Falcon 9 Dragon Launch Scrubbed
This morning’s attempt to launch a Falcon 9 with a Dragon spacecraft was scrubbed when a high pressure reading was discovered in first stage engine 5. The launch vehicle is now being put into safe mode. The next launch window will be on Tuesday at 3:44 am EDT.
Marc’s update: Here’s my story and the post-launch attempt briefing video.
SpaceX Falcon 9 Dragon Launch Scrubbed (Updated with video)
“Right up to t-minus 0.5 seconds it looked like there was going to be a launch. Unfortunately the Falcon 9 computer shutdown the rocket just as it was set to launch due to a high pressure reading on engine number 5, one of nine engines on the Falcon 9 first stage.”
Folks:
Good! Spacex doesn’t launch unless it’s safe. See ya on Tuesday.
Look, failure is going to mean more than success on this flight. Failure will be touted far and wide, whereas we’ll have an uphill battle convincing the public that America’s human space program is back on track if it succeeds.
tinker
Absolutely.
SpaceX is under enormous pressure. NASA too. The more they can catch things on the ground, the better for all.
Everyone’s impatient, but for different reasons.
You have to have the patience of Job to do what they are doing. The hard part of changing the launch services market means to evolve a different platform/model/processes/CONOPs than basically what the military initiated and ULA optimized – which can’t be the same.
With only one model for success, it’s easy to conclude that’s the only way. And they are so close, there’s a temptation to push it into that model and accept “half a loaf” success of partially lower launch costs, rather than learn/gain experience to make the newer model work.
We also don’t know if the newer model will ever work – the old hands at this have many well-earned scars to be skeptical rightly. But even the most skeptical of them would love to be proven wrong, given a massive gain returned.
So we need this to play out – all the way out.
You want to focus on Alan Lindenmoyer’s evident concern – my read is that he saw enough issues developing at the last seconds to concern him of a “white knuckle ride”.Â
His concerns are my concerns for COTS 2+.
 What are Mr. Lindenmoyer’s specific concerns?
any new space system is go to have problems I am sure they will sort it out
How is this a failure? The launch was aborted to investigate the high-pressure buildup. The rocket didn’t blow up. Now that would be a failure.
The troll’s comments were removed.
I don’t think this joint program between spacex and nasa is working very well.
If you watched the nasa and spacex briefing you can feel a certain uneasy tension between the two teams. When the guy on the right started to speak he just kept says “we are ready, space station is ready, launch window ready, we are ready, and finally we are ready when spacex is ready”
I’m beginning to think that the nasa folks don’t want spacex to be successful and don’t like the whole idea of a private capsule rendezvous with ISS.
Compared to the other tests launches that Spacex put on this one seemed a little more stuffy to me. Not sure way?
It also felt like Nasa was spending as much money to watch Spacex as they spent doing it.
 The unspoken truth here is that many fear that we are already dependent on this launch going well – for many, many reasons that can’t be admitted to.
So NASA is clearly anxious, and for very good reasons. My read is that both pro- and anti-Â “commercial” factions are highly critical.
SpaceX is ready. But they aren’t experienced. Nor is NASA experienced in the way SpaceX does launch services. Looks to me like the engine evaluation was highly unexpected … remember it has been awhile since a new launcher has been on the cape … and even more … they are regarding this as a HSF vehicle … even longer since a new HSF launcher.
People highly underestimate what its like to do this – everytime its a new experience. Uncomfortable. Because historically we have done too little of this over too long a time.
Ironically, as a side effects of this, a) the value of the novel experience gained is thus in excess of the budget consumed – because it predicates a known result by that path, b) all other like contemporaneous efforts perform in the shadow of this experience and will be measured/adapted by it, and c)Â schedules/budgets of all of these efforts will depend on how these first test flights work out.
In short, Falcon/Dragon sets much of the outcome for all followers simply because they are first.
NASA knows this all too well.
Yohan is right –
While the US Government has given SpaceX about $450 million in COTS funds, all we have are two successful flights, two classes of rockets, five different engines, and a capsule that has orbited the earth twice and landed safely.
