Relativity Space Preparing For Terran R First Flight

Relativity Space has released an in-depth update on the progress of its Terran R program, showcasing significant strides in hardware development, manufacturing, and testing as it moves closer to the first flight of its fully reusable heavy-lift launch vehicle. Company leadership highlighted key achievements in the vehicle’s primary structure, propulsion system, and supply chain development, reinforcing their confidence in the rocket’s potential for commercial viability.

From Design to Production: A Year of Rapid Advancement

Relativity Space has rapidly transitioned from conceptual designs to the production of actual flight hardware.

Over the past year and a half, the company has successfully completed conceptual and preliminary design reviews and is now advancing through critical design reviews (CDRs); with approximately 50% of the overall vehicle design having already passed the CDR phase, with a particular focus on primary structural elements and major subsystems.

Key elements of the Terran R that are now in active production include:

Thrust Structure & Tank Sections: Barrel sections are being fabricated from aluminum-lithium alloy using a combination of forming, welding, and advanced manufacturing techniques.

Avionics & Flight Software: The avionics boxes and harnessing are now being built in-house, and Relativity's software team continues to refine flight control algorithms.

Propulsion Systems: The company is testing flight-intent Aeon R engines daily at Stennis Space Center, preparing for full-scale engine qualification.

Fluid Systems: Piping assembly throughout the rocket is underway, including Composite Overwrapped Pressure Vessels (COPVs) for helium storage within the cryogenic tanks.

Launch Site Infrastructure: Modifications at Launch Complex 6 (LC-6) at Cape Canaveral are progressing in preparation for vehicle integration and maiden launch operations.

The Terran R Rocket

Terran R is designed for full reusability and high-cadence launches, making it a competitive option for satellite constellation deployments and deep-space missions.

The first stage booster will be powered by 13 Aeon R liquid oxygen (LOX)/methane engines, producing a total thrust of 3.5 million pounds at sea level. Nine engines will be gimbaled for steering, while four remain fixed. A single vacuum-optimized Aeon R engine will propel payloads on the second stage to orbit, featuring an expansion ratio of 25:1 and a vacuum thrust of 323,000 pounds.

The Terran R tanks are fabricated using friction stir-welded 2195 aluminum-lithium, with welded Z-stringers for optimal structural performance.

A Phased Approach to Reusability

The first stage will be equipped with four deployable landing legs and grid fins, enabling controlled aerodynamic reentry and landing on an offshore barge. In its reusable configuration, Terran R will deliver 20 metric tons to low Earth orbit (LEO), with future upgrades aimed at increasing that capacity.

Relativity Space is adopting a block upgrade strategy to iteratively enhance the Terran R’s capabilities over time. The program is structured in three main phases:

• Block 1 (First Flights, 2025-2026): Initial focus on payload delivery and soft ocean landings to gather flight data for full reusability.

• Block 2 (Early Reusability, 2027-2028): Expansion of recovery operations, transitioning from ocean landings to controlled landings on a dedicated barge.

• Block 3 (High-Cadence Operations, 2029 and Beyond): Optimization for 50-100 flights per year, reducing turnaround times for rapid reuse and scaling up production for commercial and government missions.

Advanced Manufacturing and Propulsion Innovations

Relativity Space will leverage its heritage in additive manufacturing to streamline production while integrating traditional manufacturing techniques where beneficial.

The Aeon R engine program, a crucial component of the Terran R, is undergoing extensive development and testing. Aeon R engines incorporate 3D-printed components for the injector, combustion chamber, and turbomachinery. Testing iterations (AR 1.1 through AR 1.4) have provided valuable lessons, leading to refinements in the engine’s ignition and throttle control systems.

Terran R’s engines are designed for multiple flights, featuring a gas generator cycle optimized for throttle control, high restart reliability, and long engine life.

Industry Demand and Market Strategy

Relativity Space is positioning Terran R as a key player in the expanding commercial launch market, particularly for large satellite constellations. With demand growing for direct-to-cell communications, broadband internet constellations, and Earth observation missions, the company aims to provide an economically competitive alternative to larger, single-use rockets.

The company has already secured $2.9 billion in contracts, indicating strong industry confidence in its launch services.

The 20-ton payload capacity is strategically sized to provide cost-effective solutions for constellation operators, ensuring fully booked launches while maintaining affordability.

Near Term Plans

Relativity Space has set 2025 as the year it will assemble and test its first flight vehicle. Major milestones expected this year include:

• Completion of primary structures and tank welding

• Engine qualification testing at Stennis Space Center

• Integration of avionics and flight software

• Stage-level testing, including full-duration static fires

• Final preparations for launch from Cape Canaveral’s LC-6

As the Terran R program continues to accelerate, Relativity Space remains committed to its goal of providing a fully reusable, high-cadence launch system that meets the evolving needs of the global space industry.

With a $2.9 billion customer backlog, the company is well-positioned to become a major force in the commercial spaceflight sector, when Terran R comes online.