Tag Archives: Edwards Air Force Base

That Time the Luftwaffe Experimented with a Rocket-Launched F-104G Starfighter

“Zero Length Launch” Was Tested in Germany on an F-104G. Here’s the Video.

Almost every aviation enthusiast has probably seen the famous June 1957 test videos of a North American F-100 Super Saber being launched from a portable trailer using a large rocket booster.

The origin of “Zero Length Launch”, often called “ZeLL”, was the perceived necessity that aircraft would need to be boosted into flight after available airfields and runways in Europe were destroyed in a nuclear attack. Using motor vehicle highways as improvised runways, often practiced by NATO and former Warsaw Pact air forces, may not have worked as well since the aircraft would be more vulnerable to air attack. With the Zero Length Launch concept, aircraft could actually be boosted into flight using a disposable rocket booster from inside a hardened aircraft shelter, presuming no one else like hapless ground crew were inside the shelter at the time of launch.

“ZeLL” was an interesting, if ultimately impractical, concept. It could be argued that the “ZeLL” concept somehow validated the need for V/STOL (Vertical/Short Take Off and Landing) aircraft such as the Harrier and, decades later, even the F-35B Lightning II.

What many aviation history buffs don’t know is that the German Air Force, the Luftwaffe, experimented with a Zero Launch System on their F-104 Starfighters. The concept made more sense with the F-104 Starfighter, an aircraft conceived almost purely as an interceptor.

Rocketing the F-104 into flight as a sort of “manned missile”, the interceptor would rapidly climb to altitude and engage an approaching bomber formation. The Starfighter was a suitable candidate for ZeLL launch operations since it began setting altitude records as early as May, 1958, when USAF test pilot Major Howard C. “Scrappy” Johnson zoom-climbed to an astonishing altitude Record of 27,811m (91,243 feet, or 17.2 miles high) from a conventional take-off.

Interestingly, Germany had tested a rocket-powered, vertical launch interceptor during WWII called the “Bachem Ba-349 Natter”. The aircraft would be fired from a launch tower, fly to the allied bomber formations using rocket boosters and engage them with unguided high velocity aircraft rockets (HVARs) mounted in the nose. If all went according to design, the aircraft and pilot would then recover to earth using separate parachutes. The concept did not do well for the Germans in WWII, with the only manned test flight ending in disaster and the death of Luftwaffe test pilot Lothar Sieber.

Apparently undaunted by their WWII experiences with the Ba-349, the modern Luftwaffe working in collaboration with the U.S. Air Force, used a single F-104G Starfighter to test the ZeLL concept in 1963. Oddly enough, the German F-104G version of the Starfighter was a multi-role aircraft evolved from the original pure interceptor design mandate of the F-104.

Unlike its early, distant predecessor the Ba-349, the Luftwaffe F-104G Starfighter ZeLL launch tests went well. Lockheed company test pilot Eldon “Ed” W. Brown Jr. remarked after the first of eight ZeLL take-offs at Edwards AFB in California during 1963 that, “All I did was push the rocket booster button and sit back. The plane was on its own for the first few seconds and then I took over. I was surprised at the smoothness, even smoother than a steam catapult launch from an aircraft carrier.”

Lockheed company test pilot Eldon “Ed” W. Brown Jr. flew the initial Luftwaffe F-104G ZeLL tests at Edwards AFB. (Photo: Lockheed)

The first Luftwaffe F-104G used in the ZeLL test program wore a distinctive and sensational looking test paint scheme, one of many beautiful and unusual liveries the F-104 Starfighter wore in its career. The first launch aircraft was coded “DA-102” and was natural aluminum metal on the bottom of the aircraft with a brilliant high visibility orange horizontal and vertical stripe and a bright white upper surface except for the nose, which had a flat-black anti-glare panel. It also wore the modern Luftwaffe insignia crosses, making it appear all the more remarkable.