Meanwhile, the $7 Billion dollar SLS program is stuck on powerpoint. Â
The delays of SpaceX haven’t cost the taxpayer a dime, thanks to SAAs. Â
Because SLS is so far behind Orion has to ride a Delta IV Heavy and is costing $100s of millions in additional spending. Â
The SLS mafia will continue to be exposed for the frauds that they are. Â People can hate on SAAs, COTS, CCDev, and the continued push for privatization. Â However, it will not stop.Finally, clearly you have no clue of what you are talking about – the NASA/SpaceX team is very close. Â The communications are very good.
The only people who do not want SpaceX to be successful are the politicians and certain centers which will loose billions of taxpayer dollars annually once the private sector proves itself.
You have about three more years SLS.
Respectfully,
Andrew GasserTEA Party in Space
I would say this morning’s test was a real success. It demonstrated the ability to quickly analyze the situation and maintain control over it. Not a failure by any means or interpretation.
I’ll agree, the SpaceX scrub is not a failure by any means, but it’s not a success either. Being able to scrub safely isn’t something special, it’s the minimum that should be expected from any launch provider. The mission objectives are clear, and success can be declared when those objectives have been achieved. As of now, SpaceX has yet to fulfill those objectives.
1) If SpaceX is maxed out on weight on a simple cargo flight and have just enough fuel to get to the ISS launching at the most optimal window, how does he intend to launch a heavier manned dragon or, following up on his lovely animation, to launch a fully reusable F9 w/Dragon with all parts having heatshields and fuel to return to launch site?
2) If they’re having this much problems with 9 engines, how will they manage to launch 27 engines on time?
 Jim:
1) The fuel margin Spacex is reserving is for the Dragon capsule which will have to maneuver three times as much as a routine mission plus having some left over for contingencies. The second stage will have lots of fuel left over which won’t be used because it doesn’t fit the flight profile. Falcon/Dragon have the fuel margin for a full-up mission and will have even more payload capacity when Falcon 9 v1.1 hits the launch pad next year.
2) Soyuz first stage has five engines, twenty combustion chambers and five separation events in three stages. Falcon is simpler .
tinker
Falcon is simpler. didn’t know that 🙂
“Everything should be as simple as possible, and no simpler.” Do not confuse component reliability with system reliability. Redundancy through the intelligent use of more components can be a highly effective technique for system reliability. Â
At least liquid fueled engines can be shut down if there is a problem. You don’t have that option with solids, which I have seen blow up at least four times. SpaceX is the only company that uses only liquid fuel. Atlas uses a medium sized (1.55m diameter) solid fuel booster, similar to the one which blew up on a Delta a few years ago, and the Liberty and SLS both use ATK’s giant SRB, the most problematic part of the Shuttle propulsion system.Â
The last failure of a solid rocket motor on a US launch vehicle was a Delta 2 Jan 17, 1997, over 15 years ago, not quite what I would call a few years. I found a SpaceX sponsored study that shows the failure rate between liquid and solids are about the same (from 1984 to 2004 solids had 7 failures and liquids had 6 failures).
Wasn’t the first shuttle accident occurred because of solid rocket booster failure?
 If you get away with driving a truck filled with high explosive into a city as your “daily driver” for years … that does not make it a safe practice.
Do not confuse safe handling record of an unsafe object as improving its intrinsic safety – it is still unsafe. This gets drilled into your head if you ever routinely use munitions – it is also the origins of gun safety / handling.
Case in point – nuclear weapons. They are designed to be benign (even in accidents) until armed. Solids by definition aren’t.
What would they need to be as safe as nuclear weapons? Something to inhibit combustion – like happens with hybrids.
Solids are thus unsafe by chosen economics in design.
And people use mind games to make them seem otherwise. It is unworthy of any great culture to indulge in this.
Where are solids ideal? Weapons. Inert/loss tolerant payloads.
However, look what happens if you get cheap, reliable, safe LV’s that are liquid. Does the price for solids go up or down?
Down. And so does available market size for them.
