SpaceX completed a Static Fire test at Vandenberg Air Force Base on Thursday. The test, a pivotal pre-launch requirement of the fully integrated Falcon 9, comes close on the heels of the company’s previous test at its Florida launch facility. The Iridium NEXT 3 launch is slated for Monday, 9 October 2017 at 05:37 PDT (12:37 UTC) from SLC-4E. Following Iridium NEXT 3, there are currently four remaining orbital launches off the Western Range this year.
Static Fire:
At the center of the static fire – the second-to-last critical step for the Falcon 9 ahead of its early Monday morning launch – was Falcon 9 core B1041, a brand new Falcon 9 core stage.
For this particular first stage, B1041 completed construction in Hawthorne, CA, and was transported under security escort by road to McGregor, Texas, where it was erected on the S1 test stand and put through a series of tests, including a full duration hot fire.
It appears that this core was hot fire tested at McGregor in either very late August or very early September, with spotters on the ground noting the core, under security escort, headed east toward McGregor on 15 August and then west for Vandenberg on 5 September.
At that time, static fire was slated for 30 September with launch following on 4 October.
However, according to Iridium CEO Matt Desch via his Twitter account, SpaceX ran into an issue with second stage processing and ran out of contingency time in the schedule to make the 4 October launch target.
Launch was realigned to 9 October, and static fire was moved to 5 October.
The Static Fire sees the Falcon 9 first and second stages undergo a launch countdown – complete with fueling of RP-1 kerosene and LOX (Liquid Oxygen) – that culminates with a planned firing of all nine Merlin 1D engines on the base of the first stage for an average of 3.5 seconds in duration based on usual tests.
In preparation for static fire, the Falcon 9 and its mated second stage were transported from the Horizontal Integration Facility (HIF) on the Transporter/Erector/Launcher to the launch pad at SLC-4E Wednesday.
Once Static Fire was accomplished, a quick look data review occurred to verify everything has gone according to plan and that the launch team can continue toward the scheduled Monday morning launch.
A more detailed data review will follow, culminating in the Launch Readiness Review (LRR) two days before launch.
The LRR will see all elements of the launch campaign and static fire discussed to formally clear the Falcon 9 and its payload for launch.
Launch and recovery:
If all goes well, SpaceX will launch the Falcon 9 with a new batch of 10 Iridium NEXT satellites on Monday, 9 October in an instantaneous launch window of 05:37 PDT (12:37 UTC).
The launch was scheduled to come just 39 hours 44 minutes after the scheduled Falcon 9 launch of SES-11 / Echostar 105 from LC-39A at the Kennedy Space Center.
However, it appears the SES-11 launch has been slipped to October 11.
This would still result in a rapid double header and will be the second such event attempted – with the previous being the BulgariaSat and Iridium NEXT 2 campaigns, which were separated by 49 hours 15 minutes.
According to information obtained and available on L2, the two day separation between SES-11 and Iridium NEXT 3 appears to be at or very close to the minimum time SpaceX can support two launches from two coasts.
After liftoff, the Falcon 9 will perform a sea landing on the Just Read The Instructions ASDS (Autonomous Spaceport Drone Ship).
According to the landing licenses requested from SpaceX and granted by the FCC for Iridium NEXT 3, Just Read The Instructions will be positioned 244 km (151.62 mi) downrange from Vandenberg and will catch the booster 257.5 km (160 mi) west of San Diego, California.
After Iridium NEXT 3, the Western Range will shift gears for the remainder of its busy 2017 Vandenberg launch manifest.
Under the current manifest, the remaining missions from Vandenberg this year are:
| Date | Rocket | Payload | Pad | Launch Time |
| Oct. 17 | Minotaur-C 3210 | Skysat | SLC-576E | 14:37 PDT |
| Nov. 10 | Delta II 7920-10C | JPSS 1 | SLC-2W | 01:47 PST |
| NET Nov. | Falcon 9 | Iridium Next 31-40 | SLC-4E | TBD |
| Dec 13 | Delta IV M+ (5,2) | NROL-47 | SLC-6 | TBD |
The 13 December flight of the Delta IV M+ will be a special moment and close out for the 2017 launch year from Vandeberg.
It will be the retirement flight of the Delta IV M+ (5,2) variant.
The Delta IV M+ line is being phased out as part of United Launch Alliance’s transition to the Vulcan rocket.
The final currently scheduled Delta IV M+ launch is slated for “late 2018” from the Cape Canaveral Air Force Station on a mission that will loft the WGS-10 satellite to orbit.
The Delta IV Heavy will remain in operation until at least 2023 when it will retire the entire Delta IV line with the NROL-91 launch from Vandenberg.
(Images: Iridium Corporation, SpaceX, United Launch Alliance, Google Maps, and Brady Kennison at KSC for NASASpaceFlight.com)