SpaceX has conducted a critical test firing of all nine core stage engines of its Falcon 9 rocket ahead of an early-Monday/late-Sunday scheduled launch of the CRS-9 cargo resupply mission to the International Space Station. The mission will deliver food and supplies to the Station crew as well as vital experiments and a new commercial vehicle docking adaptor to the orbital lab.
Road to the Static Fire:
Originally slated to fly NET (No Earlier Than) 9 December 2015, the mission was delayed numerous months following the June 2015 launch mishap of the CRS-7 mission.
The subsequent delay to SpaceX launch operations initially moved CRS-9 to NET 21 March 2016, before manifest and ISS visiting vehicle schedule realignments pushed the mission into June.
Now targeting a 24 June launch date, SpaceX appeared poised to secure that date for launch of CRS-9; however, the Soyuz MS-01 crew transportation mission subsequently took precedence and the 24 June launch slot in the ISS manifest.
SpaceX then agreed to target 27 June for launch of CRS-9, but ultimately had to delay the flight again until the middle of July due to subsequent delays to the Soyuz MS-01 mission.
When Soyuz MS-01 finally settled on a launch date of 7 July, SpaceX was pushed behind the Progress 64P cargo resupply mission that had originally been set to launch on 7 July but was displaced, as CRS-9 had been, by Soyuz MS-01.
Nonetheless, through these realignments, SpaceX continued to process the Dragon capsule out toward its launch, with the capsule leaving its production facility in Hawthorne, California, in mid-May for the cross-country trip to the Cape Canaveral Air Force Station in Florida.
When the Dragon arrived at its launch site, it was moved into the Horizontal Integration Facility (HIF) at SLC-40.
Since its arrival, the capsule has undergone final preparations for integration with the second stage of the Falcon 9 rocket as well as loading of nearly all of its cargo elements.
At the same time, engineers also completed manufacturing of the second stage and transported it to the launch site for its role in ensuring that Dragon is inserted into a stable and precise orbit for rendezvous with the ISS.
Additionally, work also progressed on the first stage for the CRS-9 flight.
As with all Falcon 9 first stages, it was transported from its production facility in Hawthorne, California, to SpaceX’s McGregor, Texas, test site, where it underwent a battery of tests to ensure that all propulsion elements and associated systems operated nominally under hot fire conditions.
By the latter part of June, the first stage was wrapped in its black, protective transport attire and taken under security escort across the southern portion of the United States to the launch site.
To date, processing has been extremely smooth for all elements of the CRS-9 mission.
Following the arrival of the first stage at SLC-40 in late June, the stage was received and inspected prior to engineers’ mating it with the second stage.
The Dragon capsule itself was subsequently mated to the top of the second stage earlier this week ahead of static fire operations currently planned for Friday evening/Saturday morning.
For the static fire, SpaceX engineers moved the Falcon 9 and Dragon capsule out to the seaside launch pad Friday afternoon, where the rocket was erected vertically by the Transport Erector (TE) and all necessary and final pad connections and tests made.
Unlike previous static test fires that have all occurred in the afternoon or evening hours, this static fire aimed for a Saturday morning, 16 July (the 47th anniversary of the launch of Apollo 11), test sequence – which involved a dress rehearsal countdown and loading of super chilled cryogenic propellant into the vehicle under the same time constraints that will be experienced on launch day.
Once the super chilled cryogenic propellants were added to the rocket, a simulated launch countdown ignited all nine Merlin 1D engines at the base of the Falcon 9 rocket
With hold down clamps ensuring the rocket remained on the pad, all nine first-stage engines were fired for approximately 3 seconds, with a slew of systems monitoring the health and activity of each engine as well as the overall health and systems of the Falcon 9 itself.
With the test is complete, the vehicle was secured and safed, and its propellants drained from the tanks.
After this, SpaceX engineers will lower the Falcon 9 back to horizontal and transport it back to the HIF, where late-stow, time-sensitive cargo items will be added to the Dragon capsule.
While this is happening, an intense review of the static fire data will be undertaken by SpaceX engineers ahead of the Launch Readiness Review – which is expected to officially clear the vehicle for launch.
Assuming a good static fire, the Falcon 9 rocket will be returned to the launch pad on Sunday for a targeted 12:45 a.m. EDT (04:45 GMT) liftoff to the ISS on Monday morning (18 July).
If all goes according to plan, a launch on early Monday morning Eastern time would result in Dragon’s arrival at the International Space Station on Wednesday, 20 July — the 47th anniversary of the Apollo 11 moon landing.