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

[gongora]

Not wishing to push "luck", but does anyone know if this Dragon will have intentional defects in the heat shield in order to test micrometeoroid impact effects?

For anyone not understanding where this question came from, it was mentioned at the most recent ASAP meeting:

The modeling of MMOD is a very challenging analysis, and there are notable uncertainties in the calculation. NASA is continuing to work on the modeling problem through proposed MMOD sampling experiments on the International Space Station (ISS), which is an outstanding use of the vehicle for this type of analysis. The team is also working on some unique defect testing with the Dragon cargo mission to recover and study the Dragon after it returns to help reduce modeling uncertainties on MMOD damage. In other words, defects are being deliberately placed on Dragon to try to simulate some of the MMOD scenarios.

[gongora]

Tweet from LASP:

#LASP and #CUBoulder atmospheric scientist, Peter Pilewskie, will participate in a @Reddit AMA about all things TSIS-1 and Sun-Earth interactions: https://redd.it/7g3qxd —starting at 3 PM ET today.

[deruch]

For anyone not understanding where this question came from, it was mentioned at the most recent ASAP meeting:

The modeling of MMOD is a very challenging analysis, and there are notable uncertainties in the calculation. NASA is continuing to work on the modeling problem through proposed MMOD sampling experiments on the International Space Station (ISS), which is an outstanding use of the vehicle for this type of analysis. The team is also working on some unique defect testing with the Dragon cargo mission to recover and study the Dragon after it returns to help reduce modeling uncertainties on MMOD damage. In other words, defects are being deliberately placed on Dragon to try to simulate some of the MMOD scenarios.

Why do I get the feeling that this test has come about due to an disagreement between NASA and SpaceX on just how robust their heat shield is to MMOD damage?  Like, SpaceX's modeling and analysis shows that they believe the Dragon capsule can still survive reentry with X amount of MMOD damage having been done to the heat shield and NASA's (likely more conservative) modeling/analysis says Y.  So, since SpaceX are working hard to meet the LOC/LOM numbers requirements for Commercial Crew, they've said, "Look, we'll prove it to you with the cargo Dragon."

[russianhalo117]

For anyone not understanding where this question came from, it was mentioned at the most recent ASAP meeting:

The modeling of MMOD is a very challenging analysis, and there are notable uncertainties in the calculation. NASA is continuing to work on the modeling problem through proposed MMOD sampling experiments on the International Space Station (ISS), which is an outstanding use of the vehicle for this type of analysis. The team is also working on some unique defect testing with the Dragon cargo mission to recover and study the Dragon after it returns to help reduce modeling uncertainties on MMOD damage. In other words, defects are being deliberately placed on Dragon to try to simulate some of the MMOD scenarios.

Why do I get the feeling that this test has come about due to an disagreement between NASA and SpaceX on just how robust their heat shield is to MMOD damage?  Like, SpaceX's modeling and analysis shows that they believe the Dragon capsule can still survive reentry with X amount of MMOD damage having been done to the heat shield and NASA's (likely more conservative) modeling/analysis says Y.  So, since SpaceX are working hard to meet the LOC/LOM numbers requirements for Commercial Crew, they've said, "Look, we'll prove it to you with the cargo Dragon."

My take is that NASA is bringing about similar testing that done during post STS-107 RTF flights on Shuttle.

[ChrisGebhardt]

Launch date is now [NET] 8 December...

What the (approximate?) launch time/window, day-by-day, going forward from December 8?  (I remember that the launch time shifts several minutes earlier per day, but I do not remember the amount.)

(The December 4 launch time was 19:53 UTC--I believe it was in the middle of a 5-minute window.)

My memory is a little fuzzy, but I think the launch window gets earlier by 23 minutes for every day of delay. So four days of delay could be a window that is 92 minutes earlier, and the windows for Dragons are instantaneous.

Launch time on 8 Dec is 13:20 EST (18:20 UTC).

[mickeyjaw]

 

I booked flights from the UK to Orlando to watch this and I fly back on the 6th...

[whitelancer64]

I booked flights from the UK to Orlando to watch this and I fly back on the 6th...

Any possibility of rescheduling the flight?

[mickeyjaw]

I booked flights from the UK to Orlando to watch this and I fly back on the 6th...

Any possibility of rescheduling the flight?

