Martha Stewart Pokes Fun at Katy Perry Space Journey With 'Firework' Reference

Martha Stewart says she was into space travel before it got popular among celebrities ... sharing a clip of herself experiencing zero gravity -- and throwing in a cryptic Katy Perry reference.

The businesswoman took to Instagram this week to remind people that she once took part in a zero-gravity experience of her own ... though she didn't make it all the way up into space.

Almost 20 years ago, Martha got aboard a Boeing aircraft that moved fast enough for those onboard to experience what astronauts feel at zero gravity.

Stewart's doing a ton of flips and aerial tricks in the clip ... floating through the air like a "plastic bag drifting through the wind."

If that sounds familiar to you, it's because it's a line from Katy's iconic track "Firework" ... and, Perry just went to space herself on the all-female Blue Origin flight.

It's unclear if this is a shot at Perry ... though it's interesting Stewart would mention the singer's track while many online are roasting KP for caring way more about the cameras around her than about actually being up in space.

Katy also got clowned for kissing the ground after her flight to space despite being in space for mere minutes.

Martha's all about the moment in the vid she posted ... a stark contrast to Katy revealing the setlist for her upcoming tour.