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First American in Orbit

Fifty-five years ago today, Project Mercury Astronaut John Herschel Glenn, Jr. became the first American to orbit the Earth. Glenn’s spacecraft name and mission call sign was Friendship 7.

Mercury-Atlas 6 (MA-6) lifted-off from Cape Canaveral’s Launch Complex 14 at 14:47:39 UTC on Tuesday, 20 February 1962. It was the first time that the Atlas LV-3B booster was used for a manned spaceflight.

Three-hundred and twenty seconds after lift-off, Friendship 7 achieved an elliptical orbit measuring 143 nm (apogee) by 86 nm (perigee). Orbital inclination and period were 32.5 degrees and 88.5 minutes, respectively.

The most compelling moments in the United States’ first manned orbital mission centered around a sensor indication that Glenn’s heatshield and landing bag had become loose at the beginning of his second orbit. If true, Glenn would be incinerated during entry.

Concern for Glenn’s welfare persisted for the remainder of the flight and a decision was made to retain his retro package following completion of the retro-fire sequence. It was hoped that the 3 flimsy straps holding the retro package would also hold the heatshield in place.

During Glenn’s return to the atmosphere, both the spent retro package and its restraining straps melted in the searing heat of re-entry. Glenn saw chunks of flaming debris passing by his spacecraft window. At one point he radioed, “That’s a real fireball outside”.

Happily, the spacecraft’s heatshield held during entry and the landing bag deployed nominally. There had never really been a problem. The sensor indication was found to be false.

Friendship 7 splashed-down in the Atlantic Ocean at a point 432 nm east of Cape Canaveral at 19:43:02 UTC. John Glenn had orbited the Earth 3 times during a mission which lasted 4 hours, 55 minutes and 23 seconds. In short order, spacecraft and astronaut were successfully recovered aboard the USS Noa.

John Glenn became a national hero in the aftermath of his 3-orbit mission aboard Friendship 7. It seemed that just about every newspaper page in the days following his flight carried some sort of story about his historic fete. Indeed, it is difficult for those not around back in 1962 to fully comprehend the immensity of Glenn’s flight in terms of what it meant to the United States.

John Herschel Glenn, Jr. passed away on 08 December 2016 at the age of 95. His trusty Friendship 7 spacecraft is currently on display at the Smithsonian National Air and Space Museum in Washington, DC.

Posted in Aerospace, History

The Awesome SeaMaster

Fifty-eight years ago this month, the U.S. Navy’s first production Martin P6M-2 SeaMaster flyingboat took-off from Chesapeake Bay on its maiden flight. Martin chief test pilot George A. Rodney was at the controls of the 4-man, swept-wing naval bomber as it took to the skies on Tuesday, 17 February 1959.

Featuring a fuselage length of 134 feet, wingspan of 102 feet, and a wing leading edge sweep of 40 degrees, the P6M-2 had a GTOW of about 175,000 lbs. Armament included an ordnance load of 30,000 lbs and twin 20 mm, tail-mounted cannon. Power was provided by a quartet of Pratt and Whitney J75-P-2 turbojets; each delivering a maximum sea level thrust of 17,500 lbs.

The SeaMaster’s demonstrated top speed at sea level was in excess of Mach 0.90. This on-the-deck performance is comparable to that of the USAF/Rockwell B-1B Lancer and USAF/Northrup B-2 Spirit and exceeds that of the USAF/Boeing B-52 Stratofortress.

P6M pilots reported that the swept-wing ship handled well below 5,000 feet when flying at Mach numbers between 0.95 and 0.99. While designed for low altitude bombing and mine-laying, the aircraft was flown as high as 52,000 feet. As a result, the Navy even considered the SeaMaster as a nuclear weapons platform.

Despite the type’s impressive performance and capabilities, the SeaMaster Program was cancelled in August of 1959. Budgetary issues and the emerging Fleet Ballistic Missile System (Polaris-Poseidon-Trident) led to this decision. Loss of the P6M SeaMaster Program was devastating to the Glenn L. Martin Company and resulted in this notable aerospace business never again producing another aircraft.

