Musk shared the photo Monday morning, and noted that the spacesuit featured in the picture wasn’t a “mockup” — it is a tested version that “actually works.”

“First picture of SpaceX spacesuit. More in days to follow. Worth noting that this actually works (not a mockup). Already tested to double vacuum pressure. Was incredibly hard to balance esthetics and function. Easy to do either separately,” Musk tweeted.

He didn’t reveal any specifics about when the final SpaceX spacesuit would be ready.

https://www.instagram.com/p/BYIPmEFAIIn/

Most of SpaceX’s recent tests have focused on unmanned spaceflights and reusable rocket technology. Earlier this month, the company successfully launched another rocket — the Falcon 9 was sent to bring supplies to the International Space Station.

SpaceX is gearing up to launch the Falcon Heavy, the massive rocket that is allegedly capable of bringing people to Mars, in November, Musk announced at the beginning of the summer. But this isn’t the first time Musk has discussed an imminent Falcon Heavy launch. Back in 2011, he said the rocket would launch in “2013 or 2014.”