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Bill Gerstenmaier, SpaceX\u2019s vice president of build and flight reliability, discussed the results from Starship Flight 10 on Monday.<\/p>\n
Credit:
\n American Astronautical Society<\/p>\n<\/figure>\n
Delving into the details<\/h2>\n
Gerstenmaier went deeper during his discussion of the Starship test flight Monday.<\/p>\n
\u201cWe were essentially doing a test to see if we could get by with non-ceramic tiles, so we put three metal tiles on the side of the ship to see if they would provide adequate heat control, because they would be simpler to manufacture and more durable than the ceramic tiles. It turns out they\u2019re not,\u201d Gerstenmaier said.<\/p>\n
\u201cThe metal tiles\u2026 didn\u2019t work so well,\u201d he said. \u201cThey oxidized extremely nice in the high oxygen environment. So, that nice orange color, kind of like a [space] shuttle external tank color, maybe paying homage to the shuttle program, was created by those three little metal tiles up on top.\u201d<\/p>\n
Gerstenmaier has a talent for explaining complex technical concepts in a digestible manner. He began his career as an aerospace engineer working on the space shuttle program at NASA in 1977. He rose through the ranks at NASA to become head of all of the agency\u2019s human spaceflight programs, then joined SpaceX in 2020.<\/p>\n
The experiment with metallic tiles is emblematic of the way SpaceX is developing Starship. The company\u2019s engineers move quickly to make changes and integrate new designs into each test flight. Metallic heat shield tiles aren\u2019t a new technology. NASA tested them in labs in the 1970s but never flew them.<\/p>\n
\u201cI think we learned a lot by taking them to flight, and we still had enough protection underneath that they didn\u2019t cause a problem,\u201d Gerstenmaier said. \u201cIn most of the tiles, there are fairly large gaps, and that\u2019s where we\u2019re seeing the heat get through and get underneath.\u201d<\/p>\n
A mastery of Starship\u2019s heat shield is vital for the future of the program. The heat shield must be durable for Starship to be rapidly reusable. Musk eyes reflying Starships within 24 hours.<\/p>\n
,<\/p>\n
NASA\u2019s reusable space shuttles used approximately 24,000 delicate ceramic tiles to protect them from the hottest temperatures of reentry, but the materials were delicate and damage-prone, requiring refurbishment and touchups by hand between missions. SpaceX\u2019s Dragon crew capsule has a reusable structure that underlies the heat shield, but the heat shield material itself is only used once.<\/p>\n
For Starship, SpaceX needs a heat shield that will stand up to the rigors of spaceflight\u2014intense vibrations during launch, extreme thermal cycles in space, the scorching heat of reentry, and the crush of the launch pad\u2019s catch arms at the end of each mission. Musk has called the ship\u2019s reusable heat shield the \u201csingle biggest\u201d engineering challenge for the Starship program.<\/p>\n A (stunning) view of SpaceX\u2019s Starship rocket shortly before splashing into the Indian Ocean on August 26.<\/p>\n Credit: Continuing his presentation, Gerstenmaier pointed to a patch of white near the top of Starship\u2019s heat shield. This, he said, was caused by heat seeping between gaps in the tiles and eroding the underlying material, a thermal barrier derived from the heat shield on SpaceX\u2019s Dragon spacecraft. Technicians also intentionally removed some tiles near Starship\u2019s nose to test the vehicle\u2019s response.<\/p>\n \u201cIt\u2019s essentially a white material that sits on Dragon and it ablates away, and when it ablates, it creates this white residue,\u201d Gerstenmaier said. \u201cSo, what that\u2019s showing us is that we\u2019re having heat essentially get into that region between the tiles, go underneath the tiles, and this ablative structure is then ablating underneath. So, we learned that we need to seal the tiles.\u201d<\/p>\n The primary structure for Starship is made of a special alloy of stainless steel. Most other spacecraft designed for reentry, like the space shuttle and Dragon, are made of aluminum. The steel\u2019s higher melting point makes Starship more forgiving of heat shield damage than the shuttle.<\/p>\n ,<\/p>\n Engineers observed several more white blotches lower on Starship, where heat also leaked between tiles and burned the material underneath.<\/p>\n Not great, but SpaceX officials think they have a solution. Near the top of the ship, amid the patch of white, engineers noticed a few darker areas. These are places where SpaceX\u2019s ground team installed a new experimental material around and under the tiles.<\/p>\n \u201cWe call it crunch wrap,\u201d Gerstenmaier said. \u201cIt\u2019s like a wrapping paper that goes around each tile, and then\u2026 these tiles are mechanically held in place. They\u2019re snapped in by a robot. When we push the tile in, this little wrapping paper essentially sits around the sides of each one of the tiles, and then we cut it off on the surface.\u201d<\/p>\n Using this \u201ccrunch wrap\u201d material could seal the spaces between the tiles without using gap fillers. The gap fillers on the space shuttle added complexity to the heat shield, and they sometimes dislodged in flight.<\/p>\n \u201cThis is kind of what we\u2019re going to fly on this next flight, on Flight 11,\u201d Gerstenmaier said. \u201cWhen we fly here, we\u2019re going to put, essentially, crunch wrap everywhere, and see if we can get better sealing and better tile performance moving forward. These are areas where we\u2019re inventing things. We\u2019re doing test experiments. We\u2019re doing test envelope expansion. We\u2019re doing aerodynamic things. All these things are critical.\u201d<\/p>\n A top-down view of the Super Heavy booster for SpaceX\u2019s next Starship test flight during a static fire test on Sunday. This booster was previously flown in March and recovered with catch arms at the launch pad\u2019s tower.<\/p>\n Credit: For Flight 11, Starship will fly on a suborbital trajectory similar to the flight profile the ship has flown on all of its missions to date. The next flight could happen in October and will prepare SpaceX for the debut of an upgraded Starship\/Super Heavy rocket next year. SpaceX test-fired the Super Heavy booster for the next launch Sunday in Texas.