The Evolution Of Stealth Technology

On January 17 1991 at 2:30 a.m. the opening attack of Operation Desert Storm was set in motion tasked with crippling Iraq's commander control ship-borne tomahawk and b-52 launch agm-86 cruise missiles were employed to infiltrate targets within Baghdad alongside this initial inrush of deep striking assets was a new class of weapon this attack was the first public debut of a stealth aircraft facing off against one of the largest air defense networks in the region the iconic Lockheed f-117 nighthawk the first stealth strike platform were among the first sorties to enter the heavily defended airspace of Baghdad supported by standoff electronic jamming ef-111 aircraft and possessing no radar guns missiles or defensive countermeasures it relied entirely upon its ability to remain hidden from radar to penetrate Baghdad drop its two laser-guided 2,000 pound bombs and egress with impunity the success of these initial strikes coupled with the punching of a hole in Iraq's early warning air defenses by Apache attack helicopters paved the way for a massive bombing effort over the next 24 hours composed of over 2,600 sorties targeting command and control bunkers missile launch pads equipment storage areas communication facilities and airfields that night the need for stealth was proven cementing itself into the list of must-haves capabilities of any new aircraft program but where did this peculiar classified aircraft emerge from and what technologies made it so stealthy it all started in the 1960s with a Soviet physicist and his undervalued equations [Music] in order to understand how stealth technology emerged we need to quantify what stealth is stealth isn't one specific technology but rather a mantra of design that incorporates low observability the ability to detect an aircraft can range from simple visual and acoustical detection to more sophisticated means such as emitted radiation detection and tracking by infrared and radar a fall the potential threats faced by combat aircraft detection and tracking by radar pose the most risk radar infrared and optical detection all rely on the bouncing of electromagnetic radiation off an object in order to gather information from it however radar differs in that the source of the reflected radiation is actively emitted from the observer with passive methods of detection the targets own emissions or ambient light are used radar relies on beaming radiation out into a volume of space and analyzing the resulting reflected energy to detect and track aside from the source of the radiation the wavelength of the radiation differs between detection methods visible light has a wavelength range of 380 nanometers for violet light down to 700 nanometers for red light infrared light occupies the wavelength range below that between 700 nanometers and 1 millimeter below this is the realm of radar the region of the spectrum known as microwaves and then radio ranging from one millimeter all the way to 3 metres while detecting an aircraft provides a warning in order to defend against it it must be tracked tracking is the determining of a targets position velocity and heading from a reflected signal attract aircraft is in effect targetable by missiles and anti-aircraft artillery smaller wavelengths allow for more resolvable detail making tracking easier but this is compromised by range as a general rule the smaller the wavelength the higher the atmospheric absorption and attenuation of the wave while some air defense weapons can track optically infrared tracking is the predominant method for closed air-defense due to its ability to see the heat of an aircraft through the atmosphere infrared tracking works by using an infrared sensor similar to a camera to look for the highly contrasting signature of hot jet exhaust gases and the warm aircraft body against the ambient air temperature because of atmospheric absorption infrared radiation can only be used for tracking at short distances typically 20 miles or less infrared homing weapons are usually found on short-range anti-aromatic in contrast the longer wavelengths of radar detection and tracking are what makes it so powerful its ability to penetrate the atmosphere at much further ranges the first military use of radar began around the start of World War two one of the more notable uses was in the air defense of England by 1939 a chain of radar stations protected the east and south coasts providing early warning to incoming aircraft this early radar operated on the longer wavelengths of radio and offered very course information on incoming contacts that same year a breakthrough in research resulted in the invention of the resonant cavity magnetron this allowed for the generation of shorter wavelength microwave radiation at large amounts of power more details can now be assessed about the targets such as it's heading altitude and velocity practical tracking radar was now possible fast-forward to today and most military airborne radars including those found and radar based anti-air missiles operate in the 5 centimeter to one centimeter wavelength microwave range as it provides a good compromise between range resolution and antenna sizing at these wavelengths tracks at distances of about 50 to 80 miles are possible it should be noted that wavelengths from 5 centimeters to 30 centimeters are also used on ground-based early warning radars that can track targets up to 250 miles away with a proper radar track a firing solution can be determined with only evasion electronic jamming and the dispensing of radar cloudy known as chaff offering any form of Defense because missiles are effectively guided Rockets they have limited amounts of energy available to them to maneuver if the target can deplete this energy before it is within that nation range or obstruct the missiles ability to maintain a radar track the missile can be defeated