Under Development in Partnership with NASA CATALYST (SAAM ID 18250)

 The Lunar CATALYST initiative is a public-private partnership that began in October 2015 with the competitive selection of three U.S. companies to partner with NASA via a “no funds exchanged” space act agreement with each company. The goal of the initiative is to encourage the development of robotic lunar landers that can be integrated with U.S. Commercial launch capabilities to deliver payloads to the lunar surface.

Masten has long believed in an incremental development approach of rapid design a first POC, test it, make changes and then test again. Be in a position to test early and often.


With a launched lunar vehicle the approach can have some limitations (ie. lack of vehicle access post launch) and a way to deal with that is to test terrestrially as much as is practical. It is cost effective to test here on Earth vs in-space and XL-1T helps us in this regard. By using a terrestrial test bed early in the lunar design cycle we can buy down a lot risk with certain technical heavy hitters.

  • XL-1T (terrestrial) is our largest lander build to date with a wet mass of ~1300kg.
  • XL-1 (lunar), by comparison, is even larger at roughly 2400kg wet.
  • XL-1T lessons learned will be leveraged to evaluate and improve common systems with XL-1 or XEUS
  • XL-1T can demonstrate landing technologies that may be incorporated into XL-1 and XEUS.

XL-1 and XL-1T use Masten's MXP-351, a nontoxic and storable hypergolic propellant system.


The construction of XL-1T is underway.

We chose a mix of a bolted and welded structure. The reason for the bolted sections was to give us the flexibility to make changes in width and length if needed.

Not optimum from a structures and mass perspective but this vehicle is an engineering test article to learn from. We didn't want the design so constrained that any desired changes coming out of testing to be prohibitive to make and perhaps as a consequence not undertaken at all.

So we opted to accept the penalties in exchange for some design freedom.

Construction Status:

  • The primary structure and landing gear are complete.
  • The propellant tanks are fabricated and being integrated with the primary structure.
  • We have identified most of the avionics with procurements made.
  • We are working on the terrestrial engine design.

We recognize that ultimately real in-space exposure is where the technical 'buck' meets the design trajectory and we are working towards that as fast as we can.

Credit: MSFC - MSFC is doing the assembly and fabrication work

Credit: MSFC - MSFC is doing the assembly and fabrication work

Credit: MSFC - MSFC is doing the assembly and fabrication work

Credit: MSFC - MSFC is doing the assembly and fabrication work

Related Paper: "NASA Lander Technologies Project Status", AIAA SPACE 2016, AIAA SPACE Forum, (AIAA 2016-5221), Dr.Greg Chavers