The story of the Aurora codename

Everyone remembers a time in the late 1980s and early 1990s when rumors about the US Air Force replacing the SR-71 with a hypersonic spyplane made a splash in several publications and many people referred to the alleged hypersonic SR-71 follow-on as "Aurora" in reference to the codename Aurora, which appeared in a February 1985 Pentagon budget request for FY1986 and FY1987 above a budget line-item for the U-2. However, the story of speculation in the 1980s press about what the codename Aurora referred to is quite complicated.

When the press immediately reported on the Pentagon budget document dated February 4, 1985, it simply speculated that the line-item with the codename Aurora mentioned in the budget request for FY1986 and FY1987 had to do with either the B-2 Spirit (still officially called Advanced Technology Bomber in many USAF documents until 1988, including the above-mentioned 1985 Pentagon budget document) or the yet-to-be-classified F-117 Nighthawk:
Aurora Program May Involve Stealth Bomber or Fighter : Defense Document Tells of Secret Plane

Press speculation about Aurora being an SR-71 successor actually started with a January 1988 Los Angeles Times article (an article published in January 1988 in the New York Times also dealt with the topic of an SR-71 follow-on but did not mention Aurora), and the writer of that article assumed that Aurora might have to do with a Mach 5 hypersonic spyplane studied by Lockheed in the 1980s because the line-item Aurora appeared in the Pentagon budget document section "Other Aircraft" above the line-item for the U-2. Within a span of a few years, many publications followed the January 1988 Los Angeles Times news article in associating the Pentagon codename Aurora with a hypothetical SR-71 replacement, and rumors about the USAF deploying a hypersonic spyplane would be fed by recorded instances of "skyquakes" over Los Angeles, sightings of triangular aircraft, photos of the donuts-on-a-rope contrails, and budget holes in Lockheed financial reports for 1988-1992 which were not officially ascribed to known aerospace activity (although we now know that the US Air Force never had an operational hypersonic spyplane).

In 1994, months before his death in January 1995, Ben Rich, who headed the Lockheed Skunk Works from 1975 to 1990, published a memoir about his time at the Lockheed Skunk Works and wrote the following passage that debunked speculation about Aurora having to do with hypersonic aircraft and vindicated initial suggestions that Aurora was related to the B-2 bomber:
The funding for the [Advanced Technology Bomber] competition came out of a secret stash in the Air Force budget. A young colonel working in the Air Force “black program” office at the Pentagon, named Buz Carpenter, arbitrarily assigned the funding the code name Aurora. Somehow this name leaked out during congressional appropriations hearings, the media picked up the Aurora item in the budget, and the rumor surfaced that it was a top secret project assigned to the Skunk Works—to build America’s first hypersonic airplane. That story persists to this day even though Aurora was the code name for the B-2 competition funding. Although I expect few in the media to believe me, there is no code name for the hypersonic plane, because it simply does not exist.
While it may seem strange that the B-2 was not listed as a separate line-item in the February 1985 Pentagon budget request for FY1986 and FY1987 despite being mentioned in passing in the text for the B-1B line-item (as Advanced Technology Bomber), Adelbert "Buz" Carpenter's decision to assign the Aurora codename to requested funding for B-2 related activity was because he recognized that the total cost of the B-2 program was difficult to conceal, as noted by Peter Merlin on page 346 of his book Dreamland: The Secret History of Area 51, in which case he found it convenient to create a codename for requested funds for B-2 related activities like in-the-works test support infrastructure, airborne synthetic aperture radar, and manufacturing facilities for the B-2. Although some people believed that Aurora appeared in the budget document by mistake, Bill Sweetman conceded in the chapter "Would Your Government Lie to You?" of his 1993 book Aurora: The Pentagon's Secret Hypersonic Spyplane that Aurora might not have been the real name of the alleged hypersonic follow-on to the SR-71 (Sweetman's book also happens to correctly describe Senior Citizen as a tactical USAF program because a number of people erroneously floated Senior Citizen as another possible codename that the hypothetical USAF hypersonic spyplane). In a similar vein, Pentagon budget documents applied the codename Stingray to a USAF campaign to prepare Edwards Air Force Base for testing of the B-21 Raider.

While it's been clear since the 1994 memoir by Ben Rich that the codename Aurora pertained to requested funding for B-2 program related support/logistics activities, not to mention that revelations in the press in the 1990s about the canceled CIA- and NRO-sponsored Quartz program to develop an unmanned stealthy reconnaissance flying wing to replace the SR-71 and U-2 along with reactivation of the SR-71 called into question rumors about the USAF operating a hypersonic spyplane, Lockheed and a few other aircraft companies did undertake design studies for a hypersonic spyplane in the late 1970s and 1980s under contract from the US Air Force, including the Lockheed Mach 5 spyplane design of the early 1980s which the January 1988 LA Times and NY Times reports alluded to as well as Boeing hypersonic spyplane designs conceived under the Model 1074 umbrella company designation. The problem was, the hypersonic air-breathing engine tech was still immature in the 1980s, so in the 1989/1990 timeframe the Air Force decided to take interest in the Quartz program as a less technologically risky successor to the SR-71.