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#2400
by
John Alan
on 20 Jan, 2016 17:12
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A quick fix would be fill the open joint gaps with something to keep water out... (grease?)
A more permanent fix is add seals or hoods to keep dripping water out of joint gaps...
Suggest SES-9 gets the quick fix and the later happens as time allows...
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#2401
by
deruch
on 20 Jan, 2016 21:50
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Edit: you've since added some citations, but specific references to erroneous text in my original post would still be helpful so I know what you're objecting to.
Your interpretation implies that this case was somehow new or unusual for the FAA or that it was a stretch for the FAA to justify. The FAA has issued very similar Acceptable Risk Restriction waivers before using the same criteria and the same rationale, and expects to do so again. The Debris Containment Requirements waiver is a bit odd (mostly for what it does not say). SpaceX asked for a waivers (or more precisely were told they had to petition); there is no suggestion that SpaceX asked that the USAF's criteria be used.
<snip>
As a matter of fact, in that first waiver they said that they had previously granted a similar waiver to SpaceX on a previous launch. A little google-fu shows that there were actually 3 previous waivers for SpaceX. One for each of the two COTS demo missions and one for the CASSIOPE launch and was related to it being the first launch of the F9v1.1 and specific weather patterns for VAFB (i.e. presence of inversion layers messing with potential shock waves).
Both previous waivers make for
very interesting reading. With lots of ancillary info. I especially eye grabbing was the part of the CASSIOPE waiver where it says, "The Falcon 9 v1.1 is a new launch vehicle.
The U.S. Air Force has determined that its overall failure probability is nearly fifty percent for each of the first two launches." (emphasis added)
There's a bunch of other interesting stuff in there; definitely recommended reading (mainly cots 1 and cassiope). But most of it isn't relevant to Orbcomm or RTF, etc.
COTS 1 waiver-->
https://www.federalregister.gov/articles/2010/12/06/2010-30402/waiver-of-acceptable-mission-risk-restriction-for-reentry-and-a-reentry-vehicleCOTS 2/3 waiver-->
https://www.federalregister.gov/articles/2012/04/24/2012-9737/waiver-of-acceptable-risk-restriction-for-launch-and-reentryCASSIOPE waiver -->
https://www.federalregister.gov/articles/2013/08/27/2013-20726/waiver-to-space-exploration-technologies-corporation-of-acceptable-risk-limit-for-launchedit: found and included third waiver (cots 2/3)
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#2402
by
ZachS09
on 20 Jan, 2016 22:01
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So the next question.
Since the leg failed to lock in the last attempt (Jason 3), will that alter the risk levels for future attempts?
Had the leg failed in the Orbcomm mission; landing at the cape would have had the same results (tip over and explode) correct?
Correct.
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#2403
by
CorvusCorax
on 20 Jan, 2016 23:02
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Both previous waivers make for very interesting reading. With lots of ancillary info. I especially eye grabbing was the part of the CASSIOPE waiver where it says, "The Falcon 9 v1.1 is a new launch vehicle. The U.S. Air Force has determined that its overall failure probability is nearly fifty percent for each of the first two launches." (emphasis added)
indeed, further down the waiver states:
Second, the estimated probability of failure to the Falcon 9 v1.1 is high because it is a new launch vehicle. There is no way to reduce this estimated failure probability, which is derived from the historically high number of launch failures in new vehicles. This probability of failure is one of the most critical variables in the E c calculations.
That means for any vehicle that does not have a flight record, the record used is basically the flight record of "previous new vehicles that did not have a flight record"
Did really half of all ever developed launch vehicles fail on first or second flight? If so, does SpaceX have a significant impact on that number for the future? All 3 Falcon 9 variants worked from the get go, but then again the first 3 Falcon 1 launches were failures. I guess it depends how exactly you factor that into the statistics.
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#2404
by
QuantumG
on 20 Jan, 2016 23:13
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Did really half of all ever developed launch vehicles fail on first or second flight? If so, does SpaceX have a significant impact on that number for the future? All 3 Falcon 9 variants worked from the get go, but then again the first 3 Falcon 1 launches were failures. I guess it depends how exactly you factor that into the statistics.
Yep. Makes you wonder about the business plans of smallsat launchers. Are they small because they expect to fail three times before their first paying flight and then they'll get bigger? Could SpaceX have started smaller and iterated faster?
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#2405
by
deruch
on 20 Jan, 2016 23:30
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Did really half of all ever developed launch vehicles fail on first or second flight? If so, does SpaceX have a significant impact on that number for the future? All 3 Falcon 9 variants worked from the get go, but then again the first 3 Falcon 1 launches were failures. I guess it depends how exactly you factor that into the statistics.
Given total number of launchers ever developed, SpaceX's successes/failures shouldn't have that much overall effect.
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#2406
by
cscott
on 21 Jan, 2016 01:59
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The high probability of failure used in the calculations just means "assume it will blow up and don't put any people in harm's way if/when it does". I've got no problem with that, even if the rocket doesn't oblige by exploding.
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#2407
by
Jim
on 21 Jan, 2016 02:29
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All 3 Falcon 9 variants worked from the get go, but then again the first 3 Falcon 1 launches were failures. I guess it depends how exactly you factor that into the statistics.
