- Elon Musk posted videos of SpaceX test-firing its new Raptor rocket engine for the first time, later sharing a photo of a second test.
- The engine is a crucial part of the Starship launch system, which SpaceX hopes will rocket humans to the moon, Mars, and beyond.
- A space-industry analyst said the viability of the Starship program relies on continued and successful tests of the engine, since Raptors will power the spacecraft and are designed to be reusable.
- Starship test vehicles are being built in Texas to show that the system could safely take cargo and people into space in the early 2020s.
- SpaceX plans to replace its other rocket systems with Raptor-equipped Starships, so the company's future may also hinge on the engine's performance.
Elon Musk on Sunday debuted a huge new rocket engine that he said could deliver "insane power" - the kind of oomph that his aerospace company, SpaceX, needs to launch people to the moon, Mars, and beyond.
Musk shared two videos of a truck-size engine called Raptor spewing out flames and making earsplitting noise at SpaceX's rocket test facility in McGregor, Texas. The company performed the static-fire test, as it's called, in support of a reusable launch system it's developing called Starship-Super Heavy.
SpaceX is designing Starship to be a roughly 18-story-tall spaceship made of stainless steel that can carry about 150 tons of cargo and 100 people to the surface of Mars. Starship will ride to orbit around Earth atop Super Heavy, a colossal rocket booster that may stand 22 stories tall.
"First firing of Starship Raptor flight engine! So proud of great work by @SpaceX team!!" Musk said in a tweet on Sunday that included the photo above. The test was performed at 65% thrust, according to Ars Technica in its "Rocket Report" newsletter.
SpaceX test-fired a smaller and more experimental version of Raptor in 2016, but the tests are of a full-scale flight version.
On Wednesday, SpaceX followed up with a second test-firing of the new Raptor at greater thrust - this time achieving a "power level needed for Starship & Super Heavy," Musk tweeted while sharing the photo below on Thursday. He noted this second test was done with "warm propellant" and that, when fed cryogenically-cooled fuel and oxidizer, it could exceed its required performance by 10-20%.
Marco Cáceres, a senior space analyst at the Teal Group, which studies the aerospace and defense industry, said the first successful test is a big deal.
"If this had been a failure, that would mean going back to drawing board, a delay of six months, and a cost of billions in terms of the fast development cycle they're on," Cáceres told Business Insider.
But SpaceX is not yet through its Raptor engine test program, which may prove pivotal to the future of the company.
A lot more than Starship will ride on the success of Raptor
Until late last year, the Starship-Super Heavy system was called Big Falcon Rocket, or BFR. The rebranding came in November, when Musk said the design was being radically overhauled. His plan now is to build the system out of stainless-steel alloys instead of lightweight carbon-fiber composites.
To test the basics of the system, SpaceX has been constructing an experimental version of the Starship vehicle at its launch site in southern Texas. This "test hopper" won't reach orbit; instead, it will go no higher than 16,400 feet into the air, then land back on the ground.
Those tests may begin as soon as March, following repairs to the rocket ship, which fell over last month. A vehicle able to reach orbit may be built this summer, Musk has said.
Seeing the test hopper fly would be exciting, but analysts will be more closely tracking the progress of the Raptor engines: Each Starship may use seven, while Super Heavy could have up to 31 Raptors.
"The Starship-Super Heavy program is basically relying on this engine," Cáceres said. "If the engine fails, the program will fail."
The health of SpaceX itself may also depend on the reliability of those Raptor engines, of which there will be multiple versions developed.
If Starship can be fully reusable, as is planned, that should make the system far cheaper to launch than anything in existence - including SpaceX's own Falcon 9 and Falcon Heavy rockets. Musk has repeatedly said Starship will eventually replace all his company's other launchers.
"What they're trying to do sounds crazy to me and to many people in the industry. They want to reuse these engines hundreds of times, which has never been done," Cáceres said of the Raptor design. "These engines have to work like your car engine: You turn it on, it goes, and you never expect it to blow up."
Cáceres said he expected to see about three to five Raptor static-fire tests before the engines fly (not including the first two tests).
"Then you do one or two test launches, then you launch a payload," he said. "On Musk's timeline, you don't have a decade to do that, like NASA would. This is moving at a very, very fast pace."
Green-hued flames from the first Raptor engine firing revealed that copper was being vaporized, Musk confirmed on Thursday. Specifically, hot exhaust burned copper lining inside the engine, according to a story by Ars Technica, which may require additional insulation (no source was cited for this information).
'Extraordinarily difficult challenges ahead'
SpaceX is contending with tight deadlines for Starship and another major project.
Musk hopes to get the first experimental Starship into orbit perhaps in 2020 or 2021. He has set an "aspirational" goal of launching uncrewed cargo missions toward Mars by 2022. Depending on the Raptor engines' ability to accelerate the Starship (and thereby shorten travel time), those missions would land on the red planet later that year or in early 2023. He then wants to use the system to launch the Japanese billionaire Yusaku Maezawa around the moon with a crew of artists in 2023.
If both the Martian cargo missions and the crewed moon mission are successful, SpaceX may launch the first crewed mission to Mars in 2024. Raptor engines burn methane and oxygen - chemicals Musk thinks a crew could generate on Mars to power a return voyage to Earth.
Starship - and by extension Raptor - may also prove essential to SpaceX's efforts to launch Starlink, a network of satellites that Musk wants to use to cover Earth in ultra-high-speed broadband internet.
SpaceX plans to make Starship capable of launching satellites; each Starship launch could, in theory, deploy hundreds of Starlink satellites at once. (SpaceX already has experience in helping deploy dozens of satellites at once.)
That would enable the company to more quickly establish Starlink as a functional, moneymaking service. The Wall Street Journal reported in 2017 that Starlink could bring in $30 billion in revenue for SpaceX by 2025 - dramatically more than it makes on its rocket-launching business.
But Cáceres said that pursuing Starship and Starlink almost entirely with private funding had forced SpaceX to move quickly and exposed the company to the risk of cutting its staff. In January, citing the "extraordinarily difficult challenges ahead" in pulling off its goals, SpaceX laid off 10% of its workforce.
"They're under pressure financially in that all of these programs are going on at the same time," Cáceres said. "Musk was never under the impression that it was going to be cheap. He said [Starship] was going to cost $2 billion to $10 billion to develop, which means they really don't know how much it's going to cost to develop. But clearly it's in the billions. With that cost, you realize you can't afford to have many delays."
Taxpayer dollars may yet help fund Starship. Cáceres said NASA was most likely waiting to see whether the system is viable, since it could cost-effectively replace the agency's nonreusable and increasingly expensive Space Launch System launcher.
If NASA "can rely on private industry to fund and develop bigger, more powerful rockets at a company's own expense," he said, "there's no sense in continuing with SLS."
NASA's associate administrator also once expressed this idea to Business Insider, but the agency later walked back his comments.
The Raptor engine's success is key to SpaceX's grand ambitions - to the viability of Starship, the full and rapid rollout of Starlink, and journeys to Mars. In this sense, the company's fate seems tied to that of its engine.
"The biggest danger is that SpaceX moves too quickly," Cáceres said of Raptor and Starship. "If something of this size blows up and there are people on board, it kills the program."
This story has been updated with new information. It was originally published on February 6, 2019.