(CNN) — Imagine boarding a plane and stepping into a “cocoon-like” private bedroom fitted with a king-size bed, and a bathroom featuring the largest rain and massage shower ever built on an aircraft, which can merge with the sleeping quarters to form a self-contained retreat, providing total privacy.

That’s the centerpiece of Lufthansa Technik’s new cabin design for the upcoming BBJ 777-9 — the private jet version of Boeing’s new widebody aircraft, the 777X. Called CelestialSTAR, the design takes full advantage of the plane’s extremely spacious cabin, which offers 343 square meters (about 3,700 square feet) of space and pairs with the aircraft’s ability to stay in the air for 22 hours — which means it could connect any two cities in the world without stopovers, according to Boeing.