2020-12-09 23:23:24 UTC: Launch went smoothly as did ascent to altitude and leanover to "bellyflop" orientation. Was able to right itself back to vertical but had too much speed at time of reaching earth. Got big boom on impact. SN9 has been waiting patiently in the wings (as well as SN10 through SN15, in different degrees of completion). Which one will be next and how soon will it be? Can't wait to find out! --martyb
2020-12-09 21:25:12 UTC: Tentative T-0 now at 4:40 PM CST / 2240 UTC.
2020-12-09 21:03:13 UTC at T-02:06: "Clock paused. Standing by for new T-0."
2020-12-09 20:44:45 UTC: SpaceX has put up a new live feed for their SN8 (Serial Number 8) Starship test flight. The feed is currently active; launch is expected in the next few minutes. --martyb
Original story follows.
[2020-12-08 07:21:09 UTC: Updated to add link to NASASpaceFlight.com and to add launch window times.--martyb]
[2020-12-08 23:48:15 UTC: Updated - launch aborted.--martyb]
At T-00:01.3 it was announced "Raptor Abort". No launch today.
SpaceX has announced a high-altitude test flight of its Starship. The schedule is dynamic — there is no set time for the launch to begin. Prior launch attempts have variously been successful or catastrophic. This launch attempt promises a similar opportunity for flight or fright.
From the announcement:
As early as Tuesday, December 8, the SpaceX team will make the first attempt of a high-altitude suborbital flight test of Starship serial number 8 (SN8) from our site in Cameron County, Texas. The schedule is dynamic and likely to change, as is the case with all development testing.
This suborbital flight is designed to test a number of objectives, from how the vehicle's three Raptor engines perform to the overall aerodynamic entry capabilities of the vehicle (including its body flaps) to how the vehicle manages propellant transition. SN8 will also attempt to perform a landing flip maneuver, which would be a first for a vehicle of this size.
With a test such as this, success is not measured by completion of specific objectives but rather how much we can learn, which will inform and improve the probability of success in the future as SpaceX rapidly advances development of Starship.
This past year alone, SpaceX has completed two low-altitude flight tests with Starship SN5 and SN6 and accumulated over 16,000 seconds of run time during 330 ground engine starts, including multiple Starship static fires and four flight tests of the reusable methalox full-flow staged combustion Raptor engine. Additionally, with production accelerating and fidelity increasing, SpaceX has built 10 Starship prototypes. SN9 is almost ready to move to the pad, which now has two active stands for rapid development testing.
SN8's flight test is an exciting next step in the development of a fully reusable transportation system capable of carrying both crew and cargo to Earth orbit, the Moon, Mars, and beyond. As we venture into new territory, we continue to appreciate all of the support and encouragement we have received.
There will be a live feed of the flight test available here that will start a few minutes prior to liftoff. Given the uncertainty of the schedule, stay tuned to our social media channels for updates as we move toward our first high-altitude flight test of Starship!
Watch the flight test here.
The rocket is powered by three sea-level Raptor engines. The rocket itself it 9 meters (~29.5 feet) in diameter and 50 meters (164 feet tall). (I've also seen reports of it being 60 meters (~197 feet) tall.)
NasaSpaceFlight has posted a nice background article on the history and development of SN8 as well as information on upcoming models SN9-15.
Scheduled road closures for the launch attempt are 0800-1700 CST (1300-2200 UTC).
Related Stories
[2021-03-03 22:13:57 UTC; UPDATE #2]:
Ars Technica posted an update to their earlier story:
Update 3:45 pm EST: The SN10 Starship prototype very nearly launched on Wednesday afternoon from South Texas, but a last-second out-of-bounds reading aborted the attempt. The abort was caused by a "slightly conservative high thrust limit," SpaceX founder Elon Musk said afterward. Basically, the onboard flight computer received data from one of the engines that it was producing more thrust than anticipated.
The good news? This thrust limit can be adjusted upward in the flight software, and the vehicle is now recycling through propellant loading for another attempt. SN10 may still fly later today, time to be determined.
SpaceX's original (i.e. aborted) launch YouTube link.
Original story moved below the fold.
There is a slight possibility of a retry later today, Wednesday 2021-03-03.
