Locheed SR-75 Penetrator Projected successor to SR-71

Beginning in the mid-1980s, the U.S. Air Force and NASA have supported a number of studies of aircraft that are consistent with accounts of the “Aurora” reconnaissance aircraft project, the proposed successor to the SR-71 Blackbird which would retired in 1999. While various sources disclosed that Lockheed’s secret Skunk Works was developing a SR-75 Penetrator for the U.S. Air Force, Aviation Week and Space Technology magazine first reported the news that the term "Aurora" was inadvertently released in the 1985 US budget, as an allocation of $455 Million for aircraft construction in fiscal year 1987. As the role of the SR-71 Blackbird, it was believed that the SR-75 was designed as a reconnaissance drone mother-ship. In 1995, U.S. congress approved $100 million to bring the SR-71's back into service. One argument is that the SR-75 Penatrator project was abandoned, either due to expense or technical difficulties, and that the SR-71 had to be brought back to resume its mobile surveillance role.