SpaceX's Successful Starship High-Altitude Flight Ends In a Fiery Explosion (engadget.com) 285
Thelasko shares a report from Engadget: After a successful launch, the Starship rose and successfully maneuvered its way to the landing area. However, it appeared that the spacecraft didn't slow down enough for a proper landing, and it exploded in thrilling fashion. On the live feed, SpaceX said the test was successful and noted it would be moving on to testing the SN9 prototype next. Elon Musk tweeted "Successful ascent, switchover to header tanks & precise flap control to landing point!" In a follow-up, he explained the landing, saying that low fuel header tank pressure during the landing burn contributed to the high touchdown velocity and the massive explosion. The good news, is that the team got âoeall the data we neededâ and it appears everything is in order for future tests. You can view the full test flight here.
Stainless Steel (Score:5, Interesting)
I think it would be fair to say there were questions raised about Musk deciding to use stainless steel on starship.
Having seen a few prototypes RUD I can see the sense in using the cheaper material, for now.
The Boca Chica facility can knock ever-more complex prototypes quickly and cheaply expediting the development cycle.
Re:Stainless Steel (Score:5, Informative)
I think it would be fair to say there were questions raised about Musk deciding to use stainless steel on starship. Having seen a few prototypes RUD I can see the sense in using the cheaper material, for now. The Boca Chica facility can knock ever-more complex prototypes quickly and cheaply expediting the development cycle.
I'd just take his word that they chose stainless because it's stronger across a broader range of temperatures than carbon fiber.
Re:Stainless Steel (Score:5, Interesting)
Yup, the approach SpaceX is taking with materials the StarShip and its booster reminds me very much of the move from wood and fabric to metal construction in aircraft - it marked a huge change from extremely high maintenance, low resilience aircraft to low maintenance, high resilience workhorses. And thats what StarShip is intended to be - a workhorse.
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I'd just take his word that they chose stainless because it's stronger across a broader range of temperatures than carbon fiber.
That, and it is easier to put together than carbon fiber. Stainless steel has been around for a long time and there is no shortage of experience working with it. Starships can be put together by shipwrights Hell, 80 years ago, they made trains out of stainless steel.
Re:Stainless Steel (Score:5, Interesting)
Back when SpaceX was pursuing CF, I wrote comments on Slashdot stating that I was dubious about that approach. CF certainly has a superb strength to weight ratio, but it's also expensive, brittle and unforgiving, and performs poorly at low and high temperatures.
I couldn't be happier that they switched to stainless (at the time, I had been hoping they'd use titanium, but stainless seems to have been an even better decision). Now they're just churning out these rockets, assembly-line style, for dirt-cheap. And whatever's left after an explosion, they get back in fully recyclable scrap.
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I'd just take his word that they chose stainless because it's stronger across a broader range of temperatures than carbon fiber.
Everyone knew that before they started though. What changed is that carbon fibre was taking too long to solve the manufacturing problems, so they switched to plan B.
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The Saturn V didn't need to land again.
Re:Stainless Steel (Score:4, Insightful)
The Saturn V was a one way, one time use vehicle. It was developed by former missile designers. For some reason missiles didn't have round-trip in their feature set.
You do not understand this at all (Score:5, Informative)
Stainless steel is the material of choice here for many reasons (Musk needs it for the thermal properties and structural strength). It has many excellent properties and was used in the original Atlas rockets but it has one big drawback - weight, which is why it was used in a form so thin on Atlas that the atlas tanks were called "balloon tanks" and those original Atlas rockets would crumple if placed vertical without being pressurized. All other rocket builders abandoned steel because they did not have enough engine performance to be able to both lift the desired payload AND lift a heavy steel rocket. Musk simply scaled his rocket properly and then gave it powerful enough engines so he can use the best (and heavier) structural material.
Stainless steel not only had NOTHING to do with today's RUD, but this flight actually furthered the evidence in favor of it's design choice. Originally, he was going to use composites, and SpaceX actually built and partially tested full-size composite tanks for Starship before analysis told them that after adding all the extra thermal protection a plastic rocket would require for reentry at lunar or mars return velocities, steel actually was a better trade-off. The steel requires vastly less thermal protection and has a bunch of other advantages. The rest of the aerospace industry loves composites as a way to deal with insufficient propulsion performance, but Musk just does not have that problem with Starship.
