NASA began evaluating five habitat prototypes developed through NASAs Next Space Exploration for Technologies Partnerships, or NextSTEP, to help engineers refine requirements for the design of an American-made deep space habitat for the Gateway. Lockheed Martin turned over its prototype to NASA, and testing began with crew on March 25, 2019, at Kennedy Space Center in Florida. Pictured inside the Space Station Processing Facility on March 26, 2019, from left are astronauts Shannon Walker and Stephanie Wilson. Astronauts are participating in the evaluations to provide their perspectives as those who may one day live aboard the lunar outpost, which would be located about 250,000 miles from Earth. Ground prototypes developed by Bigelow Aerospace, Boeing, Northrop Grumman, and Sierra Nevada Corporation will be tested in the future at various facilities across the country. A sixth company, NanoRacks, plans to develop a prototype as well.