The more recent explosion of the VLS at Alcantara, with over 20 fatalities demonstrates that solids have hazards that are difficult to mitigate. Liquid fueled launch vehicles remain relatively safe until fueled. And although both can explode, and have resulted in deaths, the fact that solids are hazardous all the time makes handing them more dangerous and expensive. As the SRB demonstrates, they also are not economically reusable.
There’s also the 48 people killed in 1980 during fueling of a Vostok-2M rocket. I believe it used the same fuel and oxidizer as the Falcon, RP1/LO2.
This sounds like a similar issue, from what Ms. Shotwell said in the press conference.
http://spacenews.com/civil/…
More on that:
An Oxygen-Rich Shutdown Is Still a Shutdown.By Jim Hillhouse http://www.americaspace.org…Â
 Bob Clark
Link’s broken. Article can be found here:
http://www.americaspace.org…
Less-then-expected fuel flow could certainly have let the engine get oxydizer-rich and over-pressurized it.
The Space Shuttle experience should have more than adequately prepared us to expect this sort of thing. This is a company taking its first baby steps. To expect the company to start waltzing with their very first steps is a bit ridiculous. (though I agree it would be cool if they did) As an ex-banker I salute their prudence and caution.
If spacex has to replace an engine which takes only a few days how does that stack up with other rockets?
They are inspecting the engine why it is still vertical?? I would have thought that they would drop it as quickly as possible to get it inside, encase they are going to switch it?
About how long does it take to get this vehicle safe to drop?
What is the plus to inspecting it still vertical?
Still recall the comment on here something like “hard to make that many engines play nice together”Â
I as a kid I watched all the nasa launches leading up to the moon flights. I only watched a few shuttle flights till it became routine. I sure had fun looking forward to this attempt as I will the next.
As long as all of these problems are actually fixed for the next run it will only mean a better, more reliable rocket at the end of the day.
Good luck on the 22nd.
A launch being delayed is no big deal. Â A fully fueled rocket being cut off at T-0 is, at the very least, not the publicity SpaceX wants. Â The SpaceX cult finds a positive spin on everything, but not the general public. Â This launch was about as much perception than technology maturity. Â I highly doubt it would be launch on Wednesday, I expect more delays, but we’ll have to wait and see.
JJ:
Like Gwynne Shotwell said:
“It’s easy to criticize, more difficult to do good work…”
As I said in my first post…
tinkerÂ
… how do you know anyone that criticizes is not doing good work?
Is obvious you are part of the “SpaceX cult”. Â How many posts do you have just on this blog alone? Â All of them, of course, not with an ounce of objectivity or remotely question anything about SpaceX.
JJ, its obvious that you are part of the “Hate SpaceX” cult, so pot kettle black … once again.
Its certainly easier to criticize a company for a pad abort than it is to criticize SLS/Constellation, since a rocket that only exists on Powerpoint will never have the ’embarrassment’ of a highly-publicised pad abort …
As Frank Morring said today in AvWeek, pad aborts are hard to handle. The fact that SpaceX managed this one in a calm, collected fashion, saved the booster, spotted the N2 valve and replaced it in time for the next launch window says good things about the company’s professionalism.
It should reassure the critics who say that such boosters are riskier than old-line products. Professionalism is not a matter of company size, or sometimes, not even of experience. Instead it can be a straightforward matter of taking your highly complex work seriously.
Well JJ, here you go. Us folks here on NASA Watch can agree that a scrub is preferable to a loss of mission, and shouldn’t be considered a failure. But hey, that’s not going to stop articles like…
…try to supress your gag reflex, folks…
…”Failed space shuttle launch is really awkward”
http://news.yahoo.com/video…
If the title alone wasn’t enough to make you wince in pain, then check out the comment section at the end for opinions comparing this rocket to the recent North Korean launch attempt.
It’s sad to think that this is how a measurable portion of the public views our space program.
So how do you get the word out that getting a new human rated vehicle is hard and a test rocket is a test rocket.
Hummm
Maybe we should go back in time and ask Mr. Robert Goddard. Lol I guess he would just throw up his hands and mutter something like F em!
