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America’s Space Twins

Fifty-five years ago this week, Gemini III was launched into Earth orbit with astronauts Vigil I. “Gus” Grissom and John W. Young onboard. The 3-orbit mission marked the first time that the United States flew a multi-man spacecraft.

Project Mercury was America’s first manned spaceflight series. Project Apollo would ultimately land men on the Moon and return them safely to the Earth. In between these historic spaceflight efforts would be Project Gemini.

The purpose of Project Gemini was to develop and flight-prove a myriad of technologies required to get to the Moon. Those technologies included spacecraft power systems, rendezvous and docking, orbital maneuvering, long duration spaceflight and extravehicular activity.

The Gemini spacecraft weighed 8,500 pounds at lift-off and measured 18.6 feet in length. Gemini consisted of a reentry module (RM), an adapter module (AM) and an equipment module (EM).

The crew occupied the RM which also contained navigation, communication, telemetry, electrical and reentry reaction control systems. The AM contained maneuver thrusters and the de-boost rocket system. The EM included the spacecraft orbit attitude control thrusters and the fuel cell system. Both the AM and EM were used in orbit only and discarded prior to entry.

Gemini-Titan III (GT-3) lifted-off at 14:24 UTC from LC-19 at Cape Canaveral, Florida on Tuesday, 23 March 1965. The two-stage Titan II launch vehicle placed Gemini 3 into a 121 nautical mile x 87 nautical mile elliptical orbit.

Gemini 3’s primary objective was to put the maneuverable Gemini spacecraft through its paces. While in orbit, Grissom and Young fired thrusters to change the shape of their orbital flight path, shift their orbital plane, and dip down to a lower altitude. Gemini 3 was also the first time that a manned spacecraft used aerodynamic lift to change its entry flight path.

As spacecraft commander, Gus Grissom named his cosmic chariot The Molly Brown in reference to a then-popular Broadway show; “The Unsinkable Molly Brown”. Grissom chose the moniker in memory of his first spaceflight experience wherein his Liberty Bell 7 Mercury spacecraft sunk in almost 17,000 feet of water during post-splashdown operations.

At almost two (2) hours into the mission, pilot John Young presented Grissom with his favorite sandwich which had been smuggled onboard. Grissom and Young took a bite of the corned beef sandwich and put it away since loose crumbs could get into spacecraft electronics with catastrophic results. Not amused, NASA management reprimanded the crew after the mission.

Gemini 3 splashed-down in the Atlantic Ocean at 19:16:31 UTC following a 3 orbit mission. The spacecraft landed 45 nautical miles short of the intended splashdown point due to a mis-prediction of aerodynamic lift. Although hot and sea-sick, Commander Grissom refused to open the spacecraft hatches until the recovery ship USS Intrepid came on station.

Nine (9) additional Gemini space missions would follow the flight of Gemini 3. Indeed, the historical record shows that the Gemini Program would fly an average of every two (2) months by the time Gemini XII landed in December 1966. During that period, the United States would take the lead in the race to the Moon that it would never relinquish.

Posted in Aerospace, History

Remembering HYPER-X Flight 2

Sixteen years ago this week, the NASA X-43A scramjet-powered flight research vehicle reached a record speed of over 4,600 mph (Mach 6.83). The test marked the first time in the annals of aviation that a flight-scale scramjet accelerated an aircraft in the hypersonic Mach number regime.

NASA initiated a technology demonstration program known as HYPER-X in 1996. The fundamental goal of the HYPER-X Program was to successfully demonstrate sustained supersonic combustion and thrust production of a flight-scale scramjet propulsion system at speeds up to Mach 10. The term scramjet stands for Supersonic Combustion RAMJET.

The scramjet is a key to sustained hypersonic flight within the earth’s atmosphere. Whereas rockets are capable of producing large thrust magnitudes, both the duration of operation and the amount of thrust per unit propellant mass is low. In part, this is because a rocket has to carry its own fuel and oxidizer supplies. A scramjet is a much more efficient producer of thrust in that it only has to carry its fuel and uses the atmosphere as its oxidizer source.

