By Joe Brock

FARNBOROUGH, England, July 20 (Reuters) - NASA remains on track for next year's Artemis III mission, a key test of orbital docking and lunar landers needed for future crewed moon landings, despite an explosion involving an unmanned Blue Origin rocket during a launchpad test in May, NASA Administrator Jared Isaacman said on Monday.

The Artemis program, which aims to return astronauts to the moon in 2028, combines NASA-developed spacecraft with systems provided by private industry. NASA's Space Launch System rocket will launch a crew aboard Orion, a deep-space capsule built by Lockheed Martin LMT.N, while Elon Musk's SpaceX SPCX.N and Jeff Bezos's Blue Origin are developing landers designed to ferry astronauts between lunar orbit and the moon's surface.

Ahead of future lunar landings, Artemis III will serve as a rehearsal in low Earth orbit. Four astronauts will fly aboard Orion and test rendezvous and docking operations with versions of SpaceX's Starship Human Landing System and Blue Origin's Blue Moon.

"We are still very much planning for that," Isaacman told Reuters at the Farnborough Airshow, referring to the 2027 timeline. "The parts that are in NASA's greatest control, which would be all things SLS and Orion related, are doing incredibly well."

Both lunar landers have experienced schedule delays, and some industry executives doubt they will be ready in time for a 2027 mission. Concerns intensified in May when an uncrewed Blue Origin New Glenn rocket exploded during a hot-fire test on the company's only launch pad in Florida. Blue Origin has said it aims to complete repairs and resume flights by the end of the year.

Isaacman said NASA had contingency plans to keep the lander program on schedule if New Glenn faced further delays.

"Plan A is launching on New Glenn, and they have a year to do that. So I'm very confident they'll be able to achieve it."

SPACEX IPO A BOOST FOR NASA

NASA is also closely watching SpaceX's next Starship test flight, due this week, including the performance of its Raptor engines and heat shield, both critical to making the rocket fully reusable.

Isaacman said SpaceX's record-setting $75 billion initial public offering in June could benefit NASA by giving one of its most important contractors additional resources.

"We have a critical partner of NASA that's now very well capitalized," he said. "The more firepower and resources they have available to throw at a problem is a good thing."

At the Farnborough Airshow, Europe's push for space sovereignty is colliding with NASA's drive to beat China to the moon. While European governments want to reduce dependence on U.S. technology, Isaacman argued allies should focus on filling capability gaps rather than replicating American programs.

"Every contribution has to help us achieve our goal faster," he said, questioning whether Europe should be building its own lunar lander.

"We need our international partners to contribute in ways that enable the mission that are not overlapping."