SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION

[Steven Pietrobon]

I wonder if adaptive optics could be used to get an improved image. Here's a possible source.

http://www.stellarproducts.com/

Adaptive optics can only be used if you have a camera capable of bending/re-orienting its mirrors/lenses and guide point of light of known brightness and locality. It also cannot be done in post-processing. It is a live feedback effect done at the time of image taking.

Yes, I knew that. I didn't mean post processing of the existing video, but using an adaptive optics mirror to take the actual footage. Would it be possible?

[411rocket]

The static fire was just shy of two seconds. That is confirmed in L2 by hands on data observation. Any other suggestion is incorrect or (and I don't like people using harsh words) a misinterpretation.

Back to your regular programming.

PS We're coming to the end of this mission's coverage, but we'll keep things open until they retire the stage from testing.

That could be a while, until testing at 39A is done. Providing they keep to that plan, for this stage.

[Llian Rhydderch]

This was just posted in the update thread.  Important stuff. 

To start with, it would be cool if someone with a sharp technical mind and the ability to parse US government-bureau-speak would summarize the SpaceX request and the FAA action in each of these two waiver cases.

I hadn't seen these mentioned anywhere, they both related to the ORBCOMM-2 RTLS:

https://www.federalregister.gov/articles/2016/01/12/2016-00443/waiver-of-acceptable-risk-restriction-for-launch

https://www.federalregister.gov/articles/2016/01/12/2016-00444/waiver-of-debris-containment-requirements-for-launch

[Nomadd]

"A petition to waive the requirement that a waiver request be submitted at least 60 days before the effective date of the waiver"
 That sounds like a Scott Adams cartoon.

[DecoLV]

A rule prohibits launching rockets if a specific safety standard is exceeded. SpaceX applied for a waiver to this rule, but the launch was expected before the minimum time required for considering the waiver application (60 days). So, at the same time, it requested a waiver of the 60-day rule, so the application could be acted on without holding up the launch. FAA decided there was no hazard, thus granted both the application requirement waiver, and the waiver application itself.

[Herb Schaltegger]

It sounds to me like someone missed a deadline or else someone is considering or already has accelerated a timeframe and caused a deadline to be missed.

But that's just my take based on the title of the petition.

[cscott]

The body of the petitions makes it clear the first waiver was required based on the results of a USAF study, which was not completed before 60 days before the expected launch, and the second waiver was required after an FAA finding, which was also delivered with less than 60 days before the launch.  In both cases it is noted that SpaceX applied for the waiver shortly after being notified that one around be required, and also the waiver to the 60 days requirement at the same time, since it was already less than 60 days until launch.  If fingers were to be pointed, they'd be at the USAF and FAA, but I don't think any finger pointing is actually necessary---the bureaucracy has the ability to waive requirements like the 60 days rule when unnecessary, and they did so.

[abaddon]

Great find!  The interesting stuff:

The U.S. Air Force advised SpaceX that the preliminary calculation of E c for the launch, including the planned first stage fly back, shows the launch would exceed the 0.00003 limit imposed by section 417.107(b)(1). The 45th Space Wing Range Safety calculated the total unmitigated E c for the mission to be 0.000118 based on daytime populations on CCAFS, the worst-case December weather within the 45th Space Wing Range Safety data files, and 0.9665 reliability assigned to the flight computer with autonomous engine shutdown algorithms. The reliability of the human-activated flight termination system is 0.999. With mitigation, namely, the evacuation of all non- essential personnel including visitors and press from CCAFS, risk drops to as low as 86 × 10 −6 expected casualties, which is within the Air Force's criteria of 100 × 10 −6 expected casualties for the sum of risks due to impacting inert and impacting explosive debris, toxic release, and far field blast overpressure. Analysis indicates that almost all the risk is due to debris, with the risk associated with the latter two hazards not contributing to the overall risk. The risk for debris is comprised of 76 × 10 −6 for ascent and fly back, with almost all of that risk coming from the fly back of the Falcon 9 first stage to CCAFS. Downrange overflight of Europe contributes 7 × 10 −6, and the planned disposal of the Falcon 9 upper stage in the southern Pacific Ocean contributes less than 3 × 10 −6. The FAA recognizes that any estimate of the E c for any launch includes substantial uncertainties, and presenting these risk results as precise numbers implies better accuracy than actually exists. However, this type of presentation does allow showing the relative contributions of each of the risk components. Further, the risk computed on the day of launch may be different from the current estimate above.

I was going to bold some select lines, but it isn't really that long and most of it is relevant and interesting.

Several questions spring to mind:
-Will the risk assessment be reduced in time?
-Related, will SpaceX require a waiver for every RTLS?
-Would a two-core return be twice the hazard?

[joek]

Short versions...

