Lunar Landers: New Orion Rendezvous Spots After Gateway?

Last week, NASA Administrator Jared Isaacman unveiled a significant overhaul of the Artemis Program, aiming to put the nation on a more efficient path back to the Moon. The changes primarily focused on increasing the launch frequency of NASA’s Space Launch System (SLS) rocket and prioritizing lunar surface operations. The US Senate quickly signaled broad support for these plans. However, this shift overlooks a crucial component of Artemis: a lander capable of transporting astronauts from lunar orbit to the surface and back to rendezvous with the Orion spacecraft. NASA has contracted SpaceX and Blue Origin to develop these landers – Starship and Blue Moon MK2, respectively – and their success is now more critical than ever.

A Revised Artemis III and the Pressure to Deliver

Isaacman announced that the revamped Artemis III mission will now serve as a testing ground for one or both of these landers in a near-Earth environment before attempting a human lunar landing later this decade. He projected Artemis III to launch next year, followed by one or potentially two lunar landings by 2028. Achieving even a single landing before the end of 2028 appears ambitious, even for optimists within the space community. For this timeline to be realistic, SpaceX and Blue Origin – or both – must accelerate their development efforts significantly. The question is: can they?

“Challenge Every Requirement” – A New Approach to Collaboration

Isaacman recognizes these challenges and immediately engaged with engineers from SpaceX and Blue Origin to explore ways to expedite the Artemis timeline. Following a meeting on January 13th, Isaacman stated NASA would actively facilitate faster development of the Human Landing System (HLS). “We will challenge every requirement, clear every obstacle, delete every blocker and empower the team to deliver… and we will do it with time to spare,” he declared. This suggests a commitment to streamlining the collaboration process and reducing bureaucratic hurdles for SpaceX and Blue Origin.

For instance, the docking procedure between the lander and Orion, while seemingly routine given six decades of space rendezvous and docking experience, is currently complex. Orion is subject to thousands of requirements, and every decision regarding docking requires sign-off from the lander company, NASA, Lockheed Martin (Orion’s contractor), and Airbus (the European service module contractor). Furthermore, Orion’s sensitive systems, like thruster plumes, and the need for consistent cabin pressures between vehicles add layers of complexity. It quickly becomes a logistical and engineering challenge.

The Emergence of a “Carbonated Orbit” and the Demise of the Lunar Gateway

One significant change NASA is implementing to aid the lander companies is abandoning the requirement to dock with Orion in a Near-Rectilinear Halo Orbit (NRHO). This elliptical orbit, ranging from 3,000 km to 70,000 km from the lunar surface, was originally intended for the Lunar Gateway space station, which is now likely to be canceled. This is a major benefit for lunar landers, as NRHO requires significantly more energy for initial descent and ascent.

Why not revert to a low-lunar orbit, similar to the Apollo Program? The reason lies in limitations with the Orion spacecraft’s service module. Due to past design choices, it lacks the performance necessary to reliably reach and return from low-lunar orbit. This necessitated the use of the NRHO. However, a July 2022 research paper from NASA engineers at Johnson Space Center explored alternative circular and elliptical orbits within Orion’s capabilities.

Introducing EPO/CoLA: A More Efficient Orbit

This analysis led to the identification of another promising orbit: the Elliptical Polar Orbit with Coplanar Line of Apsides, or EPO/CoLA. This orbit features a closest approach to the Moon of just 100 km (apolune distance of 6,500 km). The research indicates that for many landing sites, an HLS vehicle can achieve a lower orbit with a single burn, reducing propellant consumption. This represents a substantial improvement in mission efficiency.

Isaacman also announced the “standardization” of the SLS rocket’s upper stage for Artemis IV and beyond. This means Artemis IV will utilize a new upper stage, likely the Centaur V built by United Launch Alliance, offering increased propulsive capabilities. This could allow Orion to reach an even more favorable orbit – closer to the Moon – than EPO/CoLA, further minimizing energy requirements for the lander.

Accelerating Starship’s Development as a Lunar Lander

While finding new orbits and relaxing requirements is beneficial, the ultimate responsibility for delivering a functional lander rests with the contractors. The sooner they can deliver, the better. Last November, GearTech examined potential strategies to accelerate Starship’s deployment as a lunar lander. A major hurdle is the need for numerous uncrewed tanker missions to refuel Starship in low-Earth orbit before its lunar transit and crew rendezvous with Orion. This could require one to two dozen launches.

One proposed solution was an optimized, expendable Starship tanker stage to maximize propellant delivery per flight. However, SpaceX founder Elon Musk dismissed this idea, believing that once Starship achieves a high launch rate, a dozen or more tanker missions per lunar flight won’t be a significant impediment. Unsurprisingly, SpaceX hasn’t proposed substantial changes to its HLS architecture. Instead, the company intends to prioritize the HLS within the broader Starship program.

Blue Origin’s Responsive Approach

Blue Origin, founded by Jeff Bezos, has demonstrated a more proactive response. Last October, GearTech reported that the company had begun developing a faster architecture that eliminates the need for orbital refueling. A month later, Blue Origin’s CEO, Dave Limp, pledged to “move heaven and Earth” to help NASA reach the Moon sooner.

Recent documents reviewed by GearTech reveal that Blue Origin is refining its human lunar landing plan. Without the NRHO requirement, a lunar landing could potentially be achieved with as few as three launches of Blue Origin’s New Glenn rocket, utilizing the more powerful 9x4 variant currently in development. The EPO/CoLA orbit enables this mission profile.

Blue Origin’s Proposed Mission Profile

One mission plan details launching a simplified MK2 lander on one New Glenn rocket, followed by two launches of transfer stages that dock in low-Earth orbit. The first transfer stage propels the stack out of low-Earth orbit before separating. The second transfer stage then maneuvers the lander into EPO/CoLA, where it docks with Orion and two astronauts transfer to the MK2. This second transfer stage then delivers the lander to a 15 x 100 km lunar orbit before separating. The MK2 then descends to the lunar surface.

After a short lunar stay, the MK2 ascends back to EPO/CoLA to rendezvous with Orion. However, questions remain regarding the readiness of Blue Origin’s hardware. The shift to Artemis IV and the potential use of new orbits for Orion rendezvous introduce further complexities. Therefore, these plans remain preliminary.

The Race to the Moon: A Critical Juncture

Neither NASA nor Blue Origin has publicly discussed these accelerated landing plans. Hopefully, this will change soon, as NASA’s best chance to reach the Moon before China may hinge on the ability of a company symbolized by a turtle to accelerate its pace. The stakes are high, and the next few years will be crucial in determining the future of lunar exploration. The success of the Artemis program, and the US’s position in the new space race, depends on the innovative solutions and rapid execution of both SpaceX and Blue Origin. The revised Artemis plan, with its focus on flexibility and streamlined requirements, offers a path forward, but ultimately, the burden of delivery rests with the private sector partners.

Key Takeaways:

• NASA is prioritizing a faster return to the Moon, focusing on increased launch cadence and lunar surface activities.
• The cancellation of the Lunar Gateway and the adoption of orbits like EPO/CoLA are simplifying mission profiles and reducing energy requirements.
• SpaceX and Blue Origin are adapting their lander designs to meet the accelerated timeline, with Blue Origin demonstrating a more responsive approach.
• The success of Artemis hinges on the ability of these companies to overcome technical challenges and deliver functional landers on schedule.