this is known as going defensive in air combat the goal of radar stealth is to both mask and aircraft from being detected tracked and fired upon from a distance this is known as beyond visual range engagement as distances close radar based engagement may transition into infrared based targeting either a low to the ground or among adversarial aircraft within a dogfight while the radar energy from air defenses can be detected infrared homing missiles are particularly hazardous to combat aircraft because they offer no warning of being tracked the only indicator of an infrared homing missile launch is through a visual identification though newer fighters such as the f-35 employ external sensors that attempt to detect launches defending against infrared missiles involve a combination of evasive maneuvers and deploying flares designed to mimic jet exhaust distracting the missiles seeker however due to the use of sophisticated signal processing in modern heat-seeking missiles the efficacy of infrared countermeasures are reduced because the reflective behavior for a dar isn't as intuitively obvious as optical properties early attempts at stealth were based on observations of radar on existing designs it was discovered early on that the shape of an aircraft determined its visibility to radar its radar cross section or RCS for example the 1960s era British bomber the Avro Vulcan was observed to have a peculiarly small radar cross-section despite its large size whereas the similarly sized Russian tupolev 95 long-range bomber had an extremely prominent radar cross-section other observations pointed towards the internal construction of the airframe certain configurations of internal structure can trap radiation causing reflections between internal faces until the energy dissipates this pseudo technique was implemented on both the a12 and the sr-71 while these observations pointed designs in the right direction for truly effective stealth a better understanding of radar diffraction was needed the first steps to overcoming this technological hurdle occurred in 1964 that year Soviet mathematician and physicist Peter Youth himself published a paper titled method of edge wave in the physical theory of the fraction in the Journal of the Moscow Institute for radio engineering extending theoretical work published by the German physicist Arnold Sommerfeld defensives paper demonstrated the first major breakthrough in the understanding of radar wave behavior you femme self conclusion was that the strength of the radar returned from an object is related to its edge configuration not its size his paper also demonstrated the ability to calculate the radar cross-section across a wing surface and along its edge the implications of this discovery was that even a large aircraft could reduce its radar signature by exploiting these principles astoundingly the Soviet administration considered his work to have no significant military or economic value allowing it to be published internationally during that time period Lockheed's elite skunkworks design team was working on a stealth proof-of-concept demonstrator called half blue the engineering team struggled with predicting stealthiness as the program they created to analyze radar cross-sections called echo one failed to produce accurate results denis Overholser a stealth engineer on the project had read you FEM says paper realizing that he had created the mathematical theory and tools to do a finite analysis of radar reflection offensive work was incorporated into echo 1 allowing for more refined and accurate results despite the objection of skunk works director kelly johnson the faceted design was chosen due to its predicted effectiveness the iconic early stealth look was a direct byproduct of the computational limits of computers of the time which limited echo one's ability to perform calculations on curved surfaces wooden mock-ups covered in metal foil were constructed and subsequently tested for radar cross-section confirming Ecco wants predictions its stealthiness was attributed to its difficult to construct faceted body jagged edges use of a wing sweep angle of 72 and 1/2 degrees and inward canted vertical tails known as an edge aligned planned form the matching set of angles of the overall shape work together to reduce radar cross-section this worked by reflecting and dispersing radar energy away from its source making it difficult to detect and track in addition simultaneously developed radar absorbent material was applied to the aircraft's flat surfaces special coatings were also applied to the windscreen giving them metallic characteristics to reduce its infrared signature non circular tailpipes were used to minimize the exhaust cross-sectional volume and maximize the mixing of hot exhaust gases with cool ambient air it was also made subsonic to prevent detection by sonic boom it was discovered that rotating components of a jet engine increases radar observability immensely to counter this the engine inlets were mounted on top of the wings with the engine Inlet being covered by a low radar cross-section group during takeoff top mounted Inlet doors would open to allow more air flow because stealth was of the highest priority the shape of the aircraft made it inherently unstable a quadruple redundant fly-by-wire control system barred from the f-16 was integrated into the aircraft to give it normal flying characteristics despite the loss of both demonstrator aircraft the aerodynamics and combat usability of the design was further refined the aircraft was scaled up in size larger engines were installed and two internal weapons bays were added the f-117 nighthawk was born from these changes reaching fully operational status in 1983 it was deployed in the 1989 u.s. invasion of Panama but its capabilities were truly put to the test and Operation Desert Storm because the f-117 diverted radar