Posted in Aerospace, History

Aquila Ultimus

Forty-two years ago this month, a USAF/McDonnell-Douglas F-15A Eagle Air Superiority Fighter zoomed to an altitude of 30 km (98,425 feet) in an elapsed time of 207.8 seconds from brake release. The pilot for the record-breaking mission was USAF Major Roger Smith.

Operation Streak Eagle was a mid-1970′s effort by the United States Air Force to set eight (8) separate time-to-climb records using the then-new McDonnell-Douglas F-15 Air Superiority Fighter. These record-setting flights originated from Grand Forks Air Force Base in North Dakota.

Starting on Thursday, 16 January 1975, the 19th pre-production F-15 Eagle aircraft (S/N 72-0119) was used to establish the following time-to-climb records during Operation Streak Eagle:

3 km, 16 January 1975, 27.57 seconds, Major Roger Smith

6 km, 16 January 1975, 39.33 seconds, Major Willard Macfarlane

9 km, 16 January 1975, 48.86 seconds, Major Willard Macfarlane

12 km, 16 January 1975, 59.38 seconds, Major Willard Macfarlane

15 km, 16 January 1975, 77.02 seconds, Major David Peterson

20 km, 19 January 1975, 122.94 seconds, Major Roger Smith

25 km, 26 January 1975, 161.02 seconds, Major David Peterson

The eighth and final time-to-climb record attempt of Operation Streak Eagle took place on Saturday, 01 February 1975. The goal was to set a new time-to-climb record to 30 km. The pilot was required to wear a full pressure suit for this mission.

At a gross take-off weight of 31,908 pounds, the Streak Eagle aircraft had a thrust-to-weight ratio in excess of 1.4. The aircraft was restrained via a hold-down device as the two Pratt and Whitney F100 turbofan engines were spooled-up to full afterburner.

Following hold-down and brake release, the Streak Eagle quickly accelerated during a low level transition following take-off. At Mach 0.65, Smith pulled the aircraft into a 2.5-g Immelman. The Streak Eagle completed this maneuver 56 seconds from brake release at Mach 1.1 and 9.75 km. Rolling the aircraft upright, Smith continued to accelerate the Streak Eagle in a shallow climb.

At an elapsed time of 151 seconds and with the aircraft at Mach 2.2 and 11.3 km, Smith executed a 4-g pull to a 60-degree zoom climb. The Steak Eagle passed through 30 km at Mach 0.7 in an elapsed time of 207.8 seconds. The apex of the zoom trajectory was about 31.4 km. With a new record in hand, Smith uneventfully recovered the aircraft to Grand Forks AFB.

Operation Streak Eagle ended with the capturing of the 30 km time-to-climb record. In December 1980, the aircraft was retired to the USAF Museum at Wright-Patterson Air Force Base in Dayton, Ohio. It is currently held in storage at the Museum and no longer on public display.

Posted in Aerospace, History

Explorer I

Fifty-nine years ago today, the United States successfully orbited the country’s first satellite. Known as Explorer I, the artificial moon went on to discover the system of radiation belts that surrounds the space environment of the Earth.

The Explorer I satellite was designed and fabricated by the Jet Propulsion Laboratory (JPL) under the direction of Dr. William J. Pickering. The satellite’s instrumentation unit measured 37.25 inches in length, 6.5 inches in diameter, and had a mass of only 18.3 lbs. With its burned-out fourth stage solid rocket motor attached, the total on-orbit mass of the pencil-like satellite was 30.8 lbs.

Explorer I was launched aboard a Jupiter-C (aka Juno I) launch vehicle from LC-26 at Cape Canaveral, Florida on Friday, 31 January 1958. Lift-off at occurred at 22:48 EST (0348 UTC). With all four stages performing as planned, Explorer I was inserted into a highly elliptical orbit having an apogee of 1,385 nm and a perigee of 196 nm.

Arguably the most historic achievement of the Explorer I mission was the discovery of a system of charged particles or plasma within the magnetosphere of the Earth. These belts extend from an altitude of roughly 540 to 32,400 nm above mean sea level. Most of the plasma that forms these belts originates from the solar wind and cosmic rays. The radiation levels within the Van Allen Radiation Belts (named in honor of the University of Iowa’s Dr. James A. Van Allen) are such that spacecraft electronics and astronaut crews must be shielded from the adverse effects thereof.

