Thirty-seven years ago this month, the Mariner 10 interplanetary space probe successfully conducted a flyby encounter with the planet Venus. The Venusian flyby served as a necessary prelude to a subsequent first-ever flyby of the planet Mercury.
The Mariner Program concentrated on the scientific exploration of the inner planets of the solar system. Namely, Mars, Venus and Mercury. A total of ten (10) Mariner missions were attempted; seven (7) of which were successful. These missions were flown between 1962 and 1974. As outlined below, the Mariner Program recorded a number of important spaceflight firsts.
Mariner spacecraft were the first to successfully conduct a flyby of Venus (Mariner 2), Mars (Mariner 4) and Mercury (Mariner 10). Additionally, the first close-up photos of Mars and Venus were taken by Mariner 4 and Mariner 10, respectively. Mariner 9 was the first spacecraft to orbit Mars. Finally, Mariner 10 was the first space probe to fly a gravity assist trajectory and perform a flyby of two (2) planets (Venus and Mercury) during a single mission.
Mariner spacecraft weighed between 450 and 950 lbs for flyby missions and 2,200 lbs for an orbital mission. Each carried a variety of mission-specific sensors including radiometers, spectrometers and television cameras. Atlas-Agena (Mariners 1 to 5) and Atlas-Centaur (Mariners 6 to 10) launch vehicles provided the energy required for Earth-escape.
Mariner 10 was the last mission of the Mariner Program. The primary objectives were to make measurements of the space, atmospheric and surface environments of Venus and Mercury. This dual-planet mission required the first-ever use of a gravity assist maneuver to get to Mercury. In particular, the gravity of Venus would be used to deflect the Mariner 10 trajectory such that it would be able to encounter Mercury.
Mariner 10 was launched from Cape Canaveral’s LC-36B at 05:45 UTC on Saturday, 03 November 1973. It took 94 days for Mariner 10 to arrive at Venus. As a bonus, the space probe trained its complement of sensors on the Comet Kohoutek along the way. On Tuesday, 05 February 1974, Mariner 10 passed within 3,100 nm of the Venusian surface at 17:01 UTC. The spacecraft then sailed on toward its future flyby encounters with Mercury.
Mariner 10 learned many things about Venus. Venus was found to have an atmospheric circulation pattern somewhat like that of Earth. Although its strength is very much less than that of Earth, Venus was found to have a magnetic field. The planet’s ionosphere also interacted with the solar wind to produce a huge bow shock flowfield in the exoatmospheric region surrounding the planet.
Between March of 1974 and March of 1975, Mariner 10 performed three (3) flybys of the planet Mercury. The closest approach to the planet’s surface was a mere 177 nm. Mercury’s surface was found to be very Moon-like in that it is heavily-cratered. Spacecraft measurements also confirmed that Mercury does not have an atmosphere. Further, Mercury was found to have a predominatly iron-laden core as well as a small magnetic field.
Following the last of the trio of flyby encounters with Mercury, Mariner 10 systems were put through a number of engineering tests. The mission was officially brought to an end on Monday, 24 March 1975 when the spacecraft attitude control system propellant supply went to zero. Today, the Mariner 10 hulk continues in an eternal orbit about the Sun.
Fifty-years ago today, NASA successfully conducted a critical flight test of the agency’s Mercury-Redstone vehicle which helped clear the way for the United States’ first manned suborbital spaceflight. Riding the Mercury spacecraft into space and back was a 44-month old chimpanzee by the name of HAM.
Project Mercury was America’s first manned spaceflight program. Simply put, Mercury helped us learn how to fly astronauts in space and return them safely to earth. A total of six (6) manned missions were flown between May of 1961 and May of 1963. The first two (2) flights were suborbital shots while the final four (4) flights were full orbital missions. All were successful.
The Mercury spacecraft weighed about 3,000 lbs, measured 9.5-ft in length and had a base diameter of 6.5-ft. Though diminutive, the vehicle contained all the systems required for manned spaceflight. Primary systems included guidance, navigation and control, environmental control, communications, launch abort, retro package, heatshield, and recovery.
