NASA just hit a huge Artemis Moon milestone for its all-important Gateway

NASA may be taking astronauts back to the Moon, but it's the orbiting Gateway which will act as a space AirBnB for Artemis. A newly finalized deal will see Northrop Grumman develop the Habitation and Logistics Outpost (HALO), a home away from home for astronauts and what's expected to be an instrumental part of future missions including NASA's first crewed trip to Mars.

The Artemis Gateway will effectively be the Moon's equivalent of the International Space Station, mixed with a transit terminal. On the one hand, it'll be a stopover point for missions to and from the lunar surface. However, it'll also be a location where zero-gravity experiments can be carried out, among other things.

To suit those multiple roles, it'll be a complex structure in its own right. There'll be pressurized living quarters, for example, where Moon missions can be run from, together with docking ports for spacecraft like NASA's own Orion, different lunar landers, and logistics resupply craft.

Key to the Gateway as a whole will be HALO. "The HALO module will serve as the backbone for command and control and power distribution across Gateway and will perform other core functions, including hosting science investigations via internal and external payload accommodations and communicating with lunar surface expeditions," NASA explains. "HALO also will enable the aggregation of additional habitable elements to expand Gateway capabilities."

Northrop Grumman's contract is worth $935 million, and will see it tasked with attaching and testing HALO with the Power and Propulsion Element (PPE). That's the thruster system which Maxar Technologies is building for NASA, and which will be used to put the Gateway into lunar orbit. In total it'll have 50 kilowatts of electric propulsion.

Another aspect of the contract is to work with SpaceX, which has been tasked with launching the Gateway and PPE. That's currently scheduled to take place in November 2024, with a SpaceX Falcon Heavy rocket lifting the whole assembly.

Once deployed, it'll maintain a fairly complex near-rectilinear halo orbit orbit, which will intentionally vary the Gateway's distance from the Moon. At its closest, it'll be near enough for the lunar landers' range; at its furthers, it'll be tens of thousands of miles from the lunar surface. "This orbit will allow NASA and its international and commercial partners to conduct unprecedented deep space science and technology investigations, and conduct sustainable lunar exploration," NASA says.

HALO will be based on Northrop Grumman's existing Cygnus spacecraft, which the company already has in use for resupply missions to the International Space Station. Although it'll be built at the company's Arizona facility, it'll be a testament to international collaboration.

The European Space Agency, for example, will be supplying the lunar communications system with which the Gateway communicates with the lunar surface; the Japan Aerospace Exploration Agency will provide the batteries with which it'll be kept operational until the solar panels can be deployed, and during times of eclipse. The Canadian Space Agency will be responsible for the robotic interfaces onto which the Canadarm3 will mount.

Eventually, the European and Japanese space agencies plan to add an international habitat, which will connect to the Gateway. The ESA also has a refueling module in the pipeline. Beyond Artemis and the return to the Moon, the station will be a staging post from which the space agencies can launch crewed missions to Mars, and potentially further still.