SpaceX Falcon 9 V1.1 - CRS-6 - Launching April 14, 2015
Screenshot from SpaceX Webcast of the launch of CRS-6
Mission Rundown: SpaceX Falcon 9 V1.1 - CRS-6
Written: February 2, 2021
Incoming. Where’s my helmet?
After six successful missions to the International Space Station, including five official resupply missions for NASA, SpaceX’s Falcon 9 rocket and Dragon spacecraft are set to liftoff from Launch Complex 40 at the Cape Canaveral Air Force Station, Florida, for their sixth official Commercial Resupply Services (CRS-6) mission to ISS.
Liftoff was targeted for Tuesday April 14, 2015, at 4:10pm EDT. Cargo Dragon C108-1 will arrive at the station approximately two days after liftoff.
Cargo Dragon C108-1 is expected to return to Earth approximately five weeks later for a parachute assisted splashdown off the coast of southern California.
The Dragon Payload
As of July 2014, the launch was tentatively scheduled by NASA for February 2015, with berthing to the station occurring two days later. However, as a result of delays in the launch of the previous SpaceX CRS-5 mission, CRS-6 launched on 14 April 2015 due to bad weather conditions the day before.
NASA has contracted for the CRS-6 mission from SpaceX and therefore determines the primary payload, date/time of launch, and orbital parameters for the Dragon space capsule. The Dragon spacecraft was filled with 2 015 kg (4,387 pounds) 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.
A part of this payload includes science experiments from high schools, such as a project from Ambassador High School in Torrance, California.
For its return journey, Dragon will be loaded with 1,370 kilograms (3,020 lb) of hardware to be brought back to Earth.
The Dragon is the only spacecraft that allows a significant amount of hardware to be returned to Earth from the space station – the only other spacecraft capable of returning items is Russia’s Soyuz, which is limited to what can be fit into the spacecraft around its crew of three cosmonauts.
Many of the US and Japanese ISS resupply missions carry CubeSats or other small payloads to be deployed from the space station. CRS-6 is no exception, as the Arkyd-3R technology demonstrator and fourteen Flock-1 Earth observation satellites are hitching a lift to orbit on the launch.
A replacement for the Arkyd-3 satellite, lost in October’s Antares launch failure, Arkyd-3R is a three-unit (3U) CubeSat to be operated by Planetary Resources as a pathfinder for its Arkyd-100 telescope constellation.
The 14 Flock-1e satellites will join Planet Labs’ Flock constellation. Utilizing a very large fleet of short-lived satellites, named Doves, Planet Labs aims to provide quick and updated good-resolution images of the Earth, at a lower cost than with bigger imaging satellites.
The test landing of booster B1015
After the separation of the second stage, SpaceX conducted a flight test and attempted to return the nearly-empty first stage of the Falcon 9 through the atmosphere and land it on a 90x50-meter (300 ft×160 ft) floating platform as an autonomous spaceport drone ship.
The Marmac 300 barge was rebuild and named “Just Read The Instructions” by SpaceX
The unmanned rocket technically landed on the floating platform, however it came down with too much lateral velocity, tipped over, and was destroyed on impact. Elon Musk later explained that the bipropellant valve was stuck, and therefore the control system could not react rapidly enough for a successful landing.
This was SpaceX's second attempt to land the booster on a floating platform after an earlier test landing attempt in January 2015 had to be abandoned due to bad weather conditions. The booster was fitted with a variety of technologies to facilitate the flight test, including grid fins and landing legs to facilitate the post-mission test.
If successful, this would have been the first time in history that a rocket booster was returned to perform a vertical landing.
On 15 April, SpaceX released a video of the terminal phase of the descent, the landing, the tip over, and a small deflagration as the stage broke up on the deck of the first ASDS “Just Read The Instruction” aka. the barge Marmac 300.
