Due to multiple malfunctions aboard Stage 2 of Relativity Space’s Terran 1 rocket, the engine did not reach full power, causing the company’s historic mission last month to be terminated just under seven minutes after takeoff.
The Long Beach-based satellite launch company announced its preliminary finding exactly three weeks after the mission, which proved its 3D-printed rocket was capable of withstanding the immense pressures of reaching space. An investigation is ongoing, the company stated, but in a series of tweets Wednesday morning, it outlined the successes and the root causes of the Stage 2 failure.
After the mission was scrubbed twice, the first Terran 1 blasted off from Launch Complex 16 at Cape Canaveral Space Force Station on March 22 at 8:25 PDT.
Dubbed “Good Luck, Have Fun,” the mission started off smoothly with successful vehicle release and flyout. The rocket reached max-q, which is the point of a launch where the vehicle is under maximum mechanical stress, at T+84 seconds.
After the Stage 1 main engine cutoff, with the rocket traveling over 4,629 mph, the stage separation system cleanly released Stage 2 at T+163 seconds. The Stage 2 igniters were given the “on” command at T+166 seconds, with performance appearing nominal, the company stated. At T+168 seconds, however, the Aeon Vac engine did not reach full thrust.
The engine’s main valves opened slower than expected, the company reported, which impacted the fuel pressure and the timing of it reaching the thrust chamber assembly and gas generator. While the fuel pump generated pressure as expected, the oxygen pump did not, which also affected fuel pressure and timing.
“The data from the oxygen pump is consistent with a vapor bubble being present at the pump inlet,” the company wrote.
🧵“Good Luck, Have Fun” First Flight update. pic.twitter.com/gwPGMGEQry
— Relativity Space (@relativityspace) April 12, 2023
Due to the pressure and timing issue, the gas generator did not light and the engine never reached full power.
Despite the malfunctions, at T+191 seconds, Stage 2 crossed the 100-kilometer Karman line into space and coasted up to 134 km above the Earth’s surface before the mission flight control officer sent the arm/terminate command functions at T+415 seconds.
“Initial data review indicates the flight termination system performed nominally,” the company stated, noting that stages 1 and 2 fell into the same designated disposal area. “No injuries, impacts to public safety or property damage were reported.”
Relativity’s investigation into the failure began immediately with Federal Aviation Administration oversight. The company is expected to submit a full report summarizing its key findings from the failed launch.
The company said its Terran 1 program allowed the company to refine its ability to develop and test its metal 3D-printing technology, adding that taking a more ambitious approach early in the company’s life gives it valuable experience for its upcoming venture.
“Building on the momentum from Terran 1’s development and flight, Relativity is shifting its focus to design, development and production of its next generation Terran R launch vehicle,” the company stated. The Terran R is “a medium-to-heavy lift reusable rocket designed to meet customer’s needs for disruptive, diversified launch capabilities in an underserved and quickly growing payload market.”