The ZeLL F-104G was moved to Germany for a total of seven ZeLL test launches at Lechfeld AB between May 4, until Jul. 12, 1966, when the program was abandoned. The German ZeLL flights were flown after the test aircraft was repainted in a more operational German camouflage scheme. The aircraft would end its career as a static display.

The Soviets tinkered with their own version of ZeLL on a MiG-19 beginning as early as 1955, but the idea died in the test phase for most of the same reasons the NATO interest in ZeLL waned.

If nothing else, ZeLL was a sensational and adventurous idea. The results were remarkable to see, confirmed by the tens of thousands of video views of the ZeLL tests using the U.S. F-100 Super Sabre today on YouTube. But the German F-104G ZeLL tests have, somewhat oddly, received far less attention. Until today.

The Luftwaffe F-104G ZeLL test aircraft was eventually turned into a static display with its unique German camouflage livery. (Photo: German Air Force)

Check Out These Stunning Aerial Photos Of The B-2 Doing The Rose Parade And Rose Bowl Flyovers

This year, the B-2 was escorted by two F-35s from Edwards AFB during the Rose Parade flyover.

On January 1, 2018, a B-2 Spirit belonging to the 509th Bomb Wing from Whiteman Air Force Base, Missouri, performed the traditional Rose Parade flyover. Noteworthy, two F-35 Lightning IIs from the 31st Test and Evaluation Squadron on Edwards Air Force Base joined this year the B-2 during the flyover at the beginning of the annual Tournament of Roses Parade and once again, Mark Holtzman, a California native with over 25 years of experience as both a photographer and pilot, founder of West Coast Aerial Photography, a company specialising in aerial photography based in Los Angeles, was airborne to take some jaw-dropping air-to-air images showing the Stealth Bomber and the F-35s from above.

The B-2 and two F-35s perform the Rose Parade flyover (Photo: Mark Holtzman)

Then, the B-2 opened the 104th Rose Bowl Game at the Rose Bowl stadium in Pasadena.

The 104th Rose Bowl Game is a semifinal for the College Football Playoff (CFP), matching two of the top four teams to compete for a spot at the 2018 College Football Playoff National Championship game. The 2018 Rose Bowl Game pit The University of Georgia Bulldogs against The University of Oklahoma Sooners.

[By the way, you can buy prints of the photos here].

Take time to visit Mark’s galleries at www.markholtzman.com to find other fantastic images of the past flyovers: indeed, Mark has been able to take some fantastic shots of the Rose Bowl flyovers from a plane: here are 2011 Rose Bowl flyover performed by U.S. Navy F/A-18s out of Lemoore; here’s 2009 Rose Bowl flyover by another B-2; here you can see the 2016 flyover and here’s the one from last year.

Image credit: Mark Holtzman

This Image Shows The Complexity Of The XB-70 Valkyrie mid-1960s Research Aircraft Cockpit Compared To That Of An Upgraded B-1 Bomber

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.

According to NASA:

“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.

Old-style monochrome displays that didn’t provide much processing nor display capabilities, were replaced by much larger color displays that can show significantly more information thus improving the situational awareness. With the IBS upgrade, data can be shown on any display of the aircraft with collaboration tools that enable the aircraft’s crew “to look at each other’s displays with a ghost cursor, so if one weapons system officer wants to see what someone else is looking at, he can see a ghost cursor over on his own display – this allows the crew to collaborate and ensures they’re all looking at the same thing,” said Dan Ruder, B-1 strategic development and advanced programs manager for Boeing, in a story published on Military Embedded Systems.

The cockpit of the B-1 with IBS upgrade. (Image credit: U.S. Air Force)

So, the instrument panel layout has remained more or less the same. The way information is displayed has significantly changed.

 

Two Edwards-based F-16s Spotted In Star Wars Canyon With Mysterious New Pod

Are you able to ID the pod carried by these two “Vipers” flying at low altitude through the Jedi Transition recently?

