Lunar landing restored for Artemis 4 mission

HUNTSVILLE, Ala. — NASA has restored plans to include a lunar landing on its Artemis 4 mission to the moon later this decade, months after saying that the mission would instead be devoted to assembly of the lunar Gateway.

In a presentation Oct. 28 at the American Astronautical Society’s Wernher von Braun Memorial Symposium here, Mark Kirasich, deputy associate administrator for Artemis Campaign Development at NASA, outlined the series of Artemis missions on the books for NASA through the late 2020s. That included Artemis 4, which he described as the “second time people land on the moon” under Artemis after the Artemis 3 mission.

However, earlier this year Kirasich and other NASA officials said that NASA was not planning to include a lunar landing on Artemis 4. Instead, they said the complexity of the mission, which will involve the delivery of the I-Hab habitation module to the Gateway on the first flight of the upgraded Block 1B version of the Space Launch System, precluded a lunar landing.

Kirasich confirmed after the panel that NASA had decided to include a landing on Artemis 4 again. The mission would likely use the “Option B” version of SpaceX’s Starship lander, he said.

NASA announced in March it would exercise that Option B in its Human Landing System (HLS) contract with SpaceX, which originally covered an Option A lander that SpaceX will demonstrate on the Artemis 3 mission. Option B would fund changes to the Starship lander to support more ambitious missions in the later “sustainable” phase of Artemis, and include a second demonstration mission.

NASA announced it would fund Option B at the same time it unveiled the Sustaining Lunar Development (SLD) effort to select a second lunar lander provider for those later missions. Kirasich said it would be unlikely that the lander selected in that program would be ready in time for Artemis 4, and instead would be demonstrated on Artemis 5.

In a schedule released as part of the agency’s fiscal year 2023 budget proposal in March, days after announcing the SLD program, NASA projected Artemis 4 launching in 2027, but without a lunar landing. That same schedule expects Artemis 3 to launch no earlier than 2025, with Artemis 5 to follow in 2028 as part of an annual cadence of missions

That date, though, will depend on several factors. One is the readiness of the Option B version of the Starship lander. During another panel at the symposium, NASA and SpaceX officials said they were making good progress on the lander but provided few technical details or a schedule.

Rene Ortega, HLS chief engineer at NASA, praised SpaceX for giving the agency access to hardware and test data from the overall Starship launch vehicle development effort. “It’s a big deal,” he said. “It’s one of the practices that I’ve been impressed with.”

The Artemis 4 schedule will also depend on the readiness of the I-Hab module, being developed by Europe and Japan, and the SLS Block 1B itself. That version of SLS, which uses the more powerful Exploration Upper Stage, in turn requires a new mobile launch platform, the Mobile Launcher (ML) 2.

NASA officials, including Administrator Bill Nelson, have been unusually publicly critical of the ML-2 prime contractor, Bechtel, for major cost overruns and schedule delays. “Right now, Mobile Launcher 2 is the critical path to Artemis 4,” said Jeremy Parsons, deputy manager of NASA’s Exploration Ground Systems program, during another conference panel Oct. 27. “It’s something we’re working the schedule very intensively on.”

Variety of second landers

NASA is currently soliciting proposals for the SLD program, formally known as Appendix P of its Next Space Technologies for Exploration Partnerships, or NextSTEP, effort. NASA issued the call for proposals Sept. 16 with an original deadline of Nov. 15. NASA pushed back the deadline Oct. 21 to Dec. 6 to provide more time for the agency to review requests by companies for use of government facilities.

During a conference panel session Oct. 28, NASA and several companies declined to discuss details about the SLD procurement because it was ongoing, including whether they would submit a proposal and, if so, with whom they were teaming. However, they did discuss work on a separate NextSTEP effort, Appendix N, to support work on sustainable lunar lander technologies. NASA selected five companies in September 2021 for $146 million in studies on key technologies for such landers.

Some of the companies have used the Appendix N awards to continue work on concepts they proposed in the original HLS competition. “Dynetics felt like we had a very sustainable lander approach even in the base period, so we really appreciated the opportunity to further mature that design during Appendix N,” said Andy Crocker, HLS program manager at Dynetics.

He said the company has been working on about 20 different tasks related to risk reduction on its lander design, including the lander’s engine, which uses liquid oxygen and methane propellants. The company performed a static-fire test of that engine a week earlier, he noted.

“I think it helped continue the momentum that we build up under the base period,” said Ben Cichy, senior director of lunar program engineering at Blue Origin, of its Appendix N activities. That included work on cryogenic fluid management for the hydrogen fuel used on its BE-7 engine, as well as precision landing technologies and dust mitigation.

Blue Origin competed for the Option A award ultimately won by SpaceX as part of the so-called “National Team” that included Lockheed Martin and Northrop Grumman, two companies that won separate Appendix N awards. Those companies are examining different approaches to lunar landers.

“Under Appendix N we’ve been given a great opportunity to step back and take a look at everything that has been developed since the Apollo missions,” said John Marzano, Northrop’s HLS program director, “and essentially pick what we think is a series of the best potential characteristics of each of those different concepts.”

He said the company is looking at two parallel efforts for lunar lander engines. One is an internal project leveraging experience dating back to TRW, which developed an engine for the Apollo lunar lander. The other is an engine from Sierra Space. The lander, he said, would use storable propellants rather than cryogenic ones.

Kirk Shireman, vice president, lunar exploration campaign at Lockheed Martin, said his company is examining incorporating nuclear thermal propulsion in its lander architecture, seeing as key to future human exploration of Mars. “Having a high-thrust, high-Isp engine is really key to our future,” he said. Isp, or specific impulse, is a measure of an engine’s efficiency.

He said the company is working on technologies such as cryogenic fluid management, fuel testing and a turbopump design. He said later that the nuclear propulsion system would be used for transit between the Earth and moon.

“We’ve been able to continue our collaboration that we established under the base period of the HLS contract,” he said of the company’s work with NASA. “It’s continuing the great work, the great relationship, that we had through Appendix N so that we can continue it, hopefully, under Appendix P. whenever that comes about.”