Rocket technology is a highly developed discipline with a deep experience and application base. In contradistinction, flight-scale scramjet technology is still in a developmental stage. Considerations such as initiating and sustaining stable combustion is a supersonic stream, efficient conversion of fuel chemical energy to kinetic energy, and optimal integration of the scramjet propulsion system into a hypersonic airframe are among the challenges that face designers.

Also known as the HYPER-X Research Vehicle (HXRV), the X-43A aircraft was a scramjet test bed. The aircraft measured 12 feet in length, 5 feet in width, and weighed nearly 3,000 pounds. The X-43A was boosted to scramjet take-over speeds with a modified Orbital Sciences Pegasus rocket booster.

The combined HXRV-Pegasus stack was referred to as the HYPER-X Launch Vehicle (HXLV). Measuring approximately 50 feet in length, the HXLV weighed slightly more than 41,000 pounds. The HXLV was air-launched from a B-52 mothership. Together, the entire assemblage constituted a 3-stage vehicle.

The second flight of the HYPER-X program took place on Saturday, 27 March 2004. The flight originated from Edwards Air Force Base, California. Using Runway 04, NASA’s venerable B-52B (S/N 52-0008) started its take-off roll at approximately 20:40 UTC. The aircraft then headed for the Pacific Ocean launch point located just west of San Nicholas Island.

At 21:59:58 UTC, the HXLV fell away from the B-52B mothership. Following a 5 second free fall, rocket motor ignition occurred and the HXLV initiated a pull-up to start its climb and acceleration to the test window. It took the HXLV about 90 seconds to reach a speed of slightly over Mach 7.

Following rocket motor burnout and a brief coast period, the HXRV (X-43A) successfully separated from the Pegasus booster at 94,069feet and Mach 6.95. The HXRV scramjet was operative by Mach 6.83. Supersonic combustion and thrust production were successfully achieved. Total power-on flight duration was approximately 11 seconds.

As the X-43A decelerated along its post-burn descent flight path, the aircraft performed a series of data gathering flight maneuvers. A vast quantity of high-quality aerodynamic and flight control system data were acquired for Mach numbers ranging from hypersonic to transonic. Finally, the X-43A impacted the Pacific Ocean at a point about 450 nautical miles due west of its launch location. Total flight time was approximately 15 minutes.

The HYPER-X Program made history that day in late March 2004. Supersonic combustion and thrust production of an airframe-integrated scramjet were achieved for the first time in flight; a goal that dated back to before the X-15 Program. Along the way, the X-43A established a speed record for airbreathing aircraft and earned a Guinness World Record for its efforts.

Posted in Aerospace, History

Final Flight: USAF/Martin XB-51

Sixty-four years ago this month, the lone remaining USAF/Martin XB-51 light attack bomber prototype crashed during take-off from El Paso International Airport in Texas. The cause of the mishap was attributed to premature rotation of the aircraft leading to an unrecoverable stall.

A product of the post-WWII 1940’s, the Martin XB-51 was envisioned as a jet-powered replacement for the piston-driven Douglas A-26 Invader. The swept-wing XB-51 utilized a unique propulsion system which consisted of a trio of General Electric J47 turbojets. Demonstrated top speed was 560 knots at sea level.

The XB-51 was a good-sized airplane. With a length of 85 feet and a wing span of 53 feet, the XB-51 had a nominal take-off weight of around 56,000 lbs. The wings were swept 35 degrees aft and incorporated 6 degrees of anhedral. The latter feature to counter the large dihedral effect produced by the type’s tee-tail.

A pair of XB-51 aircraft were built by Martin for USAF. Ship No. 1 (S/N 46-0685) first took to the air in October of 1949 followed by the flight debut of Ship No. 2 (S/N 46-0686) in April of 1950. The air crew consisted of a pilot who sat underneath a large, clear canopy and a navigator housed within the fuselage.