Mercury spacecraft launch vehicles included the Redstone and Atlas missiles. Both were originally developed as weapon systems and therefore had to be man-rated for the Mercury application. Redstone, an Intermediate Range Ballistic Missile (IRBM), was the booster for Mercury suborbital flights. Atlas, an Intercontinental Ballistic Missile (ICBM), was used for orbital missions.
Early Mercury-Redstone (MR) flight tests did not go particularly well. The subject missions, MR-1 and MR-1A, were engineering test and development flight tests flown with the intent of man-rating both the coverted launch vehicle and new spacecraft.
MR-1 hardly flew at all in that its rocket motor shut down just after lift-off. After soaring to the lofty altitude of 4-inches, the vehicle miraculously settled back on the launch pad without toppling over and detonating its full load of propellants. MR-1A flew, but owing to higher-than-predicted acceleration, went much higher and farther than planned. Nonetheless, MR flight testing continued in earnest.
The objectives of MR-2 were to verify (1) that the fixes made to correct MR-1 and MR-1A deficiencies indeed worked and (2) proper operation of a bevy of untested systems as well. These systems included environmental control, attitude stabilization, retro-propulsion, voice communications, closed-loop abort sensing and landing shock attenuation. Moreover, MR-2 would carry a live biological payload (LBP).
A 44-month old male chimpanzee was selected as the LBP. He was named HAM in honor of the Holloman Aerospace Medical Center where the primate trained. HAM was taught to pull several levers in response to external stimuli. He received a banana pellet as a reward for responding properly and a mild electric shock as punishment for incorrect responses. HAM wore a light-weight flight suit and was enclosed within a special biopack during spaceflight.
On Tuesday, 31 January 1961, MR-2 lifted-off from Cape Canaveral’s LC-5 at 16:55 UTC. Within one minute of flight, it became obvious to Mission Control that the Redstone was again overaccelerating. Thus, HAM was going to see higher-than-planned loads at burnout and during reentry. Additionally, his trajectory would take him higher and farther downrange than planned. Nevertheless, HAM kept working at his lever-pulling tasks.
The Redstone burnout velocity was 5,867 mph rather than the expected 4,400 mph. This resulted in an apogee of 137 nm (100 nm planned) and a range of 367 nm (252 nm predicted). HAM endured 14.7 g’s during entry; well above the 12 g’s planned. Total flight duration was 16.5 minutes; several minutes longer than planned.
Chillingly, HAM’s Mercury spacecraft experienced a precipitous drop in cabin pressure from 5.5 psig to 1 psig just after burnout. High flight vibrations had caused the air inlet snorkel valve to open and dump cabin pressure. HAM was both unaware of and unaffected by this anomaly since he was busy pulling levers within the safety of his biopack.
HAM’s Mercury spacecraft splashed-down at 17:12 UTC about 52 nm from the nearest recovery ship. Within 30 minutes, a P2V search aircraft had spotted HAM’s spacecraft (now spaceboat) floating in an upright position. However, by the time rescue helicopters arrived, the Mercury spacecraft was found floating on its side and taking on sea water.
Apparently, a combination of impact damage to the spacecraft’s pressure bulkhead and the open air inlet snorkel valve resulted in HAM’s spacecraft taking on roughly 800 lbs of sea water. Further, heavy ocean wave action had really hammered HAM and the Mercury spacecraft. The latter having had its beryllium heatshield torn away and lost in the process.
Fortunately, one of the Navy rescue helicopters was able to retrieve the waterlogged spacecraft and deposit it safely on the deck of the USS Donner. In short order, HAM was extracted from the Mercury spacecraft. Despite the high stress of the day’s spaceflight and recovery, HAM looked pretty good. For his efforts, HAM received an apple and an orange-half.
While the MR-2 was judged to be a success, one more flight would eventually be flown to verify that the Redstone’s overacceleration problem was fixed. That flight, MR-BD (Mercury-Redstone Booster Development) took place on Friday, 24 March 1961. Forty-two (42) days later USN Commander Alan Bartlett Shepard, Jr. became America’s first astronaut.
MR-2 was HAM’s first and only spaceflight experience. He quietly lived the next 17 years as a resident of the National Zoo in Washington, DC. His last 2 years were spent living at a North Carolina zoo. On Monday, 19 January 1983, HAM passed away at the age of 26. HAM is interred at the New Mexico Museum of Space History in Alamogordo, NM.