Explorer I operational life was limited by on-board battery life and lasted a mere 111 days. However, it soldiered-on in orbit until reentering the Earth’s atmosphere over the Pacific Ocean on Tuesday, 31 March 1970. During the 147 months it spent in space, Explorer I orbited the Earth more than 58,000 times. Data obtained and transmitted by the satellite contributed markedly to mankind’s understanding of the Earth’s space environment.

Perhaps the greatest legacy of Explorer I was that it was the first satellite orbited by the United States. Unknown to most today, this accomplishment was absolutely vital to America’s security, and indeed that of the free world, at the time. The Soviet Union had been first in space with the orbiting of the much larger Sputnik I and II satellites in late 1957. However, Explorer I showed that America also had the capability to orbit a satellite. History records that this capability would quickly grow and ultimately lead to the country’s preeminence in space.

Posted in Aerospace, History

Final Flight: AS-204 Fire

Fifty years ago to the day, the Apollo 204 prime crew perished as fire swept through their Apollo Block I Command Module (CM). The Apollo 204 crew of Command Pilot Vigil I. “Gus” Grissom, Senior Pilot Edward H. White II and Pilot Roger B. Chaffee had been scheduled to make the first manned flight of the Apollo Program some three weeks hence.

On Friday, 27 January 1967, during a plugs-out ground test on LC-34 at Cape Canaveral, Florida, a fire broke out in the Apollo 204 spacecraft at 23:31:04 UTC (6:31:04 pm EST). Shortly after, a chilling cry was heard across the communications network from Astronaut Chaffee: “We’ve got a fire in the cockpit”.

Believed to have started just below Grissom’s seat, the fire quickly erupted into an inferno that claimed the men’s lives in less than 30 seconds. While each received extensive 3rd degree burns, death was attributed to toxic smoke inhalation.

The Apollo 204 fire was most likely brought about by some minor malfunction or failure in equipment or wire insulation. This failure, which was never positively identified, initiated a sequence of events that culminated in the conflagration.

The post-mishap investigation uncovered numerous defects in CM Block I design, manufacturing, and workmanship. The use of a (1) pure oxygen atmosphere pressurized to 16.7 psia and (2) complex 3-component hatch design (that took a minimum of 90 seconds to open) sealed the astronauts’ fate.

A haunting irony of the tragedy is that America lost her first astronaut crew, not in the sideral heavens, but in a spacecraft that was firmly rooted to the ground.

Posted in Aerospace, Final Flight, History

Skyray Maiden Flight

Sixty-four years ago this month, the USN/Douglas XF4D-1 Skyray fighter flew for the first time at Edwards Air Force Base in California. Douglas test pilot Robert O. Rahn was at the controls of the single-engine, carrier-based, supersonic-capable aircraft.

The Douglas XF4D-1 was the prototype version of the United States Navy’s F4D-1 Skyray. Designed to intercept adversary aircraft at 50,000 feet within 300 seconds of take-off, development of the Skyray began in the late 1940’s. As an aside, the Skyray nickname derived from the type’s large delta wing which gave it the appearance of a Manta ray.

The Skyray was originally designed to be powered by a Westinghouse XJ40-WE-6 turbojet capable of 7,000 lbs of sea level thrust. However, when significant developmental problems were encountered with that power plant, Douglas substituted an Allison J35-A-17 turbojet to support early flight testing of the XF4D-1. With a maximum sea level thrust of 5,000 lbs, the J35 rendered these early airframes significantly underpowered.

A pair of XF4D-1 Skyray airframes were built by Douglas. Ship No. 1 was assigned tail number BuAer 124586 while Ship No. 2 received the designation BuAer 124587.

On Tuesday, 23 January 1953, XF4D-1 Ship No. 1 (BuAer No 124586) departed Edwards Air Force Base on its first ride into the wild blue. Doing the piloting honors on this occasion was highly regarded Douglas test pilot Bob Rahn. The delta-winged beauty performed well on this maiden flight which concluded with Rahn making an uneventful landing back at Edwards.