No, the first F9 launch was a failure. Uncontrolled roll at the end of the flight
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#2408
by
cuddihy
on 21 Jan, 2016 02:51
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Right but only in a mission sense, not increased risk of fatality way...
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#2409
by
QuantumG
on 21 Jan, 2016 02:54
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No, the first F9 launch was a failure. Uncontrolled roll at the end of the flight
The Dragon qualification unit didn't need the roll corrected, so they didn't correct the roll. I'm not sure they even would have had the second stage correct the roll if it was a real Dragon.. they'd just leave it to the Dragon's thrusters to correct. Not sure how you could qualify that as a failure. Seems like nitpicking.
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#2410
by
AJW
on 21 Jan, 2016 03:00
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No, the first F9 launch was a failure. Uncontrolled roll at the end of the flight
The DSQU was launched into orbit with telemetry reporting essentially a bullseye. It did roll early in the launch and after separation, but failed in the parachute recovery. Your standards for 'failure' appear to be quite different from the rest of the space industry.
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#2411
by
joek
on 21 Jan, 2016 03:17
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As a matter of fact, in that first waiver they said that they had previously granted a similar waiver to SpaceX on a previous launch. ...
Good googling. Those waivers (among others) are referenced and discussed in the rule change (link upthread).
FAA has issued waivers for every SpaceX and Orbital COTS and CRS flight, and for reentries by SpaceX.
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#2412
by
meekGee
on 21 Jan, 2016 05:31
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The DSQU was launched into orbit with telemetry reporting essentially a bullseye. It did roll early in the launch and after separation, but failed in the parachute recovery. Your standards for 'failure' appear to be quite different from the rest of the space industry.
Well there was no separation IIRC, but mission goals were achieved. The second stage fired twice, the second firing being an extra demo, not needed for LEO insertion. Roll occurred at the end of that.
Irrespective of the nits, the flight record of F9 (and subsequently SpaceX's trajectory) was beyond even this amazing people's expectations.
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#2413
by
woods170
on 21 Jan, 2016 06:48
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All 3 Falcon 9 variants worked from the get go, but then again the first 3 Falcon 1 launches were failures. I guess it depends how exactly you factor that into the statistics.
No, the first F9 launch was a failure. Uncontrolled roll at the end of the flight
Such roll would only mean failure if it prevented the primary mission objective from being reached. It didn't. At best it's an anomaly, at worst a partial failure.
The first flight of Delta IV Heavy was not a failure either, despite the underspeed. At worst it is classed a partial failure. Primary mission objective was still reached.
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#2414
by
cscott
on 21 Jan, 2016 13:44
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If we agree that "failure", for the purposes of this thread (discussing the waivers) consists only of events which increased risk to people or property on the ground, then we can focus a bit and avoid this tedious wrangling. The more general definition-of-failure discussion can go in the scrubs thread.
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#2415
by
Jim
on 21 Jan, 2016 13:45
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The Dragon qualification unit didn't need the roll corrected, so they didn't correct the roll. I'm not sure they even would have had the second stage correct the roll if it was a real Dragon.. they'd just leave it to the Dragon's thrusters to correct. Not sure how you could qualify that as a failure. Seems like nitpicking.
What says a Dragon or another spacecraft could have separated cleanly?
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#2416
by
Jim
on 21 Jan, 2016 13:47
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The DSQU was launched into orbit with telemetry reporting essentially a bullseye. It did roll early in the launch and after separation,
It rolled severely at the end of the second stage burn. It bad enough that Spacex cut the video feed.
There was no separation and the second burn failed.
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#2417
by
sublimemarsupial
on 21 Jan, 2016 14:18
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The DSQU was launched into orbit with telemetry reporting essentially a bullseye. It did roll early in the launch and after separation,
It rolled severely at the end of the second stage burn. It bad enough that Spacex cut the video feed.
There was no separation and the second burn failed.
So you agree the first flight of Delta IV heavy failed too right? Or do you just like to engage in revisionist history to make. You least favorite lawn chair company look bad?
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#2418
by
Jim
on 21 Jan, 2016 14:25
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So you agree the first flight of Delta IV heavy failed too right?
Yes, and so did one Atlas V
Or do you just like to engage in revisionist history
Just stating the facts and correcting those who were performing revisionist history
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#2419
by
Alastor
on 21 Jan, 2016 14:51
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Or do you just like to engage in revisionist history
Just stating the facts and correcting those who were performing revisionist history
Come on, guys, let's get back on topic.
That, or Jim gives a big nice kiss to Elon Musk to proove that he has really nothing against SpaceX ...
(On a side note, as per rule 34, I'm pretty sure there's a amazing people (or fangirl) from this forum, somewhere out there, writing a fanfic about the romance between Elon and Jim, right now !)
So, do you think FAA would consider the statistics of new vehicles on a general failure criterium, or specifically wether the failiure mode caused any danger to properties and population, when stating roughly 50% ?
(On a side note, as per rule 34, I'm pretty sure there's a amazing people (or fangirl) from this forum, somewhere out there, writing a fanfic about the romance between Elon and Jim, right now !)