Seven years ago this week, NASA’s Mars Exploration Rover (MER) Opportunity landed at Meridiani Planum on the surface of the planet Mars. Incredibly, the robotic rover continues to gather geological, atmospheric and astronomical data well beyond its design mission duration of ninety (90) Martian days.
Mars is the 4th planet out from the Sun. It has a diameter a little more than half that of Earth. The duration of a day on Mars is a little more than that on Earth. However, a Martian year is 88% longer than a terrestrial year. While nebulous in comparison to the Earth, Mars has an atmosphere. Atmospheric temperature ranges from -190F to +98F.
Mars has always been a source of curious speculation by we Earthlings. Does or did Mars ever have water? Does or did Mars ever have life in any form? The quest to answer these and related questions has resulted in significant exploration of the Martian space, atmosphere and surface by robotic space vehicles sent from the Earth.
In 1976, Viking 1 and Viking 2 became the first American spacecraft to land on the surface of Mars. In July of 1997, the Mars Pathfinder became the first successful United States robotic rover. While a spectacular accomplishment, that first rover’s exploration capabilities and science output were modest. Something more substantial was required to provide a quantum leap in our understanding of Mars.
That something was the Mars Exploration Rover (MER) of which there would be two (2) copies. MER-A (Spirit) and MER-B (Opportunity) would be targeted to opposite hemispheres where each rover would investigate Martian geology up-close and personal. Each was configured with a sophisticated suite of scientific equipment for doing so. Together, the rovers were destined to provide the most detailed investigation of Martian geology in history.
Each MER weighs 408 lbs and measures 7.5-feet in width, 4.9-feet in height and 5.2-feet in length. Six (6) independently-driven wheels provide for rover locomotion and hill-climbing. Vehicle systems are typical with provision made for power generation, storage and distribution, vehicle guidance, navigation and control, data management, communication, and thermal control.
MER-A (Spirit) was launched on Tuesday, 10 June 2003 from SLC-17A at Cape Canaveral. Following a nominal entry and descent, the rover landed near Gusev Crater at 04:35 Ground UTC on Sunday, January 4, 2004. MER-B (Opportunity) was launched on Monday, 07 July 2003 from SLC-17B at Cape Canaveral. MER-B safely landed near Meridiani Planum at 05:05 Ground UTC on Sunday, 25 January 2004.
Both MER vehicles have produced images of and obtained scientific data on a myriad of Martian geologic features as they have roamed the region around their respective landing sites. They have operated for several thousand days beyond their 90-day design mission. That stunning success is due in great measure to the talented and dedicated mission operations and science teams back here on Earth.
In truth, any attempt to accurately synopsize here the myriad discoveries and scientific contributions of Spirit and Opportunity does both a disservice. Thus, to better grasp and appreciate the true scope and character of their incredible achievements, the reader is hereby invited to visit the following URL: http://marsrovers.jpl.nasa.gov/mission/status.html
Spirit was last heard from officially on Monday, 22 March 2010 (2,210 Mars days on the surface). The senior rover had traveled 4.8 miles during its many exploratory surface roamings. It is suspected that the vehicle is hibernating due to seasonally-low solar power levels. The hope is that Spirit will revive from its cold winter slumber when spring arrives this March at Gusev Crater.
As for Opportunity, it continues to continue! As of this writing, the junior rover is conducting a site survey at Crater Rim. It has been on the surface for 2,489 Mars days and has traveled in excess of 16.5 miles. Where this marvelous story ends is not clear at present. However, we do not have to wait for the day when MER-B finally goes silent to realize what has long been apparent; our noble exploratory marvel has afforded us a rare Opportunity indeed.
Fifty-one years ago this month, a developmental version of the USN/Lockheed Polaris A1 Fleet Ballistic Missile was test-flown from Cape Canaveral, Florida. The successful test marked a key milestone in the flight-proving of the Polaris missile’s Inertial Navigation System (INS).
The Cold War between the United States and the Soviet Union spawned the development of a Nuclear Triad by both sides. The concept involved delivery of atomic weapons via manned bombers, land-based ballistic missiles and submarine-launched ballistic missiles. This diversity of delivery systems thus provided for deterrence by maximizing the ability for either side to retaliate in the event of a first strike by the other.