Oh, and this was built with common off-the-shelf steel, but the newer ones already in various stages of assembly (the next one is already complete) are using a different commercially available formulation which Musk already had concluded would be better, and his team has already arranged for a new custom formulation of SpaceX-specific stainless steel for the future - he has committed to stainless.
You didn't read what I wrote (Score:2)
I think everyone is getting the wrong idea about what I was saying. I certainly didn't suggest the RUD was due to the use of SS - read what I wrote again...
When Musk announced Starship would be SS I was intrigued, his arguments seemed sound and I liked the solutions he outlined for the technical challenges of the choice.
My post was really just a comment on how much faster, and cheaper, ("common off-the-shelf steel") development of the project is because of that choice.
It wasn't something that I remember bei
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Hmm, we have very different memories - I'm pretty sure the much lower cost of materials and much faster workmanship, and their implications for iterative design, was one of the big features Musk touted when announcing the change, or at least by the time of the big presentation in front of the Mk1 mockup. Something along the lines of "if it's taking too long, you're doing something wrong"
My impression is that they've tabled the "sweating" system in favor of more traditional heat shielding, at least for now.
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I wonder if they will shift to making the Superheavy Booster out of carbon composite. It doesn't get to orbital velocities and so won't need to withstand as much heat. Its return profile will be exactly the same as the Falcon 9 first stage -- boostback burn, reentry burn, grid fins to steer, propulsive landing. No orbital bellyflop like the Starship second stage.
The are definitely advantages in prototyping in stainless steel, but since the booster is basically just a scaled-up Falcon 9 using raptor engines,
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O.o No. That's utter bullshit.
Atlas used steel not because it was strong, but because it was strong at the insanely thin thicknesses needed to save weight. Why did Atlas need to save so much weight? Because it's engines weren't particularly powerful and the design was significantly inefficient. First, because it had to be lit on
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The rest of the aerospace industry loves composites as a way to deal with insufficient propulsion performance, but Musk just does not have that problem with Starship.
You make it sound like weight can be overcome simply by more thrust. But actually, weight is more important in an upper stage. Every extra kg of hull mass is one less kg of payload. Actually worse, as you need to land the hull.
Alternatively, you can scale up the booster, remembering that each extra kg of upper-stage mass means many kg of extra propellant as well as booster thrust.
With full re-usability, this becomes economical.
Starship's methalox rocket engines are less efficient than hydro
Re: Stainless Steel (Score:2)
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It was not about the development cycle. The issue was having this withstand space and be fixable.
It's because the weight increase is offset by a lighter heat shield, since the stainless can take far more heat than carbon fiber. Source: https://www.space.com/spacex-s... [space.com]
https://www.space.com/43101-el... [space.com]
https://www.popularmechanics.c... [popularmechanics.com]
Originally they planned to bleed excess fuel out the windward side of the rocket as active cooling, but then switched to a more traditional heath shield (still far reduced from what it would have been have been using carbon fiber as the main structural material).
Re: Stainless Steel (Score:2)
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boron, or camera overexposure making something look green.
Green would be the rocket engine burning up from the excess hot oxygen being pumped through. Insufficient methane pressure.
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Actual max speed, 5m/s (Score:2)
If you want a reusable rocket, having it hit the ground at faster than about 0 m/s makes it unlikely to be useful,
Since you need to be going some speed to actually land, what is the maximum speed it can land and still be usable?
A pretty good guess for the Falcon 9 is 5m/s [stackexchange.com].
That's roughly 11MPH, or for a unit no-one wanted, 9.72 knots.
0 to 11MPH is a pretty good margin for landing.
No reason to assume it wouldn't be similar for Starship. Probably they land well within that speed, if you look at videos of land
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> From my armchair position, it appears to have run out of fuel shortly before landing.
Hmmm. From my armchair, I deem such a spectacular explosion requires plenty of fuel. Maybe it was a pump that failed.
