Author Topic: SpaceX COTS Demo 1 Updates  (Read 638927 times)

Offline Jim

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Re: COTS Demo 1
« Reply #940 on: 12/08/2010 12:50 am »
I am just trying to counter balance the unwarranted and blind worship of all things Spacex.  I call a spade a spade.  I support Spacex but with tempered enthusiasm.

I was in the same boat at one time, supporting the first real commercial space company, Spacehab. 
« Last Edit: 12/08/2010 12:52 am by Jim »

Offline Chris Bergin

Re: COTS Demo 1
« Reply #941 on: 12/08/2010 12:52 am »
Still waiting for SpaceX to confirm tomorrow is on (should be).

Very long thread, remember people are looking for information so post if it's useful, not because it's fun to. And to the new people, Jim is probably the most qualified person you could ever wish to speak with on these things.
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Offline jimvela

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Re: COTS Demo 1
« Reply #942 on: 12/08/2010 12:52 am »
Now, now.  Jim's right.  They're just a bunch of kids playing with their backyard rockets...  They don't have a clue what they're doing.  Put the Kool-Aid away...  I seem to remember him saying they wouldn't get to orbit... after Falcon 1 flight 4, in fact...

Even a rocket expert is sometimes proven wrong.

He's right.

F1 Flight 1 > Failure
F1 Flight 2 > Failure
F1 Flight 3 > Failure
F1 Flight 4 > Success*  (Dummy payload)
F1 Flight 5 > Success

F9 Flight 1 > Success * (Couldn't re-start 2nd stage, steering failure on 2nd stage engine).

By my count they're no better than 50% launch success rate at present.

What is racking up is flight heritage on the Merlin 1 series engine.  F9 Flight 1 more than doubled the runtime on the engine, and F9 flight 2 will again nearly double the runtime on the engine.

If there is no problem with the Merlins on F9 Flight 2, there will be a significant amount of runtime on the design- and that is at least very promising.

Offline llo2015

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Re: COTS Demo 1
« Reply #943 on: 12/08/2010 12:55 am »
Since I just checked, I thought I would share: Gibraltar is at 36N

Thanks for your info -

Launch Azimuth of 69.7° from KSC/Cape Canaveral corresponds to an orbit of 34.5° inclination.  This launch azimuth takes the Falcon-9/Dragon in a direction north of Bermuda and a subsequent over-flight track over Gibraltar and the Mediterranean makes sense.

Concerning Jay Barbree's question, Europe or Gibraltar are basically the same concerning his main point which was over-flight due to an event of an engine-out late in powered flight and the potential consequences of an uncontrolled descent.

It's still pretty weak sauce.  By the time in F9's flight where it's IIP (Instantaneous Impact Point--the point you would hit if you lost power at any given second) is crossing over any populate area, the IIP is going to be moving so fast that the actual odds of it hurting anyone are ridiculously low.  This isn't having your IIP passing over a densely populated are right as you're doing stage separation or something like that.  This is well into the 2nd stage of flight. 

Part of the launch license that SpaceX filed involves calculating E-sub-c (expected casualties).  That's the expected number of people to be hurt from a given flight.  FAA will not let you fly if your E-sub-c is greater than .00003 (30x10^-6). 

The odds of SpaceX's F9 failing at the exact instant it would take to actually hurt someone in Gibraltar or Northern Africa is vanishingly small, even if you assume a 100% probability of launch failure.  Let's do the math.  Say your IIP is going at say 5km/s (IIP typically moves faster than your actual ground track--at the split second before your perigee gets above ground, your IIP actually is effectively going infinitely fast), and your flight is say 600s long, and the populated area is 50km long with people standing hand in hand along the flight path that whole way so there's a 100% chance of fatalities if the thing fails during that timeframe, you're only looking at 1.6% chance (50km/5km/s=10s, 10s/600s =.016).

Yawn.

~Jon

[Note: the specific numbers like flight duration and IIP velocity and 50km populated area were all total guesstimates pulled out of certain nether regions]

The nominal launch track and orbital insertion for a Falcon-9/Dragon launch occurs over the open Atlantic about 900 nautical miles from Cape Canaveral.  The over-flight issues only involves the case of a late in powered flight second stage engine-out event. 

In my view, the SpaceX representative should have told Jay that if that Falcon-9 missed orbital velocity, both the second stage and Dragon capsule could be maneuvered to a safe disposal in the Atlantic

Offline joshcryer

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Re: COTS Demo 1
« Reply #944 on: 12/08/2010 12:56 am »
I never disagreed with Jim about process. I explicitly asked my questions because I wanted to know from the guys who know things just where the process could've broken down (with regards to extension nozzle QC). Unfortunately I didn't get any solid answers in that respect.

