Outside, the weather was sunny with a slight breeze, a perfect early fall afternoon. But inside the Hart atrium, it was starting to look overcast — Alexander Calder’s Mountains and Clouds sculpture was one step closer to being restored to its original design. Workers prepped the dark metal “clouds” of the mobile to be hoisted into the air. The process isn’t done quite yet, according to Sen. Chris Murphy, who has advocated for the restoration for years. “I think the clouds are being hung this weekend,” the Connecticut Democrat said on Thursday. “It’s going to take a little while to get them motorized, and they’ve got to get them balanced.” On Friday afternoon, workers on ladders adjusted equipment to hang the new sheets of metal, getting them ready to dangle over the cavernous atrium. At one point, a worker swept dust off the top of one of the clouds. A cable protruded from the center of the structure, which would soon be anchored to the ceiling. A forklift beeped in the otherwise quiet space. Aside from a few errant staffers and tour groups passing through, the atrium was largely empty, with senators already gone and not set to return until after the weekend. Scaffolding for the restoration was constructed in August, but the project has been in the works for much longer than that. “One of our nation’s most significant works of public art has stood incomplete for decades, right here in the U.S. Senate. I’m thrilled that the restoration of Alexander Calder's Mountains and Clouds is moving forward,” Sen. Angus King, I-Maine, said in a statement. King and Murphy are among the senators who have pushed to see the project completed. Calder, an artist known for his large stationary sculptures and dynamic mobiles, spent much of his adult life in Murphy’s home state. In February, the Calder Foundation said restoration of the clouds would be completed later this year and that private funding had been secured for the project. Murphy said he expects a ceremony will be held at some point to mark the mobile’s return. “We’re excited about the progress that has been made so far in this historic restoration and look forward to sharing more soon,” a spokesperson for the Calder Foundation said in a statement Friday. The Architect of the Capitol did not respond to a request for comment. Calder’s sculpture was installed in Hart in the 1980s with a stationary “mountains” portion rising from the floor and a dangling “clouds” portion hanging above it in the air. While the mountains have stood in place since then, the clouds were removed in 2014 for a “safety study” and never replaced. The late artist’s original design had the clouds rotating, powered by a motor, but the clouds had eventually stopped spinning. Murphy said he does expect the new clouds to spin. But those wanting to see them rotate like Calder originally envisioned may have to wait a little longer. “I don’t think they’ll be moving until potentially after the election,” he said.