SpaceX CRS-3, also known as SpX-3, was a Commercial Resupply Service mission to the International Space Station (ISS), contracted to NASA, which was launched on 18 April 2014. It was the fifth flight for SpaceX's uncrewed Dragon cargo spacecraft and the third SpaceX operational mission contracted to NASA under a Commercial Resupply Services (CRS-1) contract. This was the first launch of a Dragon capsule on the Falcon 9 v1.1 launch vehicle, as previous launches used the smaller v1.0 configuration. It was also the first time the F9 v1.1 has flown without a payload fairing, and the first experimental flight test of an ocean landing of the first stage on a NASA/Dragon mission. The Falcon 9 with CRS-3 on board launched on time at 19:25 UTC on 18 April 2014, and was grappled on 20 April at 11:14 UTC by Expedition 39 commander Koichi Wakata. The spacecraft was berthed to the ISS from 14:06 UTC on that day to 11:55 UTC on 18 May 2014. CRS-3 then successfully de-orbited and splashed down in the Pacific Ocean off the coast of California at 19:05 UTC on 18 May 2014.
Launch schedule history
The launch was notionally scheduled by NASA, as of November 2012, to be no earlier than 30 September 2013, with berthing to the station occurring three days later on 2 October 2013. By March 2013, the launch was scheduled by NASA for no earlier than 28 November 2013, with berthing to the station occurring three days later on 1 December 2013. By August 2013, the launch date had been moved to no earlier than 15 January 2014, but by October 2013 it was moved to 11 February 2014. As of 23 January 2014, the launch was rescheduled again to 1 March 2014, and then rescheduled to 16 March 2014 in early February 2014. The several delays — from the nominal December 2013 date that had been in place since early 2013 — have been mostly due to limited berthing windows in the ISS Visiting Vehicle schedule, and delays to both Orbital Sciences Corporation's Cygnus and SpaceX's Dragon resulted from the December 2013 cooling issue on the ISS which required several spacewalks to mitigate. On 12 March 2014, the launch was rescheduled to 30 March or 2 April 2014, for a variety of reasons including data buffering issues, working some issues with the Eastern Range, some operational issues with the new Dragon design, and some contamination of the impact shielding blanket. SpaceX ultimately decided to move forward and use the shielding blanket with the minor contamination problems, believing it would not impact the optical payloads being carried in the Dragon trunk. On 26 March 2014, a further delay was announced related to a fire at one of the radar facilities on the Eastern Range. There is mandatory radar coverage for any launches from Cape Canaveral, and the fire forced a delay until that section of the launch trajectory could be covered, possibly by alternative means that would have telemetry communication capability to the Air Force facility responsible for launch safety. By 4 April 2014, the Eastern Range radars were repaired and back online to support launches, and the CRS-3 launch was slated for no earlier than 14 April 2014 with a backup date of 18 April 2014, contingent upon a United Launch Alliance (ULA) Atlas V flight scheduled for as early as 10 April 2014. On 11 April 2014, the International Space Station (ISS) suffered a failure of an external computer known as a Multiplexer/Demultiplexer (MDM), which required a spacewalk on 22 April 2014 to replace in order to restore vital redundancy to the station. Despite the challenges, the CRS-3 mission – which could have been impacted by the MDM failure – was still on for 14 April 2014, with ISS berthing scheduled to take place two days later on 16 April 2014. However, during the launch attempt on 14 April 2014, a primary helium supply valve used in the stage separation system failed a pre-launch diagnostic test approximately one hour prior to the scheduled launch, so the SpaceX launch manager scrubbed the mission. In ground tests following the scrub, the redundant backup helium supply valve tested okay so the mission would likely have succeeded; however, it is SpaceX policy to not launch with any known anomalies. The launch was immediately rescheduled for no earlier than the backup date, 18 April 2014. That date was confirmed two days later, following replacement of the defective valve, but also noted that weather constraints may prevent the launch on 18 April 2014 from occurring at the instantaneous launch window of 19:25 UTC. If that launch had been scrubbed, the next launch window would have been 19 April 2014 at 19:02 UTC. On 18 April 2014 at 19:25:21 UTC, the vehicle was successfully launched. Hours prior to the launch, a liquid oxygen leak in the ground support equipment was detected; SpaceX engineers applied water from the fire suppression system, which froze on contact with the liquid oxygen and plugged the leak. Excess water pooled in the flame trench and dramatically surged upwards as the engines ignited, covering the rocket with grime and soot. Despite the unusual event, the rocket was unlikely to have been in any danger.
Primary payload and downmass NASA has contracted for the CRS-3 mission from SpaceX and therefore determines the primary payload, date/time of launch, and orbital parameters for the Dragon space capsule. Among other NASA cargo, including repair parts for the ISS, the SpaceX CRS-3 mission carried a large number of experiments to the space station, including:
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