The 322-foot (98-meter) rocket has the task of sending NASA's ESCAPADE twin spacecraft to Mars, a bid to study the Red Planet's climate history and pave the way for eventual human exploration.

Blue Origin's launch will also serve as a key test of whether it can achieve booster recovery -- what would prove a technical breakthrough for the company if successful.

The rocket is set to blast off Sunday during an 88-minute launch window that will begin at 2:45pm (1945 GMT).

If delayed by weather or a technical glitch, rescheduling could prove challenging given the US government shutdown. To relieve airspace congestion, the Federal Aviation Administration is limiting commercial rocket lift-offs starting Monday.

New Glenn's inaugural flight in January was marked as a success as its payload achieved orbit and successfully performed tests.

But its first-stage booster, which was meant to be reusable, did not stick its landing on a platform in the Atlantic, and instead was lost during descent.

This time it will try once more to recover the booster stage. Thus far, only Musk's company SpaceX has managed to do that.

- 'Indicator' of progress -

The competing space companies of billionaires Musk and Bezos are locked in a commercial space race that recently escalated, as the US federal space agency opened up bids for its planned Moon mission as complaints emerged that SpaceX was "behind."

George Nield -- a senior aerospace executive whose work promotes the commercial space industry, and who has flown with Blue Origin in the past -- told AFP the stakes of Sunday's launch are high.

How the launch plays out will be an indicator of "how well they're doing and how much progress they've made," he said.

If all goes to plan, the twin satellites aboard New Glenn are slated to reach Martian orbit in 2027.

US President Donald Trump's second term in the White House has seen the administration pile pressure on NASA to accelerate its progress to send a crewed mission to the moon amid a race with China.

Mason Peck, an aeronautics professor at Cornell University and former NASA chief technologist, said increased competition between SpaceX and Blue Origin could "expand our options with regard to launch."

"More launches means more ideas in space," Peck said. "It can't be a bad thing to have Blue Origin even trailing behind."