Overview of Balloon Flights and Their Biomedical Impact on Human Spaceflight
Balloons carrying animals and humans date back to the late 1700s, and over the ensuing centuries, scientific balloons have had a huge impact in terms of taking animals and humans to near space. From studying the effects of cosmic radiation at high altitudes, to testing the life support systems and space suits intended for spacecraft, and evaluating the physiological effects of high altitude, exploration via balloons has played an integral part in studying the lower boundary of space. The unique opportunity of ballooning and taking humans to the edge of space has allowed scientists to perform a wide range of studies pertaining to neurological, physiological, and operational behaviors on the human body in these extreme conditions. Additionally, a wide array of ballooning experiments has given insight to novel ideas on operational risks, mechanical components, medical contingency plans, and flight test protocols. Starting in eighteenth-century France and continuing through the 1930s balloon race to the stratosphere and into the modern commercial space race, ballooning has established a blueprint for breakthroughs in space exploration. Balloons provided access to near space in the 1930s to study cosmic radiation. Ballooning has also played a major role in military applications, from observation balloons employed in the US Civil War and World War I, the 1870 medical evacuation by balloons during the siege of Paris, to a World War II weapons delivery system launched from Japan and carried to the US mainland via the jet stream. During the Cold War, a high-altitude surveillance program was conducted, including stratospheric nuclear monitoring and weapons detonation and military testing of high-altitude life support and crew escape systems. Many space agencies, including NASA, use high-altitude balloons for affordable access to near space.
Early Ballooning History
On 19 September 1783, a sheep, rooster, and duck flew for 8 min over Versailles, France, in a paper-lined silk balloon built by Joseph and Jacques Montgolfier and lifted by hot air. On 21 November 1783, Pilatre de Rozier and Marquis d’Arlandes were the first humans to fly on a Montgolfiere hot air balloon, flying at 500 ft for 25 min over Paris, France. One week later, on 1 December 1783, Jacques Charles and Nicholas Louis Robert flew in the first gas (hydrogen) balloon over Paris, to almost 2,000 ft, during which they remained aloft for over 2 h, covering 27 miles. On 19 January 1784, a huge Montgolfiere hot air balloon carried seven passengers to a height of 3,000 ft over the city of Lyons. Jean-Francois Pilatre de Rozier combined hot air and lifting gas in a hybrid hot air/hydrogen balloon in an attempt to cross the English Channel in 1785. He and his copilot Pierre Romain became the first balloon fatalities when their balloon crashed and exploded on 15 June 1785. The hybrid hot air and lifting gas de Rozier balloon design would later be used to first circumnavigate the globe on the Breitling Orbiter 3 in March 1999, this time using noncombustible helium. In 1862 James Glaisher and Henry Coxwell became the first pilots to ascend to over 29,000 ft in a hot air balloon. They developed marked neurologic symptoms, which they named balloon sickness, including paralysis, blindness, and eventual loss of consciousness. During this time the French physiologist Paul Bert conducted experiments on balloonists, and their response to barometric pressure changes. By 1862 Bert and Glaisher had conducted 25 scientific ascents and compiled a large list of neurological complaints, including an impaired state, altered mental clarity, and clumsiness. Paul Bert even used a low-pressure chamber to conduct experiments on himself and established that symptoms remitted with oxygen supplementation. In 1878 Paul Bert published La Pression Barométrique, in which he summarized altitude-related problems.
In April 1875 balloonists Gaston Tissandier, Théodore Sivel, and Joseph Crocé-Spinelli ascended in the balloon Zénith to 28,215 ft, along with oxygen bags and a delivery system. They confirmed that balloon sickness symptoms improved with oxygen during the journey. Unfortunately they did not bring enough oxygen and threw the aspirator overboard as ballast, no doubt as a result of cognitive impairment. They were overcome with motor and cognitive impairment and eventually became unconscious. Sivel and Crocé-Spinelli eventually died from oxygen deprivation. Balloon sickness likely involved decompression illness, hypoxemia, hypothermia, and low barometric pressure.
