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In the Beginning

One-hundred and six years ago this month, the Wright Flyer became the first aircraft in history to achieve powered flight.  The site of this historic event was Kill Devil Hills near Kitty Hawk, North Carolina.

Americans Wilbur and Orville Wright began their legendary aeronautical careers in 1899.  In just four short years, the brothers would go from complete aeronautical novices to inventors and pilots of the world’s first successful powered aircraft.  Interestingly, neither man attended college nor received even a high school diploma.

The Wright Flyer measured roughly 21 feet in length and had a wing span of approximately 40 feet.  The biplane aircraft had an empty weight of 605 lbs.  Power was provided by a single 12 horsepower, 4-cylinder engine that drove twin 8.5 foot , two-blade propellers. 

The Flyer made a powered take-off run along a 60-foot wooden guide rail.  The aircraft was mounted on a two-wheel dolly that rode along the track and was jettisoned at lift-off.   The Flyer pilot lay prone in the middle of the lower wing.  Twin elevator and rudder surfaces provided pitch and yaw control, respectively.  Roll control was via differential wing warping.   

The Wright Brothers had come close to achieving a successful powered flight with the Wright Flyer on Monday, 14 December 1903.  Wilbur, who had won the coin toss, was the pilot for the initial attempt.  However, the Flyer stalled and hit the ground sharply just after take-off.  Wilbur was unhurt, but repair of the damaged aircraft would take two days.

The next attempt flight took place on Thursday, 17 December 1903.  The weather was terrible.  Windy and rainy.  Even after the rain abated, the wind continued to blow in excess of 20 mph.  The Wrights decided to fly anyway.  It was now Orville’s turn as command pilot.

Orville took his position on the Flyer and was quickly launched into the wind.  Once airborne, the aircraft proved difficult to control as it porpoised up and down along the flight path.  Nonetheless, Orville kept the Flyer in the air for 12 seconds before landing 120 feet from the take-off point.  Other than a damaged skid, the aircraft was intact and the pilot unhurt.  Powered flight was a reality! 

Three more flights followed on that momentous occasion as the brothers alternated piloting assignments.  The fourth flight was the longest in both time aloft and distance flown.  With Wilbur at the controls, the Wright Flyer flew for 59 seconds and landed 852 feet from the take-off point.

The Wright Brothers father, Milton, would soon learn of the epic events that December day in North Carolina.  Orville’s verbatim Western Union telegram message sent to Dayton, Ohio read: 

Success   four flights  thursday morning   all against twenty one mile wind started from Level with engine power alone   average speed through air thirty one miles    longest 57 [sic] seconds    inform Press    home Christmas. 

Posted in Aerospace, History

Trouble in the Thin Air

Fifty-six years ago this month, USAF Major Charles E. Yeager set an unofficial world speed record of 1,650 mph (Mach 2.44) in the Bell X-1A flight research aircraft.  In the process, Yeager nearly lost his life.

The USAF/Bell X-1A was a second generation X-aircraft intended to explore flight beyond Mach 2.  It measured 35.5 feet in length and had a wing span of 28 feet.  Gross take-off weight was 16,500 pounds.

Like its XS-1 forebear, the X-1A was powered by an XLR-11 rocket motor which produced a maximum sea level thrust of 6,000 lbs.  The XLR-11 burned 9,200 pounds of propellants (alcohol and liquid oxygen) in roughly 270 seconds of operation.

Departing Edwards Air Force Base, California on Saturday, 12 December 1953, Yeager and the X-1A (S/N 48-1384) were carried to altitude by a USAF B-29 mothership (S/N 45-21800 ).  X-1A drop occurred at 240 knots and 30,500 feet.  Within ten seconds, Yeager lit off three of the XLR-11’s four rocket chambers and started to climb upstairs.

Yeager fired the 4th chamber of the XLR-11 passing through 43,000 feet and initiated a pushover at 62,000 feet.  The maneuver was completed at 76,000 feet; higher than planned.  In level flight now and traveling at Mach 1.9, the X-1A continued to accelerate in the thin air of the stratosphere.

