SpaceX made a late postponement to the CRS-3/SpX-3 mission to the International Space Station on Thursday, citing “open items” that require additional time to remedy. The launch – which was originally set for March 16 – will have to wait until the end of the month at the earliest, as Dragon sets her sights on a new opportunity afforded to her in the busy launch and Visiting Vehicle schedules, both on the Eastern Range and at the orbital outpost.
Dragon’s fourth trip to the ISS has been delayed several times, mostly through no fault of her own.
The launch was expected to take place in the latter part of 2013, with both Orbital’s Cygnus and Dragon initially provided with a December, 2013 placeholder for their resupply runs under NASA’s Commercial Resupply Services (CRS) contract.
As a result, the CRS-3 Dragon realigned her preparations for a mission that had an available berthing window ranging from January 17, 2014 through February 16.
Unfortunately, a coolant loop failure on the ISS – which ultimately required two EVAs over the Christmas period to fix – delayed Cygnus, causing a knock on effect for Dragon. The Cygnus CRS-1/ORB-1 mission eventually arrived at the ISS in January.
A realigned February 22 launch date target for Dragon’s CRS-3 mission held firm for a number of weeks, prior to further internal refinement that resulted in a NET (No Earlier Than) target of March 1 on the schedule.
As per the usual scenario of continually evaluating launch targets, considerations included Dragon’s EOM (End Of Mission) requirement of returning to Earth in daylight, per the preference of recovery operations, along with the flow timeline, as poor weather across the United States delayed the arrival of the Falcon 9 v1.1 core stage at Cape Canaveral.
While the flow could have supported a new NET as early as March 12, the Station’s Visiting Vehicle schedule recommended March 16 as the opening launch target.
Processing towards that latest target was on schedule, with the Falcon 9 v1.1 and Dragon enjoying a ride out to the launch pad at SLC-40 for a Static Fire test.
This was conducted on Saturday, providing a launch dress rehearsal and a health check of the Falcon 9’s Merlin 1D engines – which were fired for a short burst to provide engineering data to the SpaceX team.
The vehicle was then rolled back into the hanger at the launch complex, allowing for final processing and preparations for late loading on the Dragon spacecraft.
However, on Thursday, SpaceX announced a postponement to the launch of at least two weeks, without providing any specifics.
“To ensure the highest possible level of mission assurance and allow additional time to resolve remaining open items, SpaceX is now targeting March 30th for the CRS-3 launch, with April 2nd as a back-up,” noted the company.
“These represent the earliest available launch opportunities given existing schedules, and are currently pending approval with the Range.”
These considerations would have included the upcoming Atlas V launch with the NROL-67 satellite. Launch from next door’s SLC-41 is currently tracking a March 25 target, which will tie up the Eastern Range around this opportunity.
Per the ISS Visiting Vehicle schedule, a Russian Soyuz is set to launch en route to the Station, also on the 25th.
While Dragon and Soyuz spacecraft are berthed to a different port on the ISS, Station managers always create a level of spacing between vehicle arrivals at the outpost, for various reasons, not least the need to focus on one vehicle’s arrival at a time.
While there is no specific reason as to what caused the delay – as much as it’s understood to be related to the Dragon’s payload, with CBS’ Bill Harwood claiming there is a contamination issue – SpaceX did note their vehicle hardware is in good shape. As such, a further delay is unlikely at this time.
Falcon 9 and Dragon had passed the Flight Readiness Review (FRR) stage last week, with only the Launch Readiness Review (LRR) outstanding ahead of the original March 16 target.
“Both Falcon 9 and Dragon are in good health; given the critical payloads on board and significant upgrades to Dragon, the additional time will ensure SpaceX does everything possible on the ground to prepare for a successful launch,” the company added.
Based on the launch window to the ISS moving 24 minute per day, a March 30 launch attempt would likely take place around 11pm local time.
The CRS-3/SpX-3 flight will carry a full launch and return complement of 1,580kg/3,476lb of payload, an increase from the previous limit of 800kg, afforded by the increased upmass capabilities of the Falcon 9 v1.1.
For launch, Dragon will carry a record of one GLACIER and two MERLIN freezers for transporting ISS experiment samples.
The external payload in Dragon’s trunk includes the Optical Payload for Lasercomm Science (OPALS) – which will demonstrate high-bandwidth space to ground laser communications, and the High Definition Earth Viewing (HDEV) package consisting of four commercial HD video cameras.
The CRS-3 mission will also involve the delivery of a replacement Extravehicular Mobility Unit (EMU), allowing for the return of a faulty suit on the same vehicle when it returns to Earth. This spacesuit relay is enabled by a specially built rack inside the Dragon.
This will be Dragon’s first ride on the upgraded Falcon 9, with the v1.1 set to conduct its fourth flight.
(Images: SpaceX, and L2)
(Click here: http://www.nasaspaceflight.com/l2/ – to view how you can access the best space flight content on the entire internet and directly support NASASpaceflight.com’s running costs)