The submarine-launched ballistic missile (SLBM) is arguably the most effective leg of the Nuclear Triad when its comes to deterrence. This effectiveness stems largely from the mobility and elusiveness of the nuclear-powered submarine itself. The fact that the missile is launched while the launch platform is submerged greatly enhances the weapons’s effectiveness as well.
The challenges faced by the Navy and its contractors in developing a SLBM capability were numerous and significant. Critical among these was the need to avoid igniting the first stage rocket motor within the confines of the submarine. The solution was to eject the missile from its launch canister via a high pressure gas generation system. The rocket was then air-ignited just after it broached the ocean surface.
A key aspect of the SLBM launch process is missile stability and control both in the water and in the air. During its underwater transit from canister eject to surface broach, the missile is not under active control. However, it must be statically stable in a hydrodynamic environment. Once in the air, the rocket motor must be ignited quickly since missile 3-axis control comes only via thrust vectoring.
Polaris was the first SLBM developed and deployed by the United States. Lockheed Space and Missile Systems (LSMS) began engineering development of the Navy missile in the mid-1950’s. Aerojet was the Polaris Program’s propulsion contractor. Flight testing from land-based launch pads began in 1958 with the first submarine-based launch occuring in mid-1960.
The Polaris A1 was a two-staged launch vehicle. It measured 28.5 feet in length and had a maximum diameter of 54-inches. Weight at first stage ignition was 28,800 pounds. The type’s MK 1 reentry body delivered a single MK 47 warhead having a yield of 600 kT. Maximum range was on the order of 1,200 nm.
On Thursday, 07 January 1960, Polaris A1X-7 was launched from LC-29A at Cape Canaveral, Florida. The primary purpose of the test was to prove the proper operation of the Inertial Navigation System (INS). This system was developed jointly by MIT and the General Electric Company. The missile flew 900 nm down the Eastern Test Range (ETR). The flight was entirely successful.
Thirty-four (34) more tests in the Polaris A1X series took place by early July of 1960. The majority were successful. All set the stage for the first submarine-launch of the Polaris from a submerged Navy submarine. Indeed, Polaris A1E-1 did so on Wednesday, 20 July 1960. It was followed less than three (3) hours later by Polaris A1E-2. Both missiles were launched from the USS George Washington (SSBN-598) in the waters near Cape Canaveral. Both flights were successful.
The Polaris A1 became operational in November of 1960. It was followed in 1962 and 1964 by the more capable A2 and A3 Polaris variants, respectively. In the never-ending quest for greater performance and effectiveness, the Polaris was eventually replaced by the Poseidon in the 1970’s. The latter was subsequently replaced in the 1990’s with the mighty Trident II D5 missile which serves up to the present day as the Nation’s premier SLBM.
Forty-seven years ago today, 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, 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 it 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 center-of-gravity via fuel transfer, 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 for many years 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.
Sixty-two years ago this week, the USAF/Bell XS-1 became the first aircraft of any kind to achieve supersonic flight from a ground take-off. The daring feat took place at Muroc Air Force Base with USAF Captain Charles E. Yeager at the controls of the XS-1.
Rocket-powered X-aircraft such as the XS-1, X-1A, X-2 and X-15 were air-launched from a larger carrier aircraft. With the test aircraft as its payload, this “mothership” would take-off and climb to drop altitude using its own fuel load. This permitted the experimental aircraft to dedicate its entire propellant load to the flight research mission proper.
The USAF/Bell XS-1 was the first X-aircraft. It was carried to altitude by a USAF/Boeing B-29 mothership. XS-1 air-launch typically occurred at 220 mph and 22,000 feet. On Tuesday, 14 October 1947, the XS-1 first achieved supersonic flight. The XS-1 would ultimately fly as fast as Mach 1.45 and as high as 71,902 feet.
All but two (2) of the early X-aircraft were Air Force developments. The exceptions were products of the United States Navy flight research effort; the USN/Douglas D-558-I Skystreak and USN/Douglas D-558-II Skyrocket. The Skystreak was a turbojet-powered, straight-winged, transonic aircraft. The Skyrocket was supersonic-capable, swept-winged, and rocket-powered. Each aircraft was ground-launched.
