SpaceX Falcon 9 : CRS-13 : Dec 15, 2017 : DISCUSSION

[Norm38]

How can a launch that was originally scheduled for the 4th be delayed on the 12th for late load items?

If your flight is 8 days late and you still miss the plane, take the next one.

[Herb Schaltegger]

How can a launch that was originally scheduled for the 4th be delayed on the 12th for late load items?

If your flight is 8 days late and you still miss the plane, take the next one.

The basic reasons for the initial delay to this week were not the late-load items. However, once the mission slips, one of the consideration are the late-load items. Typically these are time-sensitive items like experimental animals or plants. Experiments are controlled by controlling the age of biological items at launch so that observations made or tests undertaken on these items can be correlated to similar or analogous samples launched on prior and subsequent missions.

In addition, other time-sensitive items might include batteries with charge that might decay too much; temperature-controlled items that will get out of their temperature ranges; etc.

Therefore, for a slip, one main consideration is ensuring that the new window/opportunity allows for time-sensitive items to be available during the new window. Animals and plants might be too young, batteries might need to have had time for a discharge/recharge cyle, and so forth.

[RocketLover0119]

i feel guilty whenever i get into this type of thought but i hope it gets scrubbed to christmas because me and family are heading up to orlando and would hope to catch the launch and landing ( would be first time seeing a landing in person)

[mme]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

[cscott]

Elaborating on late-load. Made-up example, but illustrative: Consider an experiment that should be done on an 8-day-old mouse in orbit.  Working backwards, the mouse must be 1 or 2 days old at launch.  The experimenters will continually breed the correct strain of mouse so that they always have newborn pups.  If they load the newborns on, but the flight doesn't launch within two days, they have to unload the cargo and load a new batch of newborn mice.  That's the essence of "late load" biologic cargo, and you can imagine the logistics can get quite complex to allow samples of the correct age to be loaded regardless of the launch date.

And then there are batteries that need to be charged and other non-biologic late loads.

I seem to recall that the standard spacing is 3 days: you'll have two possible launch days, then a day to stand down and load new cargo, which will then be good to go for launch in the next two days.  Returning to the mouse example, that means a new litter of mice every three days, "just in case," until launch.  In the case of consumables, your full charge must be good for two days (plus transit time to ISS, presumably.)

Caveat: I don't really know what I'm talking about; I'm just summarizing what I've learned here in discussions with actual experts.  Questions about late load seem to recur with some frequency.

[Formica]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

Totally spitballing here, but it seems logical to me. It's brand new ground support equipment, so the idea of flashing, manufacturing dust, what-have-you coming loose when being used for the first time sounds very plausible. It is interesting that they didn't catch this before the static fire though, or perhaps they discovered it upon re-examining the results of the static fire. Again, I'm just a space fan, not a rocket scientist or GSE engineer, but this sounds like the kind of teething problems one would expect from new equipment being used/pressurized/energized for the first few times. I'm glad they are erring on the side of caution, and if that means waiting til after the high beta period, so be it 

[RocketLover0119]

Is there possibility this could be a result of loose soot getting into s2?

[deruch]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

Maybe found via sampling of unloaded propellants after the static fire? 

[CyndyC]

Good on SpaceX for catching the debris, and every other thing they've ever caught and fixed before a launch for that matter, but I still haven't quite shaken the launch number. I hope if all the pad & TEL upgrades included any voltage increases, that those were well communicated, and that every last SpaceX component was modified to accept the higher voltage where necessary.

[ChrisC]

SpaceX/Dragon CRS-13 Cargo Resupply Mission Prelaunch News Conference
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=10080

SpaceX/Dragon - CRS-13 Cargo Resupply Mission "What’s on Board?" Science Briefing
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=10081

Welcome back, John44!  I was starting to wonder.

[litton4]

Good on SpaceX for catching the debris, and every other thing they've ever caught and fixed before a launch for that matter, but I still haven't quite shaken the launch number. I hope if all the pad & TEL upgrades included any voltage increases, that those were well communicated, and that every last SpaceX component was modified to accept the higher voltage where necessary.

A voltage change was one of the factors in the Apollo 13 explosion.

[mn]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

I'll add a third question: How in the world do you clean that in just a few days?

(Maybe they can take it to a local Jiffy Lube for a radiator flush  )

[rsdavis9]

Tanka and detank with propellants and look at filters for stuff.
Seems to be the safest way to clean and detect FOD.

[Mike_1179]

Tanka and detank with propellants and look at filters for stuff.
Seems to be the safest way to clean and detect FOD.

You have to determine where they came from in the first place

[the_other_Doug]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

Totally spitballing here, but it seems logical to me. It's brand new ground support equipment, so the idea of flashing, manufacturing dust, what-have-you coming loose when being used for the first time sounds very plausible. It is interesting that they didn't catch this before the static fire though, or perhaps they discovered it upon re-examining the results of the static fire. Again, I'm just a space fan, not a rocket scientist or GSE engineer, but this sounds like the kind of teething problems one would expect from new equipment being used/pressurized/energized for the first few times. I'm glad they are erring on the side of caution, and if that means waiting til after the high beta period, so be it 

Well -- they don't fire the second stage during the static fire, so nothing from the actual engine firing of stage 1 would show any issues with stage 2, obviously.

It seems the overall purpose of "test as you fly" worked here, though.  Fueling stage 2 and then examining the fill line and drain line filters (especially after the first few fills at the rebuilt launch complex) told them that there was debris remaining in the system.  And is giving them the heads-up needed to clean it out before it results in a stage 2 turbopump failure.  I can conceive of a number of situations where small amounts of debris might be left in the system that earlier tests at less-than-flight-load rates, pressures and durations did not reveal.

And recall, we're almost definitely not talking about a few pounds of sand and dirt collecting at the filters, likely tenths of grams at most; these systems allow for extremely little particulate contamination, if any at all.  It's always the last few tenths of a percent that take the longest and most work to remove, in any system.

It's not botched testing; it's that putting the system through its actual paces is the best and last test you need to run.  They did, found something that needs tweaking, and once that's done, they'll go fly.

[mdeep]

What is the launch time on Friday? I've got:

10:35 (KSC PAO)
10:36 (NASA)
10:38 (45 SW)

[Kabloona]

And it's official. NET Friday, last available window until late December.

Taking additional time for the team to conduct full inspections and cleanings due to detection of particles in 2nd stage fuel system. Now targeting CRS-13 launch from SLC-40 on Dec. 15. Next launch opportunity would be no earlier than late December.

https://twitter.com/SpaceX/status/940736321097572352

Two questions. First, how would they have discovered this? Second, how the heck could it happen?

Totally spitballing here, but it seems logical to me. It's brand new ground support equipment, so the idea of flashing, manufacturing dust, what-have-you coming loose when being used for the first time sounds very plausible.

GSE is a common source of contamination for launch vehicles/payloads. During the Mars Observer launch campaign (way back) in 1992, a payload fairing AC duct blew contamination (dust, etc) onto the Mars Observer satellite atop the rocket on the pad. The entire encapsulated payload had to be destacked, de-encapsulated, cleaned, re-encapsulated, re-stacked, etc.

IIRC, the root cause had something to do with hurried preparations for the oncoming hurricane Andrew, but my memory on that could be faulty.

[ZachS09]

Just so you guys know, I'll be covering the NASA TV portion of this launch and leave the SpaceX Webcast to other members.

[jpo234]

Space X Launch & Landing Control

Is that new?

[ZachS09]

I'm not sure. But it looks like the same location to me.