See you guys in the live thread (and sorry for the button pushing about 100% Falcon 9 success, I'm not stupid, I know that's not a relevant sample size, heh). :)

Offline Kabloona

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Re: COTS Demo 1
« Reply #945 on: 12/08/2010 12:59 am »
I am just trying to counter balance the unwarranted and blind worship of all things Spacex.  I call a spade a spade.  I support Spacex but with tempered enthusiasm.

I was in the same boat at one time, supporting the first real commercial space company, Spacehab. 

It seems to me that the only "blind worship" I've seen on this forum is from people who haven't been in the business and don't have firsthand knowledge of how hard it is.

It seems that the people on this forum who have been in the business are, in fact, the ones with "tempered enthusiasm." They know it's not easy, there are going to be growing pains and some failures, but they respect and admire what SpaceX has been able to do, and what they may be poised to accomplish.

Can't speak for everyone, but that's how it looks to me.

Offline beancounter

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Re: COTS Demo 1
« Reply #946 on: 12/08/2010 01:09 am »
I'm not in the business but was wondering whether 'test flights' are counted when considering a company's launch success/failure statistics.  Seems to me that flights specifically identified as test flights shouldn't be considered part of the launch statistics or at least a disclaimer acknowledging the basis behind the statistic.
By that measure:
F1 has a 50% success rate based on 1 failed satellite launch and 1 successful.
F9 has no record at this point since flight 1 was clearly a test, and the COTS flights are demo's or tests to prove up the system by any other name.
Cheers.
Beancounter from DownUnder

Offline Kabloona

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Re: COTS Demo 1
« Reply #947 on: 12/08/2010 01:13 am »
I'm not in the business but was wondering whether 'test flights' are counted when considering a company's launch success/failure statistics.  Seems to me that flights specifically identified as test flights shouldn't be considered part of the launch statistics or at least a disclaimer acknowledging the basis behind the statistic.
By that measure:
F1 has a 50% success rate based on 1 failed satellite launch and 1 successful.
F9 has no record at this point since flight 1 was clearly a test, and the COTS flights are demo's or tests to prove up the system by any other name.
Cheers.

Depends on whether you're a "blind worshiper" or a "tempered enthusiast."  ;)

Offline beancounter

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Re: COTS Demo 1
« Reply #948 on: 12/08/2010 01:21 am »
I'm not in the business but was wondering whether 'test flights' are counted when considering a company's launch success/failure statistics.  Seems to me that flights specifically identified as test flights shouldn't be considered part of the launch statistics or at least a disclaimer acknowledging the basis behind the statistic.
By that measure:
F1 has a 50% success rate based on 1 failed satellite launch and 1 successful.
F9 has no record at this point since flight 1 was clearly a test, and the COTS flights are demo's or tests to prove up the system by any other name.
Cheers.

Depends on whether you're a "blind worshiper" or a "tempered enthusiast."  ;)

Originally blind enthusiast turned to tempered enthusiast due to some considered study and also info' on this site.
That said, have to admire Musk for putting his money where his mouth is (along with others including NASA whom he has credited on several occasions), when he could have taken his earnings and retired to the Bahama's or wherever.

That said, 12 months should prove one way or another.  He's either got a system that works or can be made to work or he hasn't.  In the meantime, it's makes for interesting viewing.
Beancounter from DownUnder

Offline tigerade

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Re: COTS Demo 1
« Reply #949 on: 12/08/2010 01:22 am »
I am just trying to counter balance the unwarranted and blind worship of all things Spacex.  I call a spade a spade.  I support Spacex but with tempered enthusiasm.

I was in the same boat at one time, supporting the first real commercial space company, Spacehab. 

Yeah, there's nothing wrong with a healthy dose of skepticism.  However I think your view pushes towards being a bit scrooge-ish.  I mean, yeah you are right on a technical level.  But the people at SpaceX are human beings, and so are we.  It's not like they are sitting around a camp fire saying "Hey let's launch a space rocket someday".  They got a rocket, they got a space capsule, they got the systems to make it happen.  They've put millions of dollars into their investment, putting their money where their mouth is.  I've heard about employees there staying for long overtime after dark.  They are working hard.  That's what's warranted... the idea that hard work and dedication can accomplish something.  I would not be so quick to splash a bucket of cold water on their faces.  I would need to see a few more failures to give them a grim reality check.

