One of the most hotly anticipated events in commercial space this year is the maiden orbital flight of SpaceX’s Starship, a rocket designed to one day fly humans to Mars. A nearly 400-foot-tall prototype of Starship has been seen on and off a launch pad at SpaceX’s “Starbase” test site in Boca Chica, Texas, since February last year, and a liftoff could finally happen as soon as this month, SpaceX recently said.
What is Starship and why is it a big deal?
Starship is a two-stage rocket consisting of a booster and an upper stage capsule capable of carrying passengers and cargo. The structure is similar to a regular rocket but significantly larger. When fully stacked, the Starship stands 394 feet tall, equivalent to a 40-story building.
If successfully launched, Starship will be the tallest rocket ever flown, although its current version has less thrusting power than NASA’s Space Launch System (SLS) rocket (322 feet tall), which blasted off toward the Moon in November.
The prototype standing in Boca Chica now, named SN20 (“SN” stands for “serial number”), is the product of four years of development and more than a dozen generations of smaller prototypes with various configurations.
A brief history of the making of Starship
SpaceX first began developing Starship in early 2019 and ran early tests with a 65-foot-tall prototype called “Starhopper.” On its first attempt, Starhopped rose just one foot above the ground, according to SpaceX CEO Elon Musk. The lift was so subtle it was hardly visible in the video footage of the test.
By August that year, Starhopper, powered by one rocket engine, was able to fly to 500 feet in the sky, prompting SpaceX to build larger prototypes. It would take the company another year to achieve the same altitude with a prototype three times taller, called SN5. And in late 2020, SpaceX rolled out a SN8 prototype, aiming for a higher altitude of about six miles.
Over six months between December 2020 and May 2021, SpaceX test launched five Starship prototypes to the six-mile altitude. Four of them ended in explosions at various stages of the flight. With large parts of the world locked down at home for Covid, each Starship test flight—live streamed by space YouTubers and news organizations—attracted millions of viewers on the internet.
Then, Starship flights came to an abrupt halt following the successful landing of SN15. Despite SpaceX’s frequent teasing of its next flight date, it has been nearly two years without any meaningful update.
The next Starship test will aim for Earth’s orbit, which starts at about 100 miles (167 kilometers) above sea level. It will likely take many more prototypes before Starship actually attempts an interplanetary flight, but an orbital test will tell us whether the current version is ready for less ambitious space missions, such as flying astronauts to the International Space Station.
Every Starship prototype built and tested to date:
April 3, 2019: A Starhopper prototype climbed 1 foot in a tethered test hop.
April 5, 2019: A Starhopper rose 3 feet in a tethered hop, using the full length of the tether.
July 25, 2019: A Starhopper jumped to 65 feet (20 meters) in the sky in an untethered test.
Aug. 27, 2019: A Starhopper flew even higher, reaching 500 feet (150 meters) in the sky, slewed sideways and slowly descended to a nearby landing pad.
Nov. 20, 2019: A larger prototype called Mk1 was built. But it blew its top off during a cryogenic proof test, also known as a pressure stress test, rendering it unusable for a test flight.
May 29, 2020: After two more prototypes, SN1 and SN3, exploded during ground tests, SpaceX finally had success with SN4 and used it for five static firing tests until it exploded during the last one.
Aug. 5, 2020: The next Starship, SN5, successfully performed a 500-foot (150-meter) flight and landed on a nearby pad.
Sept. 3, 2020: SN6 performed another 500 feet test flight.
Dec. 9, 2020: SpaceX skipped SN7 and rolled out SN8, the first Starship prototype with fins and a nose cone because it was designed for reaching a higher altitude of 6 miles (10 km). During a test flight, this prototype successfully reached 7.8 miles (12.5 km) before it descended too fast and exploded upon landing.
Feb 2, 2021: In a second high-altitude attempt, SN9 flew to 6 miles but crashed upon a hard landing because one of its engines did not properly ignite.
March 3, 2021: SN10 had an almost successful 6-mile test but crushed its legs upon landing, causing the rocket to lean to one side and explode minutes after landing.
March 30, 2021: SN11 successfully soared to 6 miles again but exploded mid-air during descent.
(SpaceX skipped SN12, SN13 and SN14.)
May 5, 2021: SN15 finally nailed the high-altitude test and landed in one piece.