The First 3D-Printed Rocket is about to Launch into Space

US aerospace start-up Relativity Space is planning to launch its 3D-printed rocket Terran 1 on March 8, skipping planned tests and heading straight for orbit. The Terran 1 was not launched on 8 March due to an issue involving the temperature of the fuel, and Relativity Space is expected to release a new launch date soon. Terran 1 will be the largest 3D-printed object to attempt orbital flight.

The rocket is about 35 meters tall, making it one of the smallest orbital rockets in the industry, and 85 per cent of it by mass is 3D-printed. It is designed to lift up to 1250 kilograms into low-Earth orbit, and the firm is charging $12 million per flight. In comparison, SpaceX’s ubiquitous Falcon 9 can lift more than 22,000 kilograms into orbit and costs about $67 million per flight.

Terran 1 is fully expendable, and for this first test flight it will not have a payload. If the rocket makes it into space, the flight will be considered a success. The company has opted to skip one last planned test of the rocket – a static fire, in which the rocket’s engines are fired while the rocket is secured to the ground – and go straight to the launch.

By not completing static fire, Relativity Space accepts the increased likelihood of an abort on its first launch attempt.

But if all systems are performing nominally, Relativity Space would rather release and launch during its next operation than continue to wear the vehicle through additional testing on the ground. The rocket and each of its engines breezed through a barrage of tests to get here, and one more test would potentially cause more wear and tear than it is worth. Relativity Space’s stated goal is to facilitate an industrial society on Mars, and Terran 1 is far too small to make it there.

While it is designed to bring small satellites into orbit, its primary purpose is as a smaller-scale prototype for the company’s 66-meter-tall Terran R rocket, which the company intends to launch for the first time in 2024. Terran R is planned to be fully reusable, mostly 3D-printed and able to carry up to 20,000 kilograms into orbit. Aside from launching larger satellites into orbit around Earth, Terran R will also eventually offer customers a point-to-point space freighter capable of missions between the Earth, Moon, and Mars.

That is the vehicle customers need. Terran 1 is Relativity Space’s pathfinder, its development platform to get to Terran R. Relativity Space, a California-based startup that counts billionaire Mark Cuban as one of its early investors, will try to launch the first 3D-printed, methane-fueled rocket into orbit from Cape Canaveral Wednesday. The test flight has a three-hour launch window Wednesday opening at 1 p.m. EST (1800 GMT), and there is a 90% chance of favorable weather.

The two-stage rocket, called the Terran 1, will lift off from Launch Complex 16 at Cape Canaveral Space Force Station.

The mission is a demonstration for Relativity Space’s Terran 1 to haul more than a ton of cargo into low Earth orbit. The Terran 1 is aimed at the commercial launch market for small to mid-sized satellites, making Relativity Space one of several privately-developed smallsat launch companies coming online in the last few years. There are a number of firsts here potentially on this rocket.

It has the chance of being the first liquid oxygen rocket to make it to orbit. It has, by far, the highest 3D-printed content of any rocket in history. It is sitting at about 85% by mass, where no any other rocket has gone past 4%. Relativity Space has nicknamed the Terran 1’s test flight as “Good Luck, Have Fun.” It will not carry any customer satellites.

The Terran 1 could become the first methane-fueled launcher to reach orbit if the eight-minute flight goes well Wednesday, beating two much larger rockets, ULA’s Vulcan and SpaceX’s Starship, scheduled to attempt their first full-scale test flights in the coming weeks or months. Methane is the propellant choice of the future, especially for reusable rockets. Methane is a more efficient fuel than kerosene, which is used on SpaceX’s Falcon 9, Russia’s Soyuz launcher, and ULA’s Atlas 5.

It also burns cleaner and leaves less residue inside an engine than kerosene, easing refurbishment and reuse between missions.

Before the first Terran 1 has even left the launch pad, Relativity Space started development of a larger fully reusable rocket called the Terran R, a vehicle the company says will become a point-to-point space freighter capable of missions between the Earth, moon, and Mars. But the first test flight of the smaller Terran 1 is a major milestone for Relativity Space, a company founded in 2015 by Tim Ellis and Jordan Noone. Ellis, 32, is CEO of Relativity Space, while the 30-year-old Noone stepped down as the company’s chief technology officer in 2020.

