Our Story

Interstellar is a small, veteran-owned business focused on providing innovations in design and manufacturing for propulsion and space systems. With over 113 years of experience in aerospace and mechanical engineering for advanced space systems, the Interstellar team has previously worked several high-profile Government and Commercial space programs which have included the SpaceX Falcon 9 launch vehicle, the SpaceX Dragon capsule, and NASA’s Space Shuttle. In addition, the Interstellar team has experience stemming from over ten rocket engine development and flight programs including the Space Shuttle Main Engine, Air Force Integrated Powerhead Demonstrator (IPD) engine, NASA J-2X engine, SpaceX Merlin engine, SpaceX Raptor engine, SpaceX Draco and SuperDraco, NASA Additive Manufacturing Demonstrator Engine and the PGA Engine program. The Core Team at Interstellar recently completed two years of advanced development for the Stratolaunch 200,000 pound thrust PGA Engine, which had completed several key design and hardware testing milestones which would have enabled one of the fastest large engine developments in history.



Jeff Thornburg




Brock Dennison

Director of Advanced Manufacturing


Elizabeth Robertson

Director of Operations



Graham Nelson

Director of Programs and Business Development


Adam Harris

Chief Strategy Officer


Sara Ball

Director of Supply Chain and

Product Development


Emma Ainge

Senior Propulsion Engineer



Jeff Thornburg is a career space engineer and leader who brings a wealth of valuable experience to the team.  Jeff is founder and President of Interstellar Technologies, an engineering and technology development company focused on advanced research and development for launch vehicles and propulsion systems that expand our reach into the solar system.  Prior to the current focus on Interstellar, Jeff was the Vice President for Propulsion Engineering at Stratolaunch working with Paul Allen on the advanced and fast-paced PGA Engine development for Stratolaunch.  Jeff was also the Senior Director of Propulsion Engineering at SpaceX in Hawthorne, CA, and served as the principal engineer and architect of the Raptor engine development program.   Jeff also served as the Vice President of Propulsion Engineering at SpaceX overseeing flight, test, development and research operations while also supporting customer interactions; including those with NASA and the U.S. Air Force.  Jeff oversaw six successful Falcon 9 launches during his time as the VP of Propulsion, and coordinated qualification and certification activities with the U.S. Air Force and NASA. He was also a lead propulsion engineer and turbomachinery technical project manager for the J-2X engine development program at the NASA Marshall Space Flight Center, and Jeff spent 4 years working for Aerojet as an engineering director for their liquid engine turbomachinery group, and served as the site manager for the Aerojet-Woodland Hills engineering office in Woodland Hills, CA.

Jeff started his career in the U.S. Air Force as a flight commander and aircraft maintenance officer on KC-135R tanker aircraft at MacDill AFB, FL. He was selected to attend the Air Force Institute of Technology and earned his Master’s degree in Aeronautical Engineering.  Jeff was stationed at Edwards AFB, CA, where he joined the liquid rocket engine branch at the Air Force Research Laboratory where he worked on several component and engine technology programs included leadership of the joint Air Force-NASA Integrated Powerhead Demonstration engine. This program performed the world’s first hydrogen full-flow staged combustion cycle engine demonstration.  Since his first assignment to Edwards AFB, Jeff has been very fortunate to have built his career working on nearly all liquid engine technology development programs since the Space Shuttle Main Engine.  Jeff has received numerous Air Force and NASA awards including a NASA Space Flight Awareness award, the NASA Made It Happen award, the NASA Stennis Space Center Propulsion Test Director’s Leadership Award, and was an Air Force Research Laboratory Technical Program Manager of the Year.  In addition to his master’s degree, he has a Bachelor of Science in Aerospace Engineering from the Missouri University of Science and Technology.

Chief Strategy Officer

Adam Harris is a space executive with a passion for space exploration to Earth Orbit, the Moon, Mars and beyond. Adam is a founder and Chief Strategy Officer of Interstellar Technologies. Adam is focused on bringing engineering and technology solutions to market and expanding propulsion opportunities for Interstellar customers. Prior to Interstellar, Adam was President of Artemis Technologies, an aerospace consulting firm. Adam was the Inspector General of the National Reconnaissance Office and a Vice President for Government Sales at SpaceX. Earlier in his career, Adam was a Professional Staffer on the House Appropriations Committee and Senate Intelligence Committee. Adam is a graduate of the United States Air Force Academy in Astronautical Engineering and he spent 8 year in the Air Force working on EELV, Titan, Delta and Atlas launch programs.

Director of Operations

Elizabeth Robertson is a dedicated and determined Director of Operations with experience spanning both the private and public aerospace sectors. Most recently, Elizabeth worked for Stratolaunch Research as the Senior Manager of Propulsion. During her career at Stratolaunch she managed a record breaking engine development project, pushing the boundaries of revolutionary manufacturing techniques while meeting budget and schedule constraints. Prior to her time at Stratolaunch, Elizabeth worked for NASA’s Marshall Space Flight Center (MSFC) in Huntsville, AL. At MSFC, Elizabeth worked in multiple areas of propulsion from component design and development to propulsion integration. As a team lead in the Liquid Engine Branch, she was responsible for the technical products related to the RS-25 engine, the Commercial Crew Program, and small business development projects, as well as internal research and development. While at MSFC, Elizabeth also managed an internally funded engine development program to push the boundaries of additive manufacturing by designing, building and testing hardware at a rapid pace. As part of this effort, Elizabeth worked with the materials and processes department to lay the groundwork for specifications and standards to allow additive manufacturing to be implemented into human rated systems. Prior the end of the Space Shuttle Program, Elizabeth served as the Deputy Chief Engineer for Propulsion Systems Engineering and Integration. In this role, she worked across the agency to ensure that the final missions of the Shuttle Program were successful. During her time at NASA, Elizabeth received numerous awards, including the Silver Snoopy Award which is awarded by the astronaut office for outstanding performance, contributing to flight safety and mission success. Elizabeth earned a BS in mechanical engineering from Louisiana State University and a BS in business administration from Washington and Lee University.