SpaceX ignored last-minute warnings from the FAA before December Starship launch
Minutes before liftoff, Elon Musk's SpaceX ignored at least two warnings from the Federal Aviation Administration that launching its first high-altitude Starship prototype last December would violate the company's launch license, confidential documents and letters obtained by The Verge show. And while SpaceX was under investigation, it told the FAA that the agency's software was a "source of frustration" that has been "shown to be inaccurate at times or overly conservative," according to the documents.
[...] Neither SpaceX nor Musk has publicly commented on the SN8 violation. SpaceX didn't respond to a request for comment. The FAA confirmed the violation after a report by The Verge in January. But a confidential five-page report by SpaceX and letters between Shotwell and Monteith reveal what SpaceX employees knew before liftoff and detail how the company responded to its violation in the aftermath.
[...] SpaceX employees left the FAA meeting for the company's launch control room ahead of SN8's launch. Minutes before liftoff, an FAA safety inspector speaking on an open phone line warned SpaceX's staff in the launch control room that a launch would violate the company's launch license. SpaceX staff ignored the warning because they "assumed that the inspector did not have the latest information," the SpaceX report said.
(Score: 5, Interesting) by martyb on Tuesday December 08 2020, @05:51AM (6 children)
Here is a link to the earlier 150 meter SN6 test hop [youtube.com].
This upcoming test of SN8 is planned for 12,500 meters. SN8 also has active pairs of ailerons at the top and at the bottom. Instead of just up-and-down while remaining vertical, SN8 is intended to emulate a landing from entry.
During this test, SN8 launches nose-up. Flips at altitude to nose downward-ish (think horizontal). Then, as it descends, the nose pulls up from a "belly flop" orientation, back to nose-up vertical, before attempting a landing.
So, imagine a 10-story-tall grain silo or water tower falling horizonally out of the sky, and pulling up for a vertical landing at the last minute (seconds).
I wish SpaceX the very best for this test, but must admit I have some curiosity as to whether the whole test will run smoothly or whether there will be an Earth-
ShatteringShaking Ka-Boom! [youtube.com]Wit is intellect, dancing.
(Score: 2, Informative) by Anonymous Coward on Tuesday December 08 2020, @06:42AM (4 children)
The way I see this going badly is ullage. When you flop around in funny ways, the fuel sloshes away from the pumps. This is a big rocket, at a strange angle, in dense air, without much time to waste.
For example, on the Apollo missions, little solid rockets would always be fired before and while starting up the liquid-fuel engines. This would slosh the fuel into the right spot, where it could be pumped.
(Score: 2) by martyb on Tuesday December 08 2020, @06:53AM (1 child)
Wit is intellect, dancing.
(Score: 2) by takyon on Tuesday December 08 2020, @07:09AM
Yeah, they want the main tanks empty on the way down, using the header tanks in the nose cone:
https://space.stackexchange.com/questions/39259/what-are-spacexs-starships-header-tanks [stackexchange.com]
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(Score: 2) by Immerman on Thursday December 10 2020, @08:03AM (1 child)
That's exactly why they have the header tanks - two relatively tiny, fully-fueled tanks specifically reserved for operating the engines during that bizarre maneuver. Almost as though the engineers recognized the problem and designed a solution to it.
(Score: 2) by takyon on Thursday December 10 2020, @12:47PM
Well, those header tanks now seem to be the source of a problem... not that they won't be able to fix it. It will be interesting to see how long it takes them to launch SN9 and if it needs any changes to the header tanks.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by takyon on Tuesday December 08 2020, @01:01PM
https://www.nasaspaceflight.com/2020/12/from-hops-hopes-starship-sn8-test-program-next-phase/ [nasaspaceflight.com]
Launch window opens at 9 AM Central.
SN9 is practically ready to go next, SN10 almost, and SN11 through SN16 are in various states [twitter.com].
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(Score: 3, Interesting) by takyon on Tuesday December 08 2020, @05:54AM (2 children)
https://www.teslarati.com/spacex-starship-sn8-launch-debut-slips-tuesday/ [teslarati.com]
Launch that hunk of junk, and then SN9 and SN10.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by DannyB on Tuesday December 08 2020, @06:11PM (1 child)
SN8 is likely to get off the pad sooner than SLS. Or Blue Origin New Glenn. Even if SN8 does not get off the pad today. Patience.