The more things change the more they stay the same.
Lol found my book tinker lol
When evaluating the criticisms of yesterday morning’s hold, we would do well to think of all the different things in play here; a mission to the ISS is only one of them. SpaceX is only one of them.
If the SAA/fixed price contracting model succeeds in an obvious way, it could and should change procurement policies not only at NASA but at the Pentagon. The military aerospace industry would stand to lose a great deal of money — not go into the red, mind you, but profits would be smaller. Imagine what the F-35 might cost if it were developed under an agreement similar to an SAA under a fixed-price, milestone-based contract, and paid for only if successfully developed and manufactured.
Is it any wonder, then, that aerospace firms have hired armies of lobbyists and trolls-for-hire like the Lexington Institute to denigrate commercial space as everything from “unsafe” to fraudulent to a waste of money? The truth matters less than the number of votes you can control in Congress and there is a great deal of money at risk.
The SpaceX business model, using minimal outsourcing and a short, local supply chain also militates against the way things are now done in the aerospace industry. SpaceX is saving money and achieving high quality by NOT going offshore where labor is cheap and regulation is lax.
Were the SpaceX business model shown to be significantly more effective, and less costly to the taxpayer, the aerospace gravy train could be derailed. Much better for the old-line companies if SpaceX fails, and FAR/cost-plus procurement is enforced (that’s already been tried, BTW).
Finally, there is the probable loss of launch business by companies such as ULA. If SpaceX+SAA+milestone payments+fixed price is demonstrated as a cheaper way into LEO, ULA could take a major hit, as could Ariane.
Some of the criticism is coming from old-space employees smart enough to realize that if new-space succeeds their employers will have to restructure dramatically, and their jobs may be casualties of that restructuring. Can’t blame them for worrying, but I do draw the line at unwarranted sniping simply designed to create a bad reputation where none is deserved.
Of course you have to add to that the fact that most Americans are illiterate where technology, engineering, and systems development are concerned. They also have short attention spans and a desire for instant gratification–the idea of a testing period interferes with that. So some of the criticisms are just childish wailing.
So this is not just SpaceX fans supporting the home team, it’s also about backward-looking companies (and their employees) who have profited for decades under the old system, using inefficient business models to make large amounts of money. It’s also about poorly educated citizens using an Internet where anyone can comment regardless of expertise.
It’s a safe bet that lots of the criticism we are seeing has its roots in misunderstanding coupled with a desire to sink potential competitors.
 Dead on comment here – gets the “gold star”.
Cost plus has a point. Its for “Manhattan projects” – things you absolutely must have … or your country dies. So we need it … sometimes really, really badly. We need it.
And we can never allow said tool to be misused. Cause then we’ll lose it.
One way it’s misused is in a fear culture, panicking all the “chicken littles”, so they run around screaming “the sky is falling, the sky is falling” – “Mr Congressman, you just gotta spend money! Give it to Boeing/Lockheed/ATK/… fast!”.
Because then its in a businesses interest to raise the fear (like with the so-called post Shuttle gap) with “too big” projects that fail … to up the ante on the next try.
Saturn / Shuttle got dominated by “cost plus”. We spent unwisely yet got what we needed, but the habit remains.
HSF is transitioning from a cold war circus act/competition to a embryonic industry segment in the “maybe” category. While too soon to run for deterministic economic yields, it is too late to overplay by the old rules of outspend and “bury the rival” (Khrushchev). This is especially true with China – you must, must, understand China.
In this, you must realize that its not enough to, say, go to the moon to win. You need to be able to win and keep it up next win after win after win for decades. So you build and refine an architecture for winning, that keeps getting cheaper/better as you use it.
Shuttle didn’t. Saturn / SLS couldn’t – they are specifically designed to be more and more expensive as they grow. Whatever way you do it, the incentive has to be not on outspending but on getting more for your buck than the other guy ever can do, so no matter how much he spends, you win more and he quits the game!
Scrubs happen, such is life. But I refuse to allow folks to just say this is the greatest thing, especially when folks used to rip us Shuttle folks when we scrubbed. and..yo…Gywnne Shotwell….there is no such thing as ‘aborted with purpose”..
