Relativity Space Achieves Major Design and Production Milestones for Terran R, Demonstrating Momentum Towards Launch
We’ve Completed Vehicle-Level Critical Design Review and Begun Flight Production
We’re excited to share a major update on Terran R, our reusable, medium-to-heavy lift rocket. We’ve made incredible strides in advancing design fidelity across all subsystems, hitting significant hardware and software development milestones, and ramping up production as we move toward first flight.
Advancing Terran R’s Design Fidelity
We’ve moved rapidly through Terran R’s conceptual design review (CoDR) in March 2023, preliminary design review (PDR) in December 2023, and critical design review (CDR) in December 2024. We prioritized design release of the most complex, time-intensive components first, allowing us to start producing key flight hardware. Some of our recent design achievements include:
Completing vehicle system-level CDR, finalizing designs for major subsystems, and validating architecture at a detailed level.
Completing nearly half of all component CDRs and releasing drawings to manufacturing. The remaining CDRs mainly cover shorter-lead subsystems.
Releasing over half of the vehicle’s mass, including all first stage engines.
Flight Build Progress
This design fidelity has enabled us to start first flight production for Terran R. At our Long Beach headquarters, we’re manufacturing and assembling critical primary structures, including first stage panels, second stage barrels, the thrust structure, and Aeon R engines.
Our manufacturing rates have significantly increased for crucial subsystems like large fluid passages, harnesses, avionics boxes, and valves. This ramp-up will help us ensure a smooth transition to operating at scale.
Mo Shahzad, our President and Chief Financial Officer, summed it up perfectly: “We have all the elements to make Terran R a commercially competitive launch vehicle: a talented team producing flight hardware and critical subsystems every day, rapid component and system-level testing, strong financial footing, a backlog of over $2.9 billion, and the infrastructure to support both first launch and a scalable cadence in the future. We recognize there is still plenty of work ahead, but the phenomenal progress across the program gives me great confidence in our ability to deliver Terran R to market for our customers.”
Development Progress
We’re making exciting progress testing our flight-intent Aeon R engine, known as Aeon R 1.3. This marks the final development campaign before engine qualification. Over the past two years, we’ve designed, manufactured, and tested three major full-scale engine iterations. Key additions include:
Engine avionics with flight-like software stack for closed loop thrust, throttle, and valve commands and thrust vector control.
A full-length printed sea-level regeneratively cooled nozzle.
Heat exchangers for pressurant gas.
So far, our flight-intent engine has run for more than 1.5 times its reusable service life, accumulating over 2,500+ seconds of runtime. Across all engine configurations, we’ve logged over 6,300+ seconds of runtime. Meanwhile, hardware production for the qualification engine is well underway, as are components for the second stage vacuum engine, which shares roughly 80% design commonality with its first stage counterpart.
Our avionics, flight software, and guidance, navigation, and control (GNC) teams are making major progress. Recent milestones include:
Completed multiple iterations of advanced flight simulations from liftoff to orbit and landing using flight- validated, in-house tools.
Developed algorithms for engine control, mid-flight guidance, day-of-launch trajectory design, and navigation.
Vehicle software reached orbit in a Hardware Out Of The Loop (HOOTL) test with flight-like GNC algorithms.
Working towards vehicle Hardware In The Loop (HITL) build.
Key systems for vehicle reuse are advancing quickly. We’ve completed supersonic and hypersonic wind tunnel test campaigns to validate base heat shield and grid fin designs. We also qualified and are now integrating our proprietary, next-generation, reusable heat shield materials onto flight hardware.
Terran R Refresher
Designed to meet the growing demand for LEO constellations, large satellites, and rideshare missions alike, Terran R is a reusable, medium-to-heavy lift launch vehicle with a payload capacity of 23.5 tons to a 200 km low Earth orbit (LEO). We’ve designed its scalable architecture to carry up to 5.5 tons of reusable payload capacity to Geosynchronous Transfer Orbit (GTO) and as much as 30 tons to LEO in a reusable configuration.