Few days ago we have published the photographs of an Area 51-based F-16D (86-0052) flying through the famous Star Wars canyon on Nov. 14 carrying a Lockheed Martin’s AN/AAS-42, an IRST (Infra Red Search and Track) pod carried by various aircraft (including the Aggressors’ Vipers out of Nellis Air Force Base). Two things made the sighting particularly interesting: first of all, the two-seater “Viper” (as the F-16 is dubbed in the fighter pilots community) flew in the Jedi Transition hours after another F-16D (or possibly the very same one) had chased an F-117 near Rachel, Nevada. Second, the photographs of the F-16D 86-0052 clearly proved that both pilots of the aircraft wore a Red Hats patch (for more details I suggest you reading our story here).

However, some other interesting aircraft had flown over the Death Valley few days earlier.

The images in this post were taken by photographer Neil Dunridge taken on Nov. 8. They show two Edwards Air Force Base F-16 jets belonging to the 412th Test Wing, with a pretty interesting loadout: both aircraft carried one blue AN/ALQ-167, a very well-known electronic countermeasures threat simulation pod used by several aircraft (including aggressors) for training purposes, along with an unidentified grey with a black nose pod.

AF85-1560/ED with the AN/ALQ-167 pod under the left wing and the “mysterious” pod under the right one (All images credit: Neil Dunridge)

Noteworthy, as the photographs by Dunridge show, the configuration of the two aircraft is different: one (AF85-1560/ED) carried the AN/ALQ-167 pod under the left wing and the “mysterious” pod under the right one; the other one had the unidentified pod on the left and the AN/ALQ-167 on the right.

Two aircraft flew through the Jedi Transition on Nov. 8. This one had the unidentified pod under the left wing.

We haven’t been able to ID the new pod so far so, at least to us, it remains mysterious. It features a small air intake and a black dielectric blister fairing (that must be there to cover an antenna) reminds some data links pod (such as the AN/ASW-55 associated with the AGM-142 Popeye long-range missile).

Actually, the F-16 is already integrated with Lockheed Martin Legion Pod, that includes an IRST21 sensor as well as datalink to build up a “networked” battlespace where the aircraft can share a common “picture” without even turning the radar on (thus remaining “silent” from an electromagnetical point of view).

The pod shown in the photos from Neil Dunridge is quite different from the LM Legion Pod that includes IRST and data-link capabilities. (Image: Lockheed Martin).

The Legion Pod flew with the F-16 in Fort Worth, Texas, in June 2015. The aircraft carries the pod on the right hand side of the air intake (Photo by Randy Crites/LM)

Is Edwards testing some new DLP? Maybe. Or the pod can be something completely different (such a test bed for laser weapons, EW pod, etc.). If you can identify the pod, let us know. Meanwhile we can’t but notice how the Star Wars canyon continues to provide some great opportunities to see and shoot rarely seen aircraft with rarely seen payloads!

Update: it looks like the same pod, carried by an Edwards F-16, was spotted before Nov. 8. Here you can find a photo of the pod under the left wing on Oct. 29, 2017: https://www.flickr.com/photos/habujet/37946803206/in/photostream/

Update II: Our friend Tyler Rogoway from The War Zone has found what indeed seems to be the very same pod carried by a VAQ-34 EA-7L in a photo dating back to 1987!!

Here it is:

A view of two Vought EA-7L Corsair II aircraft of electronic warfare squadron VAQ-34 on the ramp during the U.S. 3rd Fleet North Pacific Exercise (NORPACEX) at Elmendorf Air Force Base, Alaska (USA) on 8 Nov 1987. VAQ-34 operated as a adversary squadron, hence the Soviet star and the red numbers on the planes. (Camera Operator: Sgt. W. Thornton via Wiki)

Indeed, in the early 1980s, eight U.S. Navy TA-7C two-seater Corsair jets were turned into electronic aggressor aircraft, under the designation EA-7L. These “electronic Corsairs”, operated by VAQ-34 out of NAS (Naval Air Station) Point Mugu, California, could carry electronic jamming pods on their underwing pylons to simulate Soviet weapons and tactics. Now, it looks like some of the pods used 30 years ago are being used again to test some new (EW/threat emitter) sensor using an existing form factor.

A big thank you to Neil Dunridge for allowing us to use his photographs. Make sure to follow him on Twitter here: @Chiv63

B-52 At Edwards AFB Sports Nose Art That Commemorates Its Past As “Mothership” In Top Secret D-21 Drone Test Program

A B-52 from the 419th Flight Test Squadron was given a new nose art to commemorate the Buff’s involvement in a top-secret test program.

An interesting image has been released by Edwards Air Force Base 412th Test Wing Public Affairs. It shows B-52 #60-0036 with a new nose art completed by renowned aviation artist Mike Machat to celebrate the involvement of the bomber in the top-secret test program named “Tagboard” about 50 years ago.

All manned flights over the Soviet Union had been discontinued by President Dwight Eisenhower after Francis Gary Powers’ U-2 spy plane was shot down May 1, 1960. Since satellites were still years away from being able to gather the required intelligence, the Central Intelligence Agency determined unmanned drones could fill the gap until satellites became viable.

Tagboard program involved testing the D-21, a ramjet-powered reconnaissance drone that could reach Mach 3 speed. In fact, the D-21 required a mothership that could air-launch the drone at a certain speed so that the ramjet could activate.

In the beginning, an M-21 (essentially a modified SR-71 Blackbird) was used to air launch the D-21 drone from its back. The idea was that, after conducting its intended spy mission, the drone would eject a hatch with photo equipment to be recovered either mid-air (by a JC-130B, as it was lowered by a parachute) or after the hatch landed.

M-21 carrying D-21 in flight (Credit: CIA)

However, as the official release recalls, “on the fourth flight test, the D-21 experienced an “asymmetric unstart” as it passed through the bow wake of the M-21 causing the mothership to pitch up and collide with the D-21 at Mach 3.25. Crewmembers Bill Park and Ray Torick ejected from the M-21, but Torick’s flight suit became ripped and filled with water when he plunged into the ocean where he drowned.”

A video of the incident, filmed by an accompanying Blackbird can be found here.

After the accident, the M-21 launch program was cancelled and Lockheed Martin decided to launch the drone from B-52Hs, one being #0036. The new code name for the D-21 project became Senior Bowl.

A D-21 reconnaissance drone is on display at Blackbird Air Park at U.S. Air Force Plant 42 in Palmdale, California. The D-21 was a ramjet-powered reconnaissance drone that could reach Mach 3 speed. Ideally, the drone would air launch from a mothership and after conducting its reconnaissance mission it would eject a hatch with photo equipment to be recovered either mid-air or after the hatch landed. (Courtesy photo by Danny Bazzell/Flight Test Historical Foundation)

“After several failed launch attempts, the first successful D-21 launch from a B-52 occurred June 16, 1968. The drone flew 3,000 miles at 90,000 feet. After a few more flight tests, the CIA and the Air Force decided to conduct four operational launches that all ended in failure in some way. Two flights were successful, however the imagery could not be recovered from the D-21’s hatch. The other two operational flights ended with one being lost in a heavily defended area and the other D-21 simply disappeared after launch.”

The D-21 program was cancelled July 15, 1971, and both B-52s used for the program were returned to operational Air Force units.

The B-52 #60-0036 is currently assigned to the 419th FLTS at Edwards, where it arrived in 2001; it has been used as a test bed ever since.

A B-52 currently used for testing by the 419th Flight Test Squadron, sits on the flightline at Edwards Air Force Base Oct. 16. The bomber, tail# 60-0036, was used in a top secret test program that began with the code name Tagboard. The program involved testing the D-21, which was a ramjet-powered reconnaissance drone that could reach Mach 3 speed. The D-21 would be launched from underneath the wings of the bomber. (U.S. Air Force photo by Kenji Thuloweit)

Considered the type of tests conducted at Mach 3 with the M-21 or the B-52 and D-21 drone some 50 years ago, one may guess: what is being secretely tested today?