In 1902, Leon Teisserene de Bort launched 238 instrumented balloons to measure air pressure and temperature. The French scientist found that temperature decreased up to a height of approximately 8 miles after which the temperature remained constant, an isothermal region he termed the “stratosphere.” In 1922, American physicist Robert Millikan sent instruments in balloons to 50,000 ft. Along with his mountain lake studies, he concluded that radiation came from beyond the Earth’s atmosphere, a phenomenon he called “cosmic rays.” This key finding demonstrated that flight research has a significant impact on radiation and physical science research. Additionally, the cosmic radiation finding sparked a debate between Millikan and another American scientist, Arthur Compton, about whether the cosmic rays were high-energy photons or charged particles.
Pre-World War II Stratospheric Balloon Flights
In 1927, US Army Air Corps captain Hawthorne Gray, an accomplished balloonist, conducted three ascents to evaluate high-altitude clothing and oxygen delivery systems. His 9 March 1927 balloon flight set an unofficial altitude record of 28,510 ft. Gray passed out from hypoxia but fortunately regained consciousness during descent. On his next flight in May 1927, he attained 42,470 ft but parachuted out at 8,000 ft due to an overly rapid balloon descent. On November 4 he reached an altitude of over 43,000 ft, but due to an oxygen system failure, he again lost consciousness. Various theories about the cause of his death included that he severed his oxygen hose while cutting open ballast bags or that he was too cold and tired to open his oxygen tank valve. The board of inquiry concluded that Gray died because his timer stopped, and he therefore lost track of his oxygen usage and exhausted his supply.
Balloon exploration and competition continued in the 1930s, with balloon ascents carrying humans into the stratosphere in open gondolas and then, as technology advanced, in sealed pressurized capsules. Apollo Soucek reached 43,166 ft on 4 June 1930. Swiss scientist Auguste Piccard made the first stratospheric flight in a pressurized capsule with Paul Kipfer on 27 May 1931 reaching an altitude of 51,775 ft over Germany in the Belgium National Fund for Scientific Research sponsored flight called FNRS (Fonds National de la Recherche Scientifique). In 1932 Piccard set a new altitude record of 52,498 ft on the second FNRS flight. A key component was his oxygen system, which he incorporated from a Draeger system built for the German U-boat, one of many military systems tested in twentieth-century ballooning.
Over the next 4 years, nine more balloon expeditions entered into the stratosphere. Cyril Uwins ascended to 43,976 ft on 16 September 1932. Auguste and Jean Piccard worked with Arthur Compton to obtain support for a manned stratospheric flight carrying cosmic ray research-related payload during the Chicago “Century of Progress” exhibition. The balloon launched from Soldiers Field in Chicago on 5 August 1933 but ruptured during ascent. The second flight launched on 20 November 1933 from Akron, Ohio, ascending to a record altitude of 61,237 ft. Their capsule contained instruments to observe stratospheric conditions, including instruments to measure cosmic rays, a cosmic ray telescope, a polariscope to study light polarization at high altitudes, fruit flies (Drosophila) to study genetic mutations, and an infrared camera to study the ozone layer. This scientific flight sparked international competition. The Soviets quickly took notice and launched a hydrogen balloon to study the Earth’s stratosphere. The Soviets launched the Stratostat USSR 1 in September 1933, with Georgi Prokofiev, Ernst Bernbaum, and Konstantin Godunov ascending to 58,700 ft (17,900 m) in the biggest balloon up to that time, which had a volume of 880,000 ft3 (24,940 m3). The following year on 30 January 1934, the Soviet Union (USSR) launched Osoaviakhim-1, a hydrogen balloon with a pressurized capsule carrying three crew that would conduct scientific studies of the stratosphere. The flight lasted over 7 h, and the balloon reached an altitude of 72,000 ft. During the descent the balloon lost buoyancy and plunged into an uncontrolled descent. The three crewmembers, Fedoseenko, Vasenko, and Usyskin, were incapacitated by g-forces in a rapidly rotating gondola and were unable to unbolt the hatch. Therefore the crew was unable to egress the capsule and bail out and as a result died from ground impact. Later that year Renato Donati ascended to 47,572 ft on 12 April 1934. The United States launched Explorer I on 28 July 1934, with three US Army Air Corps crew: Major William Kepner, Lieutenant Orvil Anderson, and Captain Albert Stevens. A tear in the balloon developed at 63,000 ft and the balloon eventually descended in an uncontrolled state; the crew bailed out just before the capsule hit the ground. Explorer I therefore represented a successful demonstration of an emergency crew escape plan. Shortly thereafter, National Geographic Society announced the launch of Explorer II in 1935, which used helium instead of hydrogen as the lifting gas. After the ground crew patched up a helium leak, Explorer II ascended and captured the first photographs of the Earth’s curvature.