To transfer files: right-click on file, pick Copy. Unplug mouse, plug mouse into other computer. Right-click, paste.
(Score: 2, Funny) by Anonymous Coward on Tuesday December 08 2020, @08:25PM
My grandmother's curio cabinet will get off the ground sooner than SLS...
(Score: 5, Funny) by DannyB on Tuesday December 08 2020, @06:08PM
If you love a starship, set it free.
If it comes back to you, it is yours.
If it explodes or crashes, it never was.
To transfer files: right-click on file, pick Copy. Unplug mouse, plug mouse into other computer. Right-click, paste.
(Score: 2) by takyon on Tuesday December 08 2020, @10:38PM
There's still some time left in the launch window, but it might be delayed to tomorrow.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by takyon on Wednesday December 09 2020, @09:38PM (2 children)
The reschedule to 4:40 PM CST was supposedly due to a plane violating the exclusion zone about two minutes before the launch.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Runaway1956 on Wednesday December 09 2020, @09:55PM (1 child)
Sounds pretty stupid. I'm not a pilot, maybe I shouldn't judge, but, that sounds stupid.
(Score: 2) by takyon on Wednesday December 09 2020, @10:23PM
If there's audio of an air traffic controller somewhere chewing out the pilot, I want to hear it.
Seems like it slipped another 4 minutes to about 4:44 PM CST. Past 5 PM and they have to scrub for the day.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Wednesday December 09 2020, @10:40PM
Is that BOTH O2 and Methane?
(Score: 0) by Anonymous Coward on Wednesday December 09 2020, @10:54PM
It exploded jut touching the ground! Now that is the way to end a movie!! Better than NASCAR!
(Score: 3, Interesting) by takyon on Wednesday December 09 2020, @10:55PM (6 children)
That was incredible. Crazy bellyflop maneuver was nearly horizontal, and it reoriented. Then landed too fast and exploded. RIP SN8.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Wednesday December 09 2020, @11:10PM (1 child)
Looked like it touched down on at a slight angle and the jerked vertical and disassembled.
The thrust vectoring on 3 engines is wierd.
They seem to be providing the containment that a bigger bell would provide by turning them inward.
With 4 they could do this and have a centered thrust line with 2 and 4 burning?
And if frogs had wings...
Definitely an awesome accomplishment this early in the testing.
(Score: 2) by takyon on Wednesday December 09 2020, @11:27PM
The vectoring seems fine. It seems that the Raptor engines shut down a little early due to lack of fuel coming from the header tanks.
Final Starship will have 6 engines, but those engines won't fire on the ground on Earth (unless they try to do the suborbital airliner thing) since the booster will handle that portion instead. I think they will do 3 for landings, but could swap a vacuum for sea level if one fails.
Something inside the rocket briefly caught on fire again.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Hartree on Wednesday December 09 2020, @11:10PM (3 children)
Absolutely spot on target landing, but it looked like one of the raptors didn't reignite and it came in too hard. I don't think they expected to stick the landing and that they got this close is excellent.
The glide control seemed to work very well.
(Score: 2) by takyon on Wednesday December 09 2020, @11:15PM
The explanation given so far is low pressure in the header tanks.
https://twitter.com/elonmusk/status/1336809767574982658 [twitter.com]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 3, Informative) by Runaway1956 on Wednesday December 09 2020, @11:50PM (1 child)
The stream has ended now, but dude did a couple of replays, lots of commentary, and some slow motion here - https://www.youtube.com/watch?v=mBj6FYUQT9Y [youtube.com]
Apparently, all three engines were cut near the peak of it's ascent, one after another. Thrusters tipped it, so that it was gliding for awhile. Thruster pushed it near upright again, and two of the 3 engines were relighted. It is believed that all 3 were meant to light off, but only two succeeded. Already falling fast, one of those two engines cut out, so the remaining working engine couldn't stop the hard landing.
(Score: 2) by takyon on Wednesday December 09 2020, @11:58PM
Everything I'm hearing points to the engine cutoffs on ascent being completely intentional, despite looking like failures in the wide angle shots (there was a bit of flame from something inside catching on fire). The engines not relighting/staying lit on landing are being blamed on the header tanks.
