Northrop Grumman dicit:
Northrop Grumman’s vision for the next step toward human space missions to Mars employs our flight-proven Cygnus advanced maneuvering spacecraft as a human habitat in cislunar space, the region between the Moon and Earth. In the early 2020s we would launch the initial habitat on NASA’s SLS rocket. Featuring a modular design, the habitat would serve both as a destination for crewed missions and as an unmanned testbed to prove-out the technologies needed for long-duration human space missions. The habitat is also envisioned as a base for lunar missions by international partners or commercial ventures. With additional habitation and propulsion modules, the habitat could be outfitted for a Mars pathfinder mission.
Video Credit: Northrop Grumman