Most recent engine test on eighth Starship prototype had issues
Capitalism in space: The most recent engine test on November 12th of SpaceX’s eighth Starship prototype had a problem that will delay its planned 50,000 foot test hop.
The Starship SN8 vehicle performed its third brief “static fire” — a test in which engines are ignited while a rocket remains tethered to the ground — at SpaceX’s South Texas facility on Thursday, near the village of Boca Chica.
Shortly after the test, which several outside organizations webcast live, material could be seen apparently dripping from SN8’s base. This looked odd, and SpaceX founder and CEO Elon Musk soon confirmed that something off-nominal had happened. “We lost vehicle pneumatics. Reason unknown at present. Liquid oxygen header tank pressure is rising. Hopefully triggers burst disk to relieve pressure, otherwise it’s going to pop the cork,” Musk said via Twitter on Thursday night. (Burst disks are single-use devices that, like valves, seal off different sections or systems of a vehicle. They relieve pressure when they open, as Musk noted.)
The cause of the problem is unknown at the moment, Musk said in another Thursday tweet: “Maybe melted an engine preburner or fuel hot gas manifold. Whatever it is caused pneumatics loss. We need to design out this problem.”
The decision to pin down the cause and redesign things so it won’t happen again makes perfect sense, but it also means that the hop will not occur in the next week or so, as hoped for by the company. Expect a delay. Based on the pace that SpaceX works, that delay however should not be longer than one or two months.
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The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
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Capitalism in space: The most recent engine test on November 12th of SpaceX’s eighth Starship prototype had a problem that will delay its planned 50,000 foot test hop.
The Starship SN8 vehicle performed its third brief “static fire” — a test in which engines are ignited while a rocket remains tethered to the ground — at SpaceX’s South Texas facility on Thursday, near the village of Boca Chica.
Shortly after the test, which several outside organizations webcast live, material could be seen apparently dripping from SN8’s base. This looked odd, and SpaceX founder and CEO Elon Musk soon confirmed that something off-nominal had happened. “We lost vehicle pneumatics. Reason unknown at present. Liquid oxygen header tank pressure is rising. Hopefully triggers burst disk to relieve pressure, otherwise it’s going to pop the cork,” Musk said via Twitter on Thursday night. (Burst disks are single-use devices that, like valves, seal off different sections or systems of a vehicle. They relieve pressure when they open, as Musk noted.)
The cause of the problem is unknown at the moment, Musk said in another Thursday tweet: “Maybe melted an engine preburner or fuel hot gas manifold. Whatever it is caused pneumatics loss. We need to design out this problem.”
The decision to pin down the cause and redesign things so it won’t happen again makes perfect sense, but it also means that the hop will not occur in the next week or so, as hoped for by the company. Expect a delay. Based on the pace that SpaceX works, that delay however should not be longer than one or two months.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Unless this turns out to be a minor problem, that probably kills any hopes for a 15 km alt. test flight this year.
Problems are bound to crop up during development of something as novel as the Starship Mars transportation system. So many people though have unrealistic high expectations of the rate of success. I think it will take SpaceX twice as long to get Starship working compared to their aspirational timeline. Meaning the first manned Starship to Mars landing is more likely to launch during 2031 than 2026.
Even so, 2021 should be a pretty exciting year to watch Starship. Probably a lot of test launches and a lot of crashes too!
@Brad, I can’t imagine SpaceX fiddling with a non-working launcher for a decade, when they’ve come so far already. With their track record and efficient learning curve I’d be surprised if Starship doesn’t (because of technical problems) put its first hardware in orbit next year or 2022.
But they do require quite some other kinds of hardware and preparations before launching people to Mars on a 30 months or so long trip. I don’t believe that will be done this decade. A test or preparatory launch to Mars can only be made every 26 months, and they need more than one.
A replacement Raptor is being installed today, so I expect to see static fires this week. Assuming the static fires pass, I expect the 15km hop sooner rather than later.
Keep in mind the speed of their prototyping cycle. I would almost call SN8 “expendable.” It’s an engineering test article, and there’s a limit to how much they can learn from it on the ground. I also would not expect the first 15km hop to be successful; there are too many unknowns that can only be understood from flight data. SN9 is nearly complete, and could probably be on the launch pad (they have two, just in case SN8 destroys one), and ready for SN9 static fires in two or three weeks.
@Diane Wilson
Installed today!? Can they just change it on the launch pad as if it were a flat tire on a car? I suppose that if it weren’t a prototype with no more than three engines, they could’ve launched anyway with only one broken engine.
“Engine rich exhaust” meaning that parts of the engine hardware flew out together with the burning fuel. No problem!
@LocalFluff,
So far, through all the Starship prototypes, they’ve mounted all of the Raptors while on the launch pad. So that’s routine. “Rocket surgery,” if you will, as opposed to rocket science. This is the second Raptor swap-out on SN8.
They really do need all three engines working for the 15km hop. In addition to launch, they’re also planning to test parts of the entry and landing profile. Flipping from vertical to almost horizontal at the top of that 15km will require two working Raptors.
No real details on the problem, yet, but discussion over on NasaSpaceFlight has focused on issues with heat and vibration in the confined area under the Starship as a possible root cause. Apparently this is a normal part of rocket development for multiple-engine rockets.