In the best tradition of inter-service rivalry, the Navy claimed that the D-558-I was the only true supersonic airplane since it took to the air under its own power. Interestingly, the Skystreak was able fly beyond Mach 1 only in a steep dive. Nonetheless, the Air Force was indignant at the Navy’s insinuation that the XS-1 was somehow less of an X-aircraft because it was air-launched.
Motivated by the Navy’s afront to Air Force honor, the junior military service devised a scheme to ground-launch the XS-1 from Rogers Dry Lake at Muroc (now Edwards) Air Force Base. The aircraft would go supersonic in what was essentially a high performance take-off and climb. To boot, the feat was timed to occur just before the Navy was to fly its rocket-powered D-558-II Skyrocket. Justice would indeed be rendered!
XS-1 Ship No. 1 (S/N 46-062) was selected for the ground take-off mission. Captain Charles E. Yeager would pilot the sleek craft with Captain Jackie L. Ridley providing vital engineering support. Due to its delicate landing gear, the XS-1 propellant load was restricted to 50% of capacity which provided about 100 seconds of powered flight.
On Wednesday, 05 January 1949, Yeager fired all four (4) barrels of his XLR-11 rocket motor. Behind 6,000 pounds of thrust, the XS-1 quickly accelerated along the smooth surface of the dry lake. After a take-off roll of 1,500 feet and with the XS-1 at 200 mph, Yeager pulled back on the control yoke. The XS-1 virtually leapt into the air.
The aerodynamic loads were so high during gear retraction that the actuator rod broke and the wing flaps tore away. Unfazed, Yeager’s eager steed climbed rapidly. Eighty seconds after brake release, the XS-1 hit Mach 1.03 passing through 23,000 feet. Yeager then brought the XS-1 to a wings level flight attitude and shutdown his XLR-11 powerplant.
Following a brief glide back to the dry lake, Yeager executed a smooth dead-stick landing. Total flight time from lift-off to touchdown was on the order of 150 seconds. While a little worst for wear, the plucky XS-1 had performed like a champ and successfully accomplished something that it was really not designed to do.
Yeager was so excited during the take-off roll and high performance climb that he forgot to put his oxygen mask on! Potentially, that was a problem since the XS-1 cockpit was inerted with nitrogen. Fortunately, late in the climb, Yeager got his mask in place just before he went night-night for good.
Suffice it to say that the United States Navy was not particularly fond of the display of bravado and airmanship exhibited on that long-ago January day. The Air Force had emerged victorious in a classic contest of one-upmanship. Indeed, Air Force honor had been upheld. And, as was often the case in the formative years of the United States Air Force, it was Chuck Yeager who brought victory home to the blue suiters.
Thirty-eight 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 38 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. And so, the historical record continues to list the name of Eugene A. Cernan as the last man to walk on the Moon.
Okay America, here’s some questions for you. When will we go back to the Moon? By extension, how about Mars and beyond? Are our greatest space achievements behind us or is the best yet to come? Are we a nation of used-to-be’s or are we that bastion of freedom where even the impossible is achievable? Does it matter? Do you even care? You choose.
Fifty-six 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 his weight.
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.
Fifty-one years ago this week, USAF Captain Joe B. Jordan zoomed a modified USAF/Lockheed F-104C Starfighter to a world altitude record of 103,395.5 feet above mean sea level. The flight originated from and recovered to the Air Force Flight Test Center (AFFTC) at Edwards Air Force Base, California.
On Tuesday, 14 July 1959, the USSR established a world altitude record for turbojet-powered aircraft when Soviet test pilot Vladimir S. Ilyushin zoomed the Sukhoi T-43-1 (a prototype of the Su-9) to an absolute altitude of 94,661 feet. By year’s end, the Soviet achievement would be topped by several American aircraft.
FAI rules stipulate that an existing absolute altitude record be surpassed by at least 3 percent for a new mark to be established. In the case of the Soviet’s 1959 altitude record, this meant that an altitude of at least 97,501 feet would need to be achieved in a record attempt.