I never minded a Shuttle abort; the system had a lot of complexity and it was easy for some component to be out of spec. Better safe than sorry. The Falcon is only on its third launch and unanticipated failures are very common in the first few launches of most LVs, see Chan’s seminal paper “Space Launch Vehicle Reliability”.
What I minded was man-rating the Shuttle on its first flight. Not only was this extremely dangerous but it made it hard to make design changes, even to correct obvious problems like the SRB joint leakage. Under no circumstances would I put people on an orbital launch vehicle with less than 10 successful flights under its belt.
Just a thought here. Although SpaceX is touting that having nine engines makes the vehicle more reliable, Falcon 9’s also subject to the famous engineering “airplane rule”, namely:
“Complexity increases the possibility of failure; a twin-engine airplane
has twice as many engine problems as a single-engine airplane.”
Note that the airplane rule doesn’t talk about the success of the mission itself – if Falcon 9 loses an engine in flight, it can still make orbit on eight, just like a twin-engine airplane can fly at reduced performance on one engine – but it’s more meant to address maintenance cost. It says that the more parts you have, the more likely you are to have a part break. Unless SpaceX plans to launch with a known problem with one engine (which, they’ve shown here, they don’t, and I can’t say I blame them for that), then it’s reasonable to expect that they’ll have a higher launch scrub rate due to engine problems compared to most of their other US launch competition.
In other words, this scrub didn’t surprise me.
The nine engine configuration seems partly due to the rapid transition from the Falcon 1 and the higher initial development cost of a larger engine like the planned Merlin 2. However assuming a cause for the engine failure can be determined and corrected, it will not contribute to the expected failure rate in the future. The fact that the other 8 engines did light properly, conversely, will lower the expected failure rate for the next launch. If the cause is not found, of course, the expected failure rate for the next launch would be increased. Eventually SpaceX presentations suggest the want to go to a single engine.
Basically, the reliability of each engine (a number between 1 and 0, hopefully close to 1) is multiplied by each other to come up with the overall reliability. So the more engines you have, the higher the lower the reliability is. When you can have a really reliable engine though you could have a higher overall reliability compared to a more complex single engine (ie 0.99×0.99×0.99=0.97 for 3 engines compared with a 0.95 for a single complex engine).
The reliability of an engine can be difficult to determine. Would the failure cause mission failure (the rocket couldn’t make it to orbit with one engine out or an engine failure take out other engines as well).
Actually, I think SpaceX takes the opposite philosophy – that system reliability is increased by using fewer engines. At least according to their web site:
http://www.spacex.com/falco…“DESIGNED FOR MAXIMUM RELIABILITYThe vast majority of launch vehicle failures in the past two decades can be attributed to three causes: engine, stage separation and, to a much lesser degree, avionics failures. An analysis of launch failure history between 1980 and 1999 by Aerospace Corporation showed that 91% of known failures can be attributed to those subsystems.ENGINE RELIABILITYIt was with this in mind that we designed Falcon 1 to have the minimum number of engines. As a result, there is only one engine per stage and only one stage separation event per flight.”
You’re looking at the Falcon 1 page. From the Falcon 9 page, under the Engine Reliability section:
“Falcon 9 has nine Merlin engines clustered together. This vehicle will be capable of sustaining an engine failure at any point in flight and still successfully completing its mission. This actually results in an even higher level of reliability than a single engine stage. The SpaceX nine engine architecture is an improved version of the architecture employed by the Saturn V and Saturn I rockets of the Apollo Program, which had flawless flight records despite losing engines on a number of missions.”
http://www.spacex.com/falco…
I agree with dogstar3 that the real reason the F9 has so many engines is that it was cheaper just to reuse and cluster the F1’s engine. The “F9’s nine is better than S5’s five” reliability angle is probably just spin from some engineering-challenged marketroid.
Good point – looks like their web site could use some editing for consistency. Makes sense that the real reason F9 has nine engines was to save development costs by clustering their existing engine design and the ‘higher reliability with more engines’ spiel is probably just sales hype.
