This is what 99% combustion efficiency looks like for LOX/Kerosene.   Thanks to LOX cooling, E-2 doesn't require chamber film cooling.  Paired with a highly efficient injector, combustion efficiency and specific impulse are maximized, boosting payload capacity and unlocking more value from every mission to orbit.

E-2 Thrust Vector Control testing is underway! This test includes frequency sweeps starting at a maximum gimbal angle of ±7 degrees, using hardware from a previous engine revision. After completing additional testing on the component stand, the actuator will be deployed to the test site for its first gimballed test fire.

The first E-2 Block 1 engine integration is complete, and our team is now preparing for test fire. This design upgrade reduces mass, simplifies manufacturing, consolidates vehicle interfaces, and incorporates thrust vector control.  More updates to come as we progress through the test campaign! Propellants: LOX/Kerosene Thrust: 23k lbf (10.4 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

At the conclusion of our longest test campaign, totaling 2033 seconds of run time, E-2 demonstrated a rapid relight test fire. This test consisted of a 212-second burn with a nominal shutdown, followed by an 8-second pause and a successful engine relight. This sequence simulates a first stage flight profile followed by the brief coast period that would occur between main engine cutoff and the burn required to return the stage for landing. This milestone represents a key step toward demonstrating rapid reusability, marking a fitting conclusion to a remarkable test campaign.  E-2 was designed for rapid reuse, which is an essential capability for the future of spaceflight.  We will continue advancing and validating this capability in future testing.

Rocket engine hardware is continuously produced from powder in our factory. We leverage 3D-printing to manufacture our single-part, LOX-cooled E-2 combustion chamber, reducing cost and part count while enabling rapid design iteration. The upgraded chamber design shown supports a lighter, simpler engine with thrust vector control. E-2 rocket engines are made in America 🇺🇸 Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

🚨 New max thrust record for E-2! 🚨 Last week, we boosted E-2 thrust by 23% to 27,000 lbf for multiple one-minute duration test fires. We’re pushing the limits to better understand the operating envelope in which E-2 can perform reliably. In parallel, our team is rolling out an upgraded design that is lighter, simpler, and incorporates thrust vector control.

Our team is the force that drives the propulsion 💎 💎 We're a highly skilled group with the experience and know-how to build the highest performance engines that maximize your value to orbit. And we have fun doing it! Here are a few of our great Launcher team members. If you're Interested in working on a one-of-a-kind rocket engine with our team, see our open roles at: vastspace.com/careers?depart…

Two E-2 development engines are fully assembled and undergoing test campaigns to validate reliability and service life. In parallel, our team is rolling out an upgraded design that is lighter, simpler, and incorporates thrust vector control. E-2 is ~75% 3D-printed by mass, produced in-house by our highly skilled manufacturing team. The highest performance LOX/kerosene engine in the small launch class is made in America 🇺🇸

E-2 delivers unmatched performance in the small launch class. Operating at an optimal mixture ratio with 99% combustion efficiency, it produces a distinctive blue, transparent plume, which is unprecedented for kerosene engines. Designed for rapid reusability, E-2 maximizes specific impulse, increasing payload capacity and overall value to orbit. For a given rocket, higher engine performance enables more payload to be flown in place of propellant compared with lower performance engines. Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

New engine test campaign kicked off! 💎💎 A trim test and a 200-second mission duty cycle test have been successfully completed on the latest brand-new E-2 engine unit, achieving a mixture ratio of 2.62 and a chamber pressure of 100 bar. Our thorough development program is critical to ensuring E-2 operates reliably and executes high-performance spaceflight missions at low cost. Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

Twenty successful engine starts, totaling 2033 seconds of cumulative run time, were completed on the latest workhorse E-2 engine sample. This breakthrough test campaign concluded with a rapid relight demonstration, validating capabilities essential for reusability.  A brand-new engine sample has now been manufactured and is scheduled to begin testing early next week. E-2 continues to be pushed through its paces to ensure it will be fully prepared for future spaceflight missions, delivering high performance propulsion at low cost.   Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

🚨 New record for E-2! 🚨 Last week we conducted an Endurance Demonstration Test Fire, setting a new record for the longest E-2 test to date at 222 seconds. Yesterday we followed it up with another 222-second run, achieving a mixture ratio of 2.75 and a chamber pressure of 101 bar. Thirteen successful engine startups totaling 1128 seconds of cumulative run time have been completed to date on the latest E-2 engine sample. Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

New E-2 engine sample is rockin’ and rollin’ on the test stand! 💎💎 Nine successful engine startups totaling 869 seconds of cumulative run time have been completed to date on the latest E-2 engine sample, including an Endurance Demonstration Test Fire.  More soon... E-2 is the highest performance LOX/kerosene engine in the small launch class.

Throwback to the first 200-second E-2 test fire with our incredible partners at @NASAStennis on April 12, 2024. Since then, our team has completed 29 engine builds and test campaigns, each bringing us closer to a repeatable, reliable product. Our rigorous development program has been key to ensuring E-2 will be ready to execute spaceflight missions successfully, delivering high performance propulsion at a low cost.   Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

Thirteen successful engine startups totaling 770 seconds of cumulative run time have been completed to date on the latest E-2 engine sample. Testing of this unit will continue to further characterize performance and extend the rated service life. E-2 is engineered to power spaceflight with rapid reusability and exceptional reliability at low cost. Propellants: LOX/Kerosene Thrust: 22k lbf (10 tf) Isp Sea Level: 290 s Isp Vacuum: 327 s Isp Vac Version: 365 s Cycle: Ox-Rich Staged Combustion

E-2 making diamonds 💎💎💎 in the desert 🏜️ On September 15, 2025, our new engine unit completed its 6th test fire, a 202 sec full mission duty cycle with zero hardware issues.  E-2 manufacturing and test cadence are accelerating.

E-2 has successfully demonstrated a full mission duty cycle with margin, completing a 201 sec run at our Mojave, CA test site. Multiple 200 sec test fires have now been completed, proving performance and reliability across engine builds. As the highest performance LOX/kerosene engine in the small launch class, E-2 is designed to maximize your payload capacity and unlock more value from every mission to orbit.

At our Mojave, CA test site, E-2 ran at boosted thrust for a 1-minute duration, achieving 25,000 lbf thrust and measured 295 seconds Isp. Although E-2 is a kerosene/LOX engine, its plume is blue and transparent, demonstrating its 99% combustion efficiency. E-2 is now available for sale.

Launcher E-2 liquid rocket engine, 200-second test fire recorded Friday, April 12, 2024 at @NASAStennis - Youtube version in 4K: youtube.com/watch?v=mzX8nTs3…

Who has ever seen a LOX/Kerosene liquid 🚀 engine with a blue plume 💎💎💎💎? Not only does it look spectacular, but it also serves as undeniable proof of the 99% combustion efficiency achieved in this test. Enjoy this 3-minute, 20-second test of E-2, a mostly 3D-printed 22k lbf (10 tf) ORSC LOX/Kerosene liquid rocket engine. Nominal pressure: 100 bar; mixture ratio: 2.7. Recorded today at @nasastennis, this test also secured the duration record for the test stand. E-2 is now available for sale to launch companies.