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Setting the Standard

Ten years ago this month, a United States Navy STANDARD Missile SM-3 Block IA interceptor engaged and destroyed a defunct NRO satellite at an altitude of 133 nautical miles. The relative velocity at intercept was in excess of 22,000 mph.

The United States Navy/Raytheon Missile Systems SM-3 (RIM-161) is the sea-based arm of the Missile Defense Agency’s Ballistic Missile Defense System (BMDS). The 3-stage missile carries a Kinetic Warhead (KW) that provides an exoatmospheric hit-to-kill capability.

In order to ensure a lethal hit, the SM-3 KW guides to a specific aimpoint on the target’s airframe. The ability to reliably do so has been impressively demonstrated in a series of intercept flight tests that began in 2002.

SM-3 rounds are launched from the MK-41 Vertical Launcher System (VLS) aboard United States Navy cruisers and destroyers. The at-sea basing concept provides for a high degree of operational flexibility in the ballistic missile intercept mission.

The Lockheed Martin-built USA-193 was launched on a classified mission from California’s Vandenberg Air Force Base (VAFB) at 2100 UTC on Thursday, 14 December 2006. However, shortly after reaching orbit, contact with the 5,000-lb defense satellite was lost.

By January 2008, USA-193′s orbit had decayed to such an extent that its reentry back into the earth’s atmosphere appeared imminent. Such events raise concerns for the safety of those on Earth who reside within the debris impact footprint. However, there was an additional concern in the case of USA-193. The satellite still had about 1,000-lbs of hydrazine propellant onboard.

Should the USA-193 hydrazine tank survive reentry, those living in the impact area would be exposed to a highly toxic cloud of the volatile substance. Officials concluded that the safest thing to do was to destroy the satellite before it reentered the atmosphere.

On Thursday, 21 February 2008, the USS Lake Erie was on station in the Pacific Ocean somewhere west of Hawaii. The US Navy cruiser fired a single SM-3 interceptor at 0326 UTC. Minutes later, the missile’s KW took out the satellite and dispersed its hydrazine load into space. Mission accomplished!

In the aftermath of the satellite take-down, Russia and others predictably accused the United States of using the USA-193 hydrazine issue as an excuse to demonstrate SM-3′s anti-satellite capability. While such capability was indeed demonstrated, noteworthy is the fact that all systems modified to execute the satellite intercept were subsequently returned to a ballistic missile defense posture.

Posted in Aerospace, History

Friendship Seven

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

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

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

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

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

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

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

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

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

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

Posted in Aerospace, History

Convair XP-81 Debut

Seventy-three years ago this month, the Consolidated Vultee XP-81 made its flight test debut at Muroc Army Air Field, California with Vultee test pilot Frank Davis in the cockpit. The XP-81 was a prototype long range escort fighter powered by a combination of single turbojet and single turboprop engines.

The XP-81 was designed to serve as an escort fighter for long range bomber aircraft. Its mission was to defend bomber formations from attack by enemy fighters. To fly and fight, an escort fighter had to match the range and endurance capabilities of the much larger bombers it was assigned to protect.

The US military wanted an escort fighter with an operating range of 1,250 miles and a maximum speed of 500 mph. Consolidated Vultee Aircraft (Convair) chose a bi-mode propulsion system to meet these requirements. The idea was to combine the excellent fuel economy of a turboprop with the high-speed capability of a turbojet. The turboprop was intended for cruise while use of the turbojet was reserved for takeoff and high speed flight.

The XP-51 was a big airplane by fighter standards. It measured almost 45 feet in length and had a wing span of 50.5 feet. Gross take-off and empty weights were 19,500 and 12,755 lbs, respectively. The type’s predicted range was estimated to be 2,500 miles at 275 mph and 25,000 feet. Service ceiling was rated at 35,500 feet.

Convair constructed a pair of XP-81 aircraft. Ship No. 1 (S/N 44-91000) and Ship No. 2 (S/N 44-91001) were completed in 1945 and transported to Muroc Army Air Field for flight testing. Ship No. 1 made the type’s first flight on Wednesday, 07 February 1945 with Vultee test pilot Frank Davis at the controls. With the exception of somewhat marginal directional stability, Davis found the test aircraft’s handling characteristics to be quite good.

Testing of the XP-81 prototypes consisted of just 10 hours in the air. While the aircraft showed decent promise, the entire program was cancelled in May of 1947. With Victory in Europe (VE) having occurred in May of 1945 and Victory in Japan (VJ) in August of 1945, the need for a long range escort fighter simply went away.

Following program cancellation, the XP-81 aircraft served for a season as photo targets on the Bombing Range at Edwards Air Force Base. Eventually they were rescued from that inglorious state and sent to storage at the National Museum of the United States Air Force in Dayton, Ohio.

Posted in Aerospace, History

Supersonic Bailout

Sixty-three years ago this month, 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 uncommanded 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 airstream 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 airstream, 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, History
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