Waiver of Debris Containment Requirements for Launch

FAA regulations require that an "...analysis must establish designated impact limit lines to bound the area where debris with a ballistic coefficient of three or more..." That requirement was waived as the existing basis for that analysis "...correlates with public safety only in part."

A key safety determinination is Ec, expected cacuallty probability.  The basis for the waiver is a "conditional Ec (CEC)".  CEC is based on the intent that "launch presents no greater risk to the general public than that imposed by the over-flight of conventional aircraft."

Waiver of Acceptable Risk Restriction for Launch

Ec calculations are based on risks from several components.  In this case, "...almost all of that that risk [Ec] coming from the fly back of the Falcon 9 first stage to CCAFS", and in particular "...almost all the risk is due to debris" (86x10^-6).  Down range Ec contributions are an order of magnitude lower (10x10^-6), with the total being within the overall limit (100x10^-6).

The nominal Ec limit for "impacting inert and impacting explosive debris" is 30x10^-6.  The waiver allows for the calculated Ec of 86x10^-6 based on "...federal launch ranges can permit the risk attributable to debris to exceed the FAA's risk threshold." (The USAF previously deemed that risk "acceptable".)

[cscott]

cscott summary: In terms of the substantial content of the waiver, the first essentially asks the FAA to use the USAF's standard for total risk from all sources, instead of the debris-specific FAA risk limit (exceeds faa debris limits, but risk from toxic release/etc was very low so summed risks met USAF's summed risk limit), and the FAA agrees this is reasonable in this case, given the national interests involved in work potentially leading to lower priced launch.

The second waiver is more interesting: it seems they couldn't manage to model the potential debris area of the return flight in exactly the way called for in the FAA regs, so they asked the FAA to waive the requirement for them to do so and instead rely on the summed risk modeling instead.

The FAA acknowledged that its debris modelling requirement was pretty bogus and used only because better modelling methods were infeasible, then hails the USAF's summed risk model as state-of-the-art and readily agrees to use it instead.  Again, national interest in lower priced launches is cited as enabling rationale.

[joek]

cscott summary: ...

You should revisit your interpretation based on the actual regulations.

edit...  Should also add proposed as referenced in the waivers.  See: Changing the Collective Risk Limits for Launches and Reentries and Clarifying the Risk Limit Used to Establish Hazard Areas for Ships and Aircraft docket, FAA Oct-2014; also several related items of interest in the supporting documents section.  See also referenced Common Risk Criteria Standards For National Test Ranges, Range Commanders Council, Dec-2010.

[cscott]

cscott summary: ...

You should revisit your interpretation based on the actual regulations.

Could you clarify?  My summary was intended to be based on the plain text of the waiver.  If I've misunderstood it, specific corrections would be welcome.

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.

[georgegassaway]

It sounds to me like someone missed a deadline or else someone is considering or already has accelerated a timeframe and caused a deadline to be missed.

Keep in mind that the RTLS was an undated goal with no landing attempt expected at all for RTF (at least no public rumors).  Waiting for FAA approval.

Then Blue Origin had that New Shepard flight on Nov 24th. 

Then after that, and the P.R. kerfluffle about Blue Origin beating SpaceX with the first reuseable rocket to fly into space and land safely (ignoring SS1 and X-15), the rumors began for RTF being an RTLS to land back at the Cape.

So, it could be that as a result of the New Shepard landing, that SpaceX decided to go for RTLS for the RTF flight.  And pressed the issue to get a waiver quickly.  So not so much as missing a deadline, as apparently accelerating a timeframe. 

Really it was very bizarre at the time to start reading rumors of SpaceX planning to do RTLS, with no FAA approval.  And taking things so close to the edge that SpaceX sent OCISLY out to sea as a default landing back-up, in case the FAA waiver did not come through (Yes, I know that OCISLY also coincidentally moved from Jacksonville on the same trip, but it loitered at sea for awhile , was not towed directly from Jax to the Cape. Then the FAA waiver was granted while it was at sea, and they brought OCISLY to the Cape).

- George Gassaway

[mme]

It sounds to me like someone missed a deadline or else someone is considering or already has accelerated a timeframe and caused a deadline to be missed.

Keep in mind that the RTLS was an undated goal with no landing attempt expected at all for RTF (at least no public rumors).  Waiting for FAA approval.

Then Blue Origin had that New Shepard flight on Nov 24th. 

Then after that, and the P.R. kerfluffle about Blue Origin beating SpaceX with the first reuseable rocket to fly into space and land safely (ignoring SS1 and X-15), the rumors began for RTF being an RTLS to land back at the Cape.

So, it could be that as a result of the New Shepard landing, that SpaceX decided to go for RTLS for the RTF flight.  And pressed the issue to get a waiver quickly.  So not so much as missing a deadline, as apparently accelerating a timeframe. 

