People in downtown DC were spooked Friday by the sight of a balloon hovering high above them. Without warning, the dirigible appeared high over city streets, just lingering there. What was it doing up there? Some secret government project? An invasion by an unidentified flying object?

There’s some kind of white and red balloon flying over Dupont Circle. Hard to see but Something is hanging off it as well. What is it, Twitter? pic.twitter.com/hqHg7oqQ0r — Sarah Mimms (@SarahMMimms) January 26, 2018

What is this UFO over downtown DC? It’s bigger than it looks in the pics. cc @PoPville pic.twitter.com/Ric9G3K6HZ — kettricken (@samtenchuwo) January 26, 2018

None of that. The balloon was being used to take aerial images on behalf of an ongoing real-estate project, according to the guy who owns it. Carl Westergard, the president of Digital Design & Imaging Service, based in Falls Church, says today’s flight was just a run-of-the-mill job to measure the development’s adjacency to downtown landmarks. The device itself is a 12-foot-long helium-filled skin large enough to support one of Westergard’s nine-eye cameras, and rises up from a trailer bed to which it is tethered. Although it’s not visible in the social-media photos shared Friday, there is a winch holding the balloon in place, controlled at ground level near 16th and P streets, Northwest.

“We went to 800 feet above ground level,” Westergard says. “Today we were looking at the building to show off its prime adjacency to things like the White House and landmark buildings.”

Westergard wouldn’t identify his client, but his company performs similar jobs for other high-rise projects, both in DC and the rest of the country. Among the buildings for which his company has scouted sight lines are the new World Trade Center and San Francisco’s Transbay Transit Center. “We figure out what the view will be from a building, as well as changes to the neighborhood through aerial imaging,” Westergard says.

Digital Design & Imaging’s balloons have been spotted over DC before when one was used in 2013 when Congress asked the District’s Office of Planning to propose changes to the 1910 Height Act, which limits how tall the city’s buildings can go. (No significant changes have been implemented.) They’ve also been used to take aerial photos of large crowds, including presidential inaugurations and the 2017 Women’s March on Washington. You might also spot one of Westergard’s balloons over large theme parks that want a look at how efficiently their guests are moving around.

Still, the spotting of a balloon hovering far above DC on Friday naturally raises other questions. Like, isn’t there a flight restriction over Washington that prohibits the operation of unmanned aerial vehicles? There is, but because the balloon is on a ground-level leash, it gets around the Federal Aviation Administration’s prohibitions on drone flights. In fact, Westergard says, sometimes his balloons help the feds keep an eye out for violators of the “no-drone zone.”

Don’t Miss Another Big Story—Get Our Weekend Newsletter Our most popular stories of the week, sent every Saturday. Or, see all of our newsletters. By signing up, you agree to our terms

Join the conversation!