Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-17-2023 06:59 AM
New T-0, from SpaceX (via Twitter):
Fueling of the Super Heavy booster is underway. Now targeting 8:20 a.m. CDT.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-17-2023 08:13 AM
No launch today. From Elon Musk:
A pressurant valve appears to be frozen...
Learned a lot today, now offloading propellant, retrying in a few days...
Due to the first stage pressurization issue, the team transitioned today's attempt to a wet dress rehearsal. The countdown was halted at T-40 seconds.
At the point, the next launch attempt will be no sooner than 48 hours.
Blackarrow Member
Posts: 3777 From: Belfast, United Kingdom Registered: Feb 2002
posted 04-17-2023 08:26 AM
Obviously better to be safe than sorry, but...
Dammit!
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-17-2023 06:47 PM
SpaceX is now targeting Thursday (April 20) for the test flight. The 62-minute window opens at 8:28 a.m. CDT and closes at 9:30 a.m. CDT (1328 to 1430 GMT).
SpaceX photo from today's first attempt:
GACspaceguy Member
Posts: 3122 From: Guyton, GA Registered: Jan 2006
posted 04-17-2023 06:50 PM
That is super! Now I just have to figure out how to convince my wife that I had something to do with SpaceX holding off "lighting that candle" until her birthday.
Headshot Member
Posts: 1351 From: Vancouver, WA, USA Registered: Feb 2012
posted 04-17-2023 08:11 PM
Any weather forecasts for Thursday?
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-17-2023 08:54 PM
There is no official forecast, but on Twitter there was talk that one of the reasons SpaceX is not trying for Wednesday was a concern for wind shear.
The fact that they are targeting Thursday suggests they have better expectations for acceptable conditions.
Blackarrow Member
Posts: 3777 From: Belfast, United Kingdom Registered: Feb 2002
posted 04-18-2023 05:29 PM
Just looking at that picture of the Super Heavy/Starship vehicle on its launch-structure, and recalling the problems SpaceX have had with the concrete below the rocket-engines being eroded and blasted away, I can't help wondering why they didn't install some kind of thrust-divider to spread the thrust in all directions during the period between ignition and pad-clearance. Have they ever explained why not?
Headshot Member
Posts: 1351 From: Vancouver, WA, USA Registered: Feb 2012
posted 04-19-2023 10:37 AM
Is the flight termination system used on the Super Heavy booster SpaceX's standard system? Since Super Heavy is constructed of much stronger stainless steel rather than aircraft grade aluminum, one might believe a more robust FTS is needed.
Has SpaceX ever tested the FTS on one of the previous iterations of the Super Heavy booster?
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-19-2023 11:58 AM
SpaceX has not shared many technical details about Starship (or Super Heavy) with the public. All that is really known is from the limited information published on the company's website and the occasional tidbits that Elon Musk has posted on Twitter or said in his occasional interviews.
I don't recall any information being shared about the launch mount or flight termination system. At least with regards to the latter, the FAA has signed off on its ability to do its job as part of issuing SpaceX a launch license.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 07:28 AM
SpaceX video
Fueling of the Super Heavy booster and Starship's upper stage is now underway. Today's (April 20) 62 minute launch window opens at 8:28 a.m. CDT and closes at 9:30 a.m. CDT (1228 to 1330 GMT).
Jim Behling Member
Posts: 1949 From: Cape Canaveral, FL Registered: Mar 2010
posted 04-20-2023 08:15 AM
quote:Originally posted by Headshot: Since Super Heavy is constructed of much stronger stainless steel rather than aircraft grade aluminum, one might believe a more robust FTS is needed.
Atlas was stainless steel. Centaur is still stainless steel. Shaped charges are used for the FTS. Doesn't take much to cut through either aluminum or stainless steel. The steel is likely thinner than aluminum used on other vehicles.
FTS doesn't get tested on a vehicle. no need for it.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 08:30 AM
Hold at T-40 seconds for final countdown checks. Booster tank pressurization and some final some second stage purging. Count will pick up at T-40 seconds soon...
