Updated 9:25 p.m. Eastern.

WASHINGTON — Blue Origin revealed new details about a lunar lander concept that the company’s founder says can support a human return to the moon by 2024.

At an invitation-only event here May 9, company founder Jeff Bezos unveiled a full-sized model of the Blue Moon lander the company has been developing, along with an engine named BE-7 that will power the spacecraft. That unveiling, with the theatrical flourish of a curtain raising to reveal the lander, took place about a half-hour into an hour-long event about the company’s plans and vision.

The spacecraft is able to land 3.6 metric tons of cargo on the lunar surface, with a “stretch tank” version capable of landing 6.5 metric tons on the surface. The lander has a deck on the top for hosting payloads and a davit, or crane, to lower them to the lunar surface.

The lander uses liquid hydrogen and liquid oxygen propellants, rather than storable hypergolics. “It’s very high performance,” he said of the choice of propellants. “Ultimately, we’re going to be able to get hydrogen from that water on the moon, and be able to refuel these vehicles on the surface of the moon.”

The liquid hydrogen in particular will be used for other aspects of the vehicle. Boiloff from the liquid hydrogen can be used to keep the liquid oxygen tanks cold, he said. It will also be used for fuel cells that will produce electrical power for the lander instead of solar cells. “We chose hydrogen fuel cells for this vehicle rather than solar cells because we want to be able to survive the lunar night,” he said, which lasts for two weeks.

Those propellants will be used by a new engine, called BE-7, on the lander. The engine will be able to produce 10,000 pounds-force of thrust and is deeply throttlable. “We’re going to hot fire it for the first time this summer,” Bezos said. “The only reason we can do that is we’ve been working on it for three years.”

Bezos emphasized the work that the company has put over the last three years into the Blue Moon lander, which the company first started talking about in 2017 but with few details about its design prior to this event.

A company source, speaking on background, said later that the lander has gone through several design cycles to arrive at the current concept. That work has included refining the requirements and the vehicle design, although the lander is not yet at a preliminary design review level of maturity.

That work has been aided by NASA, which awarded Blue Origin two awards in August 2018 through its Tipping Point program to mature key exploration technologies. One of those awards covers cryogenic fluid management needed for the lander’s propulsion system and the other involves testing of landing technologies, such as lidars and altimetry sensors. In both cases the company plans to test those technologies on its New Shepard suborbital vehicle.

Bezos didn’t provide other details about the development of Blue Moon, including how close the vehicle is to a first flight or its development cost. Bezos took no questions from the media or other guests in attendance, including NASA officials, former astronauts and scientists.

Bezos though, did endorse the new policy announced by Vice President Mike Pence in March to land humans on the moon in 2024, and hinted that only Blue Origin is able to meet that deadline in terms of developing a lunar lander.

“I love this. It’s the right thing to do,” he said of the goal. “We can help meet that timeline, but only because we started three years ago.”

Blue Origin’s announcement comes as NASA looks to industry for concepts for lunar landers to achieve that goal. That includes plans to issue a broad agency announcement for integrated lunar lander designs. The company did submit a proposal for an earlier announcement for studies of descent stages and transfer vehicles when NASA was still planning for a human landing in 2028. The deadline for those proposals was March 25, one day before Pence’s speech.

In the speech, Bezos did show a version of the Blue Moon lander with the stretched tanks and an ascent stage on top. The company does have plans for an ascent stage that it may offer in that upcoming NASA announcement, once NASA releases the final version of it.

The company’s development approach foresees having an initial version of the lander ready for a 2023 mission to the moon, one that could preposition some cargo for later human missions in addition to demonstrating the lander’s capabilities. The full lander, with both descent and ascent stages, would be tested in 2024 with astronauts on board, followed by a crewed landing using the system by the end of 2024.

Much of the speech focused on Bezos’ long-term vision of millions of people living and working in space, tapping the resources needed for humanity’s future. He also briefly touched upon development of the New Shepard suborbital vehicle and New Glenn orbital vehicle, but only reiterated current timelines that call for starting to launch people on New Shepard this year and carry out a first orbital launch of New Glenn in 2021.

That vision includes creating what Bezos called “infrastructure” needed for future space entrepreneurs to cost-effectively carry out that vision. “It’s this generation’s job to build that road to space so that the future generations can unleash their creativity,” he said. “Big things start small.”