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Re:Stainless Steel (Score:5, Informative)
I don't like how elon does not give credit to his team.
Re: Stainless Steel (Score:2)
He meant he hates how Elon instead of his team is always credited in the media, and didn't know that was just the media. Because neither did I and probably most people. Which is the whole problem of the media portraying him like that
You should have told him that. Since actual people don't read PR ejacualtion bukkake like Twatter, so you got a special insight for ua, may your sanity rest in peace. ;)
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Elon maybe took the decision maybe didn't, but for sure he was fed data by a team of engineers. I don't like how elon does not give credit to his team.
He never claimed it was his idea, just that he had to get other people to recognize it was the best idea.
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Re: What the??? (Score:5, Insightful)
And now you know why so many people are annoyed with journalists who write nonsense that one can debunk with 15 seconds searching on Google - sometimes out of ignorance, but sometimes to pursue petty ideological vendettas. If you want to know what Elon actually thinks, don't use a filter - listen to what he actually says.
He certainly is a person with flaws. But being an egoist who never gives credit to others is definitely not one of them. Seriously, just search his Twitter feed for the word team [twitter.com] - and that's just the start.
The reality is that sociopaths and con men are usually actually the opposite - they're good at convincing you that they're nice, kind, honest people, the sort of person you want to be your friend. Elizabeth Holmes, Trevor Milton, etc - they were all superb at coming across as just "nice". Elon... doesn't. He comes across like an alien in a human suit trying to do his best impression of humanity based on it's reading of chats on Reddit. He's awkward and nerdy and emotional and looks uncomfortable in his own skin.
But he's also ideologically driven for creating a better future, a workaholic towards said goals, and constantly expresses his appreciation for the people who help him to achieve them.
Ridiculously Successful (Score:5, Interesting)
I have to say I'm incredibly impressed. I thought it would probably blow up at some point into the flight. It looked like something went wrong when the first engine went out during the ascent (the other engines gimballed like crazy and there was a lot of fire in the wrong places) but it appeared to recover and make it to apogee. Then when it started coming back down those flap actuators were jittering an awful lot as well. When it flipped, stabilised and relit, right on target, I couldn't believe they had managed that on the first test flight.
It appears that everything went well except something caused the engines to fail at the end. Elon tweeted this was due to a loss of header tank pressurisation, so it doesn't sound that big a deal to hunt down and fix.
At this rate they will be testing sub-orbital re-entry by early next year. What an achievement. Having a bunch of cheap tin-can launchers that can slug mass into orbit is going to change our civilisation forever.
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I have to say I'm incredibly impressed. I thought it would probably blow up at some point into the flight.
Absolutely. I full expect catastrophic failure every launch. This stuff is hard and dangerous. Also, they're still iterating and pushing the technology. Rockets reused more times than before, more rapid turnaround... this is still not a mature technology.
I figure sooner or later a mistake has to be made. I just hope that we don't stall out and become super timid when it does.
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Having a bunch of cheap tin-can launchers that can slug mass into orbit is going to change our civilisation forever.
In what way? Serious question.
Reasons to want to slug mass to/from orbit (Score:5, Interesting)
I can think of a few:
- Mining. There is a lot of titanium on the moon and asteroids have thousands of tons of materials, including rare earths which have toxic extraction processes (and are often done by countries with less than stellar human rights records)
- Microgravity manufacturing. The two big ones would be in terms of pharmaceuticals and high performance metal smelting/fabricating (Create foamed metals with the strength of fully solid materials at a few percentage of the mass)
- People. For any kind of effective operations in space, there needs to be a way of getting dozens of people into space rather than the three or six or seven that is possible with existing solutions
- Space Power Stations (SPS), the Gerard O'Neill concept going back to the 1970s. I would argue that this won't come along until the previous bullet items are moving forwards
I should point out that the real game changer will be when somebody can bring *down* lots of mass from orbit. This is something that it looks like Starship will be very good at, but it's not really recognized as yet.
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- Space Power Stations (SPS)
Go ask Elon Musk what he thinks of space power stations. Or don't, because he might bite your head off for asking again about this stupid idea after having explained many many times on how this can never be feasible.
I'll summarize the problem as best I can. There is a loss in converting solar power in orbit and transmitting it to Earth. There is a loss in how much sunlight reaches the Earth surface through the atmosphere, battery storage, etc. No matter what you do the losses of an orbital station will
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One advantage solar power satellites have over ground-based solar power is that they work at night. Atmospheric loss is nothing compared to the losses through eight thousand miles of rock.
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>I should point out that the real game changer will be when somebody can bring *down* lots of mass from orbit.
That's actually trivially easy in comparison. Consider all the multiple stages of engines, tanks, and other complexity needed to launch a tiny space capsule into orbit - and then consider that that tiny capsule also contains everything needed to return astronauts safely and gently to the surface.
Getting it up has to fight gravity and air resistance the whole way. Getting it down, particularly f
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In what way? Serious question.
1. In the short run, cheap mass-to-orbit makes stuff like StarLink possible and affordable. That could mean pervasive global communication that governments can't block.
2. In the long run, it means humans moving into space. That may mean Mars, Lunar colonies, or O'Neill Cylinders. Being able to move stuff up to the colonies at low cost makes all the difference.
Re:Ridiculously Successful (Score:4, Interesting)
>That could mean pervasive global communication that governments can't block.
That's... optimistic. We already have cheap global communication that governments can't block - it's called ham radio. Guess what - governments still (effectively) block it by banning private ownership of the equipment needed to access it. Plus, so long as providing access is driven by the profit motive, the satellite network operator is going to have to either comply with government requirements, or engage in some pretty shady practices to sell illegal access.
And if we're talking, just for the sake of argument, about Starlink circumventing the Great Firewall of China, how long do you think that would last before China shut down access to their markets for SpaceX Suborbital flights and Tesla vehicles?
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Most likely China will just ask them to switch the service off when the satellites are over China, fucking over nearby countries as well. If they refuse they will simply jam it.
Meanwhile China will probably have its own network up in a few years if Starlink proves viable. They will use it to build soft power by offering it to developing nations at very low cost, and advertise the fact that porn and other "bad" stuff is blocked as a feature.
Re: Ridiculously Successful (Score:3)
Starling is a great example of the kinds of changes that can happen, and thatâ(TM)s only the beginning. When you can easily put 40,000 seats in orbit, telecommunications arrays, or mapping satellites, or telescope arrays become easy. Want a radio telescope the size of the whole earth? Cool, put 100,000 radio telescope satellites into a fairly high orbit. Use them as one giant array. JWST has so far cost $10bn. 1000 launches on starship, each carrying 100 radio telescopes to a fairly high orbit wo
Re:Ridiculously Successful (Score:4, Interesting)
Not only was this ridiculously successful, the root cause of the crash was known pretty much before the fireball died down. AND they've got another prototype mostly assembled, and two more in production.
So first try, they got all of the data they need to make the 2nd one most likely successful, the only issue is already known and easily resolved, and the next iteration is standing >>> over there.
Other than not going boom, you can't get much more successful than that. After looking at the success of Falcon and Dragon, anyone who doesn't think Musk is going to be successful with this is crazy.
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Do we know whether the engine cuttoffs during launch were intentional? For my money, that would be the biggest potential problem with the launch.
There doesn't seem to be any good reason to shut them off on a "real" mission - so the question is were they shut down intentionally as part of the testing flight plan (perhaps to test recovery capability in response to engine loss), or did they encounter problems in-flight? I'm really hoping it was intentional, but I'm not prepared to assume so.
Re:Ridiculously Successful (Score:4, Interesting)
Also, by shutting down one engine and adjusting thrust through the center of gravity, the rocket tips slightly, moving it off shore in case of any need to terminate the flight. Remember that SN4 exploded *after* the engine shut down from the static fire. Yes, SN4 was due to a ground service equipment leak, but still, there's no proof that Raptors don't have hard shutdowns. Even Elon said he was happy they made it to apogee without blowing up, so its clear that they're still not 100% confident in the Raptors.
Finally, the engines relit at touchdown (well, at least two of them did) so it's not like there was an actual fatal problem with the engine as it wouldn't have restarted.
I admit, that when I saw the first raptor cut out, I had a moment of, "oh no," but it rapidly passed when I realized what they must be doing to both manage acceleration and to direct the Starship out over the water.
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With gimballed engines there's no need to shut one off to steer, but your other reasons make sense, and were more or less what I was thinking. Except for avoiding supersonic flight - I hadn't thought of that. In addition to regulatory issues, I could easily see them not wanting to subject the flaps and airframe to those stresses on the maiden flight. Plenty of time to test the "shouldn't be a problem" stuff on future flights after they've tested the really innovative belly flop and landing flip maneuver
Re:Ridiculously Successful (Score:4, Informative)
Yes, Elon confirmed [twitter.com] it:
Tim Dodd: Was that engine shutdown on ascent intentional? Did it reached planned apogee? Can’t believe how epic that was!
Elon Musk: Yeah, engines did great!
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Umm.... No. While the cause was low fuel tank pressure, so far as is publically known - we have no idea why the pressure was low.
As I said, no. The issue is not known, at least not publically. So, no, we don't know if it can be easily resolved.
Ruined by the voice overs (Score:2, Insightful)
They need to get some better people to talk about this. I mean, who gets 14 yo girls to talk about rocketships?
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No one is getting interested in space flight because some grown men screaming like teenage girls over a rocket test flight. Not even teenage girls.
Re:Ruined by the voice overs (Score:5, Informative)
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Now THAT's the feed I wanted. Thank you kind stranger.
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So close! Green is the color of a copper rocket combustion chamber eating itself. That final part is well trod ground for SpaceX and won't hold things up; it looks like they succeeded in the areas that were really unknown.
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I don't know you got downvoted. TEB ignition fuel green flame would not show up mid-burn.
Re: Ruined by the voice overs (Score:2)
Also, Starship doesnâ(TM)t use TEB - it uses a spark ignitor to light a methane/oxygen blowtorch, which in turn ignites the contents of the combustion chamber.
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That was my first thought as well, but I've also heard speculation that it was simply a result of burning extremely oxygen-rich as the methane header lost pressure. Oxygen also has a strong green emission line, its strongest in fact.
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If you want to keep up with what is going on
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I pretty much follow Scott Manley and follow a bunch of reddit subs. These guys do not interest me at all.
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Their live streams are generally way more controlled than this - but they were just geeking out today.
Oh yes (Score:2)
Yup.squeaky schoolgirls on their first bottle of fizzy wine.
If software could scream.. (Score:4, Funny)
AAAAH! I've got the throttles wide open, it's not enough, I'm coming in too hot! I. AM. GOING. TO. CRASH! AAAAH!
* * * THUD * **
* * * KABOOM * * *
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I can't hold her... she's breaking up... she's breaking up....
Re: If software could scream.. (Score:2)
Iâ(TM)m givin it all sheâ(TM)s got capâ(TM)n
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T+6:42 hard landing - hard landing - hard landing
Meh... (Score:2)
Musk was insanely successful on that flight. (Score:5, Interesting)
Consider:
This flight was powered by 3 Raptor engines. Raptor engines are very unique - they burn Methane and LOX and do it with great efficiency; they were designed to use methane (not usually used in rocketry) because methane can be made from the Martian atmosphere without too much trouble and Musk has been doggedly following his plans to get humanity a way to move back and forth between Earth and Mars. [1] No vehicle has ever been flown before with more than 1 Raptor. [2] No Raptor has ever lifted any vehicle more than several hundred feet into the air.
This flight was the first of a Starship prototype to be equipped with the upper 1/3 of the stage (the payload section) and with all four fins.
This was the highest flight and longest duration flight for any Starship prototype.
This was the first time a Starship shut down all engines in flight and maneuvered into its belly-flop/skydiver reentry attitude.
This was the first time a Starship ever fell in skydiver attitude and used its four flappers like a skydiver's arms and legs to steer and control attitude while falling.
