Sen. Bill Nelson (D-FL) brokered an agreement among Senators who have been at sharp odds over how to transition U.S. rocket launches away from reliance on Russian RD-180 engines to a new American-made engine. The Nelson amendment passed the Senate this morning by voice vote as part of the FY2017 National Defense Authorization Act (NDAA). The NDAA itself then passed the Senate by a vote of 85-13.
In brief, the compromise sets December 31, 2022 as the end date for use of the RD-180 by the United Launch Alliance (ULA) for Atlas V launches of national security satellites. It also limits to 18 the number of RD-180s that can be used between the date that the FY2017 NDAA is signed into law (enacted) and that end date.