When SpaceX’s Falcon Heavy lifts off for the first time this summer it will rank as the most powerful operational rocket in the world by a factor of two – but its payload will less than serious.

That’s according to Tweets on Friday from company Chief Executive Elon Musk, who wrote the heavy-lift rocket’s test cargo would be the “silliest thing we can imagine!”

The rocket, which would potentially cost between $180 million and $200 million when fully loaded, could shake up the heavy lift segment of the commercial launch services industry with lower costs per kilogram of cargo. Musk also said on Thursday that the rocket, which is essentially three Falcon 9 boosters strapped together, would be constructed with two previously used boosters from earlier missions.

When SpaceX’s crew capsule was test-launched for the first time in 2010, the company chose an irreverent payload as well.

“Secret payload of 1st Dragon flight was a giant wheel of cheese,” wrote Musk on Twitter. “Inspired by a friend & Monty Python.”

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.