March 29, 2023

SpaceX is making progress on its next rocket

SpaceX is making progress on its next rocket
SpaceX is making progress on its next rocketSpaceX is making progress on its next rocket

IT WAS, the wags of Twitter noted, the quickest relaunch of a SpaceX rocket yet. SN10, the latest prototype of the next-generation rocket, Starship, with which the company’s boss, Elon Musk, hopes to send people to Mars, took off from the company’s facility in Boca Chica on the Texas coast at 5.15pm local time on March 3rd. Six minutes and 20 seconds later, returning from an altitude of around 10km, it set itself back onto its landing pad, the first of the three prototypes to have attempted this test flight to achieve touchdown without blowing up.

Or, at least, without doing so promptly. Eight minutes after landing, an explosion at its base threw the rocket into the sky again—this time blown into fiery pieces. But the spectacular coda should not diminish the fact that although the Starship programme may not achieve its goals quite as rapidly as Mr Musk would like, it is making real progress towards creating a fully reusable launch system more powerful than the Saturn Vs used in the Apollo missions.

The company’s Falcon 9 rockets, which have made it the world’s leading satellite-launch company, distinguish themselves from the competition in part by having reusable first stages. Having pushed the second stage out of the atmosphere and to a fair fraction of orbital speed, these first stages—hollow metal pillars the height of a 14-storey building—return to Earth, landing either close to their launch pads or on barges in the ocean. Starship is to be the reusable second stage of a much bigger system. With six Raptor engines, a new design providing more than twice as much thrust as the Merlins used on the Falcon 9, it will be launched into space by a reusable first stage, the “Super Heavy” booster, with 28 of the same engines.

SN10, like its predecessors SN9 and SN8, was equipped with only three Raptors, and got nowhere close to orbit. But it got high enough to test one of the technologies which Starship will need and Falcon lacks. The Falcon first stage relies on its engines to slow it down as it returns, vertically, to Earth; the Super Heavy will, in time, do much the same. But Starship, which will return at higher speeds, will need to use the atmosphere as a brake. SN10 tried this out by twisting around after it had finished its vertical ascent so as to fall back towards the Earth in a belly flop, with the fins at its base and the canards mounted just behind its nose cone keeping it level and pointed the right way. Less than two kilometres from the surface it relit its engines, flipped itself vertical again, turned two of the engines off and used the remaining engine to set itself down. The landing was not quite as soft as anticipated, leaving the rocket with a distinct tilt, and flame was visible at its base after the last engine had turned off. Damage sustained in landing may well have accounted for the subsequent explosion.

One of the unusual aspects of the Starship’s development is the rate at which it gets through prototypes. SN10 was already assembled and sitting on the pad when SN9 met its fiery end on February 2nd. SN11 is expected to roll out of the building in which it is being assembled soon. Mr Musk says that SN15, already under construction, will include significant upgrades. That may mean a capacity for supersonic flight and for climbing beyond the atmosphere.

This is all happening very quickly, by the standards of aerospace development schedules. But it will still take time. Mr Musk had at one point talked of getting Starship to orbit last year. When Maezawa Yusaku, a Japanese billionaire who has a contract with SpaceX for a mission that would take him and a crew of eight around the Moon on a Starship, says he plans to make the trip just two years from now he seems hopelessly optimistic. But SpaceX is not short of money; a recent round of financing brought $850m in new investment, valuing the company at $74bn. Though some of that will go into expanding the company’s vast constellation of Starlink satellites, designed to provide broadband connectivity worldwide, some will doubtless flow to Boca Chica, allowing further prototypes to pass new milestones—and doubtless providing a few more entertaining explosions along the way.