Yeager quickly exceeded Scott Crossfield’s briefly-held Mach 2.005 record set on Friday, 20 November 1953.  However, he now had to be very careful.  Wind tunnel testing had revealed that the X-1A would be neutrally stable in the directional channel as it approached Mach 2.3.

As Yeager cut the throttle around Mach 2.44, the X-1A started an uncommanded roll to the left.  Yeager quickly countered with aileron and rudder.  The X-1A then rapidly rolled right.  Full aileron and opposite rudder failed to control the roll.  After 8 to 10 complete revolutions, the aircraft ceased rolling, but was now inverted. 

In an instant, the X-1A started rolling left and then went divergent in all three axes.  The aircraft tumbled and gyrated through the sky.  Control inputs had no effect.  Yeager was in serious trouble.  He could not control his aircraft and punching-out was not an option.   The X-1A had no ejection seat.

Chuck Yeager took a tremendous physical and emotional beating for more than 70 seconds as the X-1A wildly tumbled.  Normal acceleration varied between plus-8 and negative 1.3 G’s.  His helmet hit the canopy and cracked it.  He struck the control column so hard that it was physically bent.  His frantic air-to-ground communications were distinctly those of a man who was convinced that he was about to die.

As the X-1A tumbled, it decelerated and lost altitude.  At 33,000 feet, a battered and groggy Yeager found himself in an inverted spin.  The aircraft suddenly fell into a normal spin from which Yeager recovered at 25,000 feet over the Tehachapi Mountains situated northwest of Edwards.  Somehow, Yeager managed to get himself and the X-1A back home intact.

The culprit in Yeager’s wide ride was the then little-known phenomenon identified as roll inertial coupling.  That is, inertial moments produced by gyroscopic and centripetal accelerations overwhelmed aerodynamic control moments and thus caused the aircraft to depart controlled flight.  Roll rate was the critical mechanism since it coupled pitch and yaw motion.

The X-1A held the distiction of being the fastest-flying of the early X-aircraft until the Bell X-2 reached 1,900 mph (Mach 2.87) in July of 1956.  Yeager’s harrowing experience in December 1953 would be his last flight at the controls of a rocket-powered X-aircraft.  For his record-setting X-1A mission, he was awarded the 1953 Harmon Trophy.

Posted in Aerospace, History

Zoom Flight

Forty-six years ago this month, USAF Major Robert W. Smith zoomed the rocket-powered Lockheed NF-104A to an unofficial record altitude of 120,800 feet.  This mark still stands as the highest altitude ever achieved by a United States aircraft from a runway take-off.

A zoom maneuver is one in which aircraft kinetic energy (speed) is traded for potential energy (altitude).  In doing so, an aircraft can soar well beyond its maximum steady, level altitude (service ceiling).  The zoom maneuver has both military and civilian flight operations value.

The USAF/Lockheed NF-104A was designed to provide spaceflight-like training  experience for test pilots attending the Aerospace Research Pilot School (ARPS) at Edwards Air Force Base, California.  The type was a modification of the basic F-104A aircraft.  Three copies of the NF-104A were produced (S/N’s 56-0756, 56-0760 and 56-0762).  It was the ultimate zoom flight platform. 

In addition to a stock General Electric J79-GE-3 turbojet, the NF-104A was powered by a Rocketdyne LR121-NA-1 rocket motor.  The J79 generated 15,000 pounds of thrust in afterburner and burned JP-4.  The LR-121 produced 6,000 pounds of thrust and burned a combination of JP-4 and 90% hydrogen peroxide.  Rocket motor burn time was on the order of 90 seconds.

The NF-104A was kinematically capable of zooming to altitudes approaching 125,000 feet.  As such, it was a combined aircraft and spacecraft.  The pilot had to blend aerodynamic and reaction controls in the low dynamic pressure environment near the zoom apex.  He was also required to fly in a full pressure suit for survival at altitudes beyond the Armstrong Line.