Relativity Space now boasts some 1,000 employees, a million-square-foot headquarters, a factory in Long Beach, California, and $1.3 billion in venture capital and equity fundraising, including an early $500,000 investment from billionaire Mark Cuban. In 2021, the company reached a valuation of $4.2 billion before launching any rockets. Now the Terran 1 is on the launch pad in Florida, ready for an inaugural test flight to demonstrate the rocket’s 3D-printed tanks, structures, and engine components can withstand the rigors of launch.

No new company has ever had their liquid rocket make it to space on their first attempt. So if everything goes incredibly well, and Relativity Space achieve orbit on its first launch Wednesday, that would be a remarkable milestone. But that does not define success for Relativity Space. There are many other things that could happen on launch that would still be considered very successful for Relativity Space.

The Terran 1 can carry up to 2,755 pounds, or 1,250 kilograms, of cargo to a low-altitude orbit.

That is significantly more than other commercial small satellite launchers, such as Rocket Lab’s Electron vehicle. Relativity Space sells a dedicated launch on a Terran 1 for $12 million, about twice the price of a flight on the smaller Rocket Lab vehicle. Relativity Space not only developed the Terran 1 and designed a new rocket engine from scratch, the company has introduced four generations of 3D printers, each capable of building more rocket components faster and at lower cost.

About 85% of the 20,458-pound (9,280-kilogram) structural mass of the Terran 1 is manufactured with 3D printing technology, including its Aeon engines, fed by methane fuel and super-cold liquid oxygen. 3D printing allows Relativity Space to manufacture rockets with 100 times fewer parts than launch vehicles built using conventional methods. Relativity Space produced the Terran 1’s primary structure and propellant tanks on its 3D printers.

The engine thrust chambers, injectors, and turbopumps, reaction control thrusters, and pressurization systems also rely on 3D printing tech. Other parts, such as avionics and flight computers, were manufactured using conventional methods. The nine Aeon 1 engines on the first stage of the Terran 1 will generate about 207,000 pounds of thrust at full power.

Relativity Space has completed six ignitions and more than 185 seconds of hotfire time for all nine Aeon 1 engines on the first stage of the Terran 1, with no ignition failures, premature engine shutdowns, or engine swaps.

The engines and the Terran 1’s autogenous pressurization system, which uses self-generated gases to maintain pressure in the propellant tanks, have performed well during the ground tests. Relativity Space would skip a full-duration test-firing of all nine Aeon 1 engines on the first stage of the Terran 1, opting instead to proceed into final launch preparations. Relativity Space was very intentional about trying to get to the pad as fast as it could to maximize the rate of learning.

Relativity Space is trying to balance the risk of wear and tear on the Terran 1 from continued testing with the risk of proceeding with the test flight. Computers check the health of all launch vehicle systems, including engines, before giving the command to release the rocket for flight. If there is a problem, the countdown will abort and the engines will shut down on the pad.

If all systems are working normally, hold-down restraints will release to allow the Terran 1 to climb off the launch pad and accelerate into orbit. Overall, Relativity Space has completed 191 Aeon 1 hotfire tests with 10,900 seconds of run time during engine qualification and acceptance testing on a firing stand at NASA’s Stennis Space Center in Mississippi. The second stage of the Terran 1, powered by a single “Aeon Vac” engine optimized for firings in space, completed a full “mission duty cycle” simulating the burn it will perform on the test flight.

Relativity Space also completed structural loads testing on the first and second stages of the Terran 1, and functional testing on stage separation and other “flight-critical” mechanisms.

Aeon engines have been test-fired more than 2,000 times. The engines were designed and built in-house by Relativity Space, with the exception of the upper stage’s nozzle extension. The Terran 1 will take off from Launch Complex 16, a long-dormant facility at Cape Canaveral once used by Titan and Pershing missile tests, and test-firings of NASA’s Apollo service module engine.

Launch Complex 16 was last used for a launch in 1988, and is located on the historic “missile row” at Cape Canaveral, south of United Launch Alliance’s Delta 4 launch pad and north of SpaceX’s rocket landing zone. After announcing in 2016 it received the military’s approval to use Launch Complex 16, Relativity Space built a rocket processing hangar, erected lightning protection towers, and installed propellant holding tanks at the site. Relativity Space delivered the Terran 1 to Cape Canaveral last June for final integration and testing.

The Terran 1 will begin steering on a path due east after a 12-second vertical climb away from Launch Complex 16. Around 42 seconds after liftoff, the rocket will be far enough downrange to ensure debris would not fall on the launch pad if the vehicle broke apart in flight. When the clock gets to zero, a million things can happen, and only one of them is good.

