Masten Achieves First Hot-Fire of Broadsword Rocket Engine

Masten Space Systems ©2016

Mojave, CA – On September 30, 2016, Masten Space Systems successfully concluded the 13-month design, build, and test period for the first development unit of the Broadsword 25 rocket engine, funded as a technology demonstration under the Defense Advanced Research Projects Agency (DARPA)’s Experimental Spaceplane (XS-1) program. This first phase of the engine development effort included commissioning Masten’s largest mobile engine test stand and firing of the company’s highest-thrust rocket engine to date.

The Broadsword 25 is a liquid oxygen- and liquid methane-propelled rocket engine with a full-throttle sea-level thrust rating of 25,000 lbf. Masten initiated development of the Broadsword in August 2015, as a cost-effective reusable engine suitable for use in both boost and upper-stage applications.

Broadsword employs a novel dual-expander cycle, which allows high efficiency at sea level while maintaining the benign turbomachinery conditions characteristic of traditional expander cycle engines. It is made primarily via additive manufacturing, or “3D printing”—a technology that enables complex design geometries, reduces part count by an order of magnitude, and compresses manufacturing times, all of which enable rapid engine development.

The goal of this initial hot-fire test campaign comprised ignition and startup sequence development. The effort concluded with demonstrating six successful engine starts. Masten has subsequently begun the design and build of a second development unit, incorporating lessons learned during manufacturing and testing, and plans to proceed with main-stage hot-fire testing in the next phase.

Masten aims to continue Broadsword development over the course of 2017 and 2018 in collaboration with NASA under the Tipping Point program, and anticipates moving into flight qualification after the conclusion of that effort.

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What’s the Point?

That is a question that comes up from time to time when people see Xaero-B and Xodiac. Both vehicles seem to be doing what other rocket companies have already *demonstrated* and to greater lengths at that. The underlying premise of the question is this: you are not seeing anything that hasn’t already been done. And there is some truth to that on the surface, the VTVL part is not any different. It is in this perception of us vs them that the question sort of belies the real activity at hand…..

(Click here to keep reading…) Developing rocket technology is more than a skin deep proposition.

Masten’s Green Bipropellant: MXP-351

As part of our partnership with NASA through the Lunar CATALYST (Lunar Cargo Transportation and Landing by Soft Touchdown) program, we have been actively developing a proprietary new bipropellant – MXP-351. This propellant is intended to be flown on our XL-1 lunar lander which is capable of bringing up to 100 kg (221 lb) softly to the lunar surface. MXP-351 represents the next step in Masten’s internal propulsion development program in improving our capabilities closer towards spaceflight.

MXP-351 is a nontoxic, storable and hypergolic bipropellant combination. These storable propellants, as opposed to cryogenic propellants like Liquid Oxygen or Liquid Hydrogen, are stable for long periods of time at room temperature. Hypergolic propellants mean that the fuel and oxidizer will ignite spontaneously as soon as they come into contact with each other. Storable and hypergolic systems eliminate the need for separate igniter systems and typically only need minimal thermal conditioning of the propellants, improving their reliability and performance. Consequently, such systems are favored highly for in-space missions like the XL-1 lunar lander.

Historically, spacecraft have used cocktails of Hydrazines and Nitrogen Tetroxide (NTO) as storable hypergolic propellants. These propellants have very high performance and were used in the Apollo Lunar Module Ascent and Descent engines, as well as part of the Space Shuttle’s Orbital Maneuvering System (OMS). However, they are both extremely toxic, requiring exhaustive procedures for safe procurement, handling, spill control, and disposal. The nontoxic MXP-351, by comparison, is exceptionally easy to handle. They have very low vapor pressures, meaning they don’t evaporate easily and pose inhalation hazards to any workers. Spills are easily rectified by simply diluting with water and rinsing away. These greatly reduced operational constraints have the potential to reduce recurring costs for spaceflight applications.

More importantly, it allows us to safely and thoroughly test out our propulsion systems here in Mojave with the same regularity as we fly our vehicles. In 2016, we successfully fired the first generation of our 225 lb XL-1 main engine, dubbed ‘Machete’. This simple ‘boilerplate’ engine validated our injector design, performance estimates, and applicability of MXP-351 in a rocket test environment. Future tests with MXP-351 will use additively-manufactured technology to test regeneratively-cooled thrust chambers, as well as scaling up the thrust capability up to 1,000 lb for a terrestrial testbed version dubbed (XL-1T) that is currently in manufacture.

