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

[Coastal Ron]

Yeah, and McCain's rants about the RD-180 are really about sending money to Russia and were not influenced in any way by any supporters of SpaceX. 

I'm not aware Musk, or SpaceX, have donated to Senator John McCain.  Have they?

Nor am I aware of any SpaceX facilities located in the Arizona Senators state.

Though not as common as we like, sometimes our politicians do act in what they feel is the best interests of our nation, and not just those that give them money (directly & indirectly).  Whether McCain is one of those in this case is up to each of us to decide...

[Gordon C]

It's coming from CO and Louisiana.  ULA and SLS.   Then, spacex did file suit against the US air force screaming about ULA.  Goose  and gander something or other.

Orbital will come out looking responsible.  Some tantrum action with Aerojet, but buying he Atlas flight for the good of their contact is totally righteous.

The GAO can brush off the request, but even if they do the big guys will come back at them from another direction.

What's the connection with SLS?  I can understand Orion but SLS & Cargo?   We got to be careful this isn't too far off topic    But congress could affect a RTF my (who knows).

Oh yeah, there is a gigantic p!ace where they built a welder and stuff right by new orleans, for sls.  That area is dabbling in serious economic disaater, so it is important that they continue.  To people who live there and care about the place it's I important, for the forward thinking in California it's great spot to get drunk.

Then, the GAO thing will not affect return to flight.  That is just lawyer behavior, accumulating evidence for later.  Return to flight is just about spacex engineers and such, as was the loss of mission in the first place.

[docmordrid]

Yeah, and McCain's rants about the RD-180 are really about sending money to Russia and were not influenced in any way by any supporters of SpaceX. 

I'm not aware Musk, or SpaceX, have donated to Senator John McCain.  Have they?
>

Here's his re-election  donors list for 2016. Don't see any.

http://www.campaignmoney.com/political/campaigns/john_s_mccain.asp?cycle=10#MoneySummary

[Chris Bergin]

Oh no we don't!

Let's focus on RTF please. PS My article is ETA Monday.

[RonM]

I'd say three tops. One at Vandy and two at Pad 40. That's assuming RTF in mid November.

If I was a betting man, since we're talking RTF, only one more launch for 2015.

[oldAtlas_Eguy]

Speaking of launches during the holidays I was part of an Atlas E/F launch back in 1981 that launched on Christmas eve. It was even a failure so the launch crews had to stick around for the initial failure meeting later that evening (after 6PM).

The range is always open as long as it is scheduled in advanced. Major slips into the last week on Dec from only a month or two out probably would not be supported.

Edit: Spelling

[JoerTex]

If they're to launch 3 or more, where are the cores?  They need test at McGregor, lots of shipping.  The folks watching McGregor don't see the equipment.  The cows are bored. and with no 'show' are eating un-popped corn and grass.

[411rocket]

If they're to launch 3 or more, where are the cores?  They need test at McGregor, lots of shipping.  The folks watching McGregor don't see the equipment.  The cows are bored. and with no 'show' are eating un-popped corn and grass.

No idea, if Jason 3 core, needs to go back there, for re-test, after strut change out or not. Others should be ready to transport soon, as well.

[LastStarFighter]

If they're to launch 3 or more, where are the cores?  They need test at McGregor, lots of shipping.  The folks watching McGregor don't see the equipment.  The cows are bored. and with no 'show' are eating un-popped corn and grass.

No idea, if Jason 3 core, needs to go back there, for re-test, after strut change out or not. Others should be ready to transport soon, as well.

If it truly is just the strut problem then I can't imagine any stages being sent back to Texas. I don't think the integrated tests run there can even test this issue. They should only need to send the struts back for testing or install new struts. Unless accessing the struts requires shipment back to Texas.

[MP99]

If they're to launch 3 or more, where are the cores?  They need test at McGregor, lots of shipping.  The folks watching McGregor don't see the equipment.  The cows are bored. and with no 'show' are eating un-popped corn and grass.

No idea, if Jason 3 core, needs to go back there, for re-test, after strut change out or not. Others should be ready to transport soon, as well.

If it truly is just the strut problem then I can't imagine any stages being sent back to Texas. I don't think the integrated tests run there can even test this issue. They should only need to send the struts back for testing or install new struts. Unless accessing the struts requires shipment back to Texas.

In order to replace the struts they will need to remove and then reinstall various components, including the COPVs.

This would justify testing to ensure it's all connected correctly and working OK, but a WDR at the launch pad may be sufficient?

Cheers, Martin

[Space Ghost 1962]

Correct - there is no stage test other than flight to structurally test a complete second stage.

The point of a WDR or hot fire would be to assure that the retrofit/repair activity on a stage itself did not affect the stage - it does nothing for the LOM issue by itself, they are separate.

Technically back to the beginning - relying on component stress tests and simulations, albeit improved by a ton of flight data.

Thinking outside the box for a minute, supposing that they'd been able to recover a first stage, even in adverse circumstance as well as with significant additional length/mass ...

One then might, in theory ... fly the same flight profile with an heavily instrumented second stage, not stage, and recover the vehicle. Then compare sims with flight data including the additional instrumentation.

Lots of "if's", but the point of the exercise here is the potential for a reusable vehicle to gain insight where there wasn't the opportunity before.

Would this yield an additional value to offset the risk/cost of such a mission (beyond demonstrating that one could do such in any case)?

The answer here isn't a clear advantage in the case of the current issue - testing as a system might not reveal any more than component destructive testing. However, as a platform for advancing U/S enhancement perhaps a recoverable strategy might return an advantage, although still unclear if enough to develop/deploy such.

