SpaceX's Dragon: Robotic Capsule Undocks from Canadarm on Space Station

SpaceX's Dragon capsule was released from the International Space Station's robotic arm at 9:26 a.m. EDT (1326 GMT) on May 18, 2014.
Credit: NASA TV

SpaceX's Dragon robotic, unmanned, capsule departed the International Space Station today, putting it on a path back to Earth after about one month attached to the orbiting outpost.

The robotic spacecraft is loaded down with more than 3,500 lbs. (1,587 kg) worth of science samples and supplies which should be safely delivered to Earth once the SpaceX capsule splashes down in the Pacific Ocean later today (May 18).

Splashdown is expected to occur at about 3:02 p.m. EDT (1902 GMT) off the coast of Baja California where officials can recover the supply craft.

The SpaceX Dragon capsule orbits with the International Space Station before its release on May 18, 2014.

Credit: NASA TV

Ground controllers maneuvered the space station's robotic arm to pluck Dragon from the Harmony module and move it into position for release.

The spacecraft was let go from the station at 9:26 a.m. EDT (1326 GMT) as both flew 266 miles (428 kilometers) above the ocean south of Australia, according to NASA.

SpaceX's Dragon also performed a series of thruster burns to move a safe distance from the station before it is expected to execute its deorbit burn at about 2:12 p.m. EDT (1812 GMT).

Dragon has been attached to the space station since April 20, after its launch atop the private spaceflight company's Falcon 9 rocket on April 18 from Florida.

SpaceX successfully performed a daring reusable rocket test during the April 18 launch.

The spaceflight company brought the boost stage of the Falcon 9 rocket back to Earth, landing it upright in the ocean, after delivering Dragon to the proper orbit.

SpaceX's Dragon capsule flies above Angola while attached to the International Space Station just before its release on May 18, 2014. 

Credit: NASA TV

JAXA HTV departure from ISS to test revised robotic Dextre operations plan

The JAXA HTV 4 spacecraft is pictured with the Canadian robot arm and Dextre. Credit: NASA

Japan's fourth H-2 Transfer Vehicle will leave the International Space Station on Wednesday, and the astronauts in charge of releasing the unmanned cargo carrier will use a new technique to keep the HTV steady and avoid the recurrence of a hair-trigger abort that expedited the departure of a previous mission.

Filled with trash and other unneeded gear, the HTV will be released from the space station's 58-foot robotic arm at about 12 p.m. EDT (1600 GMT) Wednesday.

Using a control panel inside the space station, astronauts will command the HTV to retreat from the complex a few minutes later, beginning a preprogrammed sequence of two separation burns with the ship's rocket thrusters.

Space station flight engineers Karen Nyberg and Luca Parmitano closed the HTV's hatches Tuesday to prepare for the departure.

The robotic cargo freighter delivered 3.6 tons of supplies and experiments to the space station Aug. 9 after a five-day transit from a Japanese launch pad to the orbiting outpost.

The astronauts unpacked food, spare parts, experiments and other equipment from the HTV's pressurized compartment, while ground controllers put two robotic arms and a two-armed robotic handyman to work outside the space station to handle the spacecraft's cache of external cargo.

The Canadian-built Dextre robot stowed a main bus switching unit, utility transfer assembly, and an experiment package sponsored by the U.S. Defense Department on platforms mounted on the space station's truss.

Dextre retrieved an older U.S. military experiment - part of the Air Force's Space Test Program - and placed it on the HTV's exposed cargo pallet, then the platform was put back inside the cargo craft Aug. 30.

The trash and experiment box packed inside the HTV will be destroyed during re-entry over the Pacific Ocean on Saturday.

Perched on the end of the station's Canadian robot arm, the HTV will be removed from its berthing port on the Harmony module early Wednesday and maneuvered to a location about 30 feet below the complex.

When astronauts get the go to release the 33-foot-long spacecraft, they will follow a new plan devised after trouble encountered when the third HTV left the space station in September 2012.

After its release from the robot arm, the HTV 3 spacecraft began to drift outside of a predetermined box. Its on-board computers sensed the unplanned movement.

"When we released it with the arm, it imparted a moment on the spacecraft, which caused the spacecraft to translate a little bit," said Mike Suffredini, NASA's space station program manager.

"The abort itself was required because of the moment put on it with the arm. The big thing about the abort was it used the main engines, which put a higher plume and heating load out there close to ISS. Both of those issues have been dealt with between then and now," Suffredini said.

Kounotori, Japan's HTV3 berths with International Space Station

JAXA HTV-3 Kounotori, Docked with ISS.

HTV-3, a Japanese cargo ship carrying 3.5 tons of supplies successfully berthed with the International Space Station yesterday, six and a half days after it was launched.

NASA astronaut Joe Acaba swung the orbiting outpost's robotic arm Canadarm2 to grab hold of the HTV3 spacecraft at 12.23 UT when it was flying high over the Indian Ocean.

Nasa Astronaut Joe Acaba

The space freighter, also known as Kounotori, meaning White Stork, was then drawn in to mate with the ISS's Harmony module where 16 bolts were connected and tightened to complete capture by 14.35 UT.

Acaba was assisted by fellow astronaut Akihiko (Aki) Hoshide, of the Japanese space agency JAXA during the HTV's critical approach to the station. They watched from the Cupola viewing room while at Canadarm2's controls.

The unmanned space craft had earlier moved in to wait at two pre-planned points below the ISS as final checks were made. An onboard laser sensor fired beams at reflectors attached to the bottom of the ISS to deliver precise positional information.

Then, with both the ISS and HTV speeding around the Earth at 27,700 km per hour, the bus-sized freighter moved to a distance of 10 metres ready to be grappled by the robotic arm.

As the moment approached, a NASA mission controller told the astronauts: "It looks beautiful from here. We are go for HTV3 capture."

HTV3 arrived carrying fresh food and supplies for the Expedition 32 crew aboard the space station, an aquarium or Aquatic Habitat (AQH) for fish that will follow on the next missions, a JEM-Small Satellite Orbital Deployer (J-SSOD), five CubeSats and the winning science experiments of the YouTube SpaceLab competition.

This Kounotori is the third HTV mission to the ISS. HTV1 demonstrated the craft's autonomous and remotely-controlled rendezvous capabilities in 2009. It was followed by HTV2 in January 2011 which delivered 6.7 tons of supplies to the ISS.

HTV3 will remain berthed to the space station until September when, having been loaded with rubbish, it will burn up in a controlled descent through the atmosphere.

NASA ISS and CSA Canadarm over Aurora

This image was taken by Nasa astronaut Joe Acaba the flight engineer on board the International Space Station. 

The photograph, taken from an altitude of approximately 240 miles, shows the ISS Canadarm Two robot arm in the foreground with the Southern Lights in the background.