While the XB-51 flew hundreds of hours in flight test and made many lasting contributions to the aviation field, the aircraft never went into production. This fate was primarily the result of having lost a head-to-head competitive fly-off against the English Electric Canberra B-57A light attack bomber in 1951.

The No. 1 XB-51 aircraft was lost on Sunday, 25 March 1956 during take-off from El Paso International Airport. The mishap aircraft accelerated more slowly than normal and with the end of the runway coming up quickly, the pilot rotated the aircraft in a attempt to get airborne. Unfortunately, the rotation was premature and the wing stalled. The aircraft exploded on impact and the crew of USAF Major James O. Rudolph and Staff-Sargent Wilbur R. Savage were killed.

The loss of the No. 1 XB-51 was preceded by the destruction of Ship No. 2 (S/N 46-0686) on Friday, 09 May 1952. That tragedy occurred during low-altitude aerobatic maneuvers at Edwards Air Force Base in California. The pilot, USAF Major Neil H. Lathrop, perished in the resulting post-impact explosion and inferno.

As a footnote, the XB-51 was never assigned an official nickname by the Air Force. However, it was unofficially referred to in some aviation circles as the Panther. Due to its prominently-long fuselage, the less majestic monicker of “Flying Cigar” was sometimes used as well.

Posted in Aerospace, Final Flight, History

Bail Out!!!

Sixty-five years ago today, North American test pilot George F. Smith became the first man to survive a high dynamic pressure ejection from an aircraft in supersonic flight. Smith ejected from his F-100A Super Sabre at 777 MPH (Mach 1.05) as the crippled aircraft passed through 6,500 feet in a near-vertical dive.

On the morning of Saturday, 26 February 1955, North American Aviation (NAA) test pilot George F. Smith stopped by the company’s plant at Los Angeles International Airport to submit some test reports. Returning to his car, he was abruptly hailed by the company dispatcher. A brand-new F-100A Super Sabre needed to be test flown prior to its delivery to the Air Force. Would Mr. Smith mind doing the honors?

Replying in the affirmative, Smith quickly donned a company flight suit over his street clothes, got the rest of his flight gear and pre-flighted the F-100A Super Sabre (S/N 53-1659). After strapping into the big jet, Smith went through the normal sequence of aircraft pre-launch flight control and system checks. While the control column did seem a bit stiff in pitch, Smith nonetheless decided that his aerial steed was ready for flight.

Smith executed a full afterburner take-off to the west. The fleet Super Sabre eagerly took to the air. Accelerating and climbing, the aircraft was almost supersonic as it passed through 35,000 feet. Peaking out around 37,000 feet, Smith sensed a heaviness in the flight control column. Something wasn’t quite right. The jet was decidedly nose heavy. Smith countered by pulling aft stick.

The Super Sabre did not respond at all to Smith’s control inputs. Instead, it continued an un-commanded dive. Shallow at first, the dive steepened even as the 215-lb pilot pulled back on the stick with all of his might. But all to no avail. The jet’s hydraulic system had failed. As the stricken aircraft now accelerated toward the ground, Smith rightly concluded that this was going to be a short ride.

George Smith knew that he had only one alternative now; Eject. However, he also knew that the chances were quite small that he would survive what was quickly shaping-up to be a quasi-supersonic ejection. Suddenly, over the radio, Smith heard another Super Sabre pilot flying in his vicinity frantically yell: “Bail out, George!” So exhorted, the test pilot complied.

Smith jettisoned his canopy. The roar from the air-stream around him was unlike anything he had ever heard. Almost paralyzed with fear, Smith reflexively hunkered-down in the cockpit. The exact wrong thing to do. His head needed to be positioned up against the seat’s headrest and his feet placed within retraining stirrups prior to ejection. But there was no time for any of that now. Smith pulled the ejection seat trigger.