Non-refundable and non-changeable unfortunately but I might ditch the return and buy a new one-way ticket home.  I just need to convince my boss to let me take one day more holiday than I have left for the year though...

[russianhalo117]

MISSE-FF wasn't ready in time.

AFAIU, MISSE-FF MISSE Sample Carrier (MSC's) arrival and integration into MISSE-FF is reason.

[deruch]

MISSE-FF wasn't ready in time.

AFAIU, MISSE-FF MISSE Sample Carrier (MSC's) arrival and integration into MISSE-FF is reason.

Does that mean they won't launch the Facility? 

[gongora]

[Elthiryel]

The source above gives the total payload mass of 2930 kg, while the NASA post (https://blogs.nasa.gov/spacex/2017/11/22/dragon-to-make-resupply-run-to-international-space-station/) states it's about 2180 kg (about 4800 pounds). So there is an inconsistency here.

[Jarnis]

I booked flights from the UK to Orlando to watch this and I fly back on the 6th...

Any possibility of rescheduling the flight?

Non-refundable and non-changeable unfortunately but I might ditch the return and buy a new one-way ticket home.  I just need to convince my boss to let me take one day more holiday than I have left for the year though...

This being first flight from rebuilt SLC-40, 8th is... possible but not certain. Lets hope static fire works perfectly on Saturday, then 8th becomes far more likely from hardware/pad standpoint. Then it is up to Florida weather, any wayward boats or planes and so on...

[cscott]

The source above gives the total payload mass of 2930 kg, while the NASA post (https://blogs.nasa.gov/spacex/2017/11/22/dragon-to-make-resupply-run-to-international-space-station/) states it's about 2180 kg (about 4800 pounds). So there is an inconsistency here.

The "source above" lists MISSE-FF as an unpressurized payload, where the post just above that states that it won't be flying on this mission:

MISSE-FF wasn't ready in time.

AFAIU, MISSE-FF MISSE Sample Carrier (MSC's) arrival and integration into MISSE-FF is reason.

 So that could explain the discrepancy.

[whitelancer64]

The source above gives the total payload mass of 2930 kg, while the NASA post (https://blogs.nasa.gov/spacex/2017/11/22/dragon-to-make-resupply-run-to-international-space-station/) states it's about 2180 kg (about 4800 pounds). So there is an inconsistency here.

The discrepancy is probably from including / not including the mass of packing materials, mounting brackets, payload bags, etc. plus the use of the word "about" in the blog post indicates the number is rounded.

[ChrisGebhardt]

I booked flights from the UK to Orlando to watch this and I fly back on the 6th...

Any possibility of rescheduling the flight?

Non-refundable and non-changeable unfortunately but I might ditch the return and buy a new one-way ticket home.  I just need to convince my boss to let me take one day more holiday than I have left for the year though...

This being first flight from rebuilt SLC-40, 8th is... possible but not certain. Lets hope static fire works perfectly on Saturday, then 8th becomes far more likely from hardware/pad standpoint. [b[Then it is up to Florida weather[/b], any wayward boats or planes and so on...

Florida weather this time of year is extreme stable unless a cold front moves through.  Right now, the long range forecasts (9 days out) show absolutely nothing from the weather side to be even remotely worried about on the 8th or the two surrounding days.

[wannamoonbase]

This being first flight from rebuilt SLC-40, 8th is... possible but not certain. Lets hope static fire works perfectly on Saturday, then 8th becomes far more likely from hardware/pad standpoint. Then it is up to Florida weather, any wayward boats or planes and so on...

It would be very impressive if they got to a successful static fire on the first roll out. 

From past flows it would seem they could try Saturday, Sunday and finally go to Monday with a static fire and still make the 8th.

The fairing problems have been a downer, but re-activating 40 is very exciting. 

It should make 2018 a very interesting year.

[envy887]

Also there is a claim the F9 will "look" a bit different than you'd expect. Nothing dramatic, more amusing (and practicable), but I want to "see" it before blurting anything else in public. I'll see if SpaceX want to confirm/comment on it before we see the booster rollout.

Did they decide not to wash the booster this time? Saving some money right there.

[Hauerg]

Has to be.
Theother option woud be a differnt paintjob. But why?

[abaddon]

Well, Block 5 is supposed to look a little different, so that was what I was thinking.  But I think @envy887's guess is likely better, based on what was written.