Speaking at a tech conference in San Francisco on Tuesday, Garman threw some cold water on the idea of ​​space-based data centers, which Elon Musk and others have pointed to as the future of AI.

While putting AI data centers in space has obvious benefits, including the ability to use energy directly from the sun and the ability to cool heating equipment in the cold atmosphere of space, Garman said there are also some major obstacles to putting data centers in space or on other planets. Foremost among them is the cost of transportation of the equipment.

“I don’t know if you’ve seen a rack of servers lately: They’re heavy,” Garman said in an interview at the Cisco AI Summit in response to a question about the feasibility of space-based data centers. “And last I checked, humanity has yet to build a permanent structure in space. So … maybe.”

Comments will come a day later Musk announced the merger of SpaceX, his rocket company, with his AI company, xAI, in a deal that reportedly values ​​the combined companies at a staggering $1.25 billion.

“The capabilities we unlock by making space-based data centers a reality will fund and enable the growth of our own bases on the Moon, an entire civilization on Mars, and ultimately the expansion of the Universe,” Musk wrote in a blog post Monday announcing the deal.

The modern data centers that power AI servicesincluding chatbots like OpenAI’s ChatGPT and xAI’s Grok, are huge behemoths that span millions of square feet and are packed with so much hardware that they have to be built on top of a reinforced concrete slab.

said Musk SpaceX has a successful track record of launching thousands of its internet-facing Starlink satellites into orbit on its Falcon rockets, and Musk has floated ambitious plans to use his Starship rocket to launch as many 1 million satellites into space—an amount greater than the total number of objects launched into space in history. The Starlink launch blizzard will lead to improvements in SpaceX rockets that will make space-based data centers a reality, Musk wrote on Monday, though he did not provide a timeline for when he expects that to happen.

Amazon has plans to build a constellation of internet beaming satellites, called Leo, to compete with SpaceX’s Starlink. The company has allocated $10 billion for the project, according to CNBCbut progress has been slow, with Amazon recently asking the US FCC to extend the timeline to launch 1,600 Leo satellites.

Garman cited Musk’s 1-million-satellite plan during Tuesday’s speech, and acknowledged that improvements in fuel and other aspects will make transportation into space less expensive. But for now, he stressed, costs are a major bottleneck.