31 engines sufficient to reach orbital velocity
In the long human effort to extend its reach beyond Earth, SpaceX marked a quiet but consequential moment in early February 2023, firing 31 of 33 Raptor engines on its Super Heavy booster — more than twice any previous attempt — while the rocket stood anchored to its pad in South Texas. Two engines fell silent, yet the company's leadership called it a success, arguing that 31 was enough to carry the vehicle to orbital velocity. The test was not an end in itself, but a threshold: one more deliberate step in a methodical progression toward a flight that carries implications not just for a private company, but for humanity's next return to the Moon.
- SpaceX fired 31 of 33 Raptor engines simultaneously for the first time, shattering its own record of 14 and crossing a threshold the company had been building toward for over a year.
- Two engines failed to perform — one deliberately shut down beforehand, one cutting out mid-burn — introducing a note of imperfection into a moment the company needed to go well.
- Elon Musk moved quickly to frame the result as sufficient, publicly stating that 31 engines were capable of reaching orbital velocity, containing the narrative before doubt could settle in.
- CEO Gwynne Shotwell confirmed the static fire was the final ground test, with an orbital launch attempt now targeting March 2023 — a timeline that had already shifted multiple times.
- The stakes extend well beyond SpaceX: without a successful orbital Starship demonstration, NASA's Artemis III Moon landing in 2025 and Artemis IV in 2027 face the risk of slipping further into the future.
In early February 2023, SpaceX cleared a significant milestone in its push toward orbital flight, firing 31 of the 33 Raptor engines on its Super Heavy booster in a static test at its South Texas facility. The roughly ten-second burn kept the rocket anchored to the pad while producing a dramatic plume of smoke — proof of life at a scale the company had never before demonstrated. Two engines did not perform as intended: one was deliberately shut down by the team before ignition, and another cut out on its own during the burn. Elon Musk acknowledged both but declared the result a success, noting that 31 engines were sufficient to achieve orbital velocity.
The test was the product of months of incremental preparation. In January, SpaceX had conducted a full dress rehearsal — mating the Starship spacecraft to the Super Heavy booster and fueling both vehicles for the first time together, without actually launching. That rehearsal set the stage for the engine test, which in turn set the stage for what came next: stacking the full vehicle again for one final ground validation before committing to flight.
CEO Gwynne Shotwell described the static fire as the last ground test the company needed, and indicated an orbital launch attempt could come as early as March 2023 — though the timeline had compressed and expanded repeatedly over the preceding eighteen months. The pressure behind that date was not merely corporate. NASA had selected Starship as the lunar lander for its Artemis III mission, targeting a return of humans to the Moon in 2025 for the first time since 1972, with a follow-on crewed mission planned for 2027. A successful orbital demonstration was a prerequisite for all of it. The February engine test, imperfect but meaningful, moved that possibility one step closer.
SpaceX has been methodically working toward an orbital test flight of its Starship vehicle, and on this day in early February, the company cleared a significant hurdle. The Super Heavy booster—the first stage of the Starship system—fired 31 of its 33 Raptor engines in a static test, meaning the engines burned while the rocket remained anchored to the launch pad. It was not a flawless run. Two engines did not ignite as planned: one had been deliberately shut down by the team before ignition, and another cut out on its own during the burn. But for SpaceX, the result represented genuine progress. The company had never before fired more than 14 of the 33 engines simultaneously. Elon Musk, the company's owner, stated on Twitter that 31 engines were sufficient to reach orbital velocity, framing the test as a success despite the two silent motors.
The test itself lasted roughly ten seconds. The Super Heavy sat motionless on the launch pad while the engines roared to life, producing a massive plume of smoke visible in video footage the company released. No Starship spacecraft was attached to the booster during this particular test—the engineers were focused solely on validating the engine cluster. The burn generated the kind of raw, visible proof that the system was moving forward. For a company that had experienced setbacks before, including a dramatic explosion of a Super Heavy prototype during a ground test the previous summer, this moment carried weight.
The path to this test had been deliberate and incremental. In January, SpaceX had conducted what it called a crucial rehearsal: the team mated the Starship spacecraft to the Super Heavy booster, filled both vehicles with fuel, and walked through the full sequence of procedures that would precede an actual launch. That test marked the first time the two components had been fully fueled together. It was a dress rehearsal without the actual performance. Now, with the engine test complete, the company was preparing to stack the Starship back onto the Super Heavy and conduct what SpaceX's CEO Gwynne Shotwell described to CNN as the final ground test before attempting an actual orbital flight.
Shotwell indicated that an orbital launch could happen in March 2023. The timeline had been compressed and extended multiple times over the preceding eighteen months as the company worked through a methodical series of tests, some successful and some not. The stakes were substantial. An orbital test flight of Starship was not merely a company milestone—it was a prerequisite for SpaceX's involvement in NASA's Artemis program. The space agency planned to use Starship as a lunar lander for Artemis III, scheduled for 2025, which would return humans to the Moon for the first time since 1972. A follow-up crewed mission, Artemis IV, was planned for 2027. Without a successful orbital demonstration of Starship's capabilities, those timelines would slip.
The February engine test, then, was one more step in a longer sequence. It proved that the Super Heavy's engine cluster could operate at scale, even if not perfectly. It demonstrated that the team understood the system well enough to deliberately disable one engine and manage the failure of another. And it positioned SpaceX to move into the final phase of ground testing before attempting to send the vehicle into space. The next test would involve the full stack—booster and spacecraft together—and would be the last chance to validate the system on the ground before committing to flight. If that test went well, Musk and Shotwell had indicated, the orbital launch would follow.
Notable Quotes
31 engines were sufficient to reach orbital velocity— Elon Musk, via Twitter
Final ground test completed, with orbital launch potentially occurring in March— Gwynne Shotwell, SpaceX CEO, to CNN
The Hearth Conversation Another angle on the story
Why does firing 31 engines instead of all 33 count as a success? Shouldn't the goal be perfect?
In rocketry, you design for redundancy. You need more engines than the minimum required to reach orbit. If you can reach your target with 31, then losing two is acceptable. The test proved the system can handle that loss and still perform.
What about the two engines that didn't fire—was that really planned?
One was deliberately shut down before ignition by the team. The other failed during the burn. So it's mixed: one was controlled, one was not. Musk framed it positively, but it's worth noting the distinction.
Why does this matter for the Moon missions?
NASA needs Starship to land astronauts on the lunar surface in 2025. You can't use a vehicle you haven't flown in orbit. This test is the proof of concept that has to work before anything else can happen.
How close is SpaceX to actually launching this thing?
They say March. But they've said that before and slipped. The next step is a full ground test with the spacecraft attached. If that works, then they'll attempt the orbital flight. It's still weeks away at minimum.
What happens if the orbital test fails?
The Artemis timeline slips. NASA's plan to return to the Moon in 2025 depends on this vehicle being ready. A failure doesn't end the program, but it delays everything downstream.