I believe also there is a function on cost versus reliability. Sacrifice some reliability to lower overall cost.
I believe Musk wants to bang those engines out for under a million if he isn’t there already.
Some of the news reports say the launch window was only one second. Anybody here have an explanation why it was so short? (Just curious, not trying to stir up debate.)
Bernardo:
Spacex is maximizing fuel margin for Dragon on this mission to give lots of leeway for two passes of the ISS plus contingencies. On future missions, even with a full load, Falcon launches will be more flexible.
tinker
Â
 Political pressure to be “operational”.
Is engine 5 the center engine and if so, wasn’t there a similar engine 5 problem on the first flight of F9?
YA:
Yes and yes to your questions. In theory, the no. 5 engine would have the shortest fuel/oxidizer lines. Could that be an issue? I’m sure Spacex is looking into that.
tinker
 Would make sense . Not to simplify things , in some diesel engines the high pressure lines are all of the same length to equalize pressure .
Interesting fact: “Spacex entire history, including rocket design, testing, and launch operations, has cost less than Facebook paid for Instagram”
https://twitter.com/#!/geor…
They don’t call it rocket science for nothing. A year from now, everyone will see this as the very minor glitch that it is. And SpaceX’s detractors will have moved on to other strategies for insisting that the young whippersnapper can’t possibly do what it says it’s going to do.
They stated that if the engine needed to be replaced they would swap it with another Falcon 9 that’s at the Cape. My question is why don’t they have spare ones standing by not attacked to any Falcon 9 to be replaced immediately for these situations. So, if the engine needs to be replaced they need to remove it from the second Falcon 9, and install it on this one. Would it not be better if they had a box with a spare engine ready to be installed.
 They test them together on a stand “as in use”. Then ship.
The idea is to minimize process risk economically. This is correct.
Do not obsess over the exceptional case and neglect the common case.
How you build an effective business. Never been done before with LV’s. Maybe they can do it. Maybe it will matter.
All before are variations in weapons system processes which may not follow an effective business model because they don’t have to.
From Elon: Engine pressure anomaly traced to turbopump valve. Replacing on engine 5 and verifying no common mode.
Oops, double post…
 Folks:
Woo Hoo! Sounds like we’re good for a Tuesday morning launch… as well as another failure mode identified and hopefully mitigated.
As test flights go, it’s already producing results.
Take that, naysayers! 🙂
tinker
Are they launching to cargo mission requirements or human rating? Wonder if they would have gotten flight rationale that quickly if it would have been a manned mission.
 engineer:
No, probably not. At least we hope not. By the time Falcon launches crew Dragon the bugs will be worked out.
tinker
tinker
Lets just hope they got the bugs worked out on the approach and docking system. Since they will interface with a crewed vehicle.
I woke up , went outside , and realized a few minutes later that it didn’t go as planned . I’m glad SpaceX is being careful with this launch though .
This is the first time in a long time there has been so mutch news coverige with out some thing blowing up.
For the abort, it seem to be a valve that caused the problem. So tuesday lanch is on . Cross fingers.Â
Official update from SpaceX:
“We have discovered root cause and repairs are underway.
During
rigorous inspections of the engine, SpaceX engineers discovered a
faulty check valve on the Merlin engine. We are now in the process of
replacing the failed valve. Those repairs should be complete tonight.Â
We will continue to review data on Sunday. If things look good, we will
be ready to attempt to launch on Tuesday, May 22nd at 3:44 AM Eastern.”
It would be very interesting to know why the check valve failed. One does not replace a fuse without first learning why it blew.
I have always plugged new fuses in .. problems were usually self evident.
Well, there you go: you knew what the problem was, and presumably fixed the cause of it, before pressing on.Â
Bernardo:
Valid point. That was Spacex doctrine then. Falcon 9 is a tradeoff between complexity and launch success. “The truth last week is not the truth today” sort of thing (A comment used in business for years to explain… change).
