Jeff Bezos‘ space venture Blue Origin auctioned off a seat on its upcoming first crewed spaceflight on Saturday for $28 million.

The winning bidder, whose name wasn’t released, will fly to the edge of space with the Amazon founder and his brother Mark on Blue Origin’s New Shepard rocket scheduled to launch on July 20. The company will reveal the name of the auction winner “in the weeks following.”

New Shepard, a rocket that carries a capsule to an altitude of over 340,000 feet, has flown more than a dozen successful test flights without passengers, including one in April at the company’s facility in the Texas desert. The autonomous system is designed to carry up to six people. The capsule has massive windows to give passengers a view of the earth below during about three minutes in zero gravity, before returning to Earth.

Blue Origin’s system launches vertically, and both New Shepard’s rocket and capsule are reusable. The boosters land vertically on a concrete pad at the company’s facility in Van Horn, Texas, while the capsules land using a set of parachutes.

Bezos founded Blue Origin in 2000 and still owns the company, funding it through share sales of his Amazon stock.

July 20 also marks the 52nd anniversary of the Apollo 11 moon landing.