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The last launch of a Falcon 9 (Intelsat 35e) took place on July 5, but the next launch of a falcon 9 (CRS-12) won't take place until August 10. Elon said that SpaceX still had 12 launches to go this year to finish their manifest for this year. So what's the reason for the month delay between falcon 9 launches?

I found a wikipedia article that stated that CRS-12 was supposed to use the transitional falcon 9 block 4, so is SpaceX putting the final touches on it? I also thought maybe SpaceX was fixing SLC-40 for the next falcon 9 launch but Spaceflightnow lists CRS-12 for 39A.

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The Eastern Range run by the Air Force has a 2 or 3 week maintenance window. Thus no one is launching from either Cape Canaveral (Where LC-39A is located), nor the CCAFS (Cape Caneveral Air Force Station, where LC-40 is located) locations.

SpaceX is using the time the range is down to modify the RSS (Rotating Support Structure) that is left over from Shuttle days, to remove more of it, and to work towards installing the Crew Access Arm, needed for manned Dragon V2 flights.

SpaceX has two (at least) major modifications on the books for LC-39A. Install the Crew Access Arm, and add the Falcon Heavy hold downs and equipment. It is unclear how much of the work they will get finished in this window.

They have said the Falcon Heavy modifications with take 60 days, and will start once LC-40 is reactivated and flying. I.e. They need to keep a pad open and launching.

That is why they were in a hurry to get the Intelsat 35e launch off before the range shut down.

Then once the range is ready again, they have to find a launch time, and the CRS-12 mission, which is next, has ISS requirements for launch dates. The ISS has a lot of Visiting Vehicles (Soyuz, Progress, Dragon, Cygnus, and soon CST-100 and Dragon V2) and scheduling crew time to unload and reload is a complex ballet. Thus the date of CRS-12 is set by the ISS schedule and there may not have been time to slide another launch in beforehand.

Here is a mostly information null article on this very issue.

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  • $\begingroup$ Is there any hold for west coast launches, or just no customers ready to go at the moment? $\endgroup$ – Dan Neely Jul 19 '17 at 18:12
  • $\begingroup$ Just no customers ready. Iridium has an insurance clause that implies 60 days between launches or somesuch, to ensure a design flaw does not kill the fleet. Next known booked launch after CRS-12 is Formosasta, Aug 24 from Vandenberg. $\endgroup$ – geoffc Jul 19 '17 at 19:03
  • $\begingroup$ Actually, I forgot about the X-37B launch, Aug 28 from LC-39A. So Aug 10, 18 days later a launch from LC-39A. I would guess from Aug 3 to Aug 10 they could not slip in another launch. $\endgroup$ – geoffc Jul 20 '17 at 13:40
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The range is closed for maintenance during most of July. The next planned launch is ULA Atlas V with TDRS-M on August 3, but that one is now under review after an incident.

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