Richard Simmons' Staff Shares Recent Pic of Him, Post He Wrote Before Death

Richard Simmons' team's keeping his legacy alive ... sharing a post the late star approved before he passed -- including what looks like a recent pic of the fitness guru.

The people behind Simmons' X account shared a post they say Richard worked on tirelessly that was supposed to go up last Sunday -- the day after he passed away.

In the post, the account managers explain how RS would go over posts multiple times ... holding off on posting until he'd written them exactly how he wanted.

The staff says on weekends he would post a photo, but he would write a caption for it by Friday night ... so, he'd completed the one for last weekend before he passed.

This last one Richard prepared showed him with a head full of gray hair in a bright orange astronaut suit ... which they say he planned to caption, "Let me fly you to the moon so we can gaze among the stars.  Love, Richard."

We broke the story ... Simmons was found unresponsive by his housekeeper last Saturday, a day after his 76th birthday. First responders arrived and pronounced him dead at the scene.

As we told you ... Richard fell in the bathroom the night before his death after feeling dizzy earlier on -- refusing to go to a doctor so as not to spoil his birthday.