On Sunday, 06 December 1959, USN Commander Lawrence E. Flint wrested the months-old absolute altitude record from the Soviets by zooming to 98,561 feet. Flint piloted the second USN/McDonnell Douglas YF4H-1 (F4 Phantom II prototype) in accomplishing the feat. In a show of inter-service cooperation, the record flight was made from the AFFTC at Edwards Air Force Base.
Meanwhile, USAF was feverishly working on its own record attempt. The aircraft of choice was the Lockheed F-104C Starfighter. However, with the record now held by the Navy, the Starfighter would have to achieve an absolute altitude of at least 101,518 feet to set a new mark. (Per the FAI 3 percent rule.)
On Tuesday, 24 November 1959, the AFFTC accepted delivery of the record attempt aircraft, F-104C (S/N 56-0885), from the Air Force Special Weapons Center at Kirtland AFB in New Mexico. This aircraft was configured with a J79-GE-7 turbojet capable of generating nearly 18,000 pounds of sea level thrust in afterburner.
Modifications were made to the J79 to maximize the aircraft’s zoom kinematic performance. The primary enhancements included increasing afterburner fuel flow rate by 10 percent and maximum RPM from 100 to 103.5 percent. Top reset RPM was rated at 104.5 percent. Both the ‘A’ and ‘B’ engine flow bypass flaps were operated in the open position as well. These changes provided for increased thrust and stall margin.
An additional engine mod involved reducing the minimum engine fuel flow rate from 500 to 250 pounds per hour. Doing so increased the altitude at which the engine needed to be shut down to prevent overspeed or over-temperature conditions. Another change included increasing the maximum allowable compressor face temperature from 250 F to 390 F.
The F-104C external airframe was modified for the maximum altitude mission as well. The compression cones were lengthened on the bifurcated inlets to allow optimal pressure recovery at the higher Mach number expected during the record attempt. High Mach number directional stability was improved by swapping out the F-104C empannage with the larger F-104B tail assembly.
USAF Captain Joe B. Jordan was assigned as the altitude record attempt Project Pilot. USAF 1st Lt and future AFFTC icon Johnny G. Armstrong was assigned as the Project Engineer. Following an 8-flight test series to shake out the bugs on the modified aircraft, the record attempt proper started on Thursday, 10 December 1959.
On Monday, 14 December 1959, F-104C (S/N 56-0885) broke the existing absolute altitude record for turbojet-powered aircraft on its 5th attempt. Jordan did so by accelerating the aircraft to Mach 2.36 at 39,600 feet. He then executed a 3.15-g pull to an inertial climb angle of 49.5 degrees. Jordan came out of afterburner at 70,000 feet and stop-cocked the J79 turbojet at 81,700 feet.
Roughly 105 seconds from initiation of the pull-up, Joe Jordan reached the top of the zoom. The official altitude achieved was 103,395.5 feet above mean sea level based on range radar and Askania camera tracking. True airspeed over the top was on the order of 455 knots. Jordan started the pull-up to level flight at 60,000 feet; completing the recovery at 25,000 feet. Landing was entirely uneventful.
Jordan’s piloting achievement in setting the new altitude record was truly remarkable. His conversion of kinetic energy to altitude (potential energy) during the zoom was extremely efficient; realizing only a 2.5 percent energy loss from pull-up to apex. Jordan also exhibited exceptional piloting skill in controlling the aircraft over the top of the zoom where the dynamic pressure was a mere 14 psf. He did so using aerodynamic controls only. The aircraft did not have a reaction control system ala the X-15.
Armstrong’s contributions to shattering the existing altitude record were equally substantial. Skillful flight planning and effective use of available resources (including time available for the record attempt) were pivotal to mission success. Armstrong significantly helped maximize aircraft zoom performance through proper selection of pull-up flight conditions and intelligent use of accurate day-of-flight meteorological information.
For his skillful piloting efforts in setting the world absolute altitude record for turbojet-powered aircraft in December of 1959, Joe Jordan received the 1959 Harmon Trophy.
Forty-five years ago this month, Gemini 7 set a new record for long-duration manned spaceflight. The official lift-off-to-splashdown flight duration was 330 hours, 35 minutes and 1 second.
