The holder of half a dozen world records will walk across the Grand Canyon on a steel cable with nothing but the Little Colorado River 1,500 feet below on June 23. With no tethers or safety nets, the walk will be the highest tightrope attempt ever for the 34-year-old, at a height taller than the Empire State Building. Last year, Wallenda, a seventh-generation member of the “Flying Wallendas” family of acrobats, became the only person to walk a wire over the brink of Niagara Falls. Photo: Nik Wallenda walks across a tightrope 200 feet above U.S. 41 on January 29, 2013 in Sarasota, Florida. (Photo by Tim Boyles)

This photo provided by NASA shows a full moon rising behind the United Launch Alliance Atlas V rocket with NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft onboard at the Cape Canaveral Air Force Station Space Launch Complex 41, Sunday, November 17, 2013, Cape Canaveral, Florida. NASA's next Mars-bound spacecraft, the Mars Atmosphere and Volatile Evolution, or MAVEN, is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. (Photo by Bill Ingalls/AP Photo/NASA)

Spectators watch from Canaveral National Seashore as a SpaceX Falcon 9 rocket carrying 60 Starlink satellites launches from pad 39A at the Kennedy Space Center on October 6, 2020 in Cape Canaveral, Florida. This is the 13th batch of satellites placed into orbit by SpaceX as part of a constellation designed to provide broadband internet service around the globe. (Photo by Paul Hennessy/NurPhoto via Getty Images)

A vervet monkey walks over a parked car in the Park 'N Fly airport lot which lies adjacent to the mangrove preserve where the monkey colony lives, Tuesday, March 1, 2022, in Dania Beach, Fla. For 70 years, a group of non-native monkeys has made their home next to a South Florida airport, delighting visitors and becoming local celebrities. (Photo by Rebecca Blackwell/AP Photo)

People await the arrival of former U.S. President Donald Trump during a rally for Sen. Marco Rubio (R-FL) at the Miami-Dade Country Fair and Exposition on November 6, 2022 in Miami, Florida. Rubio faces U.S. Rep. Val Demings (D-FL) in his reelection bid in Tuesday's general election. (Photo by Joe Raedle/Getty Images)

Olga Conover of Palm Bay, Fla., walks down the bridge at sunset carrying her merged American-Ukraine flag near the end of a march marking the one-year anniversary of Russia invading Ukraine, late Thursday afternoon, February 23, 2022, in Melbourne, Fla. A small but passionate group of Ukraine supporters took the Melbourne Causeway to show their support, organized by the Ukrainian Space Coast group. (Photo by Malcolm Denemark/Florida Today via AP Photo)

A gopher tortoise walks the grounds of NASA's Kennedy Space Center in Florida, near the Vehicle Assembly Building on January 18, 2024. An all-European crew including Turkey's first astronaut are poised to blast off to the International Space Station in a mission with Axiom Space, as countries hungry for a taste of space turn increasingly to the private sector. (Photo by Chandan Khanna/AFP Photo)

A young person wearing military special forces gear holds a gun in the army village during Memorial Day weekend celebrations in Miami Beach, Florida, USA, 25 May 2024. The two day Hyundai Air & Sea Show event showcases the men, women, technology and equipment from all five branches of the United States Military as well as police, firefighters and first responder agencies. (Photo by Cristobal Herrera/EPA)