic projects that could help future missions. Former US astronaut Cady Coleman is an adviser to the scheme.

The team is planning to test out the blowing technique in a thermal vacuum chamber in January, before moving to parabolic flights to mimic micro-gravity and eventually carry out trials in the International Space Station.

Tests on the lunar surface itself could happen within the next few years.

Humans could be returning to the Moon within the next five years under Nasa's Artemis programme, and the space agency is currently looking for suitable habitats.

"We're in a race against time, because Artemis is moving so fast," Dr Bermudez added.

"Mental health is going to be important on long-duration missions and it will be important for astronauts to be able to see outside, and perhaps even see the Earth.

"If we can create layers of bubbles, one surface can be warm and the other cooler, so we create condensation and we can plant vegetables and plants and get an ecosystem going that produces oxygen.

"We are looking into creating a glass shell that can create electricity to power the entire habitat, you can imagine megawatts that a glass dome this big could produce.

"I would love to see whole communities of these, a city of them, housing parks, water systems and homes, all connected through glass bridges.

"You will never replicate Earth, but this is something that gets pretty close, and we could even put them into orbit one day."

Clayton Turner, associate administrator for Nasa's Space Technology Mission Directorate in Washington, said "Our next steps and giant leaps rely on innovation, and the concepts born from NIAC can radically change how we explore deep space, work in low-Earth orbit, and protect our home planet.

"From developing small robots that could swim through the oceans of other worlds to growing space habitats from fungi, this programme continues to change the possible."

In 2023, experts at Aalen University in Germany suggested buildings and roads on the Moon could be made from bricks created by zapping lunar dust with a laser.