Terran 1 is powered by Aeon engines using liquid oxygen and liquid natural gas -- the "propellants of the future," according to Relativity, capable of eventually fueling a voyage to Mars.
Vulcan rockets being developed by United Launch Alliance and SpaceX's Starship use the same fuel.
Terran 1 has nine 3D printed Aeon 1 engines on its first stage and one 3D printed Aeon Vacuum engine on its second stage.
Built in 60 days
Relativity is also building a larger rocket, Terran R, capable of putting a payload of 44,000 pounds (20,000 kgs) into low Earth orbit.
The first launch of a Terran R, which is designed to be fully reusable, is scheduled for next year from Cape Canaveral.
A satellite operator can wait for years for a spot on an Arianespace or SpaceX rocket, and Relativity Space hopes to accelerate the timeline with its 3D printed rockets.
"Long-term, a major benefit of 3D printing is the ability to more rapidly democratize space due to the incredible cost effectiveness, radical flexibility and customization," the company said.
Relativity said its 3D printed rockets use 100 times fewer parts than a traditional rocket and a Terran 1 and a Terran R can be built from raw materials in just 60 days.
Relativity has already signed commercial launch contracts worth $1.65 billion, mostly for the Terran R, according to CEO Tim Ellis, who cofounded the company in 2015.
"Medium-heavy lift is clearly where the biggest market opportunity is for the remaining decade, with a massive launch shortage in this payload class," Ellis tweeted.