This was the first time any Raptor engine has ever been re-started in flight, (and without any ground support equipment attached) and it was done using the header tanks rather than the mains tanks (similar to the tanking system used on aerobatic aircraft, and a way of getting weightless fuel into an engine while the vehicle is falling). Most 1st stage rocket engines cannot be restarted in flight - the ones on the Space Shuttle were incapable of it, just like the ones on the Saturn, Delta, Atlas, SLS, Ariane, and Soyuz rockets.
This was the first time a Starship has re-oriented itself back into the vertical from the skydiver attitude in flight.
This flight of Starship prototype #8 achieved ALL of these objectives before arriving at the landing pad with too much vertical velocity. This was insanely successful and proved that the entire flight profile, the hardware, the flight algorithms etc are ALL good and the entire scheme WILL work - all that's needed is some software tweeks and the next prototype will probably nail it. This thing so nearly completed the list of test objectives that it completed its rapid unscheduled disassembly right on the landing pad - that's breathtakingly successful for this sort of wildly complex test flight and my hat's off to the entire SpaceX team.
Oh, and Musk assumed he'd lose this vehicle on this flight - vehicle number 9 is essentially ready to go, and several more are in various stages of assembly - I would not be surprised if #9 rolled to the pad within days.
Colonies on the moon, and Man on Mars, just became a MUCH more real thing today, as did a FAR more connected Earth. If you witnessed that test flight today, then you saw something that will go down in history as a far more significant event than Chuck Yeager's 1947 flight - this will revolutionize spaceflight and even transport on Earth; while all the other companies are trying to send 2 to 4 people to the moon on throw-away rockets in exchange for billions of tax dollars, Musk laid the groundwork for people to go to the Moon and Mars in groups of 100, Satellites to be launched hundreds at a time, and for people to fly Earth-to-Earth routes like Sydney-to-London or Paris to Los Angeles or Tokyo to New York in 90minutes.
If you are an executive at Boeing or Lockheed and you are not freaking out right now, you need your head examined (and your shareholders need to fire you before your company gets so far behind that it cannot avoid becoming as obsolete as a maker of chain mail for draft horses).
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Excellent summary. I made a lot of the same points above (although well after your post) with the added point:
Before the fireball died down they knew the cause of the failure.
Think about that.
All of the other spacecraft which have been lost have resulted in months of inquiry, all sorts of sleuthing and theories. It's a major bureaucratic endeavor to investigate a spacecraft failure.
They're going to tweak SN9 and roll it out to the pad.
I think the telemetry paired with the rapid development cycle and willing
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They're going to tweak SN9 and roll it out to the pad.
/Meesa guess the tweak is only going to be slightly more fuel on board, and maybe a software upgrade
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I thought the problem was lack of pressure, not lack of fuel. In which case they'd likely need to revise the header tanks and/or pressurization system to avoid a repeat. Unless it was a software bug.
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And then there is the superheavy under construction now, too... The pace is insane.
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There's many reasons to use methane fuel besides the possibility to synthesize it on Mars. There's potential to synthesize other rocket fuels on Mars than methane, such as liquid hydrogen and kerosene, both very popular fuels for rockets launched from Earth. I recall a video on YouTude by Tim Dodd, the Everyday Astronaut, discussing the benefits of methane as a rocket fuel.
Earth to Earth rocket trips are not all that practical. I believe Tim Dodd discussed this too but on a podcast he co-hosts called Our
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So are you trolling or ignorant?
Thanks (Score:3)
I work in aerospace and I have been involved in flight tests, so I have an appreciation of just what it took to pull that off. I've also worked at two of the big aerospace defense contractors and know a bit about how incapable they have become (it's not that the engineers and techs etc are incompetent or not dedicated, it's just a combination of bureaucracy, management (fixating on forms, procedures and rules, assigning every damned thing a code and billing everything to accounts so managers can assign/avoi
Reminds me of the classic message (Score:2)
"Error - the operation completed successfully"
I got so many questions (Score:2)
Wow, so many things happened during that test flight.
T+01:40 : Something seemed to make the 3 engines jingle around for no reason (gyro's glitch?), forcing one of the engines to turn off. Or was it planned?
T+01:51 : Some gas starts to be released from SN8. Is it the fuel that was supposed to be burned by the shutted down engine so there's not too much in the tank at MECO?