NASA CATALYST has been instrumental in aiding our development in the program, giving advice from industry experts who have worked with similar propellants in the past, as well as providing advanced analytical capabilities to characterize engines with these propellants.

Summer 2017 Internship

Masten is now accepting intern applications for the Summer of 2017.

If you’ve followed us you know we’ve had a great history of outstanding interns working with us. There are few places like us that can deliver an internship with this level of responsibility and hands on work. We’re not looking for gophers, we’re looking for team members.

For those not familiar, our interns are part of flight crew, essential in the shop, and expected to contribute to solving the engineering challenges we face.

Please share this link with individuals who would fit well with our team and have the passion, skills, and tenacity to work with us!

Internship Page


Introducing Xodiac and XaeroB

Introducing the next generation of reusable rockets – Masten’s Xodiac and XaeroB.

These two new rockets are designed and built on the success of their predecessors – Xombie, Xoie, and Xaero. For those who have followed us, you will see the obvious connection to our previous vehicles. With this new iteration, we are bringing greater capability and more flexibility to better to serve our partners.

Both Xodiac (open frame) and XaeroB (aeroshell) share the core architecture that has powered Masten’s rockets to date – LOX/IPA; pressure fed, regeneratively cooled engine; Masten avionics and GNC. The two new vehicles also share many of the same components, enabling Masten to have more efficient operations and less risk of service interruption.


These new rocket vehicles continue to offer the features of Masten terrestrial test bed:
– precision vertical landing
– custom flight profile
– rapid iteration
– custom physical/mechanical integration
– rocket powered station keeping


This flexible, adaptable platform is available now to help you solve challenges that limited access to space imposes.

Leap over that TRL valley of death. Get real world data. Fly.

Drop us a line to start taking advantage of these new vehicles and enhanced capabilities.


Masten Space Systems selected by Defense Advanced Research Projects Agency for XS-1 Program

Mojave, CA (July 23, 2014) — Masten Space Systems, Inc. (Masten) announced today that the company has been awarded a contract from the Defense Advanced Research Projects Agency (DARPA) as part of Phase 1 of the Experimental Spaceplane (XS-1) program to develop a reusable launch vehicle. Over the last decade, Masten has built three highly operable, vertical takeoff/vertical landing, reusable rockets which are flown by small teams of five to seven people. Masten’s experience with vertical takeoff/vertical landing rockets has shown that the company’s flight vehicles can offer greater flexibility than reusable launch vehicles that require runways to land. Masten has logged well over 300 flights to date with its Xoie, Xombie and Xaero reusable rockets.

The goals of the XS-1 program include designing and building a rocket capable of flying 10 times in 10 days, lifting payloads greater than 3,000 pounds to low Earth orbit, and dramatically lowering the cost of launch. Masten’s team intends to utilize the first year of the XS-1 program to demonstrate critical technologies and refine the preliminary design of its “Xephyr” launch vehicle.

Phase 1 of the XS-1 program is scheduled to last 13 months, with vehicle construction and flight demonstration envisioned for subsequent phases. In Phase 2, DARPA plans to select one of its XS-1 partners to build its launch vehicle for eventual transition to future commercial or military operations.

“XS-1 comes at the right time for the industry and the right time for Masten,” said Masten CEO Sean Mahoney. “The tide is turning and space access is opening up. We’re thrilled to lead a team to tackle the hard problems DARPA has put in front of us.”

Company founder and CTO David Masten said, “It’s time. Our team is ready. We’ve been working towards this for years. XS-1 is a great program to join with our vertical landing technology.”

“The vision here is to break the cycle of escalating space system costs and enable routine space access and hypersonic vehicles,” said Dennis Poulos, Masten’s XS-1 program manager. “The XS-1 program represents a return to the bold aerospace projects of decades past, when engineers from various government agencies came together to push the spaceflight envelope.”

XS-1 Press Release Image



The mission of the Defense Advanced Research Projects Agency (DARPA) is to make the pivotal early technology investments that create or prevent decisive surprise for U.S. national security. By investing in new technology-driven ideas for next-generation capabilities, DARPA creates options for a better, more secure future. Since its establishment in 1958 as part of the U.S. Department of Defense (DoD), DARPA has demonstrated time and again how thinking well beyond the borders of what is deemed possible can yield extraordinary results.


