Chinese security stands near a Long March 2F rocket carrying Tiangong-1, China's first unmanned space module, stands at the Jiuquan Satellite Launch Center on September 28, 2011 in Jiuquan, Gansu Province of China. Tiangong-1,a small unmanned space lab, will be launched at 21:19 (Beijing time) on September 29, 2011, and will attempt a docking procedure with a Shenzhou 8 spacecraft later in the mission. (Photo by Lintao Zhang/Getty Images)

“Google is launching balloons into near space to provide internet access to buildings below on the ground. About 30 of the superpressure balloons are being launched from New Zealand from where they will drift around the world on a controlled path. Attached equipment will offer 3G-like speeds to 50 testers in the country”. – BBC News. Photo: A Google balloon sails through the air with the Southern Alps mountains in the background, in Tekapo, New Zealand. (Photo by Jon Shenk/Associated Press)

Google's vice president Alan Eustace looks out of his spacesuit into the stratosphere prior to a record-breaking skydive over New Mexico, in this still image taken from video October 24, 2014, a handout courtesy of the Paragon Space Development Corporation. Eustace was lifted up 135,890 ft (41,420 metres) by an enormous balloon while wearing a specially designed pressurized space suit, the Paragon Space Development Corporation said. Eustace remained in a free fall for approximately 4.5 minutes before landing safely nearly 70 miles (43.4 kms) from his launch point, setting a world record for the highest skydive and breaking the sound barrier in the process. Eustace landed safely on the ground just 15 minutes after he was lifted into the air. (Photo by Reuters/Paragon Space Development Corporation)

A policewoman wipes her tears as she stands in front of metal caskets containing the bodies of Special Action Force (SAF) police who were killed in Sunday's clash with Muslim rebels, at Villamor Air Base in Pasay city, metro Manila January 29, 2015. Philippine President Benigno Aquino urged legislators on Wednesday not to abandon a plan for autonomy for Muslims to end a decades-old insurgency after the clash in which dozens of people were killed, saying doing so would dash hopes for peace. (Photo by Romeo Ranoco/Reuters)

A military AWAC aircraft lands at the British RAF Akrotiri airbase on March 20, 2011 in Cyprus. Defence analysts said the sovereign military airfield at Akrotiri could be used by the RAF to help enforce a no-fly zone over Libya against Col Gaddafi’s offensive against outgunned Libyan rebels. (Photo by Matt Cardy/Getty Images)

A Polish MiG-29 flies beneath dark skies at the annual RNAS Yeovilton Air Day on July 9, 2011 in Yeovil, England. The annual air day at RNAS Yeovilton in Somerset, attracts over 35,000 people to what is one of the biggest air shows in the region and gives visitors the chance to see a host of aircraft as well as a number of historic and classic cars. (Photo by Matt Cardy/Getty Images)

A plane carrying a wing walker crashed at an air show and exploded into flames Saturday, killing the pilot and stunt walker, authorities said. The crash of the 450 HP Stearman happened at around 12:45 p.m. at the Vectren Air Show near Dayton in front of thousands of horrified spectators. No one else was hurt.

Photo: A wing walker performs at the Vectren Air Show just before crashing, Saturday, June 22, 2013, in Dayton, Ohio. The crash killed the pilot and the stunt walker instantly, authorities said. (Photo by Thanh V. Tran/AP Photo)

The space shuttle Endeavour is transported to the California Science Center in Exposition Park from Los Angeles International Airport (LAX) in Los Angeles, California. (Photo by Kevork Djansezian)