A major limitation of balloons at the time was the use of rubberized cotton cloth, which was heavy and semipermeable to the lifting gas, limiting payload and float altitude. In 1935 and 1936, the use of plastics in balloon construction began independently by Cosyns, Regener, Johnson, and Piccard. Auguste Piccard’s twin brother Jean Piccard and his wife co-invented and flew a cellophane plastic balloon which carried a tracking radio up to 50,000 ft on a 10-h flight, over 600 miles. Of course stratospheric research also included unmanned balloons, which are cheaper and could carry a payload higher without the added weight of a human and the required life support systems.
Similar comparisons accompany the human crewed versus unmanned space missions, yet in reality manned and unmanned systems complement each other. Unmanned balloonsondes carried meteorological payloads that improved weather prediction. For payloads utilizing complex instruments, crew could often provide that flexibility in payload operations and contingency events. With the advent of automated or ground-controlled telemetered systems, many previous crew operations could be performed by unmanned systems. Later on, the development of stabilization and tracking systems for optical payloads also reduced the need for crew involvement.
Military Stratospheric Balloons
Along with the 1930s balloon race, new technology developed during World War II and the Cold War which also fueled international competition and the ability to send humans to space. In 1944 and 1945, the Japanese launched 9,300 high-altitude “Fu-Go” balloons carrying incendiary bombs via the jet stream to the northwestern United States and Canada, in an attempt to start forest fires. The name came from “Fu,” being the first character of the Japanese word for balloon. The balloon had an altitude sensing ballast release system to stay afloat across the Pacific. This was the first intercontinental weapon system, and one bomb actually hit the Seattle Boeing plant and power lines leading to the Hanford nuclear plant which was shut down for 3 days. Due to censorship, the general public was unaware of the threat, and one adult and five children were killed on a picnic when they found a balloon bomb and it detonated. The concern was that biological agents, such as anthrax and Japanese B encephalitis, could be delivered by balloon bombs, but this capability was never established. Launch sites were determined by geologic analysis of the sand in recovered ballast bags. Balloons were recovered from Alaska and Canada to the southwest (i.e., Mexico and Texas) and as far east as Iowa and Nebraska. A biologic defense plan entitled “Project Lightning” was in place to counter the potential threat. Project Sunset was the air defense plan to detect the balloons and shoot them down by aircraft. In an obscure British project entitled “Operation Outward,” fire bombs were carried by balloons in a similar fashion against Nazi Europe and did cause substantial damage. Some 100,000 of these balloons were launched, with several coming down in neutral Sweden and Switzerland.
In the post WW II era of the Cold War, stratospheric balloons interested the military for the purposes of studying atmospheric parameters. Objectives included improving understanding of long range communications, ballistic reentry, and aerial reconnaissance, although basic science payloads were also carried. With those strategic needs apparent, Jean Piccard and Otto Winzen, in cooperation with General Mills Corporation, proposed a project called Pleiades II to the United States Navy in 1945. Pleiades II would carry a spherical capsule up to 100,000 ft by a cluster of cellophane balloons. Pleiades I was a multi-balloon cluster concept that had been successfully flight tested in 1937, but further research had been put on hold due to the WW II. The Pleiades project name became known as Helios. The multi-balloon cluster proved complicated, and Helios reverted to a single balloon design which became referred to as Project Skyhook in September 1947. The pressurized capsule developed for Helios would later be used in Navy Strato-Lab flights.