Masten Space Systems designs, builds and operates reusable vertical takeoff and landing rockets to help lower the barriers to space access. With over 300 flights successfully completed since May 2009, Masten continues to push the boundaries of reusable launch vehicle development and autonomous precision landing. Built on the foundation of reusability and small operations teams, the XPRIZE-winning company offers rockets-as-a-service for Entry Descent and Landing development, sub-orbital, and orbital flights.


For parties interested in offering products or services to Masten for XS-1: Contact Form

For parties interested in more information on flying on Masten’s XS-1: Contact Form

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Astrobotic Technology And Masten Space Systems Perform Visually Guided Precision Landing


John Thornton

Sean Mahoney


Groundbreaking effort integrates two privately developed technology platforms to validate performance of autonomous precision landing capability

Mojave, CA: Astrobotic Technology and Masten Space Systems announced today that the Astrobotic Autolanding System (AAS) successfully directed the Xombie vertical-takeoff vertical-landing suborbital rocket in a closed-loop test on June 20, 2014. In this technology demonstration, a computer vision system scanned the landscape, selected a landing spot, and directed a rocket-powered lander to a safe touchdown point, all without a human operator. The flight test was funded by the Flight Opportunities Program of NASA’s Space Technology Mission Directorate and conducted at the Mojave Air and Space Port in Mojave, CA.

The combined AAS/XA-0.1-B system landing in the hazard field at Mojave. Credit: Masten Space Systems, Inc.

Future NASA and commercial missions will likely target destinations with challenging topography and limited communication, such as unmapped asteroids, surface rendezvous sites for sample return, and terrain features like polar peaks, crater rims, and skylights on Mars and the Moon. The Astrobotic Autolanding System (AAS) autonomously selects a landing location for a robotic spacecraft to safely land at a precise location, a capability that is critical for landing in such hazardous terrain.

Unlike typical drone landings, which rely on GPS, the AAS uses a technique called Terrain Relative Navigation to precisely track the spacecraft’s location and attitude using only cameras and an inertial measurement unit (IMU). This is necessary in environments where GPS is not available, like the Moon. The AAS then uses LIDAR to detect hazards and select a landing point. “Conceptually, this is like the Apollo missions where the astronauts navigated to a safe landing by looking out the window of the LEM,” said Kevin Peterson, Astrobotic’s CTO. “In this case, we have an onboard computer instead of an astronaut, and the cameras, IMU (Inertial Measurement Unit), and software are so precise that they can track the craft’s location to within a few meters.”

Developing navigation and hazard avoidance for a self-landing, rocket-powered spacecraft on Earth is challenging, due to the need to test in the same operating conditions that the system would encounter in a planetary landing. Astrobotic and Masten collaborated on a framework that enabled the test flight without prior knowledge of exactly where the rocket would choose to land. Astrobotic’s AAS scanned the landscape and selected a safe landing point. Masten’s onboard flight system received input from the Astrobotic vision and navigation system, validated the input, and accepted the selection of a path to the touchdown point. The flexible architecture enables flight testing while simultaneously limiting risk to vehicle, payload, and people. The successful flight was the capstone of only a few months of work together.

This is a representation of hazard detection during the landing test. The red shaded regions represent hazardous terrain. The green regions represent safe landing areas detected during flight. Credit: Astrobotic Technology, Inc.

Masten’s CEO Sean Mahoney said, “Today was a great demonstration of how a rocket powered lander can select a safe landing site without human intervention. There are so many innovations on display in this flight campaign from both teams that it really drives home the reality that barriers to space access are falling.”

This successful closed-loop flight was an end-to-end validation of the Astrobotic Autolanding System’s precision landing capability in a relevant flight environment. The development focus will now shift to implementing the AAS with space-rated sensors and avionics in order to land Astrobotic’s Griffin lander safely on the Moon.

Masten’s terrestrial rocket testbed next takes to flight later this year in support of future rocket landing technologies, while the company continues to build the next generation of vertical take off/vertical landing vehicles.

About Astrobotic
Astrobotic makes high-capability space missions practical for a broad spectrum of business, scientific, and commercial applications. With its partner Carnegie Mellon University, Astrobotic is pursuing the Google Lunar XPRIZE. Astrobotic was founded in 2008 and is headquartered in Pittsburgh, PA.

About Masten Space Systems
Masten Space Systems designs, builds and operates reusable vertical takeoff and landing rockets to help lower the barriers to space access. With over 300 flights successfully completed since May 2009, Masten continues to push the boundaries of reusable launch vehicle development. Built on the foundation of reusability and small operations teams, the XPRIZE winning company offers rockets-as-a-service for Entry Descent and Landing development, suborbital, and orbital flights.