Masten Space Systems was a
Mojave, California based rocket company that was developing a line of reusable VTVL spacecraft, and related rocket propulsion hardware. Masten Space Systems competed in the NASA and Northrop Grumman
Lunar Lander Challenge X Prize in 2009, winning the level one second prize of US$150,000 Masten Space Systems was selected for the
Lunar CATALYST initiative of the
NASA on 30 April 2014.
Xombie Masten's
Xombie (model XA-0.1B) won the second prize in the Level One competition of the
Lunar Lander Challenge on 7 October 2009 with an average landing accuracy of . The primary goal of these two airframes was to demonstrate stable, controlled flight using a
GN&C system developed in-house at Masten. XA-0.1B originally featured four engines with thrust, but was converted in Spring 2009 to be powered by one engine of thrust. By October 2009, the regeneratively cooled
isopropyl alcohol and
liquid oxygen rocket engine was running at around . XA-0.1B, nicknamed "Xombie", first flew free of tether 19 September 2009, and qualified for the
Lunar Lander Challenge Level One second prize of $150,000 on 7 October 2009. In October 2016, NASA reported using Xombie to test the Landing Vision System (LVS), as part of the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT) experimental technologies, for the
Mars 2020 mission landing. After seeing Masten's success with Xombie in-air relight and vertical landing, SpaceX began evaluating this technique for use on the
Falcon 9 booster. , Xombie had flown 224 times. Xoie had an aluminum frame and featured a version of Masten's thrust engine that produced around of thrust. "Xoie", as the craft was nicknamed, qualified for the Lunar Lander Challenge level two on October 30, 2009.
Xaero The
Xaero reusable
launch vehicle was a vertical-takeoff, vertical-landing (VTVL) rocket which was being developed by Masten in 2010–2011. It was proposed to NASA as a potential
suborbital reusable launch vehicle (sRLV) for carrying research payloads under NASA's Flight Opportunities Program (initially known as the Commercial Reusable Suborbital Research/CRuSR program), projecting altitude in initial flights of five to six minutes duration, while carrying a research payload. The first Xaero test vehicle flew 110 test flights before being destroyed in its 111th flight. During the record-setting The final test flight was intended to test the vehicle at higher wind loads and altitudes, flying to an altitude of one kilometer while testing the flight controls at the higher ascent and descent velocities before returning to a precise landing point. The ascent and initial portion of the descent was nominal, prior to the stuck throttle valve which resulted in the termination of the flight prior to the planned precision landing.
Xaero-B Xaero-B was a follow-up to Xaero with the ability to reach altitude with engine on throughout. Xaero-B was between 15 and 16 feet tall where Xaero was 12 feet tall. Xaero-B performed hot-fire testing and test flights. It would have been used for the bulk of research flights up to initial altitudes between to . The vehicle has now been retired due to damage on a test flight in April 2017. It flew 75 times.
Xodiac The
Xodiac was a VTVL rocket introduced in 2016. It featured pressure-fed
LOX/
IPA propellant, and a regeneratively cooled engine. Flights could simulate landing on the Moon or Mars. Video of Xodiac performing in-flight air flow tests Tuft strings. Xodiac was lost during its 176th flight due to an in-flight anomaly on May 28, 2025.
Xogdor Xogdor was a VTVL vehicle that Masten planned to introduce in 2023. As the sixth VTVL testbed developed at Masten, Xogdor would have improved upon the work done with Xodiac and tested descent and landing technologies at speeds up to .
Xeus Xeus (pronounced Zeus) was a vertical-landing, vertical-takeoff lunar lander demonstrator. Xeus consisted of a
Centaur upper stage (from
United Launch Alliance) with
RL-10 main engine to which four Katana vertical thrusters have been added. Production Xeus was estimated to be able to land on the Moon with up to 14 tonnes (revised to 10 tonnes) payload when using the expendable version or 5 tonnes payload when using the reusable version. Each of the Katanas used on a Xeus lander were likely to produce when performing a horizontal touchdown. In December 2012, Masten demonstrated their all-aluminum regeneratively-cooled engine, the KA6A. The talk in this video announced the Xeus and also showed NASA's
Space Exploration Vehicle rover with its two astronauts as a possible payload for the XEUS. NASA signed an unfunded Space Act Agreement (SAA) with Masten in September 2014. The SAA lasts until August 2017, has 22 milestones and calls for "End-to-end demonstration of hardware and software that enables a commercial lander on the Moon." In December 2015,
United Launch Alliance (ULA) were planning to upgrade the XEUS's main body from a Centaur Upper Stage to the
Advanced Cryogenic Evolved Stage (ACES) which they were developing, significantly increasing the payload. Masten Space intended to incorporate experience from developing the XL family of cargo landers into the XEUS family of landers.
XL-1 The
XL-1 was a small cargo lunar lander that Masten was developing as part of the
Lunar CATALYST program (SAAM ID 18250). On 11 October 2016, Masten Space Tweeted a video showing the test firing of its new bi-propellant combination, internally called MXP-351. The test used an existing engine with an experimental injector, the first 'Machete', producing thrust. Development of their 3D printed regen lunar engine that would use MXP-351 to land on the Moon continued. , a thrust version of Machete for the terrestrial testbed of the lander, dubbed XL-1T, was being manufactured. In October 2017, NASA extended the
Lunar CATALYST agreement for 2 years. On 29 November 2018, it was announced that Masten was eligible to bid at a
Commercial Lunar Payload Services (CLPS) contract by
NASA. Should the proposal be accepted by NASA to be built, the landing to Moon would be no earlier than 2021. On 8 April 2020, NASA selected Masten to deliver eight payloads – with nine science and technology instruments – to the South Pole of the Moon in 2022 with the XL-1 lander. Masten would also operate the payloads, helping to lay the foundation for human expeditions to the lunar surface beginning in 2024. The payloads, which included instruments to assess the composition of the lunar surface, test precision landing technologies, and evaluate the radiation on the Moon, were being delivered under NASA's Commercial Lunar Payload Services (CLPS) initiative as part of the agency's
Artemis program. The US$75.9 million award included end-to-end services for delivery of the instruments, including payload integration, launch from Earth, landing on the surface of the Moon, and operation for at least 12 days. The payloads had predominantly been developed through two recent NASA Provided Lunar Payloads (NPLP) and Lunar Surface Instrument and Technology Payloads (LSITP) solicitations. On 26 August 2020, Masten announced that the first XL-1 mission, Masten Mission One, would be launched by
SpaceX, although it was not at the time publicly known which SpaceX launch vehicle it would fly on. On 23 June 2021, Masten announced that the launch of Masten Mission One had been delayed to November 2023 due to
COVID-19 pandemic related issues. The XL-1T was expected to have a dry mass of 588.93 kg and a wet mass of 1270.68 kg which was less than the XL-1. The vehicle had 4 off Machete 4400 N main engines able to throttle between 25% and 100% (4:1). The propellant was MPX-351. Yaw and pitch were controlled by differential throttling. There were 4 off 22 N ACS thrusters to control roll. Project ended as DARPA awarded the Phase 2 to Boeing. ==Other products and services==