SN9 already has changes from SN8, but they might take some time to make adjustments to the header tanks.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by takyon on Thursday December 10 2020, @12:03AM (2 children)
Damaged tent near the landing zone caught on fire nearly an hour after the test.
https://www.youtube.com/watch?v=D8bZkTjEnXw [youtube.com]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Runaway1956 on Thursday December 10 2020, @01:16PM (1 child)
I just watched the video you linked to. The commentary was enlightening. These guys were expecting the engines to shut off, they were expecting the ship to reorient horizontally and then vertically again, and they were expecting reignition of all three raptors. The live video I watched was lacking in all of those details. Thanks for the link!
I'm trying now to locate when the tent catches fire, there is definitely smoke rising from the wreckage all of the time from hard landing, to more than an hour after landing.
From the comments, I got this link to the the lady responsible for much of the video - https://twitter.com/BocaChicaGal [twitter.com] She has a lot of photos and video on her page you might like to browse through.
(Score: 2) by takyon on Thursday December 10 2020, @01:33PM
They had multiple angles from multiple videographers associated with NASASpaceFlight.com [nasaspaceflight.com], which is probably the top quality website and discussion community about space launches and SpaceX. I think they said BocaChicaGal got some of the best footage despite that being her first launch (she is instead known for taking high quality photographs and videos of Starships under construction, because she lives in the village near there AFAIK).
https://youtu.be/D8bZkTjEnXw?t=41205 [youtu.be]
Liftoff was around 10:11:38. They pan to and discuss the damaged tent at 10:29:40, you can see a giant gash in it, some smoke, no giant fire. They start talking about and panning to the tent fire at around 11:26:45, linked above. So yeah, over an hour between the launch and fire. Shows how dangerous this place can be and why they have to clear everyone out of there before launch and use drones and robots to investigate after launch or pad incidents.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Interesting) by DECbot on Thursday December 10 2020, @12:35AM (9 children)
So, completely armchair analysis from an amateur here, but what do you suppose generated the green flames from the raptor engine after re-ignition? I admit to passing high school chemistry with an A decades ago, but that only fuels my speculation and doesn't really help beyond what you can find on google. Musk tweeted the excess velocity was related to low fuel header pressure. To me, the green flame means something was burning that wasn't supposed to burn, like engine parts. My limited knowledge would say it's either Copper (II) or Boron. Anyone else have any ideas?
My guess is the volume and velocity of the compressed gas moving through the engine is one of the primary methods to keep the engine cool. With the reduce pressure, the cooling effects of the fuel and oxidizer was minimized and thus the engine overheated and started to ablatively "cool," which generated a green flame because it happened to be a copper alloy (or another element that burns green, like boron, though in my head copper is the most likely green burning element to be seen in a rocket engine) that began to burn when the cooling effects of the propellent diminished. The lack of fuel was significant enough that the two other raptors could not compensate sufficiently to reduce the vehicle's velocity, ultimately causing the rocket to slam into the ground and then burst into a fire ball once the remaining fuel and LOX were no longer confined to their tanks.
Does anybody else have thoughts on what might have caused the green flames?
cats~$ sudo chown -R us /home/base
(Score: 0) by Anonymous Coward on Thursday December 10 2020, @01:09AM
This thread on Y Combinator [ycombinator.com] has some guys who sound like they know this stuff speculating that there was too much O2 going in to the engine, which burned copper alloys inside the engine.
(Score: 2) by Runaway1956 on Thursday December 10 2020, @06:47AM (2 children)
The commentary in the video I watched above said that they use an additive to aid in sparking the rocket motor's ignition. There's copper in the additive, along with some other stuff. Sorry, I can't remember the name of the additive, or the other components.
I was about to give up on searching, when I found this video - https://www.youtube.com/watch?v=pqCatb2oApU [youtube.com] Still haven't found the term used for the stuff, but it apparently spontaneously combusts upon contact with oxygen.
(Score: 2) by Immerman on Thursday December 10 2020, @08:11AM
I watched that video a while back, but I'm pretty sure that Raptor uses an electric spark rather than the spontaneous-combustion igniter. (something starting with T?)
Could it possibly have been just an extremely oxygen-rich flame as the methane lost pressure? Oxygen has a strong green emission line.