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 08:42 AM
Successful liftoff and ascent for Starship and Super Heavy! The second stage separation failed and the vehicle entered a tumble, ending in the stack breaking apart.
Still a great first test flight with what is to be sure a great amount of data for SpaceX to analyze.
Congrats SpaceX team on an exciting test launch of Starship! Learned a lot for next test launch in a few months.
Philip Member
Posts: 6284 From: Brussels, Belgium Registered: Jan 2001
posted 04-20-2023 09:08 AM
What's with all the screaming? I don't remember NASA and IBM engineers screaming when Saturn V vehicles launched!
Headshot Member
Posts: 1351 From: Vancouver, WA, USA Registered: Feb 2012
posted 04-20-2023 09:22 AM
I do not know how accurate their little graphic was, but it looked like somewhere around 5-6 engines did not function properly. That is around a 15% failure rate.
Would that be better or worse than the old USSR N-1 failure rates?
issman1 Member
Posts: 1143 From: UK Registered: Apr 2005
posted 04-20-2023 09:35 AM
It exceeded my expectations by clearing the tower and passing Max Q.
Hopefully, Starship separates from Super Heavy next time.
NukeGuy Member
Posts: 121 From: Irvine, CA USA Registered: May 2014
posted 04-20-2023 10:43 AM
Even if the Raptor engines are 99% reliable (which is debatable at this point in their development), there is a 70% chance of not having any fail in flight, neglecting common cause failures.
If the reliability can be demonstrated to match the 99.9% reported for the Merlin engine, that probability increases to about 96%.
SkyMan1958 Member
Posts: 1399 From: CA. Registered: Jan 2011
posted 04-20-2023 10:53 AM
At 0:29 into the flight there is debris around the engines. At first I thought it was condensed ice falling off the rocket, but it seems more energetic than that, and you’ll see that something goes on in the engine area... a bright flash or two, and then it looks like an engine or two are dark. At 1:17 into the flight, I count 27 engines running.
For what it's worth, top speed looks to be about 2,150 kph (~1,335 mph), and a top altitude of roughly 39 km (~128,000 feet).
Blackarrow Member
Posts: 3777 From: Belfast, United Kingdom Registered: Feb 2002
posted 04-20-2023 11:11 AM
quote:Originally posted by Philip: What's with all the screaming?
That's what I was thinking. Who cheers when their rocket blows up? It was notable and entirely understandable that Elon Musk wasn't cheering and fist-pumping. His pensive expression precisely fitted the situation.
That said, it was a first attempt and there will have been much learned today. In particular, I want to understand the engine failures that clearly occurred.
OLDIE Member
Posts: 374 From: Portsmouth, England Registered: Sep 2004
posted 04-20-2023 12:03 PM
I couldn't quite decide whether this had more similarities to Dieppe or Dunkirk.
Glint Member
Posts: 1148 From: New Windsor, Maryland USA Registered: Jan 2004
posted 04-20-2023 12:23 PM
Great test and all that. Still, I cannot help being reminded of Russia's similarly spectacular N1 rocket failures.
Sure, Starship will one day work right. However one recalls Von Braun's perfect record of successful Saturn V launches with never a single "unscheduled disassembly." And that with 1950s/60s technology.
ea757grrl Member
Posts: 816 From: South Carolina Registered: Jul 2006
posted 04-20-2023 01:52 PM
quote:Originally posted by Philip: What's with all the screaming?
I love watching the launches but I have to mute the sound when the screaming and cheering starts. I really can't take it.
I don't deny the onlookers their glee, and maybe I'm a humorless old-timer who doesn't get it, but I'm there to watch the launch and listen to the flight commentary and whatever data comes in.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 02:18 PM
quote:Originally posted by Headshot: ...one might believe a more robust FTS is needed.
