WASHINGTON — A long-overdue exploration roadmap report released by NASA Sept. 24 offers an overview of the agency’s plans to send humans back to the moon and on to Mars, but few new details about how to carry out those plans.

The “National Space Exploration Campaign Report” was released by NASA with little fanfare, appearing on its website Sept. 24. The 21-page report was required by the NASA authorization act of 2017, which called for a “human exploration roadmap” to be delivered to Congress by Dec. 1, 2017.

That document, according to the act, would provide “an integrated set of exploration, science, and other goals and objectives” for NASA’s human spaceflight program leading to “human missions near or on the surface of Mars in the 2030s.” That includes development of capabilities in cislunar space, but no explicit mention of humans on the surface of the moon.

The report, though, primarily focuses on plans to implement Space Policy Directive 1, signed by President Trump in December 2017, which calls for NASA to “return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations.”

The National Space Exploration Campaign outlined in the report has five strategic goals, ranging from transitioning activities in low Earth orbit to the private sector to returning astronauts to the surface of the moon and demonstrating capabilities there for later missions to Mars and other destinations.

However, it offers few new details about how it will achieve those goals. The report describes development of the Gateway in cislunar space as well as a series of lunar landers, starting with payload space NASA plans to acquire on commercial landers and leading up to a larger one capable of carrying both astronauts and cargo by the late 2020s.

NASA, though, had been communicating such plans for the Gateway and lunar landers for months, including using some of the same charts included in the new report.

“We’re not really going back to the moon. We’re going forward to the moon,” said Steve Jurczyk, NASA associate administrator, during a panel discussion at the American Institute of Aeronautics and Astronautics Space Forum in Orlando Sept. 19 that covered much of the same ground as the report. “We’re going to the moon to prove out the capabilities and technologies and operational concepts to eventually move on to Mars and other destinations.”

Many of the details about establishing the Gateway and developing that series of lunar landers have yet to be determined, and the roadmap report provides few specifics about how they will be developed. In a “critical decisions and milestones” section, the report states NASA will make the decision this year to develop the Gateway, including use of international and commercial partnerships and the facility’s final configuration. However, a decision on “appropriate Gateway requirements” and its final orbit in cislunar space would not come until 2019.

Beyond the release of a broad agency announcement Sept. 6 for the Gateway’s first module, the power and propulsion element, NASA hasn’t described in detail how additional modules of the Gateway will be developed, including roles for international partners.

“We’re going to be assessing capabilities from a whole host of different companies across the United States and, in fact, international partners to determine who can provide what,” NASA Administrator Jim Bridenstine said of plans for the Gateway during a Sept. 24 interview at a Washington Space Business Roundtable luncheon. “All that is in development right now, and I’m not at this juncture willing to step out and say who’s where in the process.”

The report is also silent about costs of the exploration campaign, offering no specific estimates for the Gateway, landers, or other elements of the plan. “The National Space Exploration Campaign does not assume or require significant funding increases,” the report states, one of the few mentions of funding or budgets in the report.

The report offers few specifics about the original goal specified in the authorization act language, human missions to Mars. There’s little mention of future robotic or human missions, other than initial planning for returning samples from Mars and an “eventual series of crewed Mars missions planned to start in the 2030’s and culminating in a surface landing.”

The report comes days before NASA officials are scheduled to testify before House and Senate committees at hearings that are likely to include discussion of the report and NASA’s exploration plans. Bridenstine is scheduled to testify at a Senate space subcommittee hearing Sept. 26 on “Global Space Race: Ensuring the United States Remains the Leader in Space.”

The House space subcommittee will be holding a hearing at the same time on “60 Years of NASA Leadership in Human Space Exploration: Past, Present, and Future” with Bill Gerstenmaier, NASA associate administrator for human exploration and operations, as well as the directors of the Johnson Space Center, Kennedy Space Center and Marshall Space Flight Center.