[6] After a framework was approved by the United States Congress in December 2018, the agency published a draft for its request for proposals for resupply services to the Gateway on June 14, 2019.
[7] Shortly following an industry day at the Kennedy Space Center for potential bidders on June 26,[7] the final version of the request was published on August 16.
[4][5] Procuring fixed-price contracts worth US$7 billion in total over fifteen years,[8][9][10] the request detailed requirements for American commercial providers to be able to deliver spacecraft capable of carrying at least 3,400 kilograms (7,500 pounds) of pressurized cargo and 1,000 kilograms (2,200 pounds) of unpressurized cargo to the Gateway on each flight, and disposing of an equivalent mass at the end of the flight.
[9][10] Sierra Nevada Space Systems publicized their interest during a November 2019 event celebrating progress on their Dream Chaser Cargo System, with the company's Vice President, Steve Lindsey, noting that spacecraft met the requirements for pressurized and unpressurized cargo mass.
[13] In March 2020, NASA announced SpaceX as the first GLS contractor,[14][15][16] with the company simultaneously unveiling the Dragon XL spacecraft to be used in their flights to the Gateway.