Space diving

Similar to skydiving, space diving is the act of jumping from an aircraft or spacecraft in near space and falling towards Earth. The Kármán line is a common definition as to where space begins, 100 km (62 mi) above sea level. This definition is accepted by the Fédération Aéronautique Internationale (FAI), which is an international standard setting and record-keeping body for aeronautics and astronautics. The United States Air Force uses 50 nautical miles (300,000 feet) to award astronaut wings.

No successful space dives (above 100 km) have been completed to date. In 1959 Joseph Kittinger accomplished a jump from 74700 ft; he then set a long-standing record in 1960 when he jumped from 102800 ft. In 1962, Yevgeni Andreyev jumped from 83523 ft and set a new longest-distance free fall record that was surpassed by Felix Baumgartner who made three jumps in 2012 from 71581 ft, 96640 ft, and 128000 ft, respectively. Alan Eustace set the current world record for highest and longest-distance free fall jump in 2014 when he jumped from 135898 ft. However, Joseph Kittinger still holds the record for longest-duration free fall, at 4 minutes and 36 seconds, which he accomplished during his 1960 jump from 102800 ft.

Higher jumps from the mesosphere or thermosphere have yet to be successfully performed, though Orbital Outfitters, now defunct, was working to create a suit that was supposed to enable space diving. Space diving from beyond the stratosphere was first imagined in 1934, appearing in E. E. "Doc" Smith's science fiction novel Triplanetary.

History
The first stratospheric space dive was in 1959 when Colonel Joseph William Kittinger II (July 27, 1928 - December 9, 2022) in Tampa, Florida, United States a former command pilot, career military officer and retired Colonel in the United States Air Force dived from a high-altitude balloon. He participated in Project Excelsior, testing the effects on pilots of ejecting at high altitude and in 1960 set a record for the highest, longest-distance, and longest-duration skydive, from a height greater than 31 km.

On 1 November 1962, Yevgeni Andreyev and Pyotr Dolgov ascended from Volsk, near Saratov. Andreyev jumped from the capsule at 83523 ft and free fell 80380 ft before successfully deploying his parachute. Dolgov remained in the capsule and ascended to 93970 ft. Dolgov was primarily testing an experimental pressure suit, and would have deployed a drogue chute like Kittinger's earlier jump. As he exited the gondola, he struck his helmet and cracked the visor, leading to depressurization and his death.

In 1965–1966, Nick Piantanida accomplished a set of unsuccessful attempts to jump from 123500 ft and 120000 ft. During the last attempt Piantanida's face mask had depressurized. His ground controllers immediately jettisoned the balloon at close to 56000 ft. Piantanida barely survived the fall, and the lack of oxygen left him brain damaged and in a coma from which he never recovered.

In the early 1990s, Kittinger played a lead role with NASA assisting British SAS Soldier Charles "Nish" Bruce to break his highest parachute jump record. The project was suspended in 1994 following Bruce's mental health breakdown.

In 1997 parachutist and pilot Cheryl Stearns formed Stratoquest, aiming to break Kittinger's record as the first female space diver. Due either to a significant shoulder injury or funding issues for the project this plan did not come to fruition. By the time Stearns was prepared to attempt her jump, Felix Baumgartner had completed his jump and Stearns shelved her event.

In 2012, Felix Baumgartner broke Kittinger's highest altitude and Andreyev's longest-distance free fall records, when, on October 14, he jumped from over 128,000 ft.

In 2014, Alan Eustace set the current world record highest and longest-distance free fall jump when he jumped from 135908 ft and remained in free fall for 123334 ft. However, Joseph Kittinger still holds the record for longest-duration free fall, at 4 minutes and 36 seconds, which he accomplished during his 1960 jump from 102800 ft.

Challenges to safe space diving
There are several technical requirements and challenges to the possibility of space jumping. These requirements would be somewhat eased when entering the atmosphere from a simple drop, where the heat of reentry would be considerably less than that of reentering from orbit. At any given density of air, the terminal velocity of a person is much lower than that of a heavy spacecraft. This is because starting from a stationary platform means that fall speed never exceeds the local terminal velocity (though this is quite high in thin atmosphere) and a small light body slows down relatively quickly as the atmosphere thickens.

Parachutes would require increased strength to slow the higher weights associated with the added equipment.

NASA is known to have investigated the concept in case of an emergency situation on Space Shuttle orbiters where alternative methods of reentry are not available. However, such planning has not moved beyond the conceptual stage given the high energies involved in reentry from orbital speeds.

Jumpers and prospective jumpers

 * Yevgeni Nikolayevich Andreyev
 * Cheryl Stearns, plans for Stratoquest
 * Steve Truglia, plans for Space Jump
 * Michel Fournier, Le Grand Saut attempts
 * Nick Piantanida, died after Strato Jump III attempt in 1966
 * Olav Zipser, Free Fly Astronaut Project
 * Charles "Nish" Bruce
 * Victor Prather

Fictional accounts

 * In Dark Star, 1974 film, Doolittle decides to 'surf' on debris to the planet or die in the attempt.
 * Star Trek: Generations, in a deleted scene from 1994 film which depicts a fictional space jump
 * Star Trek: Voyager, in 1998 the season 5 episode 3 titled Extreme Risks which depicts a fictional space jump
 * Star Trek, a 2009 film which depicts a fictional space jump
 * Ad Astra, a 2019 film which depicts a fictional space jump