T+03:12 : The same glitch seems to happen again, forcing the 2nd engine to cut off. Again, was it part of the test? Again, more gas seems
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I also thought something had gone wrong, but watching it again, I think they just cut engines as the fuel load got lighter to stop the vehicle going too fast. It really didn't climb very quickly. In fact, it took ~4.30m (270 seconds) to complete the climb, so assuming it reached the 12.5km mark, it was climbing at roughly 12500/270=46m/s which is an average of around 170kph. Not very fast at all considering during orbital launches it will be going supersonic.
I think they just didn't want to stress the rocke
Re:I got so many questions (Score:5, Informative)
Wow, so many things happened during that test flight.
T+01:40 : Something seemed to make the 3 engines jingle around for no reason (gyro's glitch?), forcing one of the engines to turn off. Or was it planned?
It appears to have been planned, I think you have the cause and effect backwards. The engines gimbaled just before shutting down to compensate for the expected loss of thrust. The consensus that I have seen is that the engines shut down to limit velocity as the vehicle became lighter. They didn't want to get going too fast, in fact they wanted to come to a hover at the end to go into the bellyflop position.
T+01:51 : Some gas starts to be released from SN8. Is it the fuel that was supposed to be burned by the shutted down engine so there's not too much in the tank at MECO?
T+03:12 : The same glitch seems to happen again, forcing the 2nd engine to cut off. Again, was it part of the test? Again, more gas seems to be released but it's hard to see from the angle of the video.
These appear to be normal engine shutdowns and venting. The only thing that appeared abnormal was the small fire under the skirt after the first engine shutdown but it seemed to go out pretty quick.
T+04:41 : MECO and the SN8 flip on the side for the fall. I guess it was planned but I'm wondering why falling sideways? Is the same maneuver planned for the final Starship booster as well?
Nope, the booster will use grid fins like the Falcon booster. The Starship is going to be coming in from orbit and wants to present as large a surface area as possible to shed orbital speed, give some measure of control, and to slow down as much as it can before landing.
T+06:31 : To my surprise, the 2 engine that seems to have failed during accent are the one to ignite for the landing. I'm guessing those two engines were planned to ignite to make the SN8 flip rapidly before landing but I'm not sure.
T+06:36 : The first engine that failed during ascent start bursting green flame? Is it because a propellant is missing?
T+06:39 : The other engine (second that failed during assent) stops. Out of propellant?
But all in all, an amazing accomplishment. Can't wait for the next one!
Yeah, the green flame is most likely because of lack of propellant. The combustion chamber is copper and is cooled by the liquid CH4. If there's no methane (or no pressure to feed it) then you'll have a bunch of hot oxygen and uncooled copper in the combustion chamber. Results: pretty green flame then spectacular fireball.
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I think the engine shutdown was deliberate. The wild engine gimbaling was just the response to a sudden change in the center of thrust. It looks extreme, but it seems to have done it's job.
The "skydiver" maneuver was planned. I believe it's to provide more drag for reentry in an actual mission flight.
Aaaaand if NASA had done that... (Score:2)
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For an unmanned flight, any landing that doesn't damage anything/anyone on the ground will suffice. It crashed in the perfect spot to make cleanup really easy.
Of course, no other launch provider is even trying to land orbital class rockets yet. Doing it at re-entry velocity/heat will be harder, but this test proved the skydiving maneuver fundamentally sound.
Re:Any landing you can walk away from... (Score:5, Insightful)
What you do need to keep in mind is that, prior to Starship, EVERY first flight of an orbital booster was just understood to result in destruction of the booster.
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Aside from the Shuttle, right? And possibly the Buran (although I'd discount it because the Energia was its booster and that was destroyed on each launch).
Re:Any landing you can walk away from... (Score:5, Informative)
Aside from the Shuttle, right?
The Shuttle boosters cost more to recover and repair than to build from scratch.
So that was actually worse than being destroyed.
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This is where the scientists might be smart in engineering, but pretty clueless in management of resources and money.
Collect the booster, and store it for analysis , but dont bother rebuilding it, just make a new one from scratch and tell management - we are reusing the Nasa logo, thats it. WTF is the point of refurbishment if its more costly and longer.