It has been rumored for some time that Spacex is working on a large engine, although fuel and maximum thrust vary with each telling. They may be working to regain that original philosophy. I think we’ll find out soon enough. Elon Musk has so much as said that he’ll be revealing a full blown Mars strategy within a year. All this work they’ve done over the last decade gives Spacex some pretty good idea of how to build stuff and how much it’ll cost. Development is determining what materials to use and what shapes they made into. The more they learn, the more they can do. The more they can do, the more they learn. It’s a bootstrap process and Spacex is well on it’s way.
tinker
Â
It’s amazing what can happen when you have a goal that you stick with. Develop a PLAN to achieve that goal and go for it. No congress, no elections, no pork.
May I suggest that NASA find a way to educate the public to support ELONS plan when it’s revealed and we go DO something in space or on Mars.
NASAs new role as NACA for new Space lol
SpaceX confirms the faulty valve was replaced and things are looking for a Tuesday launch attempt.
 This was done at the pad with no roll-back?
Yes
 MM42:
The rocket engines are right there at the bottom. Easy access.
It wouldn’t surprise me in the least if Spacex does a static test before launch. It’s gotten them to flight before. They should make a pre-launch static fire routine, especially on these ones that have short launch windows. They have a customer to please this time.
I’m sure folks will liken this valve change-out to the (some say reckless) second stage nozzle nipping (trimming) before Falcon 9/Flight 2… if they haven’t already.
tinker
Ah yes, a static test… something that is hard to do with a solid.
A solid has fewer moving parts than a liquid so it’s not necessary.
Wouldn’t this be considered an abort rather than just a scrub?
Some news articles have been using the word “scrub” and some the word “abort”. Who cares?
There’s no dispute about what happened: the engines were turned on while the vehicle was being held down, then they were turned off. The vehicle was never released and there’s nothing to prevent another launch attempt in short order. Why manufacture an artificial dispute about the word “scrub” versus “abort” when to many people either word is fine for this situation?
IMHO there is a significant difference between a scrub and an
abort.
Scrubs are called by the launch team during the countdown when a
certain parameter is outside the required limits. In that case the team decides
that they cannot safely launch, before the commitment of engine start is made.
If the launch is aborted the commitment to start the engines has
been made and the system is in control and stops the nominal launch sequence.
To put it bluntly:Â
Scrub: Test team decides no go.
Abort: Hardware/software decides no go. After the test team
‘though’ they were ready.
A few people are still badmouthing Apollo 13 which was a huge success for NASA and the engineering community. Not that the tank explosion was a good thing, but the capsule + LEM design had enough flexibility built into it so that some very inventive engineers on the ground could bring the crew back alive.Â
Some will always mistake success for failure if it does not meet their preconceptions.
There were certainly some positives to be seen in Apollo 13. But calling it a “huge success” is, I think, quite misleading. It was not billed as a test launch. It was billed as an operational mission. The mission objective was to land two astronauts on the moon and bring them back alive. That did not happen. I think a more accurate characterization is “disaster narrowly averted” rather than “huge success”.
 No, he’s right it was a success. Lets be clear on what that success was though.
The success was in having enough reserve capability in spacecraft / operations / teams that when things went wrong, we could accomplish “plan B” when “plan A” failed.
So people didn’t just sit around (like this thread) and pour out blame. It was part of the American spirit that we celebrated on the safe return of the crew. Everyone was pulling for the success. Not that it had to only come one way.
We don’t have a shared American spirit in this polarized climate today.
“It was part of the American spirit that we celebrated on the safe return of the crew. Everyone was pulling for the success.”
Everyone cheered when the Chilean miners were rescued. It’s not as if would no longer celebrate survival after disaster. But that doesn’t change the fact that a successful rescue is a successful rescue, not a successful mission. Saying the mission failed does nothing to diminish the success of the rescue, or the roles of those doing the rescue. People need to stop being so damn thin skinned about such things, otherwise we can’t learn from failure. “Criticism is the only known antidote to error.”