Well, any question about the effectiveness of the FTS was answered today. The FAA confirmed that the FTS was used to destroy the vehicle.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 02:35 PM
SpaceX update
Starship Flight Test
Starship gave us quite a show during today's first flight test of a fully integrated Starship and Super Heavy rocket from Starbase in Texas.
At 8:33 a.m. CT, Starship successfully lifted off from the orbital launch pad for the first time. The vehicle cleared the pad and beach as Starship climbed to an apogee of ~39 km over the Gulf of Mexico – the highest of any Starship to-date. The vehicle experienced multiple engines out during the flight test, lost altitude, and began to tumble. The flight termination system was commanded on both the booster and ship. As is standard procedure, the pad and surrounding area was cleared well in advance of the test, and we expect the road and beach near the pad to remain closed until tomorrow.
With a test like this, success comes from what we learn, and we learned a tremendous amount about the vehicle and ground systems today that will help us improve on future flights of Starship.
Thank you to our customers, Cameron County, and the wider community for the continued support and encouragement. And congratulations to the entire SpaceX team on an exciting first flight test of Starship!
YankeeClipper61 New Member
Posts: 8 From: Registered: Jan 2016
posted 04-20-2023 02:38 PM
quote:Originally posted by Glint: ...perfect record of successful Saturn V launches
I agree with regards to the Saturn V. Heck, Apollo 13 had an engine in the S1C shutdown early and the other engines still managed to push it to staging and to eventually to orbit. One engine loss in the S1C equalled 20% of all first stage engines.
Still not feeling warm and fuzzy about Starship being my HLS of choice...
Headshot Member
Posts: 1351 From: Vancouver, WA, USA Registered: Feb 2012
posted 04-20-2023 03:35 PM
I wonder why SpaceX's Super Heavy booster did not have the modern equivalent of the Soviet N-1's KORD system? The Kontrol Roboti Dvigvateli system was designed to sense failures of any of the N-1 first stage engines, shut that engine down, and shut down the engine opposite the failed engine to as to preserve the symmetry of the vehicles' thrust. It would also reprogram the vehicle to lengthen the burn so as to make up for the lost thrust.
Of course in the case of the Super Heavy launch today, that would have resulted in 10 to 12 engines out, or a loss of almost 30+% of the thrust.
Still, one wonders why the vehicle started to tumble so badly.
Glint Member
Posts: 1148 From: New Windsor, Maryland USA Registered: Jan 2004
posted 04-20-2023 03:47 PM
quote:Originally posted by Philip: What's with all the screaming?
By screaming, I think you mean cheering when the entire stack went bang? It is particularly troubling when inexperienced or improperly prepared persons react inappropriately to disaster.
Specifically I recall a video of backup school teacher Barbara Morgan clapping and cheering at the moment seven astronauts were killed on space shuttle Challenger. And of course, she wasn't alone in that regard.
Blackarrow Member
Posts: 3777 From: Belfast, United Kingdom Registered: Feb 2002
posted 04-20-2023 04:15 PM
quote:Originally posted by SkyMan1958: Much as I wish Elon well, I think at the top of his to do list is to make the Falcon 9 a reliable transport system...
The above from September 2016. Job done, I would say! Let's hope similar reliability is established for Starship in the (near as possible) future.
Robert Pearlman Editor
Posts: 53515 From: Houston, TX Registered: Nov 1999
posted 04-20-2023 04:46 PM
quote:Originally posted by Headshot: ...preserve the symmetry of the vehicles' thrust.
The N1 had to maintain symmetry because its 30 NK-15 engines could not gimbal. On Super Heavy, only the outer ring of 20 Raptor engines are static. The 13 engines in the middle can gimbal, so they can offset any uneven thrust by just adjusting the angle at which they are firing.
But that may have nothing to do why the vehicle began to tumble. The Super Heavy appeared to lose control near when it was expected to cut off its engines and separate from Starship. Hence, it was near the depletion of its propellant supply. At that point, even if all 33 engines were firing, there would be little that could be done to save the vehicle.
