Boeing proposes SLS-launched lunar lander

Artist’s concept of Boeing’s lunar lander taking off from the moon. Credit: Boeing

Boeing is touting a lunar lander concept that the company claims could launch in one piece on an upgraded version of NASA’s Space Launch System heavy-lift rocket — which Boeing largely builds — and deliver astronauts to the lunar surface in 2024 without going through NASA’s planned Gateway mini-space station.

The lunar lander proposal submitted by Boeing to NASA is one of multiple concepts proposed by U.S. industry. Companies had to send in their lunar lander proposals to NASA by Tuesday, Nov. 5, on an accelerated timetable to meet the Trump administration’s goal of landing astronauts on the moon’s south pole by the end of 2024.

Details of two of the lunar lander proposals have been revealed.

Blue Origin, the company established billionaire Jeff Bezos, is partnering with Lockheed Martin, Northrop Grumman and Draper to develop a three-component lunar lander that could launch on commercial rockets, such as Blue Origin’s own New Glenn booster. Boeing is taking a different approach, proposing to launch a lunar lander on a single flight of the Space Launch System.

“When you try to carve that (lander) up into smaller pieces, some of the smaller pieces don’t work on some of the existing commercial launchers, so we ended up backing into an architecture that really works best using the largest rocket possible,” said Peter McGrath, director of global sales and marketing for Boeing’s space exploration division.

Boeing builds the SLS core stage, and NASA has charged Boeing with developing an upgraded Exploration Upper Stage to upgrade the SLS’s lift capability. The uprated SLS, known as the Block 1B configuration, could launch Boeing’s lander on a single flight, according to McGrath.

Boeing argues that using the SLS Block 1B to launch the lunar lander on a single launch “reduces the complexity and risk of sending multiple segments to orbit on multiple launches.” The company said its proposal enables a crewed landing on the moon requiring only five “mission critical events instead of the 11 or more required by alternate strategies,” where individual lander elements would rendezvous together near the moon and be assembled robotically.

In its solicitation for Human Landing System proposals, NASA requested companies propose commercially-developed vehicles, in which the contractors would be responsible for designing, building and launching the landers. Commercial operators would then fly the landers to an orbit near the moon for the rendezvous of an Orion crew capsule carrying NASA astronauts, who would board the landers for descent to the lunar surface.

In parallel with work on the human-rated landers, the SLS and Orion crew capsule, NASA is moving forward with plans to build a mini-space station near the moon. The combined lunar exploration initiative is named Artemis, after the twin sister of Apollo in Greek mythology.

The first piece of the Gateway station, known as the Power and Propulsion Element, is being built by Maxar for launch by the end of 2022. A Northrop Grumman-built mini-habitation module would join the Gateway after a launch in late 2023, setting the stage for the arrival of a landing craft in 2024, followed by the docking of an Orion crew capsule with the lunar landing crew.

The Gateway is slated to fly in an elliptical near rectilinear halo orbit, taking the complex as close as 1,000 miles (1,500 kilometers) and as far as 43,500 miles (70,000 kilometers) from the moon. NASA selected the orbit because it allows a continuous communications link with Earth, and landers departing from the Gateway can reach any place on the lunar surface with only modest propellant usage.

McGrath said Boeing determined the most effective way to land astronauts on the moon in 2024 is to develop a lander with just two elements — without a orbit transfer module — that could achieve its mission with or without NASA’s planned Gateway station in lunar orbit.

“It’s an ascent element and a descent element, where the ascent element actually performs the function of all the transfer to get you from the halo orbit that Gateway or Orion are in, all the way to the surface of the moon,” McGrath said in an interview with Spaceflight Now. “Then the ascent element is capable from taking you from the south pole all the way back to rendezvous with the Gateway or Orion.”

Artist’s concept of Boeing’s lunar lander launching on the Space Launch System. Credit: Boeing

“The way we’ve sized it, you avoid needing a third element, which really simplifies the architecture because you really have one rendezvous in space instead of a ballet of rendezvous (operations) in space,” McGrath said. “With the ascent (and) descent elements flying integrated on one launch, our architecture also offers a lot of flexibility in the sense that we can either dock directly with Orion or we can dock with the Gateway, whichever NASA prefers.

“And in the case the Gateway is delayed, it doesn’t delay your (Artemis 3) launch in ’24,” McGrath said. “So it really allows you to do the minimal number of maneuvers and dockings to actually get to the surface of the moon.

“Our architecture still assumes that we’re all arriving in the near rectilinear halo orbit, so we’re all going to that same orbit and doing all the maneuvers off that orbit to the surface,” McGrath said.

McGrath said NASA will eventually need the Gateway to enable a more “extensible architecture” for exploration of the lunar surface.

McGrath said Boeing could assess other commercial launch alternatives for the lander if the SLS Block 1B is not available in 2024.

“Getting a descent element of any size on a commercial launcher becomes a constraint, which is what drove us toward SLS,” McGrath said. “Depending on what the actual (commercial) launch performance numbers are, which are not known right now, we could look at that, but the baseline right now is SLS, and that’s where the right performance needs to be.”

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