Moving swiftly and learning through failure, SpaceX says it’s already looking ahead to version 2 of the Starship upper stage.
In a tweet posted on November 24, company CEO Elon Musk shared a photo showing four Starship upper stages standing vertically at SpaceX’s Boca Chica facility in south Texas, and saying the quartet will be “the last of V1.” Version 2 comes next, marking the next phase in the company’s iterative development process. Starship is not yet operational, but it represents SpaceX’s ambitious vision for a fully reusable, cost-efficient launch system capable of interplanetary travel with high payload capacity.
The news of the pending upgrades comes after two tests of the megarocket, the first in April and the second earlier this month. Both tests ended with the destruction of the rocket. However, the second test, conducted on November 18 and lasting approximately eight minutes, demonstrated a smoother launch; the IFT-2 mission featured an improved performance from the booster’s 33 Raptor engines, the debut of a new stage separation technique called hot staging, and some independent flying of the Starship upper stage with all six engines alight.
If you were expecting a radical departure from Version 1, you’re in for a disappointment. The tweaks being made to Starship, while important, are fairly subtle. In a separate tweet, Musk said the upgraded versions will hold more propellant, feature a reduced dry mass (i.e. the rocket’s weight sans payload), and exhibit greater overall reliability. And to be clear, we’re talking about the Starship upper stage, and not the Super Heavy booster.
Musk didn’t divulge any more information about Starship V2, but Payload pointed to a batch of modifications that SpaceX could incorporate over time. Last week, Musk said he’s “very excited” about the next-gen Raptor engine, saying it’ll be tough enough to not require a heat shield (which will lessen the rocket’s weight). Raptor 3 also promises higher Isp (i.e. specific impulse, a measure of how efficiently a rocket engine uses its fuel), more thrust, “and many other improvements,” Musk said. The current Raptor 2 engines produce 230 tons of thrust, whereas the Raptor 3 engines are expected to generate roughly 269 tons of thrust, marking a 17 per cent improvement.
Starship V2 might also debut a configuration featuring nine Raptor engines, an increase from the current six, marking a long-anticipated change by SpaceX. Of the nine engines, three would be optimized for use in the atmosphere and six in the vacuum of space (the current configuration features three of each). Naturally, the added engines would increase payload capacity.
Finally, the company is considering an increase in propellant volume. This would involve modifying the fuel tanks’ shape and possibly extending Starship’s height by 16 to 33 feet (5 to 10 meters), allowing for greater fuel capacity and extended mission range, according to Payload.
It does appear, however, that SpaceX will continue to launch its Version 1 Starships prior to debuting the upgraded version. Space Explored listed the final four as being Ships 28, 29, 30, and 32 (31 was moved to Starbase’s Rocket Garden, a sign that it’ll likely be scrapped). It’s not clear if all four of these will be used in future tests, but Ship 28 is currently being prepared for launch.
As for the third flight test, Musk said the hardware needed for this launch should be available in about three to four weeks. Personally, I wouldn’t bet on a launch happening within that time frame, but given how well things went with the second test (including the successful implementation of a water deluge system), it could conceivably happen in early 2024.