On Friday, 06 December 1963, Bob Smith took-off from Edwards and headed west for the Pacific Ocean.  Out over the sea, he changed heading by 180 degrees in preparation for the zoom run-in.  At a point roughly 100 miles out, Smith then accelerated the NF-104A (S/N 56-0760) along a line that would take him just north of the base.  Arriving at Mach 2.4 and 37,000 feet, Smith then initiated a 3.75-g pull to a 70-degree aircraft pitch angle.  Turbojet and rocket were at full throttle.

Things happened very quickly now.  Smith brought the turbojet out of afterburner at 65,000 feet and then moved the throttle to the idle detent at 80,000 feet.  The rocket motor burned-out around 90,000 feet.  Smith controlled the aircraft (now spacecraft) over the top of the zoom using 3-axis reaction controls.  The NF-104A’s arcing parabolic trajectory subjected him to 73 seconds of weightlessness.  Peak altitude achieved was 120,800 feet above mean sea level. 

On the back side of the zoom profile, Bob Smith restarted the windmilling J79 turbojet and set-up for landing at Edwards.  He touched down on the main runway and rolled out uneventfully.  Total mission time from brake-release to wheels-stop was approximately 25 minutes.

Much more could be said about the NF-104A and its unique mission.  Suffice it to say here that two of the aircraft ultimately went on to serve in the ARPS from 1968 to 1971.  The only remaining aircraft today is 56-0760 which sits on a pole in front of the USAF Test Pilot School at Edwards.

Bob Smith went on to make many other noteworthy contributions to aviation and his nation.  Having flown the F-86 Sabre in Korea, he volunteered to fly combat in Viet Nam in his 40th year.   Stationed at Korat AFB in Thailand, he commanded the 34th Fighter Squadron of the 388th Tactical Fighter Wing.  Smith flew 100 combat missions in the F-105; many of which involved the infamous Pack VI route in North Viet Nam.

Bob Smith is a true American hero.  Like so many of the airmen of his day, Smith is a man whose dedication, service, and courage went largely unnoticed and unappreciated by his fellow countrymen.  However, for those who know the true character and heart of Bob Smith and those of his ilk, we offer this sincere, but clearly inadequate sentiment:  Thank You.

Posted in Aerospace, History

First South Pole Flight

Eighty years ago this month, a four-man crew became the first Antarctic explorers to fly over the Earth’s South Pole.  The aircraft used to make the historic flight was a Ford Trimotor.

While substantial exploration of the Artic and Antarctic by land and sea had occurred far earlier, exploration of these regions by air was in its infancy during the decade of the 1920’s.  Of particular focus was the goal to fly over both the North and South Poles.

The historic first flight to the South Pole originated from Little America, an exploration base camp situated on Antartica’s Ross Ice Shelf.  Distance to the South Pole was about 800 miles as the crow flies.

A Ford Trimotor aircraft, the Floyd Bennett (S/N NX4542), was selected for the epic polar air journey.  The crew consisted of pilot Bernt Balchen, co-pilot Harold June, navigator Richard E. Byrd, and radio operator Ashley McKinley.

The fabled Trimotor was well-suited for the rigors of polar flight.  The all-metal aircraft measured 50-feet in length and had a wing span of 76-feet.  Empty weight was roughly 6,500 pounds.  Power was provided by a single 520-HP Wright Cylone and a pair of 200-HP Wright Whirlwind radial engines.

Following departure from Little America at 02:39 UTC, the Floyd Bennett headed for the South Pole.  Navigation was via sun compass due to the proximity of the South Magnetic Pole. 

Myriad glaciers, massifs, plateaus, and crevasses marked the stark, rugged landscape unfolding under the Floyd Bennett’s flight path.  The most imposing of these geological features were the Queen Maud Mountains that towered more than 11,000 feet above sea level.

Pilot Balchen struggled to get his aircraft over the high mountain pass that runs between Mounts Fridtjof and Fisher.  The crew jettisoned empty fuel cans and hundreds of pounds of precious food to lighten the load.  The Floyd Bennett cleared the terrain by about 600 feet.