Really it was very bizarre at the time to start reading rumors of SpaceX planning to do RTLS, with no FAA approval.  And taking things so close to the edge that SpaceX sent OCISLY out to sea as a default landing back-up, in case the FAA waiver did not come through (Yes, I know that OCISLY also coincidentally moved from Jacksonville on the same trip, but it loitered at sea for awhile , was not towed directly from Jax to the Cape. Then the FAA waiver was granted while it was at sea, and they brought OCISLY to the Cape).

- George Gassaway

SpaceX filed for the waiver before Blue Origin landed the booster.

https://www.federalregister.gov/articles/2016/01/12/2016-00443/waiver-of-acceptable-risk-restriction-for-launch

On November 19, 2015, SpaceX submitted a petition, which it revised on November 24, 2015, to the Federal Aviation Administration's (FAA's) Office of Commercial Space Transportation (AST) requesting ...

SpaceX has been working on this for years.  I don't think there is any need for some external "motivation."

[Herb Schaltegger]

And before more people keep repeating my partial quote, remember I also said I was going off the title of the petition filed, having not read the docs. There is no need to infer malice or incompetence to SpaceX by their filings - governmental agencies routinely extend deadlines upon a showing of good cause and/or lack of prejudice. Stuff happens, paperwork gets delayed, life overtakes plans. Not a big deal generally.

[joek]

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.

I added that comment and citations to reflect practices and direction, not just current regulations.

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.

The FAA's use of aggregate Ec vs. solely component Ec values began years ago, although the proposed rule change was not published until 2014.  That better aligns FAA and Federal Ranges.  It is also expected to reduce the need for these types of waivers in the future based on practice.  As the FAA has stated, "To date, the FAA has had to issue a waiver to the collective Ec limit for every commercial space operation that sought to reach the ISS."

The debris modeling requirement is not bogus and serves a useful purpose; it is also a Range requirement and not unique to the FAA.  In this case it told them "Specifically, impact limit lines cannot be developed to ensure all debris with a ballistic coefficient of 3 pounds per square foot (psf) or greater remains on CCAFS."[1]  The term "developed" does not mean they could not model it.  They certainly did model it, and it told them they needed to do more work...

"Further, analysis...demonstrates that the consequence of events that could produce debris outside of the impact limit lines for a small portion of the ORBCOMM-2 fly back operations (where the concern exists) is within this threshold..."  That threshold being the CEC for general aviation, stated as 0.01 (that appears to be a typo).  While part of that analysis was undoubtedly input to the risk waiver, the USAF's "summed risk model" was not a part of the debris containment waiver.  In any case the FAA utlimately made the call that risk to public safety was acceptable.  Maybe some day we will get the details on how they arrived at that conclusion.

National interest etc. is pretty standard boilerplate (they have to state those, which is why there is a separate Public Interests section).  I seriously doubt that was a compelling factor in the decisions.  The other factors would weigh far more heavily and there was no compelling time constraint or national security factors.

In short, what you are seeing is  refinement and progress, not "How can we rationalize this?  Maybe the USAF has something!"  Hope that helps clarify.


[1]  Obviously they are referring to debris impacts exclusive of the ocean exclusion zone outside CCAFS as those would not require a waiver.

[cscott]

Thanks for the clarification.  It appears part of your objection was perhaps to my tone: I certainly did not mean to imply that this waiver was unusual, or the rationale suspect.

The fact that the FAA has a proposed rule change to unify its methodology is news to me.  Why are flights to ISS especially problematic?  In the case of Orbcomm2, the debris issue was specifically called out as related to RTLS.  Does the inclination of ISS flights cause a similar debris problem?

[abaddon]

Since the leg failed to lock in the last attempt (Jason 3), will that alter the risk levels for future attempts?

Unlikely.  The landing pad is big and isolated enough that a tip-over and explosion would be contained in the pad area.  Debris risk is more about something happening on the way in.

Had the leg failed in the Orbcomm mission;  landing at the cape would have had the same results (tip over and explode) correct?

Elon has said it is likely, that's probably the best information we have to go on.

[Kabloona]

Since the leg failed to lock in the last attempt (Jason 3), will that alter the risk levels for future attempts?

IMHO it will reduce risk, since it's now a known failure mode that the MechE's will be working to mitigate before SES-9.

[jabe]

Since the leg failed to lock in the last attempt (Jason 3), will that alter the risk levels for future attempts?

IMHO it will reduce risk, since it's now a known failure mode that the MechE's will be working to mitigate before SES-9.

Elon mentioned a root cause may have been the fog at launch site.  The cold temps of oxygen had the fog frost up on the collet...so may be not an issue if no fog...
jb
edit:link to post regarding root cause.  https://www.instagram.com/p/BAqirNbwEc0/