Terran 1 was an expendabletwo-stagesmall-liftlaunch vehicle developed by Relativity Space. Development began in 2017 and the rocket was retired in 2023.[2] Most structures and components in the vehicle were manufactured with 3D printing processes.[3] The maximum payload was expected to be 1,250 kg (2,760 lb) to 185 km (115 mi) low Earth orbit (LEO). Relativity's advertised launch price was $12 million USD per Terran 1 mission.
Terran 1's first and only launch took place March 23, 2023 from Cape Canaveral. It passed max q and reached space but did not achieve orbit due to a failure of the second stage.[3] Following the failed launch, Relativity retired the rocket in favor of developing the much larger, reusable Terran R vehicle.[4]
Design
Terran 1 consisted of two stages. The first stage was powered by nine Aeon 1 engines burning methane and oxygen propellants (methalox) in a gas-generator cycle, each producing 100 kN (23,000 lbf) of thrust. The second stage was powered by a single vacuum-optimized version of Aeon 1,[5] known as AeonVac, producing 126 kN (28,300 lbf) of thrust in vacuum.[6] Both stages were autogenously pressurized.[7]
The payload fairing measured 6.8 m (22 ft) long and had a diameter of 3 m (9.8 ft). Terran 1 was capable of up to 1,500 kg (3,300 lb) to low Earth orbit.[8] Relativity commonly stated a payload capacity of 1,250 kg (2,760 lb) to lower inclination low-Earth orbits and 900 kg (2,000 lb) to a sun-synchronous orbit (SSO).[6][9]
The primary and secondary structures of Terran 1 were manufactured with Relativity's Stargate 3D printer out of aluminum alloy.[8] 90% of Terran 1 by mass consisted of printed components;[8] Relativity claimed that they could reduce the part count in the vehicle by 100 times compared to traditionally-manufactured rockets and manufacture an entire flight article from raw materials in 60 days.[8][10] Relativity's in-development Terran R launch vehicle will utilize the same tooling used to manufacture Terran 1.[5][11]
Relativity advertised a price per launch for Terran 1 of US$10 million in 2019.[12] The advertised price per launch had been increased to $12 million USD in 2021.[5]
Proposed upgrades
In February 2022, Relativity CEO Tim Ellis stated in an interview with Ars Technica the nine Aeon 1 engines on the first stage could be replaced with a single Aeon R engine with substantially higher thrust. The Aeon R engine is planned to be used on Relativity's much larger Terran R rocket.[13] Had the vehicle not been retired, the upgrade would have likely been done by the fourth flight.[13]
Launch
Relativity received a Federal Aviation Administration (FAA) launch license to conduct the first launch of Terran 1, not-earlier-than (NET) 8 March 2023 from Cape Canaveral Space Force Station's Launch Complex 16.[14] Originally, another static fire was planned with the full rocket stack before first launch. Relativity believed it performed enough tests and instead attempted a launch.[7]
Terran 1's initial flight scheduled for 8 March 2023 was scrubbed due to "exceeding launch commit criteria limits for propellant thermal conditions on stage two". A second launch attempt on 11 March was also scrubbed. Set for 18:00 UTC (14:00 EDT), high upper level winds prevented liftoff for over an hour. A second attempt at 19:35 UTC (15:35 EDT) was cancelled at T-70 seconds from a boat in the launch safety range. A third attempt at 19:42 UTC (15:42 EDT) was cancelled half a second before liftoff. The engines briefly lit up before shutting down from a "launch commit criteria violation". A final attempt occurred at 21:00 UTC (17:00 EDT). An issue with the automatic stage separation promptly closed the launch window.[15]
Another launch window for Terran 1's initial flight opened on March 23. After holding twice from a boat in the launch safety range, and high upper-level winds, the rocket lifted off at 03:25 UTC (23:25 EDT). Following a nominal liftoff and powered flight of the first stage, the second stage failed to ignite, leading to the loss of the mission. Preliminary investigations blamed the failure on a slower-than-expected valve opening as well as vapor ingestion into the liquid oxygen turbopump causing reduced performance.[16] Although the launch did not orbit, Relativity acknowledged the successful performance of the vehicle's 3D printed structures under flight loads.[17]
Following the loss of the first mission, the company abandoned further plans for Terran 1, instead choosing to focus efforts on developing the much larger reusable Terran R vehicle. Existing payloads on Terran 1 will likely have to be remanifested to Terran R or other flights.[4]
Planned launches
The following table was the list of planned launches prior to the vehicle's cancellation:
First flight of Terran 1, with the mission name "Good Luck, Have Fun". Instead of a payload, the non-deploying nose cone carried a metal ring, which was an early test article from Relativity's 3D printing process, weighing approximately 1.5 kg.[18]
A stated goal for the mission was to demonstrate the viability of 3D printing for major structural components of a rocket, the first such components to be used in an orbital launch attempt. These were proven in flight when Terran 1 passed max q and continued to perform nominally. After stage separation, the second stage failed to ignite, ending the mission.[19]
$3 million contract for unspecified payload(s) in NASA's Venture Class Launch Services (VCLS) 2 program.[20] The ELaNa 42 mission, consisting of three CubeSats, would have launched on this flight.[21]
Third flight of Terran 1, as detailed by Tim Ellis in an interview, would have carried a payload for an undisclosed customer.[13] Would have been last flight of Terran 1 before previously planned block upgrade.
The 2019 contract with Momentus included a first flight originally scheduled for 2021, with option for five additional flights in the future. The five flights would have included the launch of a Momentus Vigoride Extended space tug.[23]
Launch site would have been either be Cape Canaveral or Vandenberg. TriSept stated that the launch would have featured one large primary payload accompanied with several smaller payloads.[25]
This Template lists historical, current, and future space rockets that at least once attempted (but not necessarily succeeded in) an orbital launch or that are planned to attempt such a launch in the future
Symbol † indicates past or current rockets that attempted orbital launches but never succeeded (never did or has yet to perform a successful orbital launch)
