NASA is considering a spectacular airship concept for Venus exploration. The space agency’s Systems Analysis and Concepts Directorate (SACD) has posted potential designs of the High Altitude Venus Operational Concept (HAVOC) on its website. The airships have even been compared to a “cloud city” by Space.com. A similar size to Earth, Venus is our closest planetary neighbor. However, exploring Venus poses a unique set of challenges, according to NASA. “Though its internal geology is similar to Earth’s, its surface is hot enough to melt lead and is covered with craters, volcanoes, mountains, and lava plains,” it explains.