s NASA prepares to request proposals from industry to develop the first element of its proposed cislunar gateway, the agency says it may be open to buying more than one of the modules.NASA’s Lunar Orbital Platform-Gateway, previously known as the Deep Space Gateway, will incorporate several modules, starting with one called the Power and Propulsion Element (PPE). That element will provide power for the gateway and also use electric propulsion to maneuver the complex in cislunar space.During a March 27 meeting of the NASA Advisory Council’s human exploration and operations committee, Michele Gates, director of the Power and Propulsion Element at NASA Headquarters, said the agency was ready to move ahead with procurement of the module after five industry studies wrapped up earlier this month.The four-month studies, led by Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada Corporation and Space Systems Loral, examined nearly two dozen topics, ranging from the overall design approach for the PPE to specific engineering details.Some of those companies were involved in previous studies for NASA’s Asteroid Redirect Mission, which also intended to use electric propulsion on its robotic spacecraft to retrieve a boulder from a near Earth asteroid. “Our strategy is to leverage all of the work that’s been done, including on the Asteroid Redirect Mission,” said Gates, who previously managed those efforts.For the PPE, NASA plans to develop the module in a public private partnership with industry. Once the module is launched and its performance demonstrated in space, NASA would have the option to then buy the module for use in the gateway.Gates said that NASA expects to issue a draft solicitation for the PPE in April, with an industry day to take place in late April or early May. A final solicitation will then follow, with proposals due to NASA in late July.NASA envisions a 2022 launch of the PPE on a commercial launch vehicle. There is “substantial” funding planned to support its development, she said, including $51.5 million for the current fiscal year and $542.1 million projected through fiscal year 2022.However, NASA is not restricted to buying a single PPE. The proposal synopsis, released in February, states that NASA is planning “potentially one or more contract awards” for PPE development.