ARSTECHNICA.COM
The key moment came 38 minutes after Starship roared off the launch pad
Turning point The key moment came 38 minutes after Starship roared off the launch pad SpaceX wasn't able to catch the Super Heavy booster, but Starship is on the cusp of orbital flight. Stephen Clark Nov 19, 2024 11:57 pm | 36 The sixth flight of Starship lifts off from SpaceX's Starbase launch site at Boca Chica Beach, Texas. Credit: SpaceX. The sixth flight of Starship lifts off from SpaceX's Starbase launch site at Boca Chica Beach, Texas. Credit: SpaceX. Story textSizeSmallStandardLargeWidth *StandardWideLinksStandardOrange* Subscribers only Learn moreSpaceX launched its sixth Starship rocket Tuesday, proving for the first time that the stainless steel ship can maneuver in space and paving the way for an even larger, upgraded vehicle slated to debut on the next test flight.The only hiccup was an abortive attempt to catch the rocket's Super Heavy booster back at the launch site in South Texas, something SpaceX achieved on the previous flight October 13. The Starship upper stage flew halfway around the world, reaching an altitude of 118 miles (190 kilometers) before plunging through the atmosphere for a pinpoint slow-speed splashdown in the Indian Ocean.The sixth flight of the world's largest launcherstanding 398 feet (121.3 meters) tallbegan with a lumbering liftoff from SpaceX's Starbase facility near the US-Mexico border at 4 pm CST (22:00 UTC) Tuesday. The rocket headed east over the Gulf of Mexico propelled by 33 Raptor engines clustered on the bottom of its Super Heavy first stage.A few miles away, President-elect Donald Trump joined SpaceX founder Elon Musk to witness the launch. The SpaceX boss became one of Trump's closest allies in this year's presidential election, giving the world's richest man extraordinary influence in US space policy. Sen. Ted Cruz (R-Texas) was there, too, among other lawmakers. Gen. Chance Saltzman, the top commander in the US Space Force, stood nearby, chatting with Trump and other VIPs. Elon Musk, SpaceX's CEO, President-elect Donald Trump, and Gen. Chance Saltzman of the US Space Force watch the sixth launch of Starship Tuesday. Credit: Brandon Bell/Getty Images From their viewing platform, they watched Starship climb into a clear autumn sky. At full power, the 33 Raptors chugged more than 40,000 pounds of super-cold liquid methane and liquid oxygen per second. The engines generated 16.7 million pounds of thrust, 60 percent more than the Soviet N1, the second-largest rocket in history.Eight minutes later, the rocket's upper stage, itself also known as Starship, was in space, completing the program's fourth straight near-flawless launch. The first two test flights faltered before reaching their planned trajectory.A brief but crucial demoAs exciting as it was, we've seen all that before. One of the most important new things engineers desired to test on this flight occurred about 38 minutes after liftoff.That's when Starship reignited one of its six Raptor engines for a brief burn to make a slight adjustment to its flight path. The burn only lasted a few seconds, and the impulse was smalljust a 48 mph (77 km/hour) change in velocity, or delta-Vbut it demonstrated the ship can safely deorbit itself on future missions.With this achievement, Starship will likely soon be cleared to travel into orbit around Earth and deploy Starlink internet satellites or conduct in-space refueling experiments, two of the near-term objectives on SpaceX's Starship development roadmap.Launching Starlinks aboard Starship will allow SpaceX to expand the capacity and reach of commercial consumer broadband network, which, in turn, provides revenue for Musk to reinvest into Starship. Orbital refueling is an enabler for Starship voyages beyond low-Earth orbit, fulfilling SpaceX's multibillion-dollar contract with NASA to provide a human-rated Moon lander for the agency's Artemis program. Likewise, transferring cryogenic propellants in orbit is a prerequisite for sending Starships to Mars, making real Musk's dream of creating a settlement on the red planet. Artist's illustration of Starship on the surface of the Moon. Credit: SpaceX Until now, SpaceX has intentionally launched Starships to speeds just shy of the blistering velocities needed to maintain orbit. Engineers wanted to test the Raptor's ability to reignite in space on the third Starship test flight in March, but the ship lost control of its orientation, and SpaceX canceled the engine firing.Before going for a full orbital flight, officials needed to confirm Starship could steer itself back into the atmosphere for reentry, ensuring it wouldn't present any risk to the public with an unguided descent over a populated area. After Tuesday, SpaceX can check this off its to-do list."Congrats to SpaceX on Starship's sixth test flight," NASA Administrator Bill Nelson posted on X. "Exciting to see the Raptor engine restart in spacemajor progress towards orbital flight. Starships success is Artemis 'success. Together, we will return humanity to the Moon & set our sights on Mars."While it lacks the pizazz of a fiery launch or landing, the engine relight unlocks a new phase of Starship development. SpaceX has now proven the rocket is capable of reaching space with a fair measure of reliability. Next, engineers will fine-tune how to reliably recover the booster and the ship, and learn how to use them.Acid testSpaceX appears well on the way to doing this. While SpaceX didn't catch the Super Heavy booster with the launch tower's mechanical arms Tuesday, engineers have shown they can do it. The challenge of catching Starship itself back at the launch pad is more daunting. The ship starts its reentry thousands of miles from Starbase, traveling approximately 17,000 mph (27,000 km/hour), and must thread the gap between the tower's catch arms within a matter of inches.The good news here is SpaceX has now twice proven it can bring Starship back to a precision splashdown in the Indian Ocean. In October, the ship settled into the sea in darkness. SpaceX moved the launch time for Tuesday's flight to the late afternoon, setting up for splashdown shortly after sunrise northwest of Australia.The shift in time paid off with some stunning new visuals. Cameras mounted on the outside of Starship beamed dazzling live views back to SpaceX through the Starlink network, showing a now-familiar glow of plasma encasing the spacecraft as it plowed deeper into the atmosphere. But this time, daylight