NASA has finally given a name to its program to return astronauts to the surface of the Moon by 2024 — Artemis. JFK had the Apollo program. In Greek mythology, Artemis was Apollo’s twin sister. The announcement came at the end of a media teleconference where NASA explained its $1.6 billion FY2020 supplemental budget request to make returning to the Moon a reality.

The symbolism of the female name is obvious as White House and NASA officials constantly assert that the program will land the next man “and the first woman” on the lunar surface.

Since March 26 when Vice President Pence directed NASA to accelerate its plans to land people on the Moon by four years, from 2028 to 2024, the two big questions have been how much will it cost, and why President Trump was silent about it if he was truly behind the plan.

Trump finally tweeted about it today for the first time and signed off on the additional $1.6 billion for NASA. It is part of a larger supplemental appropriations package that includes funds for the Special Olympics and environmental restoration projects.

As for the cost, NASA Administrator Jim Bridenstine said at a media teleconference this evening that NASA is still working on developing that estimate. The $1.6 billion is a “down payment” and much more money will be needed in the future. But this “gets us out of the gate in strong fashion.”

The plan itself has changed only slightly since Pence’s speech. Astronauts will launch on the Space Launch System (SLS) aboard on Orion spacecraft and travel to the Gateway, a small space station in lunar orbit. Vehicles to take the astronauts down to and back from the lunar surface will be docked at the Gateway. Crews will transfer from Orion to a lander through the Gateway, descend to the surface, get out and perform whatever operations are needed, return to the Gateway and then to Earth.

NASA had been planning to do that by 2028. Now it must speed everything up to try and accomplish it before Trump leaves office assuming he wins a second term. While some complain about setting a deadline based on politics, Bridenstine defends it as risk reduction — reducing the political risk that a new president will change course as has happened in the past.

One of the two most obvious changes is that the initial version of the Gateway will be minimal, with just the Power and Propulsion Element (PPE) on which NASA has been working for several years, a docking port, and a minimal habitat. Plans for larger habitats and other elements provided by international partners will remain on the 2028 track although Bill Gerstenmaier, the head of NASA’s human spaceflight program, said that NASA’s focus on landing by 2024 does not preclude the partners from providing their Gateway contribution sooner than 2028 if they wish.

The second is that NASA now wants industry to come up with a plan to build the lunar landers. NASA was planning to acquire three vehicles: a transfer vehicle to get to a lower orbit, a descent vehicle to land on the surface, and an ascent vehicle to return to the Gateway.

Gerstenmaier says that the agency has become convinced it is better to let industry “do those trades” of how to get down and back instead of NASA, which will be a customer much like it is for the commercial cargo and commercial crew programs. Jeff Bezos made a big splash last week about his Blue Moon descent vehicle (it can deliver an ascent vehicle to the surface, but he did not say his company, Blue Origin, is planning to develop that part of the system), but other companies have their own plans. NASA released a pre-solicitation request on April 26 and is awaiting responses. He hopes to award contracts as early as September or October of this year.

The other critical element of the plan is lunar spacesuits. None exist today. They are quite different from the launch and reentry suits used by astronauts travelling to and from the ISS, or the Extravehicular Mobility Units used for ISS spacewalks. The lunar surface environment is quite different from space. Gerstenmaier said no money is included in the $1.6 billion supplemental for spacesuits, but they definitely will be ready by 2024.

The question remains — how much will all that cost? Today’s supplemental is only for FY2020, not the remaining four years to get people on the surface by 2024, never mind all the years after that. The White House and NASA continually stress that the Moon is just a step on the way to Mars, a proving ground for future human exploration. It is a multi-decadal program that will involve international and commercial partners, but NASA will still have to pay for much of it.

Congressional reaction to the supplemental may tell the tale of whether this attempt to return humans to the Moon will succeed where others have failed.