On April 14, 2015, SpaceX successfully conducted launch of Falcon 9 launch vehicle carrying Dragon cargo spaceship from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, for the sixth official Commercial Resupply Services (CRS) mission to the International Space Station (ISS).
Initially CRS-6 mission launch was scheduled for April 13, but the launch was scrubbed due to a bad weather. In two and a half days, on April 17, Dragon arrived to the ISS, being captured by the robotic manipulator Canadarm2, controlled by NASA's astronaut Terry Wirts and ESA's Samantha Cristoforetti.
There is one remarkable thing happened during Dragon's flight that shall be described apart here. SpaceX again attempted to softly land Falcon 9 first stage on the custom-built autonomous spaceport drone ship (ASDS) in the Atlantic Ocean, however, this time the attempt was not successful.
"Ascent successful. Dragon enroute to Space Station. Rocket landed on droneship, but too hard for survival... Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post landing." Elon Musk, SpaceX CEO, wrote in his Twitter
Before this mission SpaceX has already demonstrated three successful soft water landings, and a hard landing on an unanchored ocean platform. This time, it seems, there has been taken place hard-landing scenario as it was during CRS-5 mission. Next landing attempt is expected to be made by SpaceX during CRS-7 mission, currently scheduled for June.
Video of Falcon 9 first stage landing attempt released by SpaceX.
CRS-6 is the sixth of at least 12 missions to the ISS that SpaceX will fly for NASA under near $1.6 billion CRS contract. The Dragon spacecraft to be docked with the ISS is filled with 2,015 kg of supplies and payloads, including critical materials to directly support about 40 of the more than 250 science and research investigations that will occur during Expeditions 43 and 44.
Science payloads will study new ways to possibly counteract the microgravity-induced cell damage seen during spaceflight, the effects of microgravity on the most common cells in bones, gather new insight that could lead to treatments for osteoporosis and muscle wasting conditions, continue studies into astronaut vision changes and test a new material that could one day be used as a synthetic muscle for robotics explorers of the future. Also making the trip will be new espresso machine for space station crew (so-called ISSpresso).
According to some sources, Dragon will deliver to the ISS 17 separate spacecraft that later will be deployed from the orbital station. These are:
- 14 Flock-1e Earth imaging satellites of Planet Labs. These tiny 3U CubeSats are already sixth Planet Labs' “flock”, after 28 Flock-1, 28 Flock-1b, 11 Flock-1c, 26 Flock-1d (lost in a launch failure of Orbital Sciences' Cygnus CRS-3), and 2 Flock-1d' satellites;
- Arkyd-3 Reflight (A3R) – 3U CubeSat of Planetary Resources that will test systems for the Arkyd-100 space telescope, but does not feature a telescope itself. First such spacecraft, Arkyd-3, was also lost in Antares/Cygnus failure in October 2014.
- AggieSat-4 spacecraft, a bigger 50 kg satellite for the second mission of the LoneStar campaign, made by the University of Texas. With Bevo-2 3U CubeSat, integrated into the AggieSat-4, the combined spacecraft are to test relative-navigation solutions, three-axis stabilization, inter-satellite communications, Dragon GPS system characterization, and visual capability. In addition, after release from the ISS, AggieSat4 will release Bevo-2 to begin pointing, tracking, and relative navigation operations;
- Bevo-2 – see above.
Since Dragon is the only operational spacecraft capable of returning a significant amount of supplies back to Earth, after five weeks at the space station, it will return with more than 1,370 kg of cargo, including crew supplies, hardware and computer resources, science experiments, space station hardware, and trash.
The next SpaceX mission under CRS program is initially scheduled for June 19. The next SpaceX mission overall is TurkmenSat-1, a communications satellite for the government of Turkmenistan, expected to be conducted in just 13 days, on April 27.
CRS-6 mission launch overview is below: