The iconic SR-71 was used by NASA to undertake a series of experiments. To carry out some of these testing activities the Blackbird was installed an interesting pod.
According to official records, NASA has operated a fleet of seven Blackbirds:
YF-12A (60-6935) – December 1969 to November 1979
YF-12A (60-6936) – March 1970 to June 1971
SR-71A/YF-12C (61-7951/“06937”) – July 1971 to December 1978
SR-71A (61-7971/NASA 832) – January 1995 to June 1996
SR-71A (61-7967) – August 1995 to January 1996
SR-71B (61-7956/NASA 831) – July 1991 to October 1997
SR-71A (61-7980/NASA 844) – September 1992 to October 1999
The last SR-71 flight was made on Oct. 9, 1999, at the Edwards AFB air show. The aircraft used was NASA 844 that flew to 80,100 feet and Mach 3.21 in the very last flight of any Blackbird. Actually, the aircraft was also scheduled to make a flight the following day, but a fuel leak grounded the aircraft and prevented it from flying again. The NASA SR-71s were then put in flyable storage, where they remained until 2002. Then, they were sent to museums.
Throughout their career at NASA, Blackbirds have served as test beds for a series of high-speed and high-altitude research programs:
“As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas — aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization,” says NASA Dryden’s Blackbird website.
“The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the “peak” overpressures of sonic booms and minimize the startling affect they produce on the ground.”
This close-up, head-on view of NASA’s SR-71A Blackbird in flight shows the aircraft with an experimental test fixture mounted on the back of the airplane. (1999 NASA /Photo Jim Ross)
Among the major experiments flown with the NASA SR-71s, there was a laser air data collection system that used laser light, instead of air pressure measured by pitot tubes and vanes extending into the airstream, to determine airspeed, angle of attack, vertical speed, and other attitude reference data.
Another project involved a Dryden’s SR-71 as a platform to film with an ultraviolet video camera, celestial objects in wavelenghts that are blocked to ground-based astronomers. Moreover, the SR-71 was also a testbed in the development of Motorola’s IRIDIUM commercial satellite-based, instant wireless personal communications network, acting as a surrogate satellite for transmitters and receivers on the ground.
Between 1997 and 1998, one NASA Blackbird was used for the Linear Aerospike Rocket Engine, or LASRE Experiment, whose goal was to provide data to validate the computational predictive tools used to foresee the aerodynamic performance of future single-stage-to-orbit reusable launch vehicles (SSTO RLVs).
SR-71 #844 taking off for a LASRE experiment. (NASA)
As part of the LASRE experiment, the Blackbird completed seven initial research flights from Edwards. The first two flights were used to determine the aerodynamic characteristics of the LASRE apparatus (pod) on the back of the SR-71 whereas five later flights focused on the experiment itself.
The LASRE experiment itself was a 20-percent-scale, half-span model of a lifting body shape (X-33) without the fins. It was rotated 90 degrees and equipped with eight thrust cells of an aerospike engine and was mounted on a housing known as the “canoe,” which contained the gaseous hydrogen, helium, and instrumentation gear. The model, engine, and canoe together were called a “pod.” The experiment focused on determining how a reusable launch vehicle’s engine flume would affect the aerodynamics of its lifting-body shape at specific altitudes and speeds. The interaction of the aerodynamic flow with the engine plume could create drag; design refinements looked at minimizing this interaction. The entire pod was 41 feet in length and weighed 14,300 pounds.
Two test flights were used to cycle gaseous helium and liquid nitrogen through the experiment to check its plumbing system for leaks and to test engine operational characteristics. During the other three flights, liquid oxygen was cycled through the engine. Two engine hot-firings were also completed on the ground. A final hot-fire test flight was canceled because of liquid oxygen leaks in the test apparatus.
The experimental pod was mounted on NASA’s SR-71 #844. Lockheed Martin may use the information gained from the LASRE and X-33 Advanced Technology Demonstrator Projects to develop a potential future reusable launch vehicle.
This is a rear/side view of the Linear Aerospike SR Experiment (LASRE) pod on NASA SR-71, tail number 844. This photo was taken during the fit-check of the pod on Feb. 15, 1996, at Lockheed Martin Skunkworks in Palmdale, California. (NASA)
NASA and Lockheed Martin were partners in the X-33 program through a cooperative agreement but the program was cancelled in 2001.
A rendering of the X-33 concept (NASA)
Throughout its career, the high-altitude SR-71s, involved in test flights as well as operative missions, have probably contributed to fuel UFO (Unidentified Flying Object) conspiracy theories. For instance, according to CIA high-altitude testing of the then new and secret U-2 led to an increase in reports of UFOs:
“According to later estimates from CIA officials who worked on the U-2 project and the OXCART (SR-71, or Blackbird) project, over half of all UFO reports from the late 1950s through the 1960s were accounted for by manned reconnaissance flights (namely the U-2) over the United States. This led the Air Force to make misleading and deceptive statements to the public in order to allay public fears and to protect an extraordinarily sensitive national security project. While perhaps justified, this deception added fuel to the later conspiracy theories and the coverup controversy of the 1970s. The percentage of what the Air Force considered unexplained UFO sightings fell to 5.9 percent in 1955 and to 4 percent in 1956.”
Flash forward to 2017, we can’t but notice that, among the theories surrounding the footage of an unidentified flying object (UFO) filmed by an F/A-18F Super Hornet in 2004, there is also the one that the weird “capsule-shaped” object might have been some sort of secret aerial vehicle during a test mission rather than an alien spacecraft…. And it would not be the first time.
The composite photo gives a pretty good idea of how the cockpit of supersonic heavy bombers has evolved in about 50 years.
With a planned cruise speed of Mach 3 and operating altitude of 70,000 feet, the B-70 Valyrie was to be the ultimate high-altitude, high-speed, deep-penetration manned strategic bomber designed in the 1950s. The 6-engine aircraft was expected to be immune to Soviet interceptor aircraft thanks to its stunning performance.
“To achieve Mach 3 performance, the B-70 was designed to “ride” its own shock wave, much as a surfer rides an ocean wave. The resulting shape used a delta wing on a slab-sided fuselage that contained the six jet engines that powered the aircraft. The outer wing panels were hinged. During take off, landing, and subsonic flight, they remained in the horizontal position. This feature increased the amount of lift produced, improving the lift-to-drag ratio. Once the aircraft was supersonic, the wing panels would be hinged downward. Changing the position of the wing panels reduced the drag caused by the wingtips interacted with the inlet shock wave. The repositioned wingtips also reduced the area behind the airplane’s center of gravity, which reduced trim drag. The downturned outer panels also provided more vertical surface to improve directional stability at high Mach numbers. Attached to the delta was a long, thin forward fuselage. Behind the cockpit were two large canards, which acted as control surfaces.”
The aircraft was still under development awhen the future of the manned bomber became uncertain. Indeed, during the late 1950s and early 1960s, many believed that manned bombers had become obsolete, and the future wars would be fought by missiles. As a result, the Kennedy Administration ended plans to deploy the B-70 and the two XB-70 prototypes were under construction when the program was cancelled.
However, two experimental XB-70A prototypes were eventually built at North American Aviation and used by NASA test beds for an American supersonic transport (SST). NASA records show that XB-70A number 1 (62-001) made its first flight from Palmdale to Edwards Air Force Base, CA, on Sept. 21, 1964. Tests of the XB-70’s airworthiness occurred throughout 1964 and 1965 by North American and Air Force test pilots. The Flight Research Center prepared its instrument package.
“Although intended to cruise at Mach 3, the first XB-70 was found to have poor directional stability above Mach 2.5, and only made a single flight above Mach 3. Despite the problems, the early flights provided data on a number of issues facing SST designers. These included aircraft noise, operational problems, control system design, comparison of wind tunnel predictions with actual flight data, and high-altitude, clear-air turbulence.”
The second XB-70A (62-207) was built with an added 5 degrees of dihedral on the wings as suggested by the NASA Ames Research Center, Moffett Field, CA, wind-tunnel studies. This aircraft made its first flight on Jul. 17, 1965. “The changes resulted in much better handling, and the second XB-70 achieved Mach 3 for the first time on Jan. 3, 1966. The aircraft made a total of nine Mach 3 flights by June.
This photo shows the XB-70A parked on a ramp at Edwards Air Force Base in 1967. Originally designed as a Mach 3 bomber, the XB-70A never went into production and instead was used for flight research involving the Air Force and NASA’s Flight Research Center (FRC), which was a predecessor of today’s NASA Dryden Flight Research Center. The aircraft’s shadow indicates its unusual planform. This featured two canards behind the cockpit, followed by a large, triangular delta wing. The outboard portions of the wing were hinged so they could be folded down for improved high-speed stability. The XB-70 was the world’s largest experimental aircraft. It was capable of flight at speeds of three times the speed of sound (roughly 2,000 miles per hour) at altitudes of 70,000 feet. It was used to collect in-flight information for use in the design of future supersonic aircraft, military and civilian. Designed by North American Aviation (later North American Rockwell and still later, a division of Boeing) the XB-70 had a long fuselage with a canard or horizontal stabilizer mounted just behind the crew compartment. It had a sharply swept 65.6-percent delta wing. The outer portion of the wing could be folded down in flight to provide greater lateral-directional stability. The airplane had two windshields. A moveable outer windshield was raised for high-speed flight to reduce drag and lowered for greater visibility during takeoff and landing. The forward fuselage was constructed of riveted titanium frames and skin. The remainder of the airplane was constructed almost entirely of stainless steel. The skin was a brazed stainless-steel honeycomb material. Six General Electric YJ93-3 turbojet engines, each in the 30,000-pound-thrust class, powered the XB-70. Internal geometry of the inlets was controllable to maintain the most efficient airflow to the engines.
A joint agreement signed between NASA and the Air Force planned to use the second XB-70A prototype for high-speed research flights in support of the SST program. However, the plans went awry on June 8, 1966, when the second XB-70 collided with a civilian registered F-104N while flying in formation as part of a General Electric company publicity photo shoot outside the Edwards Air Force Base test range in the Mojave Desert, California, that involved an XB-70, a T-38 Talon, an F-4B Phantom II, an F-104N Starfighter and a YF-5A Freedom Fighter.
Toward the end of the photo shooting NASA registered F-104N Starfighter, piloted by famous test pilot Joe Walker, got too close to the right wing of the XB-70, collided, sheared off the twin vertical stabilizers of the big XB-70 and exploded as it cartwheeled behind the Valkyrie.
North American test pilot Al White ejected from the XB-70 in his escape capsule, but received serious injuries in the process. Co-pilot Maj. Carl Cross, who was making his first flight in the XB-70, was unable to eject and died in the crash.
Research activities continued with the first XB-70.
The first NASA XB-70 flight occurred on April 25, 1967, the last one was on Feb. 4, 1969 when the aircraft made a subsonic structural dynamics test and ferry flight from Edwards AFB to Wright-Patterson Air Force Base, OH, where the aircraft was put on display at the Air Force Museum after 83 test flights and 160 hours and 16 minutes, flight time. Indeed, despite research activity helped measuring its “structural response to turbulence; determine the aircraft’s handling qualities during landings; and investigate boundary layer noise, inlet performance, and structural dynamics, including fuselage bending and canard flight loads”, time had run out for the research program. NASA had reached an agreement with the Air Force to fly research missions with a pair of YF-12As and a “YF-12C,” which was actually an SR-71, that represented a far more advanced technology than that of the XB-70. Indeed, in all, the two XB-70Bs logged 1 hour and 48 minutes of Mach 3 flight time during their career, whilst a YF-12 could log this much Mach 3 time in a single flight.
Although the XB-70 program was cancelled, data collected during the Valkyrie test flights were used in other programs, including the B-1 bomber and the Soviet Tupolev Tu-144 SST program (via espionage).
This is a close-up photo of an XB-70A taken from a chase plane. The XB-70 had a movable windshield and ramp. These were raised during supersonic flight to reduce drag. When the pilot was ready to land, he lowered the assembly to give both him and his copilot a clear view of the runway. The XB-70 was the world’s largest experimental aircraft. It was capable of flight at speeds of three times the speed of sound (roughly 2,000 miles per hour) at altitudes of 70,000 feet. It was used to collect in-flight information for use in the design of future supersonic aircraft, military and civilian.
We have recently found an interesting photo of the XB-70 #1 cockpit. The photo (courtesy of NASA) shows the complexity of the mid-1960s research aircraft especially if compared to a modern B-1 Lancer with the Integrated Battle Station upgrade.
ED97-44244-1 Photo of the XB-70 #1 cockpit, which shows the complexity of this mid-1960s research aircraft. 1965 NASA
Here’s the official description of the cockpit:
On the left and right sides of the picture are the pilot’s and co-pilot’s control yokes. Forward of these, on the cockpit floor, are the rudder pedals with the NAA North American Aviation trademark. Between them is the center console. Visible are the six throttles for the XB-70’s jet engines. Above this is the center instrument panel. The bottom panel has the wing tip fold, landing gear, and flap controls, as well as the hydraulic pressure gages. In the center are three rows of engine gages. The top row are tachometers, the second are exhaust temperature gages, and the bottom row are exhaust nozzle position indicators. Above these are the engine fire and engine brake switches.
The instrument panels for the pilot left and co-pilot right differ somewhat. Both crewmen have an airspeed/Mach indicator, and altitude/vertical velocity indicator, an artificial horizon, and a heading indicator/compass directly in front of them.
The pilot’s flight instruments, from top to bottom, are total heat gage and crew warning lights; stand-by flight instruments side-slip, artificial horizon, and altitude; the engine vibration indicators; cabin altitude, ammonia, and water quantity gages, the electronic compartment air temperature gage, and the liquid oxygen quantity gage. At the bottom are the switches for the flight displays and environmental controls.
On the co-pilot’s panel, the top three rows are for the engine inlet controls. Below this is the fuel tank sequence indicator, which shows the amount of fuel in each tank. The bottom row consists of the fuel pump switches, which were used to shift fuel to maintain the proper center of gravity. Just to the right are the indicators for the total fuel top and the individual tanks bottom. Visible on the right edge of the photo are the refueling valves, while above these are switches for the flight data recording instruments.
Here below you can find a photo of the B-1 cockpit with the Integrated Battle Station upgrade which, beginning in 2014, gave the “Bone” new screens and updated avionics in both the cockpit and battle stations.
The IBS upgrade increased the situational awareness of the pilots by means of a Fully Integrated Data Link (FIDL), a Vertical Situation Display Upgrade (VSDU), and a Central Integrated System (CITS) upgrade.
Within the VSDU two unsupportable, monochrome pilot and co-pilot displays were replaced by four multifunctional color displays, that provide the pilots more situational awareness data, in a user-friendly format. The FIDL is a modern data link that allows the B-1 to interconnect and communicate in real-time, with other planes, ground stations, allied units. The CITS is an upgrade of the old LED display computers used by ground maintainers to identify and troubleshoot system failures.
If you click on the image you will find a cockpit with two control sticks, dominated by a mix of displays and moving maps (typical of glass cockpits) as well as analogue instruments: a hybrid cockpit, with common instruments such altimeter, ADI (Attitude Indicator) and Airspeed Indicator/Machmeter on the left hand side; flaps, slats and spoiler controls as well as TFR (Terrain Following Radar), fuel and engine instruments in the central part of the flight deck; and two large VSDUs that can be arranged at will to display the required information/digitized instrument, such as a moving map or a HSI (Horizontal Situation Indicator), on both sides.
Aerodynamic heating at Mach 6.72 (4,534 mph) almost melted the airframe.
On Oct. 3 1967 the North American X-15A-2 serial number 56-6671 hypersonic rocket-powered research aircraft achieved a maximum Mach 6.72 piloted by Major Pete Knight.
Operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft in the 1960s, the X-15 was a missile-shaped vehicle built in 3 examples and powered by the XLR-99 rocket engine capable of 57,000 lb of thrust.
The aircraft featured an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage.
The X-15 was brought to the launch altitude of 45,000 feet by a NASA NB-52B “mothership” then air dropped to that the rocket plane would have enough fuel to reach its high speed and altitude test points. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing.
As the X-15 was falling from the B-52 he lit the engine and locked on to 12 degrees angle of attack. He was pushed back into his seat with 1.5 g’s longitudinal acceleration. The X-15 rounded the corner and started its climb.
During the rotation as normal acceleration built up to 2 g’s Pete had to hold in considerable right deflection of the side arm controller to keep the X-15 from rolling to the left due to the heavier LOX in the left external tank. When the aircraft reached the planned pitch angle of 35 degrees his scan pattern switched from the angle of attack gauge to the attitude direction indicator and a vernier index that was set to the precise climb angle.
The climb continued as the fuel was consumed from the external tanks, then at about 60 seconds he reached the tank jettison conditions of about Mach 2 and 70,000 feet. He pushed over to low angle of attack and ejected the tanks. He was now on his way and would not be making an emergency landing at Mud Lake.
“We shut down at 6500 (fps), and I took careful note to see what the final got to. It went to 6600 maximum on the indicator. As I told Johnny before, the longest time period is going to be from zero h dot getting down to 100 to 200 feet per second starting down hill after shutdown.”
Final post flight data recorded an official max Mach number of 6.72 equivalent to a speed of 4534 miles per hour.
From there down Pete was very busy with the planned data maneuvers and managing the energy of the gliding X-15. He approached Edwards higher on energy than planned and had to keep the speed brakes out to decelerate.
On final approach he pushed the dummy ramjet eject button and landed on Rogers lakebed runway 18. He indicated he did not feel anything when he activated the ramjet eject and the ground crew reported they did not see it. Pete said that he knew something was not right when the recovery crew did not come to the cockpit area to help him out of the cockpit, but went directly to the back of the airplane.
Finally when he did get out and saw the damage to the tail of the X-15 he understood. There were large holes in the skin of the sides of the fin with evidence of melting and skin rollback. Now we are talking Inconel-X steel that melts at 2200 degrees F. Later analysis would show that the shock wave from the leading edge of the ramjet’s spike nose had intersected the fin and caused the aerodynamic heating to increase seven times higher than normal. So now maybe we knew why the ramjet was not there.
X-15-2 after the record flight (#189) on Oct. 3, 1967. The aircraft achieved the record without any NASA marking. The aircraft was painted in white that covered an ablative material that protected the fuselage. The Martin Marietta’s MA-25S ablative would erode slowly shedding the heat of aerodynamic friction. Pink in color, the ablative the MA-25S ablative reacted when exposed to liquid oxygen burned by its XLR-99 rocket engine. For this reason it was sealed under white paint. More details here.
The following 48-sec footage shows the extent of the damages to the X-15-2 aircraft. Noteworthy, the ramjet detached from the aircraft at over 90,000 feet and crashed into the desert over 100 miles from Edwards Air Force Base.
Here are some details.
Wing leading edge burns.
Reaction Control System thrusters.
Two holes appeared on the fuselage along with burns.
The nose of the aircraft shows ablative damages as well as a result of frictional heating.
The X-15A-2 never flew again after the record flight. It is currently preserved and displayed at the United States Air Force Museum, Wright-Patterson AFB, Ohio.
The top image shows the damage to one of the two ventral UHF antennas of the X-15.
U.S. Air Force test pilot Maj. Michael J. Adams was killed during X-15 Flight 191 on Nov. 15, 1967.
The North American X-15 was a hypersonic rocket-powered aircraft 50 ft long with a wingspan of 22 ft. operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft in the 1960s.
It was a missile-shaped vehicle with an unusual wedge-shaped vertical tail, thin stubby wings, and unique side fairings that extended along the side of the fuselage. It was powered by the XLR-99 rocket engine, manufactured by Thiokol Chemical Corp., pilot-controlled and capable of developing 57,000 lb of thrust.
The aircraft was brought to the launch altitude of 45,000 feet by a NASA B-52 “mothership” then air dropped to that the rocket plane would have enough fuel to reach its high speed and altitude test points. Depending on the mission, the rocket engine provided thrust for the first 80 to 120 sec of flight. The remainder of the normal 10 to 11 min. flight was powerless and ended with a 200-mph glide landing.
The X-15 was air dropped by a NASA B-52 “mothership”
The X-15 was capable of climbing to the edge of space at an altitude in excess of 300,000 feet at speed of more than 4,500 miles per hour (+7,270 km/h). Actually, the target altitude for X-15 flights was set at 360,000 feet because there were concerns about the reentry from 400,000 feet, that was the maximum altitude the rocket plane was theoretically able to reach.
Two types of flight profiles were used during test flights depending on the purposes of the mission: a high-altitude flight plan that called for the pilot to maintain a steep rate of climb, or a speed profile that called for the pilot to push over and maintain a level altitude.
For flight in the dense air of the usable atmosphere, the X-15 used conventional aerodynamic controls but to maneuver in the thin air outside of the appreciable Earth’s atmosphere, where flight control surfaces were useless, the X-15 used a reaction control system (RCS) made of hydrogen peroxide thrust rockets. Those located on the nose of the aircraft provided pitch and yaw control; those on the wings provided roll control. A similar system was used on the Space Shuttle Orbiter, decades later: indeed, experience and data gathered from the X-15 program contributed to the development of the Mercury, Gemini, Apollo and Space Shuttle manned spaceflight programs.
Cutaway drawing of the North American X-15. 1/20/62
Needless to say, handling the rocket-powered aircraft at the edge of space was particularly challenging.
X-15-3 (56-6672) made 65 flights during the program. It reached attaining a top speed of Mach 5.65 and a maximum altitude of 354,200 feet.
Official records say that only 10 of the 12 X-15 pilots flew Ship #3; eight of them earned their astronaut wings during the program (in fact, U.S. Air Force pilots who flew the X-15 to altitudes above 50 miles all received Astronaut Wings): Robert White, Joseph Walker, Robert Rushworth, John “Jack” McKay, Joseph Engle, William “Pete” Knight, William Dana, and Michael Adams all earned their astronaut wings in Ship #3.
Out of three X-15s built by North American for the program, Ship #3 is the only X-15 that has not survived, as it was lost on Nov. 15, 1967.
X-15-1, serial number 56-6670, is now located at the National Air and Space museum, Washington DC. North American X-15A-2, serial number 56-6671, is at the United States Air Force Museum, Wright-Patterson AFB, Ohio.
On 15 November 1967, Ship #3 was launched over Delamar Lake, Nevada with Maj. Michael J. Adams at the controls. The vehicle soon reached a speed of Mach 5.2, and a peak altitude of 266,000 feet.
During the climb, an electrical disturbance degraded the aircraft’s controllability. Ship #3 began a slow drift in heading, which soon became a spin. Adams radioed that the X-15 “seems squirrelly” and then said “I’m in a spin.”
Through some combination of pilot technique and basic aerodynamic stability, Adams recovered from the spin and entered an inverted Mach 4.7 dive. As the X-15 plummeted into the increasingly thicker atmosphere, the Honeywell adaptive flight control system caused the vehicle to begin oscillating. As the pitching motion increased, aerodynamic forces finally broke the aircraft into several major pieces.
Adams was killed when the forward fuselage impacted the desert. This was the only fatal accident during the entire X-15 program. The canopy from Ship #3, recovered during the original search in 1967, is displayed at the San Diego Aerospace Museum, San Diego, California.
Parts of the crashed X-15-3, serial number 56-6672, recovered in 1992 by Peter Merlin and Tony Moore (The X-Hunters) are on display at the Air Force Flight Test Center Museum at Edwards.
According to NASA, the X-15s made a total of 199 flights over a period of nearly 10 years (from June 1959 to Oct. 1968) and set world’s unofficial speed and altitude records of 4,520 miles per hour or Mach 6.7 (set by Ship #2) and 354,200 feet (set by Ship #3).
NASA is about to launch two retrofitted WB-57F aircraft to follow the shadow of the moon. The last of a long series of interesting missions…
NASA still operates three WB-57Fs, configured for air sampling and the other for photography, radar and thermal recce. The first two, NASA926 and 928 have been flying research missions since the early ’60s, whereas NASA927 is a more recent addition to the fleet, having joined NASA Johnson Space Center (JSC) in Houston, Texas, in 2013.
Based at Ellington Field, Texas, they are often deployed to different bases, both at home and abroad; to undertake missions in support of scientific projects (focusing on hurricanes, radiation impact on clouds, atmospheric data gathering, tropical storm generation analysis, and so on).
For instance, on Aug. 21, 2017, the total solar eclipse that for most of the observers will last less than two and half minutes, for one team of NASA-funded scientists, will last over seven minutes. Indeed, the eclipse will be chased by two retrofitted WB-57F jet planes: NASA926 and NASA927.
According to NASA, Amir Caspi of the Southwest Research Institute in Boulder, Colorado, and his team will use two of NASA’s WB-57F research jets to observe the eclipse from twin telescopes mounted on the noses of the planes in order to capture the clearest images of the Sun’s outer atmosphere — the corona — to date and the first-ever thermal images of Mercury, revealing how temperature varies across the planet’s surface.
The two aircraft have filled a FPL to follow the route below:
The FPL of NASA 927 (the same filed by NASA 926): a 4h 30m trip across the U.S. (credit: FlightAware.com)
This is the route that will be followed by NASA 926 and NASA 927 to chase the total solar eclipse. (credit: FlightAware).
“Due to technological limitations, no one has yet directly seen nanoflares, but the high-resolution and high-speed images to be taken from the WB-57F jets might reveal their effects on the corona. The high-definition pictures, captured 30 times per second, will be analyzed for wave motion in the corona to see if waves move towards or away from the surface of the Sun, and with what strengths and sizes,” says an official NASA release.
“The two planes, launching from Ellington Field near NASA’s Johnson Space Center in Houston will observe the total eclipse for about three and a half minutes each as they fly over Missouri, Illinois and Tennessee. By flying high in the stratosphere, observations taken with onboard telescopes will avoid looking through the majority of Earth’s atmosphere, greatly improving image quality. At the planes’ cruising altitude of 50,000 feet, the sky is 20-30 times darker than as seen from the ground, and there is much less atmospheric turbulence, allowing fine structures and motions in the Sun’s corona to be visible.
Images of the Sun will primarily be captured at visible light wavelengths, specifically the green light given off by highly ionized iron, superheated by the corona. This light is best for showing the fine structures in the Sun’s outer atmosphere. These images are complementary to space-based telescopes, like NASA’s Solar Dynamics Observatory, which takes images primarily in ultraviolet light and does not have the capacity for the high-speed imagery that can be captured aboard the WB-57F.”
Scientific research aside, NASA’s Canberras are also involved in some “special operations” every now and then.
For instance, in 2007 there were speculations and theories about the type of mission flown by the WB-57 in war zones fueled by pictures of the aircraft operating from Kandahar airfield in Afghanistan without the standard NASA logo and markings. Officially, the aircraft performed geophysical and remote sensing surveys as part of the U.S. aid to the Afghan reconstruction effort. The WB-57 collected AVIRIS (Airborne Visible Infra Red Imaging Spectrometer) data that could be analyzed to provide information on mineral assemblages that could aid in resource and hazards assessments.
Surely, with up to 6,000-lb payload carried and a pallet system under the main fuselage area, this aircraft can fulfil a wide variety of special data gathering missions,.
