Payload Pioneers 2025

Alex Reynolds, ATTX

They say space is hard for a reason. Companies building space tech have very specific requirements, and require a lot of precision. To meet those needs, they spend a lot of time and resources on designing custom software to get to space. How exhausting.

Alex Reynolds is the founder and CEO of ATTX, a two-year-old startup building the software stack for clients in the space industry. The idea: create software that can work for clients across the space ecosystem, and eliminate the need for companies to build all their own stuff.

Starting in space: After graduating from the Missouri University of Science and Technology, Reynolds started his career at what is now called Sierra Space. He worked on the Dream Chaser spaceplane as an engineer. Reynolds grew into a role as an engineering manager in the company’s software group, where he saw up close just how bespoke the software stack really was—in a way that, he thought, it didn’t have to be.

“Really, this is a problem that a lot of people deal with,” Reynolds told Payload. “Everyone is kind of creating their own stuff from scratch, and it costs a lot of money, and takes a lot of time, and it doesn’t work as well. So the idea was, let’s go solve this problem…let’s go start a company, let’s do really good engineering, let’s try to see if we can fix this and see what happens. And if it doesn’t work out, it doesn’t work out. But at least we gave it a shot.”

So the space-startup-founder journey began.

Windows for space: At ATTX, Reynolds is building, piece by piece, a software platform that he hopes will become industry standard for the space sector. The platform aims to lower costs and streamline engineering processes. He is working to make ATTX, in his words, the “Windows for space”, by providing the platform with which the industry can do whatever it needs to do.

“We tried to do our work in a way where we didn’t raise money, and we just tried to go get contracts with companies…you have no choice but to build something that someone needs if the only way for you to continue to survive as a company is to build that thing,” Reynolds said.

Psst…pass it on: Reynolds has a passion for space, and that’s what keeps him locked in on building tech for the space industry.

“Most of the people you talk to who are working in this industry are here because we love it,” Reynolds said. “They’re not here because it’s like, ‘Well, this is how I could get the biggest paycheck.’ And I think that’s awesome. There’s this whole spirit of exploration and growth.” 

As a founder, Reynolds works to bring that excitement and passion down the line.

“Alex’s impact extends beyond free and low-cost tools; He also mentors young engineers, both through paid internships and personal connections, fostering technical expertise and leadership knowledge in those who are poised to later join Payload’s 30-under-30 ranks,” Ryan Hughes, founding engineer at ATTX, said about Reynolds. Cheers to that.

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