Doesn't have to be at an orbital launch facility, as even a ballistic range would be suitable for such (not McGregor!).

But again, the options for test here are very limited.

[Chris Bergin]

Oh no we don't!

Let's focus on RTF please. PS My article is ETA Monday.

Finished this and ready to go at 9am Eastern. I'll start a new thread for it, but it may be useful if people here copy the opening post of that new thread into manifest threads and mission threads (for the ones we already have going - I'll set up the others as we go), so that everyone's on the same page (and with the caveats that all schedules are preliminary, especially one pre-RTF).

[AndyX]

Cross posting on request!

http://www.nasaspaceflight.com/2015/09/spacex-conducts-falcon-9-improvements-busy-schedule/

Notes:
Summary of some of the notes we've been working with in L2.
Schedule is highly preliminary, but confidence in it was elevated by other sites later noting they think SES-9 will ride first as RTF and the closeness of the CRS-8 date. Still totally preliminary - don't go booking any flights!

A lot of media ran with Ms. Shotwell's comments from AIAA, so tried to avoid copying that as you will already have read it.

A bit of cool stuff on the Dragons and some things you may not have heard about per the "Deep Dive" work and alternative path evaluations (one of which we think caused one journalist to think the struts weren't at fault. That one took a good bit of evaluation to show it was only a check on the fault tree, not a smoking gun, so I can see how that could have been misinterpreted by that other site).

Could have gone on a bit about 2016 with FH, but didn't want to get too wordy and kept it below 1500 words. We'll do something on FH later (probably for a milestone such as pad complete - which it nearly is, or a core shipping, etc.) Same goes with ASDS and Vandy first stage landings.

Please copy this post (all of the post) into the relevant manifest and mission threads, so people have the link and also my note about not booking hotels just yet! ) Just thought it would be a good idea to have a standalone thread, otherwise we may end up with people talking about future Dragons in a Jason-3 thread, etc.

Hope this is useful to you all.

[JasonAW3]

Quick question;

    As no one is 100% certian as to what caused the overpressure issue on the CRS-7 mission, I'd like to propose a possible scenerio of what may have happened;

     During the flight, as suspected, one of the bracing rods holding the helium tank in place did break and punctured the helium tank.  the rod became stuck in place and as the helium was released from the tank, the temperture around the hole dropped enough that the gaseous oxygen in the liquid oxygen tank froze around the hole, temporarily sealing the puncture.  This would only work if the Helium tank used liquid helium which is a liquid at -269 degrees Celcius and liquid Oxygen freezes at -210 degrees Celcius.

     With the rod still in place, the escaping helium would be under high pressure coming through the hole, further reducing the temperture around the hole, both causing expansion of the surrounding metal and precipitation of Oxygen around and in the hole.  The drop in temperture may have been enough to freeze both the O2 and escaping helium into a temorary plug, allowing just enough helium leakage to appear to have returned to a normal pressure.

     Essentially, it would be like water icing up a high pressure O2 nozzle in a normal atmosphere with a high humidity.

     This is likely wrong, but I thought I'd put it out for consideration.

[Lars-J]

Quick question;

    As no one is 100% certian as to what caused the overpressure issue on the CRS-7 mission, I'd like to propose a possible scenerio of what may have happened;

     During the flight, as suspected, one of the bracing rods holding the helium tank in place did break and punctured the helium tank.  the rod became stuck in place and as the helium was released from the tank, the temperture around the hole dropped enough that the gaseous oxygen in the liquid oxygen tank froze around the hole, temporarily sealing the puncture.  This would only work if the Helium tank used liquid helium which is a liquid at -269 degrees Celcius and liquid Oxygen freezes at -210 degrees Celcius.

     With the rod still in place, the escaping helium would be under high pressure coming through the hole, further reducing the temperture around the hole, both causing expansion of the surrounding metal and precipitation of Oxygen around and in the hole.  The drop in temperture may have been enough to freeze both the O2 and escaping helium into a temorary plug, allowing just enough helium leakage to appear to have returned to a normal pressure.

     Essentially, it would be like water icing up a high pressure O2 nozzle in a normal atmosphere with a high humidity.

     This is likely wrong, but I thought I'd put it out for consideration.

If helium needs a very strong tank to stay under pressure, I doubt a thin layer of frozen oxygen is sufficient to contain it.

[cambrianera]

No liquid helium in helium tanks.
When helium expands, it heats.
Sorry Jason, your scenario seems not likely.

[Hugo-norway]

Have spacex during the down time been building engines and other hardware, to take up the slack so to speak after RTL.

A launch every two weeks?

Hugo

[Sohl]

Have spacex during the down time been building engines and other hardware, to take up the slack so to speak after RTL.

Probably, at least for parts that are easy to set aside for later, and don't have any significant RTF safety concern.  But SpaceX might not have space to stockpile very many entire stages or even big parts of stages.

A launch every two weeks?

Hugo

We've seen SpaceX approach a two-week per flight tempo, so it's not impossible, but very many things would have to go perfectly, so I don't expect that to be sustainable.  Maybe 18 to 30 days per flight for the several months after RTF.

[macpacheco]

Have spacex during the down time been building engines and other hardware, to take up the slack so to speak after RTL.

A launch every two weeks?

Hugo

Also it's not like SpaceX has dozens of payloads ready / about to be ready to launch. If they could sustain a launch every two weeks, they would run out of payloads in 6 launches or so.

[enzo]

A launch every two weeks?

I do think they will catch up, but to add another comment, I think they will want to take time to analyze data from the new configuration and hopefully the barge landing.

But SpaceX might not have space to stockpile very many entire stages or even big parts of stages.

I would be happy to lend my back lawn...