Elon Musk wants to recycle even more parts of SpaceX rockets.

It sounds like Elon Musk is planning a shindig for 5-year-olds. 

The SpaceX founder dropped a thread onto Twitter Sunday night that started with the simultaneously exciting and portentous phrase "This is gonna sound crazy, but…"

Musk went on to suggest SpaceX will attempt to bring a rocket's upper-stage section back down to Earth using a giant party balloon and then land it on a bouncy house. The upper stage is the part of the rocket system that fires after the first stage disconnects. It escorts the payload all the way into orbit.

SpaceX has had success recapturing the first stages of its Falcon rockets, refurbishing them and using them for multiple missions, but it has yet to attempt to land and reuse a second stage. These are typically left to decay in orbit and eventually burn up when they reenter the atmosphere.

Hans Koenigsmann, SpaceX's vice president of mission assurance, participated in a NASA briefing on Sunday ahead of the launch of the space agency's new exoplanet-hunting mission TESS, which is scheduled to go into orbit on Monday aboard a SpaceX Falcon 9 rocket. 

Koenigsmann fielded a question asking if SpaceX would try to purposefully de-orbit the second stage of the rocket used for the TESS launch. 

"We will not de-orbit the second stage, but we will basically kick it out," Koenigsmann said. He said it will do a third burn that will send the second stage away from Earth as a means of disposing of it. So we shouldn't expect any party balloon antics from SpaceX for the TESS launch, but it's something we should keep an eye on for the future.

While Musk's party imagery makes the concept sound far-fetched, it's actually a reasonable idea to consider. Musk may be talking about a ballute, an inflatable parachute-like device that could look like a huge balloon. It's a technology that NASA has eyed for years. 

The bouncy house method of catching the rocket's upper stage could bear a resemblance to SpaceX's idea of using a ship equipped with a large net to catch a rocket nose cone. Musk cited this example in a follow-up tweet.

SpaceX has made strides in recycling rockets to help keep down the cost of launching satellites, cargo capsules and spacecraft. It's no wonder Musk is looking at ways to reuse even more of the rocket equipment.

So, does this sound crazy? No crazier than Musk's Boring Company selling thousands of flamethrowers or SpaceX shooting Musk's personal Tesla electric car off into the solar system.