The comparison to the Saturn V flight record seems to be a misunderstanding of the nature of today's test flight. The Saturn V did experience RUDs — on the test stand as individual stages. There are no Starship and Super Heavy test stands. SpaceX's approach is to use their developmental hops and launches as test stands that are just not secured to the ground. They accept and expect failure and they use it as a means to make the necessary changes to the next vehicle to fly.
quote:Originally posted by Glint: It is particularly troubling when inexperienced or improperly prepared persons react inappropriately to disaster.
I don't think that is what was happening at all. The people doing the clapping and cheering are SpaceX employees at the company's headquarters in Hawthorne. When the vehicle broke apart, their first reaction was a collective "Awww..." followed by cheering and applause for what was a good test flight. They, better than most, knew not to expect a total success. In fact, they may have had expectations for even less than the flight actually achieved.
It should also be noted that the video feed(s) they are watching may not be the same one, or at the same lag, as the one we are watching on the webcast. They are watching the front screens in SpaceX mission control, which are separate from the livestream. So at times, they can be heard reacting to things we have yet or may not at all see.
SpaceAholic Member
Posts: 5408 From: Sierra Vista, Arizona Registered: Nov 1999
posted 04-20-2023 04:54 PM
POGO may be another contributory factor (if for whatever reason propellant pressure was not maintained constant to each of the engines).
oly Member
Posts: 1484 From: Perth, Western Australia Registered: Apr 2015
posted 04-20-2023 05:06 PM
I was excited to see SpaceX get that rocket to launch in just the second attempt. Making it past the top of the launch tower was an added bonus, plus they got to test the vehicle behavior through Max-Q and test the flight termination system, milestones needed to be met somewhere along the testing line. Well done SpaceX. Bring on the next launch.
Jim Behling Member
Posts: 1949 From: Cape Canaveral, FL Registered: Mar 2010
posted 04-20-2023 08:09 PM
Most if not all of the non operating engines were likely damaged during liftoff from pad debris.
quote:Originally posted by Glint: However one recalls Von Braun's perfect record of successful Saturn V launches
Not true. Apollo 6 was a launch vehicle failure. Only because the CSM had excess propellant were the mission objectives met.
Paul78zephyr Member
Posts: 815 From: Hudson, MA Registered: Jul 2005
posted 04-20-2023 09:03 PM
quote:Originally posted by YankeeClipper61: Heck, Apollo 13 had an engine in the S1C shutdown early...
It was the center J-2 in the S-II second stage that shut down early on Apollo 13.
NukeGuy Member
Posts: 121 From: Irvine, CA USA Registered: May 2014
posted 04-20-2023 10:01 PM
If those engine out indications were accurate, it was pretty impressive that so many engines continued to operate despite the tumbling. There had to be some major propellant sloshing going on.
perineau Member
Posts: 408 From: FRANCE Registered: Jul 2007
posted 04-21-2023 02:09 AM
I find it a little bit odd, all this enthousiasm and whooping it up over a major launch failure.
oly Member
Posts: 1484 From: Perth, Western Australia Registered: Apr 2015
posted 04-21-2023 03:32 AM
The rocket did not fail, it launched on it's maiden test flight and achieved the goals that SpaceX stated prior to the launch that they would be happy with, it made it past the end of the launch tower.
It was also demonstrated that the first stage can fly with some engine out performance with a heavy payload, impressive for a first of type flight, especially such a complicated design consisting of all new components.
What many are saying was an explosion was just the structure releasing stored liquids and breaking up as the flight was terminated, in a similar way the Falcon 9 did during its flight termination system demonstration. It was a commanded and controlled end of the mission, not an unplanned catastrophic structural failure.
Perhaps SpaceX had an issue with the first stage engines not shutting down when planned which disrupted the stage separation sequence, however, until they can go through all the data and evaluate what happened, little can be achieved by being Waldorf and Statler or guessing.
