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)

Residents, covered with mud and dried banana leaves, ask for money and candles from police before attending a mass celebrating the feast day of the Catholic patron Saint John the Baptist in the village of Bibiclat, Nueva Ecija, north of Manila, June 24, 2013. Hundreds of devotees took part in this annual religious tradition, which has been held in the village since 1945. (Photo by Cheryl Ravelo/Reuters)

Emergency personnel respond to the scene of a train derailment in Santiago de Compostela, Spain, on Wednesday, July 24, 2013. A train derailed in northwestern Spain on Wednesday night, toppling passenger cars on their sides and leaving at least one torn open as smoke rose into the air. Dozens were feared dead, with possibly even more injured. (Photo by Antonio Hernandez/AP Photo/El correo Gallego)

Tourists play at a beach covered by a thick layer of green algae in Qingdao, China, on July 3, 2013. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit China's Qingdao coast last month. More than 20,000 tons of such seaweed has been removed from the city's beaches. This has now become an annual summer event. (Photo by Whitehotpix/ZumaPress.com)

A view of the Tianducheng development in Hangzhou, Zhejiang Province August 1, 2013. Tianducheng, developed by Zhejiang Guangsha Co. Ltd., started constructing in 2007 and was known as a knockoff of Paris with a scaled-replica of the Eiffel Tower, standing 108 metres, and Parisian houses. Although designed to accommodate at least ten thousand people, Tianducheng remains sparsely populated and is now considered as a “ghost town”, according to local media. (Photo by Aly Song/Reuters)

Lancaster Gate station displays signage after being rebranded “Ratchet and Clankaster Gate” as the PS5 goes on sale in the UK, on November 19, 2020 in London, England. The first generational upgrade to Sony's line of Playstation consoles since 2013, the launch has seen pre-orders sell out within hours and websites crash as retailers attempt to keep up with demand. (Photo by Alex Davidson/Getty Images)

Runners hoist another runner into the air after completing The Color Run All-Star 5K as part of the All-Star Baseball game festivities, Saturday, July 11, 2015, at Sawyer Point Park, in Cincinnati. After more than two years of planning and sprucing up, city organizers say everything's in place for a smooth, safe and fun five days of events that began Friday morning with the opening of Major League Baseball's fan festival. There will be concerts, exhibits, celebrity softball, the Home Run Derby and other activities capped by Tuesday night's game. (Photo by John Minchillo/AP Photo)

“SpaceShipOne was a suborbital air-launched spaceplane that completed the first manned private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mothership was named “White Knight”. Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million”. – Wikipedia

Photo: A chase plane follows SpaceShipOne after it reached a height of 62 miles in the first non-governmental flight to leave the Earth's atmosphere on June 21, 2004 in Mojave, California. SpaceShipOne spacecraft was carried to a height of 50,000 by the twin-turbojet high-altitude research aircraft, “White Knight”, where it was launched for its final climb. The space effort was funded by Microsoft co-founder Paul Allen and headed by aerospace engineer Burt Rutan. (Photo by Jim Campbell-Pool/Getty Images)