Powering Terran R’s first stage are 13 3D-printed Aeon R engines, running on LOX-methane in a gas generator cycle. Each engine delivers 269,000 pounds of thrust at sea level, with nine engines capable of gimbaling. We’ve designed the second stage with a single vacuum-optimized engine producing 323,000 pounds of thrust. The first and second stage engines share roughly 80% design commonality, with key differences being nozzle size and vehicle interfaces. Our team is leveraging experience from the Terran 1 program, where we racked up 10,900 seconds of hot fire testing and successfully completed flight qualification of the Aeon 1 engine, which was also gas generator cycle and powered by LOX-methane.
Both stages incorporate LOX-forward propellant tanks, separated by a common dome structure. The first stage tanks are reinforced with welded stringers for optimal strength, while the second stage features an integrated orthogrid. We’re using subcooled cryogenic propellants to unlock performance, except in the first-stage LOX system, where subcooling isn’t necessary to meet performance requirements. We’ve opted for a helium pressurization system, with cryogenic and ambient temperature helium stored in composite overwrapped pressure vessels (COPVs), to control tank ullage pressure during and between engine burns.
We’re designing Terran R for reusability from the onset, with key design features such as four landing legs, four grid fins, a base heat shield, engine throttle valves, and engine re-light capability.
After stage separation, the first stage will begin entry, descent, and landing (EDL) sequence. It will perform a slow flip maneuver using cold gas nitrogen thrusters before reigniting for a deceleration burn. Our actuating, non-deployable grid fins will provide precise flight control, while our next-generation thermal protection materials will protect the vehicle from atmospheric conditions during entry. As it approaches landing, the first stage will fire three engines for the landing burn while deploying its landing legs, touching down on an offshore barge.
By prioritizing early development and testing of critical entry systems, we are ensuring that we can effectively scale Terran R and improve economics to meet customer needs.
Hybrid Manufacturing for Faster Market Entry
To get Terran R to market quickly, we’re combining traditional manufacturing with additive techniques. This hybrid approach allows us to deliver a highly performant and cost-effective vehicle for our customers. Primary structures are made from friction stir welded high-strength aluminum alloys, enhanced by in-house machining and custom tooling. For the Aeon R engines, where fast iteration is critical, we’re using powder bed fusion (PBF) and wire arc additive manufacturing (WAAM) from our Stargate 3D-printing platform.
Kevin Wu, our Chief Technology Officer, explains: “We are focused on making a high-performance, scalable, and cost-effective launch vehicle for our customers. To deliver on that mission, we are using both additive and traditional manufacturing methods in-house while strategically outsourcing certain components to trusted vendors. This hybrid approach is the right decision for the early days of the Terran R program, optimizing for speed to market.”
Meeting Market Demand
We’re building Terran R to meet the growing demand for launch services. Terran R’s payload fairing is designed for flexibility, supporting dedicated payload deployments for constellation operators or single geosynchronous satellites and multi-customer rideshare missions. With a contract backlog of over $2.9 billion across more than a dozen customers, we’re confident that Terran R is serving the sweet spot of the market.
Josh Brost, our Chief Revenue Officer, summed it up well: “We’re designing a reusable rocket for the sweet spot of the market in medium-to-heavy lift launch. Our payload capacity is large enough to provide great economics on a dollar-per-satellite basis but small enough to ensure we’re filling it for each launch. This positions Terran R to meet the needs of our customers, who we’ve been in conversations with since day one to make sure our vehicle truly aligns with their goals.”
We plan to launch Terran R from Launch Complex 16 in Cape Canaveral, Florida beginning in late 2026. This rocket represents our first step toward a multi-planetary future, with long-term plans to serve missions to Mars and beyond.
Stay tuned as we continue making rapid progress towards first flight!