Extensive flight testing of the Skyray, including carrier trials, continued through 1955. The Westinghouse XJ40-WE-8 appeared on the scene during this time. Rated at 11,600 lbs of sea level thrust in afterburner, this power plant allowed the Skyray to establish several speed records in California during October of 1953. Specifically, a speed of 752.944 mph was registered within a 3-kilometer course over the Salton Sea followed by 100-kilometer closed course mark of 728.11 mph at Edwards AFB.

Unfortunately, the XJ40 would prove to be very temperamental and unreliable. Inflight engine fires, explosions, and component failures constantly plagued the Skyray program. Westinghouse never did solve these problems to the satisfaction of the Navy. As a result, the service eventually opted to power production aircraft with the Pratt and Whitney J57-P-8 turbojet (10,200 lbs of sea level thrust).

The Douglas F4D-1 Skyray went on to serve with the United States Navy and Marines from 1956 through 1964. A total of 420 aircraft were produced. While never used in anger, the Skyray was a solid performer and served well in its intended role as a point design interceptor.

The Skyray holds the distinction of being the last fighter produced by the Douglas Aircraft Company before this legendary aerospace giant merged with McDonnell Aircraft to form McDonnell Douglas.

Posted in Aerospace, History

An Unusual Tail

Fifty-three years ago this week, a USAF/Boeing B-52H Stratofortress landed safely following structual failure of its vertical tail during an encounter with unusually severe clear air turbulence. The harrowing incident occurred as the aircraft was undergoing structural flight testing in the skies over East Spanish Peak, Colorado.

Turbulence is the unsteady, erratic motion of an atmospheric air mass. It is attributable to factors such as weather fronts, jet streams, thunder storms and mountain waves. Turbulence influences the motion of aircraft that are subjected to it. These effects range from slight, annoying disturbances to violent, uncontrollable motions which can structurally damage an aircraft.

Clear Air Turbulence (CAT) occurs in the absence of clouds. Its presence cannot be visually observed and is detectable only through the use of special sensing equipment. Hence, an aircraft can encounter CAT without warning. Interestingly, the majority of in-flight injuries to aircraft crew and passengers are due to CAT.

On Friday, 10 January 1964, USAF B-52H (S/N 61-023) took-off from Wichita, Kansas on a structural flight test mission. The all-Boeing air crew consisted of instructor pilot Charles Fisher, pilot Richard Curry, co-pilot Leo Coors, and navigator James Pittman. The aircraft was equipped with accelerometers and other sensors to record in-flight loads and stresses.

An 8-hour flight was scheduled on a route that from Wichita southwest to the Rocky Mountains and back. The mission called for 10-minutes runs of 280, 350 and 400 KCAS at 500-feet AGL using the low-level mode of the autopilot. The initial portion of the mission was nominal with only light turbulence encountered.

However, as the aircraft turned north near Wagon Mound, New Mexico and headed along a course parallel to the mountains, increasing turbulence and tail loads were encountered. The B-52H crew then elected to discontinue the low level portion of the flight. The aircraft was subsequently climbed to 14,300 feet AMSL preparatory to a run at 350 KCAS.

At approximately 345 KCAS, the Stratofortress and its crew experienced an extreme turbulence event that lasted roughly 9 seconds. In rapid sequence the aircraft pitched-up, yawed to the left, yawed back to the right and then rolled right. The flight crew desperately fought for control of their mighty behemoth. But the situation looked grim. The order was given to prepare to bailout.

Finally, the big bomber’s motion was arrested using 80% left wheel authority. However, rudder pedal displacement gave no response. Control inputs to the elevator produced very poor response as well. Directional stability was also greatly reduced. Nevertheless, the crew somehow kept the Stratofortress flying nose-first.

The B-52H crew informed Boeing Wichita of their plight. A team of Boeing engineering experts was quickly assembled to deal with the emergency. Meanwhile, a Boeing-bailed F-100C formed-up with the Stratofortress and announced to the crew that most of the aircraft’s vertical tail was missing! The stricken aircraft’s rear landing was then deployed to add back some directional stability.