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Re:Any landing you can walk away from... (Score:5, Insightful)
>SpaceX proved that to be a big fat lie..
They really didn't - they weren't using shuttle boosters. And it's specifically the shuttle boosters that were more expensive to refurbish than build from scratch. Because really, the boosters weren't designed to be reused - as I recall they were just about down to just about only the metal tube being reused, and only after extensive examination and refurbishment.
That's down to several things - the biggest probably being that the boosters were dropped several miles out of the sky to land in the ocean. Oddly enough that really reduces how much equipment survives undamaged - even the stuff that survived the landing got soaked in seawater - and that's horribly damaging for precision equipment.
Gently landing the booster was a huge accomplishment for SpaceX, and something widely regarded as unrealistic by every major space agency in the world until they started doing it. To dismiss as corruption the lack of refurbishing of previous rockets, is to dismiss the incredible feats of engineering SpaceX achieved in both successful landings and designing rocket engines for cost-effective re-use.
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Morton Thiokol built the SSRB in pieces so that it could be shipped via the cheapest rail option (cheapest for them, not for NASA). Had they been built locally in a single piece (NASA's original design) they would have been stronger, lighter and more easily reused, but because Congress thinks that lawyers can design a better spaceship than rocket scientists they were built in Thiokol's main plant. The joints between the pieces also introduced the need for a seal between them, which is what failed and dest
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The problems were numerous, but include:
1) The boosters hit the water hard, with no attempt (apart from the parachutes in general) to slow before impact
2) They're solid rocket boosters. So you have to tear them apart entirely to reuse them, and re-cast the propellant.
3) Many major components, including the O-rings, were considered ruined by flight, let alone being in the ocean.
4) Many others were simply ruined by the seawater exposure.
It was reuse, but it wasn't particularly economically effective reuse.
Re:Any landing you can walk away from... (Score:5, Insightful)
WTF is the point of refurbishment if its more costly and longer.
One of the early design goals was a reusable launch system. The booster rockets were to be liquid fuelled and might even fly back. High costs and government cuts made that unaffordable so they substituted solid boosters instead and said they'd refurbish them.
Not refurbishing the SRBs would have been a failure, and that looks bad. Better, from the government and NASA management perspective, to spend more money and pretend you succeeded. The Space Shuttle had some amazing engineering but that wasn't enough to counteract the major political and management failures.
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WTF is the point of refurbishment if its more costly and longer.
A political decision had been made that the Shuttle boosters would be reusable.
Reusability, after all, was the whole point of the Shuttle.
The engineers were told to make it work, regardless of the cost.
Re:Any landing you can walk away from... (Score:5, Insightful)
That's what happens when you allow generals and politicians to run what should be an engineering program.
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ALWAYS?
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You can always walk away from a landing of an unmanned vehicle.
Not necessarily: landing (youtube) [youtu.be]
you insensitive git (Score:2)
My granddad was killed by a V1/V2/torpedo/runaway truck. And so on.
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You missed the memo [bbc.com], didn't you?
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Also keep in mind that SpaceX owes no great loyalty to the US, and could readily shift to launching from China, Russia, or just a little further south in Mexico if US regulations became too burdensome. And given his ego and ambition to reach Mars as quickly as possible, I could easily see him doing so.
Some engineers might object to relocating, but there's not necessarily any need for most of them to be on-site at the launch facility. And I suspect there's enough enthusiasm that most of them would be willi
Re:50 Shades of Success (Score:5, Informative)
You're an idiot. Prior to this flight, every orbital booster was destroyed. We didn't even try to reuse them.
So by your standard, notwithstanding the shuttle, every single spaceflight ever has been a failure, until Musk came along and tried to land rockets.
And, by the way, we didn't expect it to land successfully. The odds were about 30% going in.
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Considering how much went as they expected and the failure happened at the very end, the SpaceX team gained some very valuable experience.
SpaceX expected this flight to end in failure, that it failed at the very end of the test allowed them to gather as much information as possible.
I don't understand your complaints. We just witnessed a very success