Hopefully constructive criticism. Lol
Paul I’m up waiting for the launch now. I feel like Spacex is at the base of a stack/house of cards and they are pulling cards out from the bottom and the house of cards could fall. I know it’s silly and optimistic, but it just gives me hope that a guy like Elon can be kicking ass simply by doing the right thing. We live in a rotten world were many people are all tangled up in some mess, and it’s funny to see when someone just does the right thing they get attacked by the hordes.
In the garden trying to grow some food. I live at 32 latitude only fair soil because these acres were hayed and the hay transported to other parts of the farm. My garden is located in the old cow holding pen because that is where the cows concentrated the most nutrients.
I once read that you could grow plants with lunar soil, Steve said that you can’t so I guess that means it lacks all the good stuff.
I know they recycle some waste on ISS and end up with water you can drink.
Well if we are serious about settling Space seems to me that saving every ounce of human waste is extremely important.
Does ISS burn up / throw out any human waste now? Wouldn’t saving a dragon trunk as a septic tank/fertilizer/water/methane/ factory/storage for that future Bigelow farm just make to much sense?Â
At the landfill there was a young man running it and he had a tomato plant near his work building. Well I asked him about it? And then started asking him if he had heard of Spacex or knew anything about space. He knew very little. He had heard that we had found a planet like earth but he had no idea how far away it was. So in 5 or 10 minutes I tried to give him a mini course on our solar system and our space program. I told him about mars and moon being the only two practical candidates to settle. And to make him understand that there are resources out there if we get wise enough to exploit them. Anyway when I told him about mars, the first thing he said was, how is the soil there lol???
Pretty dam wise I thought. Lol He instinctively knew that if we are going to space, one of the first things we better do is start getting our s$&@ together and start growing our own food lol
Anyway I thought it was interesting that agriculture and plants are a good vehicle to get people interested in space settlement.
Well I’m proud to say this idea was full of it.
Dragon trunk septic systems Inc.
I want to see tourists at the ISS tourist center eating home grow organic veggie pizzas before I turn to fertilizer lol.
Out!!!!!
Humm? I wonder how much left over oxygen is going to be in each dragon second stage before they toast them or save them.
How much hydrogen is in human waste? Can’t we be using dragon trunk solar cells to create some water and fertilizer with some of that junk??? Doesn’t oxygen leak through it’s containers walls if not used pretty quickly? Don’t we need oxygen to break down our waste? Can we process our waste on a dragon trunk and separate out water, methane and others important chemicals for future use? All this junk is still worth several  1000 dollars per pound in Leo right???
Lol pretty explosive idea I think. Better let these dragon trunk factories be free flyers for a while lolÂ
In my 30 plus years of launching stuff (including a few shuttles) the distinction between a scrub and an abort is this:
A scrub happens before the engines are committed to launch (either propellant valves opened and/or ignition sequence started) and an abort is after either of those two events have occurred. Subtle yes, but very different in how they are handled both in real time and post event.
Go Dragon!
Sounds similar to the definition of a scrub as compared to a delay. From what I understand it’s a scrub only after tanking has begun.  Seems to make sense as it’s all about the implications.  If you realize that a critical engine part needs to be replaced prior to tanking that’s one thing, you can go ahead and send a team out there. However if you realize that a critical engine part needs to be replaced after tanking has begun that’s a whole new ballgame which probably involves stopping tanking, draining, and safing the vehicle before you can even begin looking at the engine. And if you realize that a critical engine part needs to be replaced after propellant has starting flowing and/or engines ignited then you are in a whole different league that is very serious, especially if it is a manned flight. Of course there is yet another distinction if you realize that you need to replace a critical engine part after the vehicle has lifted off the pad (which obviously you can’t). In that case I guess you get into specific abort terminology like they had for Shuttle, like RTLS, TAL, or ATO if you think that you can get safely to a stable orbit in spite of your broken part.
Folks:
Seems the faulty check valve was in a nitrogen purge line, not the fuel line. That’s why Elon Musk said flying with the valve open would have been OK. A few sources say Spacex will fly Tuesday morning.
tinker
Will be up late again….Go Falcon! Go Dragon!
Yet under the same conditions, on the same flight, the highly-fragile over-engineered SSMEs worked fine.