With Boeing engineers on the ground working with the B-52H flight crew, additional measures were taken in an effort to get the Stratofortress safely back on the ground. These measures included a reduction in airspeed, controlling aircraft center-of-gravity via fuel transfer, judicious use of differential thrust, and selected application of speedbrakes.

Due to high surface winds at Wichita, the B-52H was vectored to Eaker AFB in Blytheville, Arkansas. A USAF/Boeing KC-135 was dispatched to escort the still-flying B-52H to Eaker and to serve as an airborne control center as both aircraft proceeded to the base. Amazingly, after flying 6 hours sans a vertical tail, the Stratofortress and her crew landed safely.

Safe recovery of crew and aircraft brought additional benefits. There were lots of structural flight test data! It was found that at least one gust in the severe CAT encounter registered at nearly 100 mph. Not only were B-52 structural requirements revised as a result of this incident, but those of other existing and succeeding aircraft as well.

B-52H (61-023) was repaired and returned to the USAF inventory. It served long and well after its close brush with catastrophy in January 1964. The aircraft spent the latter part of its flying career as a member of the 2nd Bomb Wing at Barksdale AFB, Louisiana. The venerable bird was retired from active service in July of 2008.

Posted in Aerospace, History

Closing the Booster Gap

Fifty-three years ago this month, NASA successfully launched the first Saturn I Block II heavy-lift launch vehicle. Known as Saturn-Apollo No. 5 (SA-5), the mission featured the largest mass ever orbited up to that time in the history of spaceflight.

The Saturn I was a pathfinder rocket booster that ultimately lead to the development of the mighty Saturn V launch vehicle. Ten (10) Saturn I boosters were flown between October 1961 and July 1965. The first four (4) missions involved the Block I variant wherein only the first stage was powered. The final six (6) missions employed Block II vehicles which included live first and second stages.

The Saturn I measured 164 feet in length with a maximum diameter of 21.42 feet. The S-I first stage was powered by an octet of Rocketdyne H-1 engines that generated a total sea level thrust of 1,500,000 lbs. The S-IV seconds stage incorporated six (6) Pratt and Whitney RL10 engines rated at a total vacuum thrust of 900,000 lbs.

SA-5 was launched from LC-37 at Cape Canaveral, Florida on Wednesday, 29 January 1964. Weighing 1,121,680 lbs at first stage ignition, the vehicle lifted-off at 14:25:01 UTC. As the first and second stages functioned in splendid fashion, the second stage successfully achieved an elliptical orbit measuring 142 x 415 nm.

The SA-5 orbited mass of 37,700 lbs was a record for the time. This payload, consisting of the S-IV stage, an instrument unit, and a modified Jupiter nose cone filled with sand ballast, remained in orbit through the end of April 1966.

The SA-5 mission was significant for a variety of reasons. It featured the first live S-IV rocket stage and was the first Saturn I vehicle to achieve orbit. It also marked that moment in spaceflight history when America finally surpassed the Soviet Union in payload mass to orbit capability. Known as “closing the booster gap”, this event was an important step in the race to the moon in which America would be the ultimate victor.

Posted in Aerospace, History

Echoes From Taurus-Littrow

Forty-four years ago this month, NASA successfully conducted the sixth lunar landing mission of the Apollo Program. Known as Apollo 17, the flight marked the last time that men from the planet Earth explored the surface of the Moon.

Apollo 17 was launched from LC-39A at Cape Canaveral, Florida on Thursday, 07 December 1972. With a lift-off time of 05:33:00 UTC, Apollo 17 was the only night launch of the Apollo Program. Those who witnessed the event say that night turned into day as the incandescent exhaust plumes of the Saturn V’s quintet of F-1 engines lit up the sky around the Cape.

The target for Apollo 17 was the Taurus-Littrow valley in the lunar highlands. Located on the southeastern edge of Mare Serenitatis, the landing site was of particular interest to lunar scientists because of the unique geologic features and volcanic materials resident within the valley. Planned stay time on the lunar surface was three days.