Director of Supply Chain and Product Development

Sara Michealene Ball is an experienced and enthusiastic Director of Supply Chain and Product Development with a background that spans multiple industries. Armed with an undergraduate degree in Supply Chain Management and an MBA in Finance and Business Strategy, she is passionate about efficient supply chain management and has worked to implement techniques that bring results, regardless of the product. Most recently, Sara was the Supply Chain Manager for Stratolaunch Research, Inc's record-breaking rocket engine development project. Since beginning her career with Toyota, Sara has built a foundation in lean processes and Total Quality Management. Sara has been an integral part of several propulsion engine programs including SpaceX's Raptor development, Merlin 170k and Merlin Vacuum 210k engines. She has excelled at both propulsion Development and New Product Integration. Sara has applied her expertise to goods of all shapes and sizes -- from soap to rockets and never shies away from a challenge!

Director of Programs and Business Development

Graham Nelson, the Director of Programs and Business Development, has had a wide variety of key roles in hands-on aerospace engineering developments. After getting both a Bachelor’s and Master’s degree in Mechanical Engineering – at Tennessee and Georgia Tech, respectively – Graham joined the ranks of NASA as a Propulsion Thermal Analyst, supporting Space Shuttle missions, as well as the design and development of several propulsion elements, including both solid and liquid-fueled systems. Chief among many notable efforts at NASA was Graham’s participation in and leadership of the in-house design and development of an advanced rocket engine, the Additive Manufacturing Demonstrator Engine (AMDE). Graham had several different roles throughout his time on the project – first serving as an Analyst and Designer, then as a Systems Engineer, and finally as the Program Manager and Chief Engineer – supporting and overseeing several phases of engine development, including design, fabrication, and component and system testing. Graham enjoys collaboration, challenging undertakings, and the pursuit of pioneering technologies, as evidenced in the aforementioned role and his more recent one as a Propulsion Lead Engineer at Stratolaunch, where his chief responsibility was the development of a cutting-edge Thrust Chamber Assembly for the PGA Rocket Engine.

Director of Advanced Manufacturing

With over 20 years of experience in developing manufacturing systems, Brock Dennison brings to the Interstellar Technologies team a wealth of knowledge that crosses industries from the automotive to aerospace to semiconductor, and finally to propulsion systems.  Serving as the Advanced Manufacturing Director for Interstellar Technologies, Brock’s initial focus will be to empower all functions of additive manufacturing; leveraging his broad Design-for-Manufacturing background to enable flight ready hardware.

Prior to the current focus with Interstellar Technologies, Brock was the Lead Build Engineer at Stratolaunch Research Inc. working on the innovative and fast-paced PGA Engine development program.  Since first stepping into the manufacturing world, Brock has utilized additive manufacturing as a tool for supporting vehicle pilot builds, enhancing product development cycles and supporting end use hardware.  Brock has followed the advanced manufacturing capabilities through validation and development of industry standards, and supporting qualifications of advanced manufacturing techniques.  In his work with Stratasys Direct Manufacturing Brock was able to setup an entire Additive Manufacturing production cell; qualifying hardware for industrial turbine engines to service the energy verticals for large OEM’s.  Brock is excited to continue maturing advanced manufacturing techniques to enable space exploration and beyond for Interstellar Technologies.

Senior Propulsion Engineer

Emma Ainge is a senior propulsion engineer at Interstellar Technologies, where she manages aerospace development programs from initial concept through final testing. Prior to working at Interstellar, she was a lead propulsion engineer at Paul Allen’s Stratolaunch. She led the development of the PGA engine main injector through design, analysis, and two testing campaigns. Emma also worked at Pioneer Astronautics as a lead aerospace engineer for Robert Zubrin. She was awarded a Phase II SBIR grant for her work there on additively manufactured micro-thruster designs. Prior to Pioneer Astronautics, Emma was in the boost propulsion group at SpaceX as a propulsion development engineer. She was responsible for the Merlin Vacuum (MVacD) engine through build, propulsive testing, and launch support. Several of her designs are currently in use on commercial missions to the International Space Station. She holds a Bachelor’s degree in Aerospace Engineering from MIT and a Master’s degree in Aeronautics and Astronautics Engineering from Purdue University. Her Master’s thesis was on the development of interplanetary propulsion thrusters for travel to Mars.

Outside of her professional work, Emma pursues intensive research projects in remote areas of the world. In 2009, she flew on a Zero-G flight for the Mars Gravity Biosatellite research project. That same year she traveled to the Sinai Peninsula in Egypt for desert conservation research. In 2011, she traveled to Antarctica to work as a resident engineer on a glacier research team while living inside a minimalist green home. Most recently, in 2016 she trained as a civilian astronaut, where she operated pressurized space suits and completed simulated orbital missions. She is currently working towards her fluency in Japanese and enjoys spending time repairing her sailboat.