The SR-71 Blackbird that vanished from its display stand at NASA’s Armstrong Flight Research Center in California is being cleaned, according to agency chief Jared Isaacman. Asked whether aircraft 844 had been powered up, he replied, “We’re just cleaning it, man,” adding that it had become dusty in the desert.

The aircraft was removed from its outdoor stand earlier this year and placed in a former space shuttle hangar, according to an Aviation Week investigation published on September 29. Satellite images showed it had been moved before May 17. The change in location prompted speculation that NASA might be preparing the Blackbird to fly again.

Number 844 was the last SR-71 to fly, completing its final flight on October 9, 1999. The Lockheed-built reconnaissance aircraft had been on display at the Armstrong center, at Edwards Air Force Base, since 2002. The first Blackbird flew in 1964.

NASA has not confirmed a plan to return the aircraft to flight. A spokesperson previously said the agency had no further information to share at the time. Isaacman has, however, made comments that have kept questions alive: at an air show in July, he described the possibility of bringing back the SR-71 as “classified.”

At a Los Angeles event in mid-September, Isaacman showed the outline of an aircraft resembling the Blackbird. He said it was not an SR-71 and indicated that NASA would soon fly an aircraft at speeds and altitudes comparable to those reached decades ago. The source report says Isaacman also announced a new experimental aircraft for the coming weekend, while stressing it was unrelated to the Blackbird.

Aviation Week also reported that NASA approached former engineers from the SR-71 program about a position during the summer. Former program engineer Tim Conners has argued that a Blackbird could serve as a flying test platform for high-speed engines: while computer simulations can model aerodynamics at those speeds, he said, they are less effective at reproducing how a new engine would behave on a fast aircraft.

Sources: Numerama.