(Score: 3, Informative) by martyb on Thursday December 10 2020, @12:08PM
Two things.
It's the the SpaceX Merlin engines that use TEA/TEB as an igniter (Triethylaluminium [wikipedia.org] / Triethylborane [wikipedia.org]). The Raptor engines use an electrical igniter.
The Raptor's engine bells have a large proportion of copper in their construction. Copper is relatively inexpensive and an excellent conductor of heat. Channels in the engine bell are used to preheat propellant (and to cool the bell). With the flow rates involved with these rockets, one cannot just turn things on and off. Ideally, one would prefer to have an excess of methane over an excess of oxygen: pure oxygen and heat will burn almost anything. Seems the timing/ratio was off and some copper from the engine bell combusted... copper burns green.
In some of the discussions I'd seen were references to ERC Engine-Rich Combustion. First I learn of Rapid, Unscheduled Disassembly
(RUD) and now ERC... I love the wry sense of humor! Another favorite? "Litho-braking" — rapid deceleration caused by impact with the surface of a moon or planet.
Wit is intellect, dancing.
(Score: 2) by Rich on Thursday December 10 2020, @11:19AM (3 children)
I'm not familiar with the subject, but if it was boron, it could have been triethylborane, which is a classic hypergolic start agent and fuel additive.
https://pubchem.ncbi.nlm.nih.gov/compound/Triethylborane#section=Uses [nih.gov]
(Score: 2) by martyb on Thursday December 10 2020, @12:22PM (2 children)
Yes, it (TEB) is. And it is used in the Merlin engine. But, the Raptor engines here use an electric ignition source.
Think Mars -- electricity is much more available than TEA/TEB. See my other comment [soylentnews.org].
Wit is intellect, dancing.
(Score: 2) by DECbot on Thursday December 10 2020, @04:42PM (1 child)
Given that the green flame was constant on the landing, I doubt it was an igniter. Also, like you said above, Raptor engines use an electric ignition. I think your suggestion of ERC is probably correct. It's been months since I watched it, but Everyday Astronaut had a pretty good explanation of the Raptor engine [everydayastronaut.com] as well as other videos explaining full flow engines and such.
cats~$ sudo chown -R us /home/base
(Score: 2) by martyb on Friday December 11 2020, @08:58PM
Close up of the landing: https://twitter.com/spacex/status/1336849897987796992 - SpaceX on Twitter: "Starship landing flip maneuver… " [twitter.com]
Replaying in slo-mo, it's apparent the green flame started well *after* engine re-start.
Wit is intellect, dancing.
(Score: 2) by takyon on Thursday December 10 2020, @05:09PM
https://www.youtube.com/watch?v=egHxiX40eJY [youtube.com]
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(Score: 0) by Anonymous Coward on Thursday December 10 2020, @03:05PM (2 children)
I noticed the venting about 1/3rd of the way up. I was surprised to see the staged shutdown. Was that intentional or did an engine fail on ascent? In the descent phase flight stability looked excellent. Watching the horizon it barely moves, so the aircraft portion of the flight appears to be rock solid. The reorientation manuever at the bottom looks pretty fast. Considering the size of the thing that rotation rate would definaitely have some G-loading on crew as it reorients. The fact that it lawndarted, suggests to me that there was at least one engine failure. I do hope they have a summary report out soon, I'd love to know what the preliminary assessment is.
(Score: 3, Funny) by DECbot on Thursday December 10 2020, @04:50PM
I think the engine shutoffs on accent were scheduled to test their vectored thrust algorithms and other flight characteristics. To me, everything look planned other than the questionable restart of one raptor and the velocity of impact. With Musk's tweet about low fuel pressure at landing, that would indicate that one raptor was running fuel lean, oxygen rich, and once the flame turned green, engine rich. Too bad copper doesn't provide as much thrust as methane during combustion or the rocket might have landed.
cats~$ sudo chown -R us /home/base
(Score: 2) by takyon on Thursday December 10 2020, @05:08PM
https://www.youtube.com/watch?v=egHxiX40eJY [youtube.com]
I don't think the third engine "failed". Only two were used for the flip, and immediately after the header tanks stopped supplying enough fuel and SN8 was completely doomed.
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