Cygnus Orb-3

This would have been the third of eight flights by Orbital Sciences under the Commercial Resupply Services (CRS-1) contract with NASA. This was the first attempted flight of the Antares 130, which uses a more powerful Castor 30XL second stage, and the last flight of the standard-sized Cygnus Pressurized Cargo Module. In an Orbital Sciences tradition, this Cygnus spacecraft was named S.S. Deke Slayton after one of NASA's original Mercury Seven astronauts and Director of Flight Operations, who died in 1993. As the launch failed, the next spacecraft was also named after Deke Slayton. == Launch and early operations ==

The mission was scheduled to launch on October 27, 2014, at 22:45UTC from the Mid-Atlantic Regional Spaceport at the Wallops Flight Facility in Wallops Island, Virginia, with rendezvous and berthing with the ISS early in the morning on November 2, 2014. This was the first night-time launch for both the Antares launcher and Cygnus spacecraft. The resulting explosion was felt in Pocomoke City, Maryland, away. The fire at the site was quickly contained and allowed to burn itself out overnight. Initial review of telemetry data found no abnormalities in the pre-launch, the launch sequence, and the flight, until the time of the failure. On October 29, 2014, teams of investigators began examining debris at the crash site, while a survey the same day found that there was no serious damage to the launch pad and site fuel tanks, although repairs would be required. Subsequent investigation found that the LOX turbopump had exploded, which in turn, caused a shock wave that severed surrounding propellant lines and started a fire from leaking fuel. The fire damaged various components in the thrust section leading to the engines gradually being shut down, although a specific reason for the failure could not be determined. Possible causes were a defective pump bearing, ingestion of loose debris, or a manufacturing defect. == Payload ==

Orb-3 carried a variety of NASA-manifested payloads, some determined fairly late in the days before the launch. The Cygnus cargo vehicle carried of supplies and experiments meant for the International Space Station. It included some CubeSats to be launched from the International Space Station. Flock-1d Planet Labs was launching Flock-1d, its next flock of 26 Earth observation nanosatellites. After the accident they stated that this would not set them back due to their approach to space involving many satellites in various constellations. Arkyd-3 Arkyd-3 was a 3U CubeSat technology demonstrator from private company Planetary Resources (PRI). PRI had packaged a number of the non-optical satellite technologies of its larger Arkyd-100 telescope satellite—essentially the entire base of the Arkyd-100 satellite model revealed in January 2013, but without the space telescope—into a "cost-effective box" of Arkyd 3, or A3, for early in-space flight testing as a subscale nanosatellite. The Arkyd-3 testbed satellite was packaged as a 3U CubeSat form-factor of . The subsystems to be tested included the avionics, attitude determination and control system (both sensors and actuators), and integrated propulsion system that will enable proximity operations for the Arkyd line of prospectors in the future. This near-term attempt to validate and mature the Planetary Resources satellite technology was planned to launch in October 2014, before launch and flight test of the Arkyd-100 in 2015. Other payloads CRS Orb-3 was carrying eighteen student experiments designed to investigate crystal formation, seed germination, plant growth, and other processes in microgravity as part of the Student Spaceflight Experiments Program (SSEP). It also carried the first open source ArduLab-powered student experiments. Two amateur radio CubeSats, RACE and GOMX-2, were on board, among other satellites. On board GOMX-2 were two payloads. One payload was a pathfinder experiment for the Small Photon-Entangling Quantum System. designed by the Centre for Quantum Technologies. The other was a sail brake experiment to remove a CubeSat from orbit by increasing aerodynamic drag. == Failure analysis and aftermath ==

With some preliminary investigation completed, Orbital cited the cause of the Orb-3 launch failure as likely being a turbopump failure in one of the Aerojet Rocketdyne AJ-26 engines, a refurbished Russian NK-33 engine. A NASA report from the failure investigation was released in October 2015. Although NASA and Orbital Sciences agree that the turbopump failed, they differ as to the root cause (machining or debris). By January 2015, repairs to the Wallops Flight Facility began; they were completed in the fall of 2016. To meet its Commercial Resupply Services obligations with NASA, Orbital Sciences launched two Enhanced Cygnus cargo spacecraft via Atlas V launch vehicle—CRS OA-4 (Deke Slayton II) in December 2015 and CRS OA-6 (Rick Husband) in March 2016—while a new engine was selected and tested for the Antares launch vehicle. Orbital Sciences had been conducting an evaluation and review of an AJ-26 replacement engine prior to the incident, and in the year following the explosion they selected the NPO Energomash RD-181, the export version of the RD-191, to replace the AJ-26 on Antares. The Russians selected this same engine (RD-193), to replace the NK-33 engine used on Soyuz-2. The redesigned Antares launch vehicle flew again in 2016. == Manifest ==

Total cargo: • Science investigations: • U.S. science: • International partner science: • Crew supplies: • Equipment: • Food: • Flight procedure books: • Vehicle hardware: • U.S. hardware: • JAXA hardware: • Spacewalk equipment: • Computer resources: • Command & data handling equipment: • Photography/TV equipment: Total cargo with packing material: == Gallery ==

File:Fairing installed for Orbital CRS-3.jpg|Integration of payload fairing on Antares rocket File:Antares CRS Orb-3 rollout (201410240003HQ).jpg|Rollout of Antares to launch pad File:Antares CRS Orb-3 raised at Pad-0A (201410250004HQ).jpg|Antares being raised at pad. File:Antares CRS Orb-3 vertical at Pad-0A (201410250005HQ).jpg|Antares vertical at pad File:Antares Rocket at Sunrise, October 26, 2014.jpg|Against the disk of the rising Sun on launch day File:Antares Orb-3 launch failure (201410280011HQ).jpg|Explosion of Antares after crashing. File:Antares Orb-3 launch failure (201410280012HQ).jpg|Aftermath of explosion == See also ==