Space shuttle Discovery sits atop NASA's 747 Shuttle Carrier Aircraft (SCA) ready to transport it from Kennedy Space Center to the Washington D.C., on April 17, 2012 in Cape Canaveral, Florida. Following the retirement of the shuttle fleet, Discovery will fly to Washington for display at the Smithsonian's National Air and Space Museum. (Photo by Lofty Ambitions)

Marco Fiera from NoFit State Circus tries out the SkyWire, the new zip wire attraction which opens to the public this week at The Eden Project on July 17, 2012 in St Austell, England. The new 740m zip wire, currently the longest in England, allows the public a bird's eye view of the iconic Rainforest and Mediterranean Biome structures as well as the Cornish attractions outdoor gardens. The Eden Project – which opened in 2001 and has attracted over one million visitors – showcases 100,000 plants from around the world in two giant transparent domes, one of which is the world's largest greenhouse, each recreating different climate conditions. (Photo by Matt Cardy)

“The RSPB’s Snettisham Nature Reserve lies on the edge of The Wash, one of the most important bird estuaries in the United Kingdom. The Wash, on England’s east coast, supports over 300,000 birds, and Snettisham sometimes holds more than a third of them”. – The Palm Beach Post. Photo: Waders flock together seeking new feeding grounds during the incoming tide. (Photo by Dan Kitwood/Getty Images via The Palm Beach Post)

Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Family of passengers onboard AirAsia flight QZ8501 react at a waiting area in Juanda International Airport, Surabaya December 28, 2014. Indonesia's air force was searching for the AirAsia plane carrying 162 people that went missing on Sunday after the pilots asked to change course to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore. The Airbus 320-200 lost contact with Jakarta air traffic control at 6:17 a.m. (23:17 GMT), officials said. (Photo by Reuters/Beawiharta)

Havilland Mosquito KA 114 performs a low pass during an airshow commemorating the completion of its rebuild on September 29, 2012 in Ardmore, New Zealand. The plane was restored by Warbird Restorations at Ardmore Aerodrome and is the only flying Mosquito in the world. (Photo by Simon Watts)

A handout picture provided by the press service of MORTON Group of Companies, show the balloon of Russian adventurer Fedor Konyukhov in the sky during his solo round-the-world balloon flight just after taking off from a spot near Northam, 96 kilometres north-east of Perth in Western Australia, 12 July 2016. Fedor Konyukhov took off from Northam on 12 July 2016 in attempt to beat the record of 13 days of American aviator Steve Fossett. (Photo by EPA/Morton Press Service)

In this handout image supplied by the European Space Agency, the Soyuz TMA-03M spacecraft is raised into vertical position on December 19, 2011 at the Baikonur Cosmodrome in Kazakhstan. (Photo by Stephane Corvaja/ESA via Getty Images)