I appreciate the enthusiasm shown by the SpaceX employees. To me, they seemed to be cheering for all of the hard work their team put into that rocket and for the fact they achieved a launch. They represent everyone involved, let them have their moment.
Headshot Member
Posts: 1351 From: Vancouver, WA, USA Registered: Feb 2012
posted 04-21-2023 12:45 PM
I hate it when others (like Elon Musk) attempt to manage my expectations.
When NASA launched Apollo 4, management did not say the goal was not to blow up and destroy the launch tower. They had 16 primary objectives for the Saturn V launch vehicle used in that mission. When NASA launched Artemis I, their goal was not to destroy the pad facilities, but to circle the moon, test various systems, and return Orion safely to Earth. As the motto of JPL says, Dare Mighty Things.
Starship/Super-Heavy did not complete its mission. There was no splashdown of Starship off the Hawaii coast, which was the actual goal of the flight. The rocket blew up (or was blown up). Get over it.
Does that mean Thursday's mission was a failure? To soon to tell. If they do not learn what went wrong and correct it, then yes it was a failure. But if SpaceX learns from their mistakes and does not repeat them on the next mission, then this mission was merely unsuccessful. That is not the same as a failure.
Sorry about the rant.
Michael Davis Member
Posts: 578 From: Houston, Texas Registered: Aug 2002
posted 04-21-2023 01:04 PM
quote:Originally posted by oly: The rocket did not fail...
I agree completely with your comments. The negative reactions remind me of those voiced during the many "failures" of SpaceX's attempts to initially land a first stage. The strategy was to fail until they did not fail. Yesterday's launch seems to align with that strategy. Attempt, learn from the attempt, revise, try again. Just getting off the launch pad with a prototype of the most powerful rocket ever built seems like a huge success.
As for the cheering — well, the team probably felt joy in being a part of that huge success. They likely also know that they now have a clear path to complete success. They seemed invested in their work and in achieving that complete success. The reaction seems far better than pouting. Comparing this to Apollo 13, or any other crewed launch, seems odd - no lives were on the line yesterday - sure of course that no cheering would have happened if there had been. Also sure that no crews will be on the line until complete confidence in Super Heavy is achieved. For now, it is only flaming metal falling into the Gulf of Mexico.
Blackarrow Member
Posts: 3777 From: Belfast, United Kingdom Registered: Feb 2002
posted 04-21-2023 01:21 PM
The cheering and clapping reminds me of people cheering and clapping at a funeral (which I personally consider repulsive). It's not for me or any of us to tell SpaceX employees how to react, but I again refer to Elon Musk's sombre and pensive reaction, which I found entirely understandable. However hard he sought to manage expectations, he was clearly disappointed that the flight had to be terminated. I can't help wondering: if the SpaceX staff cheer wildly after seeing their rocket being destroyed, what will they do if the next vehicle is 100% successful?
It looked like the Super Heavy booster engines (or some of them) did not shut down on schedule. Neither did the stages separate on schedule. On Apollo 6 (and 13) premature engine cut-offs caused the remaining engines to burn longer, and - of course - staging was delayed while the remaining engines tried to make up for the velocity deficit. But why did Super Heavy/Starship tumble? Was this (as one commentator seemed to be saying) because the booster was trying to re-orientate for its retro-boost manoeuvre? But is there another explanation?
The video of the events leading up to the tumbling shows a bright plume apparently emerging sideways (from a fractured engine-bell?) and this can also be seen in the brief video looking downwards from Starship. Might this have created a "Catherine-wheel effect," inducing the tumble? I accept that it is probably too early to speculate, but the above points occurred to me, and if there is evidence to rule out such points it would be interesting to hear it.
One other point: I was very surprised that the continual tumbling of such a long, slim vehicle did not cause structural break-up before Range Safety intervened. The attachment systems between booster and Starship must have been under extreme stresses during the tumbling.
posted 04-17-2023 06:59 AM
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