Just after 1200 UTC (local midnight) on Friday, 29 November 1929, the Floyd Bennett and its crew flew over the Earth’s South Pole.  After briefly loitering around the Pole, the aircraft headed back to Little America at 1225 UTC. 

According to plan, Balchen landed the airplane to take on 200 gallons of fuel that had been pre-positioned at the base of the Liv Glacier.  The Floyd Bennett took-off again and landed back at Little America around 21:10 UTC.  Total mission time was nearly 19 hours.

United States Navy Commander Richard E. Byrd now had flown over both poles.  He would go on to successfully explore the Antarctic for many more years.  For his part in the South Pole overflight, Byrd was promoted to the rank of Rear Admiral.

Today, the aircraft that made the first flight over the South Pole in November 1929 is displayed in the Heroes of the Sky exhibit at the Henry Ford Museum in Dearborn, Michigan.

Posted in Aerospace, History

Scramjet Flight Test History

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Five years ago today, the NASA X-43A scramjet-powered flight research vehicle reached a record speed of over 6,600 mph (Mach 9.68).  In doing so, the X-43A broke its own record speed of Mach 6.83 (4,600 mph) and became the fastest airbreathing aircraft of all time.

In 1996, NASA initiated a technology demonstration program known as HYPER-X.  The central 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.

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 close to 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 third and final flight of the HYPER-X program took place on Tuesday, 16 November 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 21:08 UTC.  The aircraft then headed for the Pacific Ocean launch point located just west of San Nicholas Island.

At 22:34:43 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 75 seconds to reach a speed of slightly over Mach 10.

Following rocket motor burnout and a brief coast period, the HXRV (X-43A) successfully separated from the Pegasus booster at 109,440 feet and Mach 9.74.  The HXRV scramjet was operative by Mach 9.68.  Supersonic combustion and thrust production were successfully achieved.  Total engine-on 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 850 nautical miles due west of its launch location.  Total flight time was approximately 15 minutes.

The HYPER-X Program was now history.  Supersonic combustion and thrust production of an airframe-integrated scramjet had indeed been 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 several Guinness World Records for its efforts.   

As a footnote to the X-43A story, the HYPER-X Flight 3 mission would also be the last for NASA’s fabled B-52B mothership.  The aircraft that launched many of the historic X-15, M2-F2, M2-F3, X- 24A, X-24B and HL-10 flight research missions, and all three HYPER-X flights, would take to the air no more.  In tribute, B-52B (S/N 52-0008) now occupies a place of honor at a point near the North Gate of Edwards Air Force Base.

Posted in Aerospace, History

Gemini’s Grand Finale

Gemini XII

Forty-three years ago this month, NASA’s pioneering spaceflight program, Project Gemini, was brought to a successful conclusion with the 4-day flight of Gemini XII.  Remarkably, the mission was the tenth Gemini flight in 20 months.

Boosted to Earth orbit by a two-stage Titan II launch vehicle, Gemini XII Command Pilot James A. Lovell, Jr. and Pilot Edwin E. “Buzz” Aldrin, Jr. lifted-off from Cape Canaveral’s LC-19 at 20:46:33 UTC on Friday, 11 November 1966.  The flight was Lovell’s second trip into space and Aldrin’s first.

Like almost every Gemini mission before it, Gemini XII was not a glitch-free spaceflight.  For instance, when the spacecraft’s rendezvous radar began acting oddly, the crew had to resort to sextant and chart to complete the last 65 nautical miles of the rendezvous with their Agena Target Vehicle.  But, overcoming this and other obstacles served to provide the experience and instill the confidence needed to meet the truly daunting challenge that lay ahead; landing on the Moon.

Unquestionably, Gemini XII’s single most important contribution to the United States manned space effort was validating the notion that a well-trained astronaut could indeed do useful work in an Extra-Vehicular Activity (EVA) environment.  The exhausting and even dangerous EVA experiences of Gene Cernan on Gemini IX and Dick Gordon on Gemini XI brought into sharp focus the challenge of performing even seemingly simple work assignments outside the Gemini spacecraft.

Buzz Aldrin performed a trio of EVA’s on Gemini XII.  Two of these involved standing in his seat with the hatch open.  The third involved a tethered EVA or space walk.  On the latter, Aldrin successfully moved about the exterior of the Gemini-Agena combination without exhausting himself.  He also used a special-purpose torque wrench to perform a number of important work tasks.  Central to Aldrin’s success was the use of foot restraints and auxiliary tethers to anchor his body while floating in a weightless state.

Where others had struggled and not been able to accomplish mission EVA goals, Buzz Aldrin came off conqueror.  One of the chief reasons for his success was effective pre-flight training.  A pivotal aspect of this training was to practice EVA tasks underwater as a unique means of simulating the effects of  weightlessness.  This approach was found to be so useful that it has been used ever since to train American EVA astronauts.

Lovell and Aldrin did many more things during their highly-compressed 4-day spaceflight  in November of 1966.  Multiple dockings with the Agena, Gemini spacecraft maneuvering, tethered stationkeeping exercises, fourteen scientific experiments, and photographing a total eclipse occupied their time aloft.

On Tuesday, 15 November 1966, on their 59th orbit, a tired, but triumphant Gemini XII crew returned to Earth.  The associated reentry flight profile was automated; that is, totally controlled by computer.  Yet another first and vital accomplishment for Project Gemini.  Splashdown was in the West Atlantic at 19:21:04 UTC.

While Gemini would fly no more, both Lovell and Aldrin certainly would.  In fact, both men would play prominent roles in several historic flights to the Moon.  Jim Lovell flew on Apollo 8 in December 1968 and Apollo 13 in April 1970.  And of course, Buzz Aldrin would walk on the Moon at Mare Tranquilitatis in July 1969 as the Lunar Module Pilot for Apollo 11.

Posted in Aerospace, History

Double Sonic First

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Fifty-six years ago this month, the USN/Douglas D-558-II Skyrocket became the first aircraft to fly at twice the speed of sound.  This historic event took place on Friday, 20 November 1953 at Edwards Air Force Base, California.

The D-558-II was a United States Navy (USN) X-aircraft and first flew in February of 1948.  It was contemporaneous with the USAF/Bell XS-1.  The aircraft measured 42 feet in length with a wing span of 25 feet.  Maximum take-off weight was 15,266 pounds.  Douglas manufactured a trio of D-558-II aircraft (Bureau No.’s 37973, 37974 and 37975).

The original version of the swept-wing D-558-II had both rocket and turbojet propulsion.  The latter system providing a ground take-off capability.  However, like other early X-aircraft such as the XS-1, X-1A, X-2 and X-15), the D-558-II achieved max performance through the use of a mothership and rocket power alone.

On that record-setting day in November 1953, the D-558-II (Bureau No. 37974) was carried to the drop altitude of 32,000 feet by a USN P2B-1S (Bureau No. 84029).  NACA test pilot A. Scott Crossfield was in the D-558-II cockpit.  Although ailing with the flu, Crossfield was not about to let a little urpiness force him to miss today’s events!

Following drop, Crossfield ignited the Reaction Motors LR8-RM-6 (USN designation for the XLR-11) rocket motor and started uphill.  After closely adhering to a carefully planned climb schedule, Crossfield initiated a pushover at 72,000 feet that resulted in a shallow dive.  Passing through 62,000 feet, the D-558-II hit 1,291 mph; Mach 2.005.

The D-558-II reached Mach 2 due to a confluence of several factors.  First, Crossfield flew the profile as briefed.  Second, temperatures at altitude that day were unusually low.  This lowered the speed of sound and thus increased Mach number.  Third, the ground crew did an extraordinary job of optimizing the D-558-II for the max speed mission.

Expanding on the last point mentioned above, extension tubes were  added to the LR8-RM-6 rocket motor.  This increased thrust from 6,000 to 9,000 pounds.  The aircraft was then cold-soaked overnight in an effort to maximize its propellant load.  Finally, external airframe gaps and panel openings were taped over and the aircraft was waxed and polished in an effort to minimize aerodynamic drag.