revealed the ship's flaps moving to control its belly-first descent toward the ocean. After passing through a deck of low clouds, Starship reignited its Raptor engines and tilted from horizontal to vertical, making contact with the water tail-first within view of a floating buoy and a nearby aircraft in position to observe the moment. Here's a replay of the splashdown.The ship made it through reentry despite flying with a substandard heat shield. Starship's thermal protection system is made up of thousands of ceramic tiles to protect the ship from temperatures as high as 2,600 Fahrenheit (1,430 Celsius).Kate Tice, a SpaceX engineer hosting the company's live broadcast of the mission, said teams at Starbase removed 2,100 heat shield tiles from Starship ahead of Tuesday's launch. Their removal exposed wider swaths of the ship's stainless steel skin to super-heated plasma, and SpaceX teams were eager to see how well the spacecraft held up during reentry. In the language of flight testing, this approach is called exploring the corners of the envelope, where engineers evaluate how a new airplane or rocket performs in extreme conditions.Dont be surprised if we see some wackadoodle stuff happen here," Tice said. There was nothing of the sort. One of the ship's flaps appeared to suffer some heating damage, but it remained intact and functional, and the harm looked to be less substantial than damage seen on previous flights.Many of the removed tiles came from the sides of Starship where SpaceX plans to place catch fittings on future vehicles. These are the hardware protuberances that will catch on the top side of the launch tower's mechanical arms, similar to fittings used on the Super Heavy booster."The next flight, we want to better understand where we can install catch hardware, not necessarily to actually do the catch but to see how that hardware holds up in those spots," Tice said. "Today's flight will help inform, does the stainless steel hold up like we think it may, based on experiments that we conducted on Flight 5?"Musk wrote on his social media platform X that SpaceX could try to bring Starship back to Starbase for a catch on the eighth test flight, which is likely to occur in the first half of 2025."We will do one more ocean landing of the ship," Musk said. "If that goes well, then SpaceX will attempt to catch the ship with the tower."The heat shield, Musk added, is a focal point of SpaceX's attention. The delicate heat-absorbing tiles used on the belly of the space shuttle proved vexing to NASA technicians. Early in the shuttle's development, NASA had trouble keeping tiles adhered to the shuttle's aluminum skin. Each of the shuttle tiles was custom-machined to fit on a specific location on the orbiter, complicating refurbishment between flights. Starship's tiles are all hexagonal in shape and agnostic to where technicians place them on the vehicle."The biggest technology challenge remaining for Starship is a fully & immediately reusable heat shield," Musk wrote on X. "Being able to land the ship, refill propellant & launch right away with no refurbishment or laborious inspection. That is the acid test." This photo of the Starship vehicle for Flight 6, numbered Ship 31, shows exposed portions of the vehicle's stainless steel skin after tile removal. Credit: SpaceX There were no details available Tuesday night on what caused the Super Heavy booster to divert from its planned catch on the launch tower. After detaching from the Starship upper stage less than three minutes into the flight, the booster reversed course to begin the journey back to Starbase.Then, SpaceX's flight director announced the rocket would fly itself into the Gulf, rather than back to the launch site: "Booster offshore divert."The booster finished off its descent with a seemingly perfect landing burn using a subset of its Raptor engines. As expected after the water landing, the boosteritself 233 feet (71 meters) talltoppled and broke apart in a dramatic fireball visible to onshore spectators.In an update posted to its website after the launch, SpaceX said automated health checks of hardware on the launch and catch tower triggered the aborted catch attempt. The company did not say what system failed the health check. As a safety measure, SpaceX must send a manual command for the booster to come back to land in order to prevent a malfunction from endangering people or property.Turning it up to 11There will be plenty more opportunities for more booster catches in the coming months as SpaceX ramps up its launch cadence at Starbase. Gwynne Shotwell, SpaceX's president and chief operating officer, hinted at the scale of the company's ambitions last week."We just passed 400 launches on Falcon, and I would not be surprised if we fly 400 Starship launches in the next four years," she said at the Barron Investment Conference.The next batch of test flights will use an improved version of Starship designated Block 2, or V2. Starship Block 2 comes with larger propellant tanks, redesigned forward flaps, and a better heat shield.The new-generation Starship will hold more than 11 million pounds of fuel and oxidizer, about a million pounds more than the capacity of Starship Block 1. The booster and ship will produce more thrust, and Block 2 will measure 408 feet (124.4 meters) tall, stretching the height of the full stack by a little more than 10 feet.Put together, these modifications should give Starship the ability to heave a payload of up to 220,000 pounds (100 metric tons) into low-Earth orbit, about twice the carrying capacity of the first-generation ship. Further down the line, SpaceX plans to introduce Starship Block 3 to again double the ship's payload capacity.Just as importantly, these changes are designed to make it easier for SpaceX to recover and reuse the Super Heavy booster and Starship upper stage. SpaceX's goal of fielding a fully reusable launcher builds on the partial reuse SpaceX pioneered with its Falcon 9 rocket. This should dramatically bring down launch costs, according to SpaceX's vision.With Tuesday's flight, it's clear Starship works. Now it's time to see what it can do.Updated with additional details, quotes, and images.Stephen ClarkSpace ReporterStephen ClarkSpace Reporter Stephen Clark is a space reporter at Ars Technica, covering private space companies and the worlds space agencies. Stephen writes about the nexus of technology, science, policy, and business on and off the planet. 36 Comments Prev story
0 Commentaires
0 Parts
22 Vue