The first Skyhook balloon, launched on 25 September 1947, was a 30,000 ft3 balloon carrying a 63-pound payload to 100,000 ft. After two failures, the fourth flight stayed aloft for 3 days and collected valuable cosmic ray data. Project Skyhook was an ambitious and encompassing project, which eventually involved numerous government agencies including the US Navy Office of Naval Research (ONR), the Atomic Energy Commission (AEC), the National Science Foundation (NSF), the US Air Force (USAF) Cambridge Research Laboratory, academia (i.e., the University of Minnesota, the University of Chicago, and the University of Rochester), and industry (i.e., General Mills Corporation, Winzen Research Institute). Skyhook flew cosmic ray detection payloads, photography, and live animals, ranging from 4 h to 3 days in flight duration. Winzen and Piccard recognized cellophane’s limitations. The ideal material should be lightweight, inexpensive, strong, flexible in the cold atmosphere, and unaffected by ultraviolet radiation. Cellophane as a balloon material was replaced with polyethylene which had all of those characteristics.
The first manned polyethylene balloon flight was flown on 3 November 1949 by Charles Moore, a chemical engineer working for General Mills Corporation. Skyhook polyethylene balloons used helium as the lifting gas and used a radio command to terminate the flight, resulting in the payload being separated and returning by parachute; meanwhile the balloon was ruptured to enable a quick descent. From 1947 to 1976, Project Skyhook flew 3,000 balloons. As the balloons often caught sunlight in the stratosphere after sunset on Earth, numerous UFO sightings were likely a Skyhook balloon.
One challenging aspect of launching a balloon is the surface wind during balloon standup. The US Navy used a novel approach to deal with this challenge, using a carrier to launch the balloon and maneuvering the ship to neutralize the surface wind. Part of Project Skyhook used the balloon ascent as a first stage to launch a sounding rocket second stage. The novel architecture of using a balloon as a first stage was first used in Project Rockoon, the term “Rockoon” representing an abbreviated concatenation of “Rocket-Balloon.” There were 142 Rockoon flights from 21 August 1952 to 8 November 1957 using four different sounding rocket configurations with payloads ranging from 28 to 300 pounds. Rookoons were much cheaper than a two-stage sounding rocket and only cost $1,500 per launch. A unique aspect of this configuration was that the rocket actually launched through the balloon. In 1947, Air Force Project Blossom started using sounding rockets to test reentry parachutes, establishing that a 14-ft nylon ribbon parachute could function at an altitude of 60 miles. Sounding rockets were also used to carry upper atmospheric science payloads, to advance cosmic ray or ozone research. A sounding rocket didn’t have a long time in the stratosphere compared to balloons, and a typical Skyhook balloon mission cost only $2,000.
Stratospheric Balloons in the Early Space Race
Biological research including animal flights was also a top priority to understand the physiological effects of the space and near-space environment. The US Air Force Aeromedical Field Lab at Holloman Air Force Base in Alamogordo NM, under the direction of Dr. John Paul Stapp, conducted numerous animal research flights using balloons and rockets. They launched a variety of animals to space from the nearby White Sands Missile Range using captured German V-2 rockets in the late 1940s and early 1950s. The rhesus monkey missions, called Albert and Aerobee, were conducted to advance physiological monitoring and test high-altitude recovery systems. The Albert I monkey died before launch due to restraints preventing breathing, and the impact loads were not survivable for Albert I and II, although Albert II survived the launch and spaceflight. The first completely successful high-altitude animal flight at Holloman Air Force Base was not an Aerobee flight but a balloon that carried eight white mice to 97,000 ft on 28 September 1950.
Balloon flights could provide longer exposure to environmental parameters such as radiation, although they did not have the acceleration launch and reentry loads or the microgravity exposure typical of spaceflight. One research program was called Project MX-1450R, Physiology of Rocket Flight, and was overseen by the Wright Field Aero Medical Laboratory in Dayton, OH. Approximately 90 biological payload flight tests occurred during the 1950s, with over 20 flights conducted between 1950 and 1952. The number of launches reached a maximum in 1953, with 23 balloons carrying animals into the stratosphere, while 19 animal flights occurred during 1955–1956. Development of animal capsule life support systems was conducted by the Space Biology Branch of the Aero Medical Field Lab under Dr. David Simon’s guidance. This program provided vital insight into life support parameters for oxygen, carbon dioxide, thermal loads, and waste that was applied directly to the Manhigh stratospheric balloon program capsule. Simons would later fly the Manhigh II balloon flight in 1957.
