Weekend Warm-Up: The Stratos Project

New Mexico: August 16, 1960: Air Force Captain Joe Kittinger Jr., a former fighter pilot and a prisoner of war, flies a hot air balloon to 31,400m above the earth’s surface…. then jumps.

It was the highest freefall in history, and part of the U.S. Air Force’s Project Excelsior, a series of three missions to test a multi-stage parachute that would give fighter pilots forced to eject at high altitudes a controlled descent.

The parachutes would deploy automatically based on altimeter readings and were designed to prevent a pilot from spinning out of control at a deadly rate, sometimes as fast as 200 revolutions per minute, a phenomenon skydivers call a flat spin. It’s usually caused by a slight asymmetry in body position. Uncontrolled, it can cause a falling person to black out.

At an altitude of 19,000m, a human being’s blood will boil. At 27,000m, the temperature plummets to -68°C. All that stood between Kittinger and these threats was a crude pressurized suit. During the balloon ascent, the pressurization in his right glove malfunctioned, causing his right hand to swell to twice its normal size.

Almost — but not quite! — a space walk, Joe Kittinger Jr. launches the highest freefall in history. Photo: history.com


Kittinger fell for about five minutes, at a rate approaching the speed of sound, with only his small stabilizer parachute to protect him from spinning to death. When he reached a safe altitude, his other parachutes deployed flawlessly and delivered him safely to the ground.

The jump proved that the three-parachute system would work as designed and that human beings could withstand the extremes of the upper atmosphere. This information revolutionized high-altitude flying and paved the way toward spaceflight.

Ground crew assist Kittinger after his successful jump. Photo. wikipedia.com


Fast forward 50 years, and Austrian skydiver Felix Baumgartner, working with a team of scientists and sponsored by Red Bull, begins planning an attempt at the highest skydive in history, in what became known as the Red Bull Stratos project. The researchers planned to monitor Baumgartner’s physiological response to the extreme environment,  gather scientific data on next-generation pressure suits and the feasibility of high-altitude bailouts in the budding commercial space-flight industry.

The project stalled on in 2010, when Daniel Hogan filed a lawsuit in California, claiming that he originated the idea of the parachute dive from the edge of space in 2004 and that Red Bull stole the idea from him. The lawsuit was eventually settled out of court and the project resumed.

Baumgartner completed two test jumps. The first, in March 2012, was from an altitude of 21,818m. Baumgartner reached an estimated 580kph — the typical skydiving terminal velocity is under 200kph — during his three minutes and 43 seconds in freefall. In July of that same year, he jumped from 29,460m — three times the height of Mount Everest — and reached a top speed of 863kph in the vanishingly thin air.


Finally, on 14 October 2012, Baumgartner flew his helium balloon approximately 39km into the stratosphere over New Mexico, before freefalling in a pressure suit and parachuting to Earth.

Just 42 seconds into the descent, Baumgartner reached his maximum velocity. Here, an uncontrolled spin started which could have been fatal, but Baumgartner managed to regain stability. He had the option to use an abort switch that would have deployed a drogue parachute to arrest the spin, but that would have also prevented any speed records. The total jump lasted 10 minutes. Baumgartner’s freefall was planned between five and six minutes, but his parachute deployed after 4 minutes and 19 seconds.

On his descent, Baumgartner became the first human to break the sound barrier without any form of engine power. He reached a top speed of 1,357.64 kph, or Mach 1.25. He also achieved new records for the highest balloon flight, with a final altitude of 38,969m and bettered Kittinger’s record for the highest altitude jump set 52 years before. 

Kittinger, then aged 84, acted as Baumgartner’s mentor throughout the project and served as capsule communicator at mission control during the jump.

US Air Force Colonel (ret.) Joe Kittinger and Felix Baumgartner during Project Stratos. Photo: airandspace.si.edu

The jump drew some criticism for describing the jump’s altitude as the “edge of space”, when the more scientifically accepted definition is the Kármán line at 100km, or nearly three times the height of the project’s jump altitude. This point is also used as a defining line by the Fédération Aéronautique Internationale, which administers aeronautics records worldwide.

While the jump was viewed live by over 9.5 million users, setting a record for the most live-streamed event on YouTube, it’s definitely worth another look.