The US space agency, the National Aeronautics and Space Administration (Nasa), has announced another major step in the implementation of its Artemis crewed deep space exploration programme. It has finalised the design contract for crew module for the Gateway “outpost” that will orbit the Moon.

Formally known as the habitation and logistics outpost (Halo), it was being designed by the Orbital Science Corporation, a wholly-owned subsidiary of renowned US aerospace group Northrop Grumman. The contract was worth $187-million.

“This contract award is another significant milestone in our plan to build robust and sustainable lunar operations,” highlighted Nasa Administrator Jim Bridenstine. “The Gateway is a key component of Nasa’s long-term Artemis architecture and the Halo capability furthers our plans for human exploration at the Moon in preparation for future human missions to Mars.”

Nasa also announced a change in the implementation plan for Gateway. Halo is one of the two core elements of Gateway, the other being the power and propulsion element, or PPE. The original plan was to launch them separately and for them to dock in lunar orbit. Now they would be launched together.

Launching them together, as one unit, would reduce technical risks and costs. This change in plan was the result of Nasa’s programme status assessment.

“We’re making significant progress on these first two elements, including incorporation of components from ESA (European Space Agency), the Canadian Space Agency, the Japan Aerospace Exploration Agency, and payloads from our research communities,” reported Nasa Gateway programme manager Dan Hartman. “The new plan to integrate the two elements of Gateway demonstrates the capabilities of the agency and our partners to be flexible and reassess plans as needed. By launching the elements together, we’re able to significantly reduce Gateway’s risk profile and increase cost effectiveness.”

The solar-electric PPE would provide Gateway’s power and manoeuvring capability. Halo would give Artemis astronauts living space in lunar orbit with greater volume than that provided by their Orion spacecraft. Nasa described Halo as being about the size of a “small studio apartment”. The two units were planned to be launched in 2023.