The United States resumed manned stratospheric balloons in 1956 starting with the Strato-Lab missions. The Strato-Lab program used three different systems for low, intermediate, and high altitudes. The low altitude system was used for flights up to 12,000 ft. It consisted of a plastic balloon and an open basket (gondola). The intermediate altitude system used a larger balloon and was used for making observations up to 42,000 ft. It used an oxygen supply and the crew wore cold weather gear. A cargo parachute, which would open automatically, extended between the balloon and gondola. The Strato-Lab open gondola intermediate flights provided an opportunity to conduct atmospheric research and evaluate technologies. US Navy officers Malcolm D. Ross and M. Lee Lewis flew the first manned Strato-Lab open gondola intermediate flight to 40,000 ft on 10 August 1956. They photographed jet condensation trails, evaluated physiological monitoring of the crew, and tested their MC-3 pressure suits. On 6 May 1958, Ross flew with Naval Observatory astronomer Alfred Mikesell in an open gondola to 40,000 ft with oxygen masks and cold weather gear. Mikesell became the first astronomer to conduct observations from the stratosphere. An open gondola was used on the final high flight of the Strato-Lab program rather than a capsule to test the Mark IV pressure suit in the real environment. The High Strato-Lab system used a pressurized capsule refurbished from the Helios program. It was pressurized to 17,000 ft equivalent (i.e., 7.64 psi). This Strato-Lab capsule used a two-gas atmosphere and was supplied by two cryogenic systems, specifically 50% liquid oxygen/50% liquid nitrogen, for normal capsule atmosphere and 100% liquid oxygen for emergency pressurization of the capsule and pilots’ MC-3 partial pressure suits. Carbon dioxide and water vapor were removed by chemical scrubbers. The capsule was suspended under a 64 ft cargo parachute, and the crew also had access to individual personal parachutes for bailout if the capsule parachute were inadequate. Malcolm D. Ross and M. Lee Lewis reached an altitude of 76,000 ft during the Strato-Lab I flight. During descent they vent value malfunctioned and the crew had to dump equipment to slow the descent rate.
The second Strato-Lab high mission launched on 18 October 1957 with Ross and Lewis reaching 85,700 ft and spending several hours at float altitude. On Strato-Lab II the crew encountered uncomfortably high temperatures and humidity while wearing thermal outerwear over the MC-3 pressure suits, which seriously affected their tasks. Ross and Lewis launched on Strato-Lab III on 26–27 July 1958, reaching 82,000 ft and remaining aloft for 35 h. The Strato-Lab IV flight launched on 28 November 1959 with Malcolm Ross and Charles Moore, reaching 81,000 ft. Strato-Lab IV carried a 16-in. telescope to observe Venus. The final Strato-Lab mission (Strato-Lab V), was in an open gondola. Malcolm Ross and flight surgeon Victor Prather launched from the deck of an aircraft carrier on 4 May 1961. The crew wore the Mark IV pressure suit which was used during NASA’s Project Mercury. This flight set an altitude record of 113,740 ft the day before Alan Shepard flew the suborbital Mercury Redstone flight, which represented the first time the United States sent a human to space. Unfortunately after landing in the Gulf of Mexico, Prather slipped off the helicopter recovery sling and drowned when his suit filled with water. A pressurized capsule carried aloft by balloon was a means of testing modern spacecraft.
The US Air Force Manhigh program tested life support systems and a pressurized capsule reaching new heights in 1957. Captain Joe Kittinger launched on Manhigh I on 2 June 1957 and reached an altitude of 96,000 ft despite a system flaw resulting in his oxygen depleting earlier than planned. Two months later David Simons reached 101,500 ft in Manhigh II and remained aloft for 32 h despite problems with the CO2 scrubber and a hard landing. Manhigh III launched 8 October 1958 with Cliff McClure, who endured cabin temperatures in access of 120 °F, as well as poor ground team mission control decisions. These missions revealed the challenges of high-altitude manned flight, i.e., everything from mechanical errors in parachutes and chemical scrubbers to physiological problems and operations needed to be addressed before humans could go to space.