The Apollo 17 crew consisted of Commander Eugene A. Cernan, Command Module Pilot (CMP) Ronald E. Evans and Lunar Module Pilot (LMP) Harrison H. Schmitt. While this was Cernan’s third space mission, both Evans and Schmitt were space rookies. Astronaut Schmitt was a professional geologist and the only true scientist to explore the surface of the Moon.

With Evans circling the Moon solo in the Command Module America, Cernan and Schmitt successfully landed their Lunar Module Challenger at 19:54:57 UTC on Monday, 11 December 1972. Their lunar stay lasted more than three days. The astronauts used the Lunar Rover for transport over the lunar surface as they conducted a trio of exploratory excursions that totaled more than 22 hours.

Cernan and Schmitt collected nearly 244 pounds of lunar geologic materials while exploring Taurus-Littrow. As on previous missions, the Apollo 17 crew deployed a sophisticated set of scientific instruments used to investigate the lunar surface environment. Indeed, the Apollo Lunar Surface Experiments Package (ALSEP) deployed during during lunar landing missions measured and transmitted vital lunar environmental data back to Earth through September 1977 when the data acquisition effort was officially terminated.

The Apollo 17 landing party departed the Moon at 22:54:37 UTC on Thursday, 14 December 1972. In a little over two hours, Challenger and America were docked. Following crew and cargo transfer to America, Challenger was later intentionally deorbited and impacted the lunar surface. The Apollo 17 crew then remained in lunar orbit for almost two more days to make additional measurements of the lunar environment.

At 23:35:09 UTC on Saturday, 16 December 1972, Apollo 17 blasted out of lunar orbit and headed home. Later, CMP Ron Evans performed a trans-Earth spacewalk to retrieve film from Apollo 17 ’s SIM Bay camera. Evans’ brave spacewalk occurred on Sunday, 17 December 1972 (69th anniversary of the Wright Brothers first powered flight) and lasted 65 minutes and 44 seconds.

Apollo 17 splashdown occurred near America Samoa in the Pacific Ocean at 19:24:59 UTC on Tuesday, 19 December 1972. America and her crew were subsequently recovered by the USS Ticonderoga.

Apollo 17 set a number of spaceflight records including: longest manned lunar landing flight (301 hours, 51 minutes, 59 seconds); longest lunar stay time (74 hours, 59 minutes, 40 seconds); total lunar surface extravehicular activity time (22 hours, 3 minutes, 57 seconds); largest lunar sample return (243.7 pounds), and longest time in lunar orbit (147 hours, 43 minutes, 37 seconds).

Apollo 17 successfully concluded America’s Apollo Lunar Landing Program. Of a sudden it seemed, America’s — and the world’s — greatest adventure was over. However, the anticipation was that the United States would return in the not-too-distant future. Indeed, Gene Cernan, the last man to walk on the Moon, spoke the following words from the surface:

“As I take man’s last step from the surface, back home for some time to come — but we believe not too long into the future — I’d like to just [say] what I believe history will record — that America’s challenge of today has forged man’s destiny of tomorrow. And, as we leave the Moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind. Godspeed the crew of Apollo 17.”

It has now been 44 years since the Commander of Apollo 17 spoke those stirring words from the valley of Taurus-Littrow. Gene Cernan and most space experts of his day figured we would surely be back by now. Certainly in the 20th century. Yet, there has been no return. Moreover, there is no formal plan or funded program in the 21st century to do so. Hence, the historical record continues to list the name of Eugene A. Cernan as the last man to walk on the surface of the Moon.

Posted in Aerospace, History

Taking One For the Team

Sixty-two years ago this month, USAF Lieutenant Colonel John Paul Stapp set a record for human G-tolerance when his Sonic Wind #1 rocket-powered test sled decelerated from 632 mph to a full stop in roughly 1.4 seconds. In so doing, Stapp endured a deceleration load equal to 46.2 times the weight of his body.

The period immediately following World War II marked the beginning of a steady rise in the speed and altitude capabilities of military aircraft. These performance increases subjected aircrew to wider ranges of flight loads and physical stresses. Manifold aeromedical issues and crew safety concerns arose; particularly in the area of emergency escape from a stricken aircraft.