George Smith’s last recollection of his nightmare ride was that the Mach Meter read 1.05; 777 mph at the ejection altitude of 6,500 feet above the Pacific Ocean. These flight conditions corresponded to a dynamic pressure of 1,240 pounds per square foot. As he was fired out of the cockpit and into the harsh air-stream, Smith’s body was subjected to an astounding drag force of around 8,000 lbs producing on the order of 40-g’s of deceleration.

Mercifully, Smith did not recall what came next. The ferocious wind blast stripped him of his helmet, oxygen mask, footwear, flight gloves, wrist watch and even his ring. Blood was forced into his head which became grotesquely swollen and his facial features unrecognizable. His eyelids fluttered and his eyes were tortuously mauled by the aerodynamic and inertial load of his ejection. Smith’s internal organs, most especially his liver, were severely damaged. His body was horribly bruised and beaten as it flailed end-over-over end uncontrollably.

Smith and his seat parted company as programmed followed by automatic deployment of his parachute. The opening forces were so high that a third of the parachute material was ripped away. Thankfully, the remaining portion held together and the unconscious Smith landed about 75 yards away from a fishing vessel positioned about a half-mile form shore. Providentially, the boat’s skipper was a former Navy rescue expert. Within a minute of hitting the water, Smith was rescued and brought onboard.

George Smith was hovering near death when he arrived at the hospital. In severe shock and with only a faint pulse, doctors quickly went to work. Smith awoke on his sixth day of hospitalization. He could hear, but he couldn’t see. His eyes had sustained multiple subconjunctival hemorrhages and the prevailing thought at the time was that he would never see again.

Happily, George Smith did recover almost fully from his supersonic ejection experience. He spent seven (7) months in the hospital and endured several operations. During that time, Smith’s weight dropped to 150 lbs. He was left with a permanently damaged liver to the extent that he could no longer drink alcohol. As for Smith’s vision, it returned to normal. However, his eyes were ever after somewhat glare-sensitive and slow to adapt to darkness.

Not only did George Smith return to good health, he also got back in the cockpit. First, he was cleared to fly low and slow prop-driven aircraft. Ultimately, he got back into jets, including the F-100A Super Sabre. Much was learned about how to markedly improve high speed ejection survivability in the aftermath of Smith’s supersonic nightmare. He in essence paid the price so that others would fare better in such circumstances as he endured.

It is possible that George Smith was not the first pilot to eject supersonically. USN LCdr Authur Ray Hawkins survived ejection from his stricken Grumman F9F-6 Cougar in 1953. Aircraft speed at ejection was never definitively determined, but was estimated to be between 688 (Mach 0.99) and 782 mph (Mach 1.16). In any event, the dynamic pressure and therefore the airloads associated with Hawkins ejection were less than half that of Smith’s punch-out.

George Smith was thirty-one (31) at the time of his F-100A mishap. He lived a happy and productive thirty-nine (39) more years after its occurrence. Smith passed from this earthly scene in 1994.

Posted in Aerospace, Final Flight, History

An Improbable Landing

Fifty years ago this month, a USAF F-106A Delta Dart (S/N 58-0787) out of Malmstrom AFB, Montana made a wheels-up landing in a farmer’s field despite the fact that there was no pilot onboard.  The pilot, Lieutenant Gary Foust, had ejected earlier when he was unable to recover the aircraft from a flat spin.  This incident became known in popular culture as “The Cornfield Bomber”.

On Monday, 02 February 1970, a trio of pilots from the 71st Fighter Interceptor Squadron (FIS) took-off from Malmstrom AFB, Montana for the purpose of practicing air combat maneuvers.  A fourth pilot had intended to be part of this group but was forced to abort the mission when his aircraft’s drag parachute strangely deployed on the ramp.

The pilots who took to the air that day were Major Thomas Curtis, Major James Lowe, and Faust.  Each man was at the controls of a Convair F-106A Delta Dart; aka “The Ultimate Interceptor”.   The three-ship formation departed Malmstrom for an area roughly 90 miles north of the base designated for the flying of air combat maneuvers and engagements.

