A private US company says it has landed a spacecraft close to the Moon's South Pole but fears the machine is not upright.

The Athena spacecraft is communicating with Earth, but is not in the "correct attitude", Intuitive Machines chief executive said in a press conference.

The company hopes the scientific instruments on board can still be deployed, including a hopping robot designed to explore a nearby crater and the first lunar mobile communications antenna.

It is the second time an Intuitive Machines spacecraft has landed in an irregular position on the Moon.

The company is partnering with US space agency Nasa to look for evidence of water and ice on the lunar surface, as Nasa aims to send humans back to the Moon.

Athena landed shortly after 1730GMT (1230EST) around 100 miles (160km) from the South Pole in an area of the lunar highlands called Mons Mouton.

Intuitive Machines says the lunar reconnaissance orbiter camera will take a picture of Athena in the coming days to calculate the craft's exact position.

Athena was designed to have 10 days to complete observations and measurements with scientific instruments.

They include a jumping robot called Micro Nova Hopper or Grace, which is designed to leap and fly across the Moon's surface to reach a large crater that is in permanent shade.

The hopper is designed to fly 100m in height, and travel up to 1.2 miles (2km).

After five leaps, it could land inside the crater with a camera to take the first images of the interior.

The crater is in permanent shadow from the Sun's rays, so it has very low temperatures and is considered an ideal place to look for ice.

Intuitive Machines, which made the hopper, say it can travel to places that other machines, like robots with wheels, can't reach or would take a very long time to get to.

"These hoppers are really suited to the lunar environment because there's no atmosphere there, practically speaking, so doing a series of controlled leaps is a great way to move around," says Prof Simeon Barber, a lunar scientist with the Open University.

The IM-2 mission is also carrying three scientific instruments made by Nasa.

A drill called Trident is designed churn up rocks to reach the surface under the Moon to see if there is evidence of ice.

Then an instrument called a mass spectrometer could analyse any gases that are released.

And the company planned to plant a type of antenna mast developed with Nokia on the Moon that using the same 4G cellular technology as on Earth.

The mission is part of Nasa's long-term goal to take humans back to the lunar surface, as the agency hopes to send astronauts in 2027 with the Artemis programme.

"This is another step towards assessing the viability of the lunar South Pole as a place to go and set up future bases for humans," says Prof Barber.

Experts want to explore options for building settlements and find out if there are reserves of water that could provide drinking water and potentially be turned into oxygen.

"A lot of planning of future exploration is being predicated on the presence of water ice, but if you want to use it, you need to know where it is and how much there is," says Prof Barber.

Nasa is partnering with a range of private companies that transport spacecraft and instruments to the Moon. It says this is cheaper than developing and blasting off their own missions.

Intuitive Machines successfully landed a craft called Odysseus on the Moon in February last year, but it tipped over during the descent, meaning not all the scientific work could be carried out.

Space agencies globally are competing to build human settlements on the Moon in a race to exploit resources and advance scientific understanding of other worlds.

In the US, the Moon mission is seen as a stepping stone for the longer-term and much more ambitious goal of human settlement on Mars.

The IM-2 mission could also help to answer broader questions about why there is ice in the inner solar system, closer to the Sun's warming rays.

"The permanently shadowed regions on the Moon are kind of a store and archive of ancient water that might have been delivered to the Earth-Moon system after their formation," explains Prof Mark Fox-Powell at the Open University.