Scott Crossfield received the 1954 Lawrence B. Sperry Award for his Mach 2 exploits.  The record-setting aircraft (Bureau No. 37934) is currently displayed at the National Air and Space Museum in Washington, D.C. in tribute to its many contributions to aviation history.

Posted in Aerospace, History

Walker’s Wild Ride

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Fifty-five years ago this month, the USAF/Douglas X-3 Stiletto research aircraft exhibited a then little known dynamic instability mode during a flight test with NACA test pilot Joseph A. Walker at the controls.

The X-3 was designed to fly at speeds up to Mach 2.  The aircraft was approximately 67 feet in length and had a wing span on the order of 23 feet.  Gross weight was 23,840 pounds.

A pair of Westinghouse J46-WE-1 turbojets were intended to power the X-3.  However, protracted developmental problems and installation issues with these powerplants would eventually prevent their use in the aircraft. 

The X-3 was ultimately outfitted with a pair of Westinghouse J34-WE-17 turbojets.  The result was that the X-3 was now underpowered and could barely fly supersonically.  Maximum achieved Mach number was 1.21 and that was in a 30-deg dive!

Notwithstanding the above, the X-3 took to the air 54 times between October 1952 and May 1956 for the purpose of conducting transonic flight research.  It would be on its 43rd flight that the X-3 would make its most important contribution to aviation.

On Wednesday, 27 October 1954, Joe Walker took-off in the X-3 (S/N 49-2892) from Edwards Air Force Base, California.  At Mach 0.92 and 30,000 feet, Walker applied left aileron at fixed-rudder in an effort to develop a rapid roll response.  To Walker’s utter amazement, the X-3 went wild in both pitch and yaw.

Although it seemed to last much longer, Walker was able to recover control of the X-3 within 5 seconds of his initial left aileron input.  In true test pilot fashion, Walker again made an abrupt rudder-fixed left aileron input at Mach 1.05.  The same thing happened.  However, this time the aircraft’s motions were more violent.

Happily, Walker again recovered control of the X-3.  Having had enough of flight test frontiersmanship for one day, Walker uneventfully recovered the aircraft to Edwards.

The phenomenon that Joe Walker and the X-3 encountered that day in 1954 is known as Inertial Roll Coupling.  It is a resonant divergence in either pitch or yaw due to the presence of roll rate.  Aircraft like the X-3, which have low longitudinal and/or directional static stability as well as high pitch-to-roll and yaw-to-roll moment of inertia ratios, are especially susceptible to this phenomenon.

As a postscript to our story, the phenomenon of Inertial Roll Coupling had been hypothesized by the NACA’s William H. Phillips back in June of 1948.  For Joe Walker in October of 1954, engineering theory would become flight test fact in a few terrifying seconds high in the skies over Edwards Air Force Base.

Posted in Aerospace, History

Like a Phoenix Rising

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Forty-one years ago this month, NASA successfully conducted the first manned Apollo Earth-orbital mission with the flight of Apollo 7.  This mission was a critically-important milestone along the path to the first manned lunar landing in July 1969.

The launch of Apollo 7 took place from Launch Complex 34 at Cape Canaveral Air Force Station, Florida at 15:02:45 UTC on Friday, 11 October 1968.  The flight crew consisted of NASA astronauts Walter M. Schirra, Donn F. Eisele, and R. Walter Cunningham.  Their primary goal was to thoroughly qualify the new Apollo Block II Command Module (CM) during 11 days in space.

Apollo 7 was not only the first flight of the Block II CM, but in fact the first manned mission in the Apollo Program.  Apollo 7 also featured the first use of the Saturn IB launch vehicle in a manned mission.  Apollo 7’s critical nature stemmed from the tragic Apollo 1 fire that took the lives of Virgil I. (Gus) Grissom, Edward H. White II, and Roger B. Chaffee on Friday, 27 January 1967.

