PARIS -- A Space Exploration Technologies (SpaceX) Falcon 9 rocket launched the company’s fifth resupply mission to the International Space Station (ISS) for NASA Jan. 10, though a secondary goal to demonstrate Falcon 9 core-stage reusability was unsuccessful, according to SpaceX founder and CEO Elon Musk.

The Falcon 9 lifted off as scheduled at 4:47 a.m. from Launch Complex 40 at Cape Canaveral, five days after slipping a planned Jan. 6 mission due to a problem with an upper stage thrust vector control actuator. The mission is loaded with 2,300 kg (5,108 lbs) of supplies and payloads aboard the Dragon cargo spacecraft en route to the orbiting outpost.

Shortly after liftoff, following first stage separation, the Falcon 9’s upper-stage engine ignited for a seven-minute burn, bringing the rocket and spacecraft to low Earth orbit. Second-stage engine cutoff and spacecraft separation followed moments later, with SpaceX mission control at the company’s Hawthorne, California headquarters reporting nominal deployment of Dragon’s solar arrays.

Rendezvous and grapple of the Dragon capsule with the ISS is slated for 6:12 a.m. Jan. 12. The crew will work over the next four weeks to unload Dragon’s payload and reload it with cargo that Dragon will bring back to Earth.

In addition to food, water and clothing for ISS astronauts, Dragon is carrying supplies to support more than 250 science experiments aboard the station, as well as student projects and nanosatellites replacing some of those lost in the launch failure of an Orbital Science Corp. cargo-resupply run last October.

The mission is also carrying two payloads managed by the Center for the Advancement of Science in Space (CASIS), a non-profit organization established to sponsor commercial research aboard the ISS. These include a molecular aging experiment dubbed T-Cell Activation in Aging and the Planarian Flatworms experiment, which will study regeneration in planarians in near-zero gravity.

An Earth-science instrument known as the Cloud-Aerosol Transport System (CATS) is also onboard, and will be used to measure pollution in the atmosphere.

While the NASA portion of the cargo mission appears to be on track, the company’s effort to return the Falcon 9 first stage to Earth and land it on an unmanned barge was unsuccessful, according to Musk.

In a comment posted to his Twitter feed following the launch, Musk said the booster “made it to drone spaceport ship, but landed hard. Close, but no cigar this time. Bodes well for the future though.”

According to SpaceX, the booster was to conduct three separate engine burns to put it on course to re-enter the atmosphere and slow from 2,900 mph (4,600 km/h) to 4.5 mph at the point of touchdown on the barge, which measures 300 x 170 ft (91.5 x 52 m).

A boostback burn was to adjust the impact point of the vehicle, and supersonic retro-propulsion burn and deceleration fins were to slow its speed, followed by a single-engine landing burn.

Musk said the barge is “fine” and that some of the support equipment on its deck will need to be replaced. In addition, he said dark and foggy conditions thwarted the company’s attempt to record clear video footage of the landing attempt.

“Will piece it together from telemetry and … actual pieces,” he posted.

Prior to the attempted landing, Musk was quoted as giving it a 50% chance of success. Shortly before the failed Jan. 6 launch attempt, he told a social media audience during a question-and-answer session on that he “pretty much made that up.”