And that is because rockets are incredibly complex systems that are tightly coupled, where your avionics, your propulsion system, your structures, all these things need to work perfectly in concert to have a rocket ultimately achieve orbit.

Relativity Space is designing the rocket to have the same kind of safety factors and structural margin that you would see in any other system. Over time, Relativity Space has developed its own alloys to make the printed material both higher performance and more printable, which is part of its very unique tech stack that makes it possible to 3D-print the vast majority of a rocket. The rocket will surpass the speed of sound as it accelerates through the atmosphere, a phase of flight called Max-Q where the Terran 1 will encounter the most extreme aerodynamic forces of the mission.

Ground testing has shown the 3D-printed rocket can withstand similar forces as a launch vehicle built with more conventional materials, like aluminum, carbon fiber, or stainless steel. Relativity Space has done the testing on the ground to validate that 3D-printed structures can survive the launch environment, but obviously demonstrating that in flight will be an important milestone to get through. Max-Q is the point Relativity Space is going to get the maximum aerodynamic forces pushing on the rocket.

That really is the key validation point for Relativity Space to show not just to itself, but to the world, a 3D-printed rocket is really up to the to the task of taking on those launch environments. The Terran 1 will push through Max-Q about 1 minute and 20 seconds after liftoff. The Terran 1’s first stage will fire for 2 minutes and 40 seconds, then detach from the rocket’s upper stage.

The booster on the Terran 1 is not reusable, and will fall into an impact zone in the Atlantic Ocean.

At T+plus 2 minutes and 51 seconds, the upper stage will light its Aeon Vac engine to accelerate the rocket to orbital velocity around 17,000 mph. If the flight goes as planned, the Aeon Vac engine will burn around five minutes before injecting the upper stage into a low-altitude orbit ranging in altitude between 124 miles and 130 miles (200-by-210 kilometers). The due east trajectory from Cape Canaveral, Relativity Space will aim to place the rocket into an orbit inclined 28.5 degrees to the equator, the same latitude as the Florida spaceport.

The mission should be complete around eight minutes after liftoff. One thing the Terran 1 is not testing on Wednesday’s mission is a payload fairing, the aeroshell that protects satellites during a rocket’s initial climb through the atmosphere, then jettisons to reveal the payloads after they reach space. The Terran 1 set for launch on Relativity Space’s first test flight has an aerodynamic nose cone, which will not separate from the rocket.

The decision to forego flying a payload fairing on the Terran 1’s first test flight was simply to ensure the company kept its focus on the parts of the rocket that have to work to reach orbit. There is a number of different failure modes where systems can run into trouble, those are really where Relativity Space is focusing its efforts. That is putting Relativity Space’s effort into massive amounts of propulsion testing and significant amounts of on-ground, hardware-in-the-loop avionics testing, and full end-to-end structural testing to make sure that the system has the best chance of getting all the way to orbit, and gives it the best chance to collect massive amounts of data that it can then use to improve its systems going forward.

A small metal ring, one of the first test articles Relativity Space printed several years ago, is riding inside the Terran 1’s nose cone.

It will remain attached to the upper stage. The quality is not great, the scale is not very large, and it is riding on top of a rocket that is majority 3D-printed. So it really kind of book-ends where Relativity Space started, and Terran 1 shows where it is today. Relativity Space has a launch contract with NASA to fly a cluster of small satellites on the second Terran 1 mission from Cape Canaveral.

The company also has a contract with Telesat to launch satellites for that company’s planned low Earth orbit internet constellation. And Iridium has a long-term agreement to launch voice and data relay satellites on Relativity Space’s rockets. Last year, Iridium shifted the launch of five of its remaining six spare “Iridium Next” satellites from multiple dedicated flights on Relativity Space’s Terran 1 to a rideshare mission later this year on a single SpaceX Falcon 9.

Iridium still has one ground spare left, which could launch in the future on the Terran 1. But Iridium says its contract with Relativity includes provisions to use the launch company’s future systems, like the Terran R. OneWeb has also signed a multi-launch agreement to fly its second-generation broadband satellites on Terran R. And another startup space company, called Impulse Space, announced last year it plans to send a robotic lander to Mars with a boost from Relativity Space’s Terran R.

Relativity Space has a contract backlog with a dozen customers worth more than $1.65 billion.

The majority of the backlog is for missions to launch on the larger reusable Terran R, which Relativity Space could launch for the first time by the end of 2024.