|SpaceX static fire Formosat-5 Falcon 9, aims for another ASDS landing|
August 19, 2017 by Chris Gebhardt
Gearing up for their second Vandenberg flight in as many months, SpaceX has static fired the Falcon 9 that will lift an extremely light-weight Taiwanese satellite to orbit next week. The static fire, a key step in every Falcon 9 launch campaign, paves the way for the launch of Formosat-5 on Thursday, 24 August at 11:50 PDT from SLC-4E at Vandenberg Air Force Base, CA, ahead of a first stage landing on the ASDS “Just Read The Instructions”.
Static Fire and rearranged Western Range launch schedule:
With launch five days away, SpaceX conducted the second-to-last critical step for the Falcon 9 ahead of its Thursday launch.
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.
For this particular first stage, Core 1038 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.
The exact date of the hot fire is not known precisely, though NASASpaceflight.com aerial photos – available to view on L2 – confirm Core 1038’s presence on the S1 stand on 20 June 2017, at which point the Formosat-5 launch was roughly one month away.
Following a successful hot fire, Core 1038 was wrapped in its protective transport attire and shipped back west to Vandenberg Air Force Base, where it has undergone final pre-mission processing and integration with its second stage – which also underwent hot fire operations at McGregor.
However, the launch schedule off the Western Range began to change, with SpaceX announcing a month slip to Formosat-5’s launch – placing the mission on 24 August and behind the NROL-42 launch on United Launch Alliance’s (ULA’s) Atlas V rocket.
When NASA ran into processing issues with the TDRS-M communications satellite, which launched Friday morning from the Cape Canaveral Air Force Station in Florida after a 15 day slip, the entire ULA launch schedule was forced to shift to accommodate the delay.
The TDRS-M slip forced a near one-month delay to NROL-42’s launch, pushing it from 14 August to 11 September.
That placed Formosat-5 first on the launch manifest following the Western Range down period in July for standard maintenance and upgrades of tracking and support equipment. A similar down period also occurred on the Eastern Range in July.
Now, SpaceX was targeting a Static Fire at 12:00 PDT on 19 August for Formosat-5’s Falcon 9. The entire static fire window extends to 16:00 PDT Saturday. A sign of a smooth countdown was the confirmation the test took place at the opening of the test window.
Once Static Fire was accomplished, a quick look data review occurred to verify everything went according to plan and that the launch team can continue toward the scheduled Thursday launch. SpaceX’s tweeted confirmation came shortly after the test took place.
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 light-weight payload for launch.
If all goes well, SpaceX will launch the Falcon 9 with Formosat-5 on Thursday, 24 August in a launch window of 18:50-19:34 GMT (11:50-12:34 PDT).
After Formosat-5, the Western Range will shift gears for ULA’s NROL-42 launch on an Atlas V 541 rocket (five meter payload fairing, four solid rocket motors, and a single-engine Centaur upper stage) on 11 September before configuring back for SpaceX and the Iridium Next 21-30 launch currently slated for 30 September at 06:30 PDT.
After Iridium Next 21-30, the busy Vandenberg launch manifest for the rest of 2017 is currently:
|Date ||Rocket ||Payload ||Pad ||Launch Time |
|Oct. 12 ||Delta II 7920 ||JPSS 1 ||SLC-2W ||02:48 PDT |
|Oct. 17 ||Minotaur-C ||Skysat ||SLC-576E ||14:37 PDT |
|NET Late Nov. ||Falcon 9 ||Iridium Next 31-40 ||SLC-4E ||TBD |
|NET Dec. ||Falcon 9 ||Iridium Next 41-50 ||SLC-4E ||TBD |
|Dec. 13 ||Delta IV M+ (5,2) ||NROL-47 ||SLC-6 ||TBD |
Formosat-5 – to RTLS or not to RTLS?
A feature of all Vandenberg launches to date has been an inability to perform an RTLS (Return To Launch Site) landing of the Falcon 9 first stage due to high payload mass (e.g.: The Iridium Next flights) preventing enough margin in the Falcon 9 fuel tanks for the needed boost back, entry, and landing burns and because the official clearance investigations and forms from the USAF (U.S. Air Force), EPA (Environmental Protection Agency), FAA (Federal Aviation Administration), and DOT (Department of Transportation) were not completed.
However, on 7 October 2016, all of the above agencies completed their assessments of various environmental impacts for the construction and use of a landing pad at SLC-4W to allow for RTLS landings of Falcon 9 first stages.
“After reviewing and analyzing available data and information on existing conditions and potential impacts, including the 2016 EA (Environmental Assessment), the FAA has determined the issuance of licenses to SpaceX to conduct Falcon 9 boost-backs and landings at SLC-4W … would not significantly affect the quality of the human environment within the meaning of NEPA (National Environmental Policy Act).”
This was stated in the Federal Aviation Administration Office of Commercial Space Transportation report on Adoption of the Environmental Assessment and Finding of No Significant Impact for Boost-back and Landing of the Falcon 9 Full Thrust First Stage at SLC-4 West at Vandenberg Air Force Base, California and Offshore Landing Contingency Option.
The same report also returned a Finding of No Significant Impact for terrestial and marine life for Vandenberg RTLS landings.
After the report’s official acceptance in October 2016, SpaceX began construction of the landing pad at SLC-4W – located just 1,412 feet (center point to center point) from the launch mount at SLC-4E.
Now, a little more than 10 months after clearance to construct the landing pad at SLC-4W and the ability to issue RTLS landing licenses to SpaceX for west coast launches, the first mission with a light enough payload to support RTLS is here.
Taiwan’s Formosat-5 satellite weighs only 475 kg (1,047.2 lb) – leaving more than enough margin in Falcon 9’s tanks to perform the needed boost back, entry, and landing burns to make it safely back to SLC-4W.
However, the launch and landing licenses requested from SpaceX and granted by the FAA for Formosat-5 call for a landing of the 1st stage on the Just Read The Instructions ASDS (Autonomous Spaceport Drone Ship), which will be positioned ~344 km (214 mi) downrange from Vandenberg.
This raises the question of why an ASDS landing will occur instead of an RTLS landing, as all environmental hurdles are cleared and the Falcon 9 has the performance to conduct an RTLS.
One possibility is that the landing pad and associated facility upgrades to support and RTLS booster landing were not completed by the time SpaceX had to file for the Formosat-5 launch and landing licenses on 28 June 2017.
It’s certainly conceivable that the landing pad and facility upgrades would have to have been completed by the time a landing license was applied for as the FAA would be hard pressed to approve a landing without the ability to review the operational status of all landing assets.
It is also possible that the landing pad and associated facilities upgrades are not yet complete at this time.
Regardless of the SLC-4W landing pad’s current status, Formosat-5 will be an ASDS landing and will mark the 9th attempt this year to recover a Falcon 9 first stage.
(Images: SpaceX, Chris Gebhardt and Philip Sloss for NASASpaceflight.com, Google Maps and L2 McGregor via Gary Blair)