Abandoning an aircraft in flight under emergency conditions and surviving the experience has always been a sporty proposition. Ejection forces, wind blast, body limb flailing, parachute opening shock levels, and the like make it so. Add to this list the effects of atmospheric temperature, pressure and oxygen concentration, and one starts to get an appreciation for the severity of the situation.

John Paul Stapp was a USAF physician who had an abiding interest in the aeromedical aspects of emergency escape. He knew that too many pilots were dying in situations that could have been survivable if proper equipment and procedures were available. Stapp dedicated himself to improving the chances of aircrew survival.

Stapp was a pioneer in scientifically investigating the effects of acceleration and deceleration on the human body. In March of 1947, he began a series of deceleration tests using a 2,000-foot sled track at Edwards Air Force Base. A rocket-powered test sled named the Gee Whiz carried test subjects down the track and brought them to a sudden halt to produce specific deceleration levels.

Initially, Stapp’s test subjects were anthropomorphic dummies and primates. However, he had always held to the belief that the best test subject would be a human. Better yet, a human who possessed extensive medical knowledge. Stapp selected himself for the assignment.

Stapp took his first ride down the Edwards sled test track on Wednesday, 10 December 1947. By May of 1948, he had riden the Gee Whiz a total of 16 times. One run resulted in a deceleration of 35-G’s. This meant that Stapp briefly experienced a force equal to 35 times his normal body weight during deceleration. In so doing, he pointedly dispelled the prevailing notion that a human being could not survive a deceleration level beyond 18-G’s.

Riding the sled was a form of physical abuse. Among numerous injuries, Stapp received several concussions, broke the same wrist twice, cracked ribs, and sustained retinal hemorrhages for his time on the track. All in an effort to find ways to preserve the lives of aircrew. Stapp, other human volunteers and chimpanzees continued sled testing on the Edwards track until 1953.

Stapp transferred to the Aeromedical Field Lab at Holloman Air Force Base, New Mexico in early 1953. He now had a longer track (3,550 feet) and a faster sled (Sonic Wind #1) with which to expand his deceleration research. The system was checked-out using a new crash test dummy and then a live primate. Stapp made the first human run on the Holloman track.

John Paul Stapp completed his 29th and final experimental sled test run on Friday, 10 December 1954. Propelled by a set of 9 rocket motors producing 70,000 pounds of thrust, the Sonic Wind #1 hit a peak velocity of 632 mph (Mach 0.9 at the test site altitude). Stapp endured a maximum acceleration of 20 G’s and then an incredible peak deceleration of 46.2-G’s during 1.4 seconds of slow-down. At that moment, he weighed 6,800 pounds.

Stapp took a severe pounding during his record ride. There were the “usual” body bruises, lacerations and harness burns. However, the worse effects involved his eyes. Both hemorrhaged and were completely filled with blood. Stapp indicated that all he could see was a watery salmon-colored fluid. Happily, his vision would return to quasi-normal by the next day. Stapp sported a pair of world-class shiners as peculiar momentos of his extreme deceleration experience.

Characteristically, Stapp had plans to go faster and endure more G’s. Indeed, the proposed Sonic Wind #2 test sled would be capable of driving him in excess of 1,000 mph and decelerating at more than 80 G’s. Such was not to occur as USAF would not allow Stapp to risk all again as a sled test subject.

John Paul Stapp’s legendary work produced enormous dividends in helping develop equipment, techniques and procedures that have saved the lives of countless aircrew. But the benefits of his research have gone well beyond that. Today, automobile safety standards are based in large measure on Stapp’s pioneering deceleration work. His legacy continues in other ways as well. Indeed, the 54th Stapp Car Crash Conference was held in November of this year.

John Paul Stapp, USAF officer, physician, sled test subject, was a man of uncommon valor and a bonifide hero in the truest sense of that over-used word. He willingly risked his life numerous times so that others might live. A man can do no more than that for his friends. On Wednesday, 13 November 1999, this man among men passed away peacefully in his sleep at age 89.

Posted in Aerospace, History
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