The practice session began with a two-on-one head-on engagement.  Approaching the other two aircraft at Mach 1.90 in full afterburner, Captain Curtis pulled his aircraft into the vertical.  His intent was to induce the other pilots to follow him upstairs.  They did so.  In passing through 38,000 feet, he executed a vertical rolling scissors maneuver.  However, Curtis had superior energy at the pull-up point.   Thus, neither Lowe nor Foust could gain a tactical advantage in the fight.  When Curtis executed a high-g rudder reversal, Foust attempted to stay with him.  That’s when things deteriorated rapidly for Foust.

Foust flew his F-106A into an accelerated stall around 35,000 feet as he attempted to maintain position with Curtis.  That is, his aircraft exceeded the stall angle-of-attack while simultaneously losing speed due to the motion-retarding effects of gravity and drag due to lift.  The F-106A fell off into a series of post-stall gyrations followed by entry into a flat spin.  The flat spin is a high angle-of-attack, deep stall condition from whence recovery was typically not possible in a Delta Dart.

Notwithstanding the futility of the task, Foust diligently applied anti-spin procedures in textbook fashion.  However, the aircraft continued to fall in a flat spin.  In desperation, Foust deployed his drag chute hoping that it would act as an anti-spin device.  Unfortunately, the chute became totally useless for that purpose when it wrapped itself around the vertical tail of his falling steed.  Running out of altitude and time, Foust had no other recourse but to abandon his airplane.  He did so somewhere around 12,000 feet.

Foust was rocketed out of his Delta Dart and got a good chute.  He landed in the Bear Paw Mountains, and fortunately was brought to safety by local citizens on snowmobiles.  However, to the utter amazement of Foust, Curtis, and Lowe, the abandoned delta-winged aircraft snapped out of its flat spin and began to glide.  Apparently, the equal and opposite reaction of the aircraft to the force produced by the rocket-powered ejection seat forced the nose of the airplane below the stall angle-of-attack.  Thus, the wing began to produce lift again.  Further, as part of his anti-spin procedures, Foust had configured the controls of the Delta Dart in take-off trim and brought the throttle to idle.

The net state of affairs now was that the F-106A became a pretty good glider.  Gliding at about 175 knots, it ultimately made a wheels-up landing in a farmer’s snow-covered field near Big Sandy, Montana.  The landing was aided by ground effect which enhanced the lift on the airplane as the vehicle neared the ground.  Incredibly, the wings remained level throughout the landing slide-out.  Further, late in the landing, the F-106A magically turned 20 degrees from its touchdown azimuth and avoided running into a pile of rockets directly in its path.  In doing so, the airplane slipped through an opening in a fence around the farmer’s property and came to a stop.

When authorities approached the Delta Dart, they found that its canopy was gone, its ejection seat was gone, and so was its pilot.  A look into the cockpit revealed that the radar scope was still sweeping for targets.  And, although in idle, the still running turbojet produced a bit of thrust.  Thus, periodically, the vehicle would lurch forward when the restraining snow around the it melted.  Almost two hours later, the turbojet finally stopped running when the aircraft fuel supply ran out.

Remarkably, the pilotless Delta Dart sustained little damage despite the wheels-up landing.  The aircraft was later trucked out of the area and sent to McClellan AFB in California for repairs.  It ultimately was returned to service with the 71st FIS.  Later, it entered the inventory of the 49th Fighter Interceptor Squadron at Grifffiss AFB, New York.  Fittingly, a measure of closure was accorded (then) Major Gary Foust when he flew this same aircraft again in 1979.  Today, USAF F-106A Delta Dart, S/N 58-0787 sits on display for posterity at the USAF National Museum at Wright-Patterson AFB in Dayton, Ohio.

