GL, HF —

Relativity Space hopes to live additively ever after with Wednesday’s launch

Watch this one because there won't be many Terran 1 launches.

The Terran 1 rocket as seen on the launch pad at Cape Canaveral.
Enlarge / The Terran 1 rocket as seen on the launch pad at Cape Canaveral.
Relativity Space/Trevor Mahlmann

Relativity Space, the ambitious company that aims to additively manufacture the majority of its rockets, will try again to make the debut launch of its Terran 1 vehicle on Wednesday evening from Florida.

The California-based company has a three-hour launch window that opens at 10 pm local time at Cape Canaveral Space Force Station (02:00 UTC on Thursday). The current forecast for the launch attempt is splendid, with a 95 percent chance of acceptable conditions, according to the US Space Force officials operating the range.

If recent history is any guide, Wednesday's launch attempt may consume most of the three-hour window. Relativity's first attempt to launch Terran 1, on March 8, was scrubbed near the end of the window due to problems with a fuel-temperature sensor on the second stage. A second attempt three days later did not get off the ground due to an array of issues, including last-second aborts, weather concerns, and a boat in the protected area around the launch site.

Now, the company hopes the third time is the charm for the debut flight of its rocket, which is composed of about 85 percent 3D printed parts by mass. Eventually, the company would like to additively manufacture as much as 95 percent of its rockets, although this may be aspirational more than realizable.

This is purely a test flight. Named "Good Luck, Have Fun," the launch will carry no customer payloads. Accordingly, overall success—reaching orbit—is unlikely. No private company has ever launched its first independently developed, liquid-fueled rocket and had it reach orbit on the first try. And Relativity is pushing a lot of boundaries with its methane-fueled booster. Probably the biggest test here is whether the 3D-printed structure of Terran 1 can withstand the dynamic pressure of ascent through the lower atmosphere.

The Terran 1 booster stands about 33 meters tall and is advertised as being able to lift 1.25 metric tons to low-Earth orbit. However, there are questions about how many times Terran 1 will actually launch. In an interview, Relativity Space chief executive Tim Ellis only committed to one more flight of the Terran 1 before the company pivots to a larger, medium-lift launch vehicle called the Terran R.

To its credit, Relativity is providing a livestream of its debut launch, something startup companies do not do all that often for fear of failing in public view. And because there may not be too many more Terran 1 launches—it would not shock me if this is the only one—those who are curious about new rockets will probably want to tune in for the show.

Terran 1, launch attempt no. 3.

Channel Ars Technica