During the 1960s space race between the United States and the USSR, the two nations engaged in another high-altitude balloon race. The United States continued with project Excelsior, a program to evaluate high-altitude escape. In 1959, Kittinger survived another challenging stratospheric balloon flight during a three million cubic feet helium balloon on the Excelsior I mission. His drogue chute deployed too early into free fall, causing a flat spin resulting in unconsciousness before the reserve chute deployed automatically at 12,000 ft. On Excelsior III which launched on 16 August 1960, Kittinger jumped from 102,800 ft and experienced a free fall of 4.5 min, with a maximum speed attained of 614 miles per hour. Kittinger’s right glove leaked just prior to the commencement of his free fall. His hand was exposed to the vacuum of near space, causing his hand to swell so much it filled the glove resulting in extreme pain. Kittinger’s hand, however, returned to normal function and appearance a few hours after the flight. The Russians had their own stratospheric jump program.
In 1960, Peter I. Dolgov set the world record for the highest opening parachute jump without delay by exiting at 48,671 ft during a high-altitude high opening (HAHO) jump. The Russian Volga stratospheric balloon parachute test program used a capsule based on the Vostok capsule. In 1962 parachutists Yevgenny Andreyev and Pyotr Dolgov participated in the Volga balloon flight. Andreyev tested a new nonexplosive Vostok ejection seat and set a record for longest free fall without a drogue chute when he exited from around 83,500 ft and underwent free fall for 80,360 ft. Dolgov tested the integrity of a SI-3M pressure space suit when he exited around 86,000 ft. Unfortunately, Dolgov’s visor hit the gondola and cracked, causing suit depressurization. Dolgov died from exposure to vacuum, which resulted in ebullism. The Volga flight was a key test of ejection seat systems and space suit functionality and contributed to improved safety designs.
Manned stratospheric balloon incidents and mishaps
Maximum altitude (ft)
Pavel Fedoseenko, Andrey Vasenko, Ilya Usyskin
Ascent to higher altitude than balloon design, loss of hydrogen due to excessive heating caused the balloon to lose lift. During descent, the balloon tore and ballast was insufficient to slow descent. Crew attempted bailout but escape hatch design was faulty
William Kepner, Orvil Anderson, Albert Stevens
During ascent the balloon tore and lost lift. Crew bailed out just prior to capsule impact
Malcolm Ross and Lee Lewis
Problem with vent valve caused the capsule to descend quickly. The rapid descent was finally brought under control
Malcolm Ross and Victor Prather
Prather drowned after landing in water when he slipped during helicopter recovery, and water entered suit via an open visor
Audio communication was lost. Oxygen depleted quicker due to oxygen valve and vent line being reversed
Extreme discomfort in suit, overheating, chafing, and excess CO2 due to the scrubber being too cold
Parachute deployed inside the capsule, resulting in high workload to repack chute. Thermal system failure resulted in excess heat and high consumption of water
Drogue chute deployed prematurely and fouled around pilot’s neck resulting in 120 rpm spin and loss of consciousness; automatic opener fired and main chute opened and pilot landed safely
Pressure seal on right glove failed, causing severe pain and hand swelling
On exit, pilot’s visor hit the capsule and cracked it causing suit to depressurize; pilot died of ebullism
Strato Jump 1
Wind shear tore balloon on ascent; jumper egressed and parachuted to the ground
Strato Jump 2
At altitude, pilot couldn’t disconnect the oxygen lines and had to return in gondola
Strato Jump 3
Visor opened at altitude and pilot lost consciousness, gondola was cut from balloon, slow descent resulted in pilot’s hypoxic encephalopathy and delayed death
Manned Stratospheric Balloon Programs Current and Future
The 1930s and the 1960s balloon programs not only set the stage for the space race of the time but were the precursor to the current commercial space race. Many ballooning attempts have also taken place in the twenty-first century to test modern space technologies for future spaceflight. Balloons still play a large role in stratospheric research for the US Air Force (based at Holloman Air Force Base NM) and are launched by ATA Aerospace Corporation and at NASA’s Columbia Scientific Balloon Facility based in Palestine, TX and from Fort Sumner, NM, and other worldwide locations. NASA has used balloon launch systems to test atmospheric reentry systems, such as the Low-Density Supersonic Decelerator. Scientific balloons are launched from virtually every continent, including Antarctica, and balloon missions are also conducted by many other countries to provide cheaper access to near space. Loiter times at float altitude can be several months in duration.
