Jeff Bezos’ Blue Origin space venture has capitulated to Elon Musk’s SpaceX in a dispute over a Blue Origin patent covering the landing of rockets at sea.

In an order made public today, the U.S. Patent Trial and Appeal Board granted a motion to cancel the remaining 13 of 15 claims in the Blue Origin rocket-landing patent. Blue Origin itself had made the motion to cancel those claims, effectively acknowledging that its case was lost.

Blue Origin, based in Kent, Wash., has separately filed a “reissue” patent application covering the same general area. However, SpaceX has already attempted multiple rocket landings at sea and would likely be grandfathered in, allowing it to continue the practice, even if Blue Origin were to ultimately succeed in securing a valid patent.

SpaceX had already won a key early round in March in its attempt to invalidate the Blue Origin patent.

Representatives of both companies declined to comment on the latest ruling.

Blue Origin applied in June 2010 for the patent, “Sea landing of space launch vehicles and associated systems and methods,” outlining a system for launching a rocket from a coastal launch site and recovering the booster by landing it vertically, tail-first, on a platform at sea — using the booster engines to control the descent. The patent was granted in March of last year.

SpaceX disputed the Blue Origin patent, citing prior work by researchers and scientists who proposed techniques similar to those in Blue Origin’s patent long before the patent was filed. “The ‘rocket science’ claimed in the ‘321 patent was, at best, ‘old hat’ by 2009,” wrote SpaceX in its petition.

Blue Origin, based in Kent, Wash., is focusing heavily on vertical landings as part of its overall approach to commercial spaceflight.