Offline Jim

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Re: COTS Demo 1
« Reply #950 on: 12/08/2010 01:23 am »

In my view, the SpaceX representative should have told Jay that if that Falcon-9 missed orbital velocity, both the second stage and Dragon capsule could be maneuvered to a safe disposal in the Atlantic


There is no "maneuvering".  Launch vehicle are autonomous, they are not controlled from the ground, except for one command. And "command" may not affect the capsule, which would continue in its ballistic trajectory.
« Last Edit: 12/08/2010 01:23 am by Jim »

Offline Jim

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Re: COTS Demo 1
« Reply #951 on: 12/08/2010 01:26 am »
My main point is not that they will or not have successful flights but that they won't be any different than others in the same field. Their costs/prices will be similar.

Offline Robotbeat

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Re: COTS Demo 1
« Reply #952 on: 12/08/2010 01:29 am »
I'm not in the business but was wondering whether 'test flights' are counted when considering a company's launch success/failure statistics.  Seems to me that flights specifically identified as test flights shouldn't be considered part of the launch statistics or at least a disclaimer acknowledging the basis behind the statistic.
By that measure:
F1 has a 50% success rate based on 1 failed satellite launch and 1 successful.
F9 has no record at this point since flight 1 was clearly a test, and the COTS flights are demo's or tests to prove up the system by any other name.
Cheers.
I've been in conversations regarding this, but... a conservative approach is to include ALL launches.

Another approach might be to just count the last "n" flights, where "n" is a large number such that "one more failure" won't make a big deal in your overall failure rate (or basically assume that the next flight will fail). So, by that metric, SpaceX would need to hit AT LEAST the next 7 launches with no failure in order to hit Jim's 90% success rate. But that isn't a very large sample size. I would say a sample size of 20 is probably better, and then we're not too far away from the conservative metric, which says SpaceX needs to hit the next 24 launches successfully to be considered 90% successful.

*shrug* SpaceX will need many more successful launches for us to call them anything resembling reliable (of course, 90% reliability... "one nine"... would be unacceptable in almost any other industry, and won't be terribly acceptable even in this industry, especially for crew and strategic payloads).

Of course, if SRBs are considered 100% reliable, then so is SpaceX!
« Last Edit: 12/08/2010 01:31 am by Robotbeat »
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Offline Herb Schaltegger

Re: COTS Demo 1
« Reply #953 on: 12/08/2010 01:31 am »
It seems to me that the only "blind worship" I've seen on this forum is from people who haven't been in the business and don't have firsthand knowledge of how hard it is.

It seems that the people on this forum who have been in the business are, in fact, the ones with "tempered enthusiasm." They know it's not easy, there are going to be growing pains and some failures, but they respect and admire what SpaceX has been able to do, and what they may be poised to accomplish.

Can't speak for everyone, but that's how it looks to me.

That's a pretty good description of how I view SpaceX, personally.
Ad astra per aspirin ...

Offline joshcryer

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Re: COTS Demo 1
« Reply #954 on: 12/08/2010 01:36 am »
My main point is not that they will or not have successful flights but that they won't be any different than others in the same field. Their costs/prices will be similar.

There are already 30 launches on their manifest that are not "similar costs/prices."  ::)

What you are suggesting is that SpaceX is going to go bankrupt.

Offline telomerase99

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Re: COTS Demo 1
« Reply #955 on: 12/08/2010 01:46 am »
Yahoo news quotes Gwynne Shotwell as saying that the launch is no earlier than Thursday as of a few hours ago.

If that is the case, why is everyone saying that the launch is tommorrow? Is it just out of date information?

Offline Bubbinski

Re: COTS Demo 1
« Reply #956 on: 12/08/2010 01:48 am »
I sure hope it's tomorrow!  I have the day off. 
I'll even excitedly look forward to "flags and footprints" and suborbital missions. Just fly...somewhere.

Offline robertross

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Re: COTS Demo 1
« Reply #957 on: 12/08/2010 01:49 am »
Yahoo news quotes Gwynne Shotwell as saying that the launch is no earlier than Thursday as of a few hours ago.

If that is the case, why is everyone saying that the launch is tommorrow? Is it just out of date information?

Read back a bit. NASA was apparently jumping the gun a bit, but a SpaceX rep tried to set things straight(er). But if that (your news) was a few hours ago, then in may be stale.

Offline joshcryer

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Re: COTS Demo 1
« Reply #958 on: 12/08/2010 01:49 am »
telomerase99, no early than launch is Wednesday, which NASA has been repeating. SpaceX announced that things looked good but that they wouldn't know until 9:00 PM EST, which was about 50 minutes ago. We're just waiting for SpaceX to make the official statement. Could be any minute now.

Offline Jim

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Re: COTS Demo 1
« Reply #959 on: 12/08/2010 01:56 am »

There are already 30 launches on their manifest that are not "similar costs/prices." 


Not all real launches.  Wait until they launch a real spacecraft and not Tang, tee shirts and toilet paper or multiple spacecraft

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