The top Democrats and Republicans on the House committee that authorizes NASA activities introduced a bill today rejecting the White House’s plan to accelerate a human return to the Moon by 2024. The bill focuses on human exploration of Mars. The Moon is consigned to a limited role for precursor activities and astronauts back on the surface in 2028 as NASA originally planned, not the amped up 2024 schedule announced by Vice President Pence last year and later named the Artemis program.

The bipartisan NASA Authorization Act of 2020, H.R. 5666, was introduced by the top Democrats and Republicans on the House Science, Space, and Technology Committee and its Space Subcommittee: Rep. Kendra Horn (D-OK), Rep. Brian Babin (R-TX), Rep. Eddie Bernice Johnson (D-TX), and Rep. Frank Lucas (R-OK).

The 102-page bill covers everything NASA does, but its provisions on human spaceflight undoubtedly will capture the headlines.

The bill makes clear that human exploration of Mars, not the Moon, is the priority. The Moon is only a steppingstone and activities in or around the Moon are sharply limited to their application for Mars exploration. The “Moon to Mars” program specifically does not include lunar outposts or In Situ Resource Utilization (ISRU). If pursued by NASA, they are to be budgeted outside the Moon to Mars program.

The bill rejects Pence’s March 26, 2019 declaration that the next Americans will land on the Moon by 2024, the end of a second Trump term assuming he wins reelection. Instead, it sticks with NASA’s previous plan of achieving that in 2028.

It sets another deadline, 2033, for humans to orbit Mars, but the overall goal is landing people on Mars “in a sustainable manner as soon as practicable.” No date is specified.

The bill contains many specifics about how to implement a Moon to Mars strategy, with a heavy emphasis on use of the Space Launch System (SLS) and its Exploration Upper Stage (EUS). That also is at odds with the White House. The Administration wanted to defer work on EUS to focus NASA and Boeing on developing SLS. Boeing is the prime contractor for both SLS and EUS. The FY2020 appropriations bill already rejected that proposal, adding $300 million to continue EUS development. More broadly, the Administration envisions significant reliance on commercial rockets, not SLS, for lunar exploration. SLS would be used only for ferrying crews between Earth and a small space station, Gateway, in lunar orbit where they would transfer to Human Landing Systems (HLS) to get down to and back from the surface.

NASA is planning to award contracts as soon as next month to establish public-private partnerships where companies will develop, launch and own those HLS systems. NASA wants to purchase services from those companies as it is doing with the commercial cargo and commercial crew systems for the International Space Station. The bill rejects that, too. It requires that the U.S. government own the landers. It also calls for an “integrated lunar landing system” carried on SLS/EUS, rather than multi-component systems (transfer vehicle, descent vehicle, ascent vehicle) launched by commercial rockets and integrated at the Gateway.

For that matter, the bill does not even authorize a Gateway in lunar orbit to support lunar surface operations. The only gateway is a “Gateway to Mars” in cislunar space or at a Lagrange point that specifically “shall not be required for the conduct of human lunar landing missions.”

The Gateway to Mars, the “Lunar Precursor Program,” a Mars Enabling Technology Initiative, SLS/EUS, Orion, and a Mars Transport Vehicle are the elements of the Moon to Mars program defined in the bill.

In essence, the bill rejects the Trump Administration’s plan to quickly put humans back on the lunar surface followed by sustainable lunar exploration and exploitation and, in the longer term, humans on Mars. Instead, it wants to use the Moon only for whatever narrow precursor activities are required to enable human exploration of Mars.

The bill encourages international participation in implementing the Moon to Mars program, especially the Gateway to Mars. It also allows for commercial participation, but not to the extent currently envisioned by NASA. For example, commercial logistics support for the Gateway to Mars and the lunar surface are permitted, but only as long as the availability of those services does not become a “limiting critical path factor.” It also requires NASA to submit a report on the “definitions of ‘commercial’ being used across the Administration.”

Closer to home, the bill extends operation of the International Space Station (ISS) for another four years, to 2028, unless that would pose increased safety risks or Congress has authorized a plan to transition to an alternate platform that assures NASA can conduct necessary research to support the Moon to Mars program and other activities.

The Space Subcommittee will mark up the bill on January 29.

This article has been updated.