Posted in Aerospace, History

Final Flight: Apollo AS-204

Fifty-three years ago this month 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

Final Flight: STS-51L Challenger

Thirty-four years ago this month, the seven member crew of STS-51L perished when the Space Shuttle Challenger disintegrated 73 seconds after launch from LC-39B at Cape Canaveral, Florida. The tragedy was the first fatal in-flight mishap in the history of American manned spaceflight.

In remarks made at a memorial service held for the Challenger Seven in Houston, Texas on Friday, 31 January 1986, President Ronald Wilson Reagan expressed the following sentiments:

“The future is not free: the story of all human progress is one of a struggle against all odds. We learned again that this America, which Abraham Lincoln called the last, best hope of man on Earth, was built on heroism and noble sacrifice. It was built by men and women like our seven star voyagers, who answered a call beyond duty, who gave more than was expected or required and who gave it little thought of worldly reward.”

We take this opportunity to remember the noble fallen:

Francis R. (Dick) Scobee, Commander

Michael John Smith, Pilot

Ellison S. Onizuka, Mission Specialist One

Judith Arlene Resnik, Mission Specialist Two

Ronald Erwin McNair, Mission Specialist Three

S.Christa McAuliffe, Payload Specialist One

Gregory Bruce Jarvis, Payload Specialist Two

Speaking for grieving families and countrymen, President Reagan closed his eulogy with these words:

“Dick, Mike, Judy, El, Ron, Greg and Christa – your families and your country mourn your passing. We bid you goodbye. We will never forget you. For those who knew you well and loved you, the pain will be deep and enduring. A nation, too, will long feel the loss of her seven sons and daughters, her seven good friends. We can find consolation only in faith, for we know in our hearts that you who flew so high and so proud now make your home beyond the stars, safe in God’s promise of eternal life.”

Posted in Aerospace, Final Flight, History

Tall Tail Tale

Fifty-six years ago this week, a USAF/Boeing B-52H Stratofortress landed safely following structural 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 3-axis 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 speed brakes.

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 catastrophe 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

Upholding Honor

Seventy-one years ago this month, the USAF/Bell XS-1 became the first aircraft of any type to achieve supersonic flight during a climb from a ground take-off. The daring feat took place at Muroc Air Force Base with famed USAF Captain Charles E. “Chuck” Yeager at the controls of the rocket-powered 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 “mother ship” would take-off and climb to drop altitude using its own fuel load. This capability 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 mother ship. 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 Sky Streak and USN/Douglas D-558-II Sky Rocket. The Sky Streak was a turbojet-powered, straight-winged, transonic aircraft. The Sky Rocket was supersonic-capable, swept-winged, and rocket-powered. Each aircraft was originally designed to be ground-launched.

In the best tradition of inter-service rivalry, the Navy claimed that the D-558-I at the time was the only true supersonic airplane since it took to the air under its own power. Interestingly, the Sky Streak was able fly beyond Mach 1 only in a steep dive. Nonetheless, the Air Force was indignant at the Navy’s thinly-disguised insinuation that the XS-1 was somehow less of an X-aircraft because it was air-launched.

Motivated by the Navy’s affront 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 Sky Rocket. Justice would indeed be righteously served!

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 somewhat fragile landing gear, the XS-1 propellant load was restricted to 50% of capacity. This provided approximately 100 seconds of rocket-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 rapidly accelerated along the smooth surface of the dry lake. After a take-off roll of only 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 desert 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 continued to climb 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 power plant.

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.  At a deeper level, Air Force honor had been upheld.  And, as was often the case in the formative years of the United States Air Force, it was a test pilot named Chuck Yeager who brought victory home to the blue suiters.

Posted in Aerospace, History

Last Man

Forty-seven 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 47 years since the Commander of Apollo 17 spoke those stirring words from the valley of Taurus-Littrow.  Gene Cernan passed away  in January of 2017.  He and most space experts of his day figured we would surely have returned to the Moon by now.  Certainly in the 20th century.  Yet, there has been no return.  Thus, 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