Project Gemini was the critical bridge between America’s fledging manned spaceflight effort – Project Mercury – and the bold push to land men on the Moon – Project Apollo. While the events and importance of this program have faded somewhat with the passage of time, there would have been no manned lunar landing in the decade of the 1960’s without Project Gemini.
On Thursday, 25 May 1961, President John F. Kennedy addressed a special session of the U.S. Congress on the topic of “Urgent National Needs”. Near the end of his prepared remarks, President Kennedy proposed that the United States “should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.”
At the time of the President’s clarion call to go to the Moon, the United States had accrued a total of 15 minutes of manned spaceflight experience. That quarter hour of spacefaring activity had come just 20 days previous. Indeed, Alan B. Shephard became the first American to be launched into space when he rode his Freedom 7 Mercury spacecraft on a sub-orbital trajectory down the Eastern Test Range on Tuesday, 05 May 1961.
America responded enthusiastically to the manned lunar landing goal. However, no one really knew exactly how to go about it! After considering several versions of direct ascent from the Earth to the Moon, NASA ultimately decided to use a method proposed by engineer John C. Houbolt known as Lunar Orbit Rendezvous (LOR). As a result, NASA would have to invent and master the techniques of orbital rendezvous.
Project Gemini provided the technology and flight experience required for a manned lunar landing and return. In the 20 months between March of 1965 and November of 1966, a total of 10 two-man Gemini missions were flown. During that time, the United States learned to navigate, rendezvous and dock in space, fly for long durations and perform extra-vehicular activities.
The primary purpose of Gemini 7 was to conduct a 14-day orbital mission. This was important since the longest anticipated Apollo mission to the Moon and back would be about the same length of time. Gemini 7 was flown to show that men and spacecraft could indeed function in space for the required period. A secondary goal of Gemini 7 was to serve as the target for Gemini 6 in achieving the world’s first rendezvous between two manned spacecraft.
Gemini-Titan (GT-7) lifted-off from Cape Canaveral’s LC-19 at 19:30:03 UTC on Saturday, 04 December 1965. The Gemini 7 flight crew consisted of Commander Frank F. Borman II and Pilot James A. Lovell, Jr. They were successfully inserted into a 177-nm x 87-nm low-earth orbit. This initial orbit was later circularized to 162-nm.
Borman and Lovell spent the first 10-days of their mission conducting a variety of space experiments. They wore special lightweight spacesuits that were supposed to improve confort level for their long stay in space. However, these suits were not all that comfortable and by their second week in space, the astronauts were flying in just their long-johns.
On their 11th day in space, the Gemini 7 crew had visitors. Indeed, Gemini 6 was launched into Earth orbit from Cape Canaveral and subsequently executed the first rendezvous in space with Gemini 7 on Wednesday, 15 December 1965. Gemini 6, with Commander Walter M. Schirra, Jr. and Pilot Thomas P. Stafford on board, ultimately maneuvered to within 1 foot of the Gemini 7 spacecraft.
While Gemini 6 returned to Earth within 24 hours of launch, Gemini 7 and her weary crew soldiered on. The monotony was brutal. Borman and Lovell had conducted all of their planned space experiments. They had to drift through space to conserve fuel. They couldn’t sleep because they weren’t tired. Borman later indicated that those last 3 days on board Gemini 7 were some of the toughest of his life.
On the 14th day of flight, Saturday, 18 December 1965, Borman and Lovell successfully returned to Earth. Reentry was entirely nominal. Splashdown occurred at 14:05:04 UTC in the Atlantic Ocean roughly 400 miles east of Nassau in The Bahamas. Crew and spacecraft were recovered by the USS Wasp.
Frank Borman and Jim Lovell had orbited the Earth 206 times during their 14-day mission. Each crew member was tired and a little unsteady as he walked the flight deck of the USS Wasp. However, each man quickly recovered his native strength and vitality.
The 14 days that the Gemini 7 crew spent in space were physically and emotionally demanding. Life within the cramped confines of their little spacecraft was akin to two guys living inside a telephone booth for two weeks. Notwithstanding the challenges of that spartan existence, the Gemini 7 crew did their job. Gemini 7 was a resounding success. More, Project Gemini had achieved another key milestone. The Moon seemed a bit closer.