The Apollo 1 fire was attributed to numerous deficiencies in the design, construction, and testing of its Block I CM.  The Block II spacecraft flown on Apollo 7 was a major redesign of the Apollo Command Module and was in every sense superior to the Block I vehicle.    However, it had taken 21 months to return to flight status and the Nation’s goal of a manned lunar landing within the decade of the 1960’s was in serious jeopardy.

The Apollo 7 crew orbited the Earth 163 times at an orbital altitude that varied between 125 and 160 nautical miles.  In that time, they rigorously tested every aspect of their Block II CM.  This testing included 8 firings of the Service Propulsion System (SPS) while in orbit.  Apollo 7 splashdown occurred in the Atlantic Ocean near the Bermuda Islands at 11:11:48 UTC on Tuesday, 22 October 1968.  

The Nation’s Lunar Landing Program overwhelmingly got the unqualified success that it desperately needed from the Apollo 7 mission.  The Apollo Block II CM would provide yeoman service throughout the time of Apollo.  The spacecraft would also go on to see service in the Skylab and Apollo-Soyuz Test Project programs.

While the technical performance of the Apollo 7 crew was unquestionably superb, their interaction with Mission Control at Johnson Spacecraft Center (JSC) in Houston, Texas was quite strained.  The crew suffered from head colds through much of the mission and the food quality was poor.  Coupled with Houston’s incessant attempts to cramp more tasks into each moment of the mission, Apollo 7 Commander Schirra took control of his ship and made the ultimate decisions as to what work would be performed onboard the spacecraft. 

The flight of Apollo 7 would be Wally Schirra’s last mission in space as he had announced prior to flight.  Schirra holds the distinction of being the only astronaut to have flown Mercury, Gemini, and Apollo missions.

Interestingly, Apollo 7 was not only Schirra’s last time in space, but it was Donn Eisele’s and Walt Cunningham’s first and last space mission as well.  That there is a direct connection between this historical fact and the crew’s insubordinative behavior during Apollo 7 is obvious to the inquiring mind.

Posted in Aerospace, History

Sound Barrier Breakthrough

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Sixty-two years ago this month, the legendary USAF/Bell XS-1 experimental aircraft exceeded the speed of sound when it reached a maximum speed of 700 mph (Mach 1.06) at 45,000 feet.

Bell Aircraft Corporation of Buffalo, New York built three copies of the XS-1 under contract to the United States Army Air Forces (USAAF).  The aircraft were designed to approach and then fly beyond the speed of sound.

The Bell XS-1 was 31-feet in length and had a wing span of 28 feet.  Gross take-off weight was around 12,500 lbs.  The aircraft had an empty weight of about 7,000 lbs.  Propulsion was provided by a Reaction Motors XLR-11 rocket motor capable of generating a maximum thrust of 6,000 lbs.

On the morning of Tuesday, 14 October 1947, the XS-1 (S/N 46-062) dropped away from its B-29 mothership (S/N 45-21800 ) as the pair flew at 220 mph and 20,000 feet.  In the XS-1 cockpit was USAAF Captain and World War II ace Charles E. Yeager.  The young test pilot had named the aircraft Glamorous Glennis in honor of his wife.

Following drop, Yeager sequentially-lit all four XLR-11 rocket chambers during a climb and push-over that ultimately brought him to level flight around 45,000 feet.  The resulting acceleration profile propelled the XS-1 slightly beyond Mach 1 for about 20 seconds.  Yeager then shutdown the rocket, decelerated to subsonic speeds, and landed the XS-1 on Muroc Dry Lake at Muroc Army Airfield, California.

The world would not find out about the daring exploits of 14 October 1947 until December of the same  year.  As it was, the announcement came from a trade magazine that even today is sometimes referred to as “Aviation Leak”.

Today, Glamorous Glennis is prominently displayed in the Milestones of Flight hall of the National Air and Space Museum located in Washington, DC.  For his efforts in breaking the sound barrier, Chuck Yeager was a co-recipient of the 1948 Collier Trophy.

Posted in Aerospace, History
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