Key metrics pertaining to Felix Baumgartner’s final Red Bull Stratos jump on 14 October 2012
Maximum vertical speed
Highest exit (jump) altitude
Vertical distance of free fall
Highest manned balloon ascent
First person to break the speed of sound in free fall without protection/propulsion of vehicle
Free fall for 4 min 20 s
Highest untethered altitude outside vehicle
Largest balloon flown with a human aboard
29.47 million cubic feet
Fastest overland speed of manned balloon
Red Bull Stratos jump physiologic data summary
Time <0.1 g
3 min 40 s
3 min 48 s
4 min 20 s
4 min 52 s
6 min 54 s
4 min 58 s
Alan Eustace subsequently eclipsed Felix Baumgartner’s altitude record when he successfully jumped from over 135,000 ft. This jump was named the StratEx Space Dive and was conducted by Paragon Space Development Corporation. Eustace’s balloon altitude record exists to the present day, although his jump is classified in a different category than the Red Bull Stratos jump due to the use of a drogue stabilization parachute in free fall. The major technical advances made by the StratEx Space Dive were Paragon’s development and use of an entirely self-contained life support and thermal control system for the pressure suit and a drogue parachute that would not foul during deployment, as well as the Stiff Anti-Entanglement Bridle Ejecting Rod (SAEBER), which prevented the spin from a fouled drogue encountered by Joe Kittinger on Excelsior I.
Key metrics pertaining to Alan Eustace’s final stratospheric record jump on 24 October 2014
41,420 m (135,890 ft)
Distance of fall with drogue/stabilizing device
37,617 m (123,414 ft)
Vertical speed with drogue/stabilizing device
1,321 km/h (821 MPH, MACH 1.23)
Comparison table showing key metrics of the Red Bull Stratos and StratEx Space Dive projects
Red Bull Stratos
StratEx Space Dive
Professional base jumper
Computer engineer/corporate executive
Start of development
Sage Cheshire Aerospace Corp
Paragon Space Development Corporation
ATA Aerospace Corp
World View Enterprises
David Clark Company 3.5 psi
ILC Dover Company 5.4 psi
Free fall weight
Velocity sports equipment
United Parachute Technology
Automatic activation device
Manual or acceleration triggered
Automatic deployment, non-fouling deployment
15 Mar 2012 (71,581 ft)
25 July 2012 (97,146 ft)
14 Oct 2012 (127,852 ft)
4 Oct 2014 (56,857 ft)
15 Oct 2014 (105,678 ft)
24 Oct 2014 (135,890 ft)
4 helicopters, 2 ground vehicles
4 helicopters, 1 aircraft, 2 ground vehicles
Balloons were the first vehicles to lift humans off of the Earth into the atmosphere, giving humans their first taste of flight. Since those first sojourns in 1783, humans have continued the journey in hot air balloons, lighter-than-air gas balloons, and hybrid hot air and lifting gas balloons. The hybrid balloon allowed the first circumnavigation of the Earth. Although unmanned balloon flights continue to provide unprecedented scientific advances and long duration flights in support of atmospheric and space sciences, the recent manned stratospheric flights have inspired the next generation of explorers and scientists. Continued development of advanced life support systems and capsules and balloon control systems has continued to carry humans ever higher. Major advancements have been made in crew escape technologies from the recent stratospheric balloon free fall jumps. Now at least three commercial aerospace companies are in the development phase preparing to carry near-spaceflight participants and scientists into the stratosphere and allowing more people to experience the inspiring views of Earth.
The author wishes to acknowledge assistance from Mr. Gregory Sutton in researching this entry as well as assistance from Ms. Catherine M. Moreno in editing the content.
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