<\/p>\n ,<\/p>\n \u201cI think this next flight, we won\u2019t push quite so many different techniques in,\u201d he said. \u201cWe\u2019re going to try to go more towards the configuration we want to go fly next year.\u201d<\/p>\n \u201cNext year, we step up to another version of both ship and booster, called V3 (Version 3),\u201d Gerstenmaier said in response to a question from Ars. \u201cIt also has a new Raptor engine underneath, with more performance than the previous ones. So we\u2019ll fly V3 (suborbital) first, and then if that\u2019s successful, then we\u2019ll probably go orbital after that with the next V3.\u201d<\/p>\n That would mean an orbital flight no sooner than Flight 13. This matches a recent comment by Musk, who said SpaceX will likely attempt to catch and recover Starship back at Starbase somewhere around Flight 13 to 15, depending on the outcomes of the next couple of test flights. It also agrees with predictions from my colleague Eric Berger in a recent story on Starship.<\/p>\n To attempt a catch, Starship must accelerate to orbital velocity to fly all the way around the world and come back to Texas.<\/p>\n All of Starship\u2019s test flights so far have been suborbital, meaning they come back to Earth before circumnavigating the planet. SpaceX wants to make sure it can control where and when the ship comes back to Earth before orbiting the vehicle. An uncontrolled reentry of a vehicle as large as Starship would result in large chunks of debris falling to the ground.<\/p>\n Orbital missions will unlock the next phase of Starship\u2019s development. Recovering Starship in one piece will allow engineers to get a better handle on the performance of the ship\u2019s heat shield, among other things. Going to orbit with Starship will allow SpaceX to begin launching more powerful next-generation Starlink broadband satellites for the company\u2019s consumer Internet service. Most importantly for future flights to the Moon and Mars, orbital flight will pave the way for SpaceX to bring two ships together in space for the first demonstration of large-scale orbital refueling.<\/p>\n ,<\/p>\n \u201cWe\u2019re going to try to do that next year,\u201d Gerstenmaier said. \u201cIn 2026, that\u2019ll be the focus, to get large-scale propellant transfer. If we\u2019re going to leave Earth orbit, we\u2019re going to need propellant transfer.\u201d<\/p>\n A view of a portion of Starship\u2019s heat shield, including three experimental metallic tiles. Each tile is about the size of a dinner plate.<\/p>\n Credit: Gerstenmaier also briefly mentioned the results of experiments with Starship\u2019s Super Heavy booster on the most recent test flight.<\/p>\n On this flight, the booster splashed down in the Gulf of Mexico just off the Texas coastline after propelling Starship toward space. SpaceX used the flight to put the booster through higher stresses as it came back to Earth, guiding the rocket to a water landing in the Gulf instead of returning it to the launch pad for a catch by the tower\u2019s mechanical arms.<\/p>\n \u201cWhat we were doing there is we\u2019re looking at the angle of attack and looking at how well the booster could fly itself to understand how much ability we had to get it back to the tower in the future,\u201d Gerstenmaier said.<\/p>\n SpaceX engineers noticed the booster\u2019s performance on descent in flight doesn\u2019t match predictions from computer models or wind tunnel tests. In ground experiments, the booster encounters unstable buffeting as it slows below the speed of sound.<\/p>\n Based on those results, \u201c[we] should not be able to do what we do with our maneuver coming back with a booster, but we\u2019ve been able to essentially show through flight that we have more stability than either CFD (Computational Fluid Dynamics) or the wind tunnels show that we have,\u201d Gerstenmaier said.<\/p>\n \u201cSo, the big question to the research community is, why are we seeing these differences?\u201d he asked. \u201cWe had an inkling that it would be there, but we weren\u2019t 100 percent sure, and we were able to do that extremely well.\u201d<\/p>\n Gerstenmaier suggested that\u2019s a question best posed to universities and government labs. Companies like SpaceX innovate fast, but once they find a workable solution, they move on to something else.<\/p>\n \u201cI get what I call a minimum viable solution,\u201d Gerstenmaier said. \u201cI don\u2019t really understand why it works, but somehow it works, so we\u2019re going to use it, we\u2019re going to monetize it, we\u2019re going to make it work. You have the chance to help me understand why it works\u2026 And you may find out, hey, there\u2019s another approach that actually lets it work even better.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":" It has been two weeks since SpaceX\u2019s last Starship test flight, and engineers have diagnosed issues with its heat shield, identified improvements, and developed a preliminary plan for the next time the ship heads into space. Bill Gerstenmaier, a SpaceX executive in charge of build and flight reliability, presented the findings Monday at the American […]<\/p>\n","protected":false},"author":1,"featured_media":43788,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-43785","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/43785"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=43785"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/43785\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/43788"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=43785"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=43785"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=43785"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/cdn.arstechnica.net\/wp-content\/uploads\/2025\/08\/starship.jpg\")
<\/p>\n
\n SpaceX<\/p>\n<\/figure>\nPreviewing Flight 11<\/h2>\n
![\"\"](\"https:\/\/cdn.arstechnica.net\/wp-content\/uploads\/2025\/09\/booster15-2-static.jpg\")
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\n SpaceX<\/p>\n<\/figure>\nGoing to orbit<\/h2>\n
![\"\"](\"https:\/\/cdn.arstechnica.net\/wp-content\/uploads\/2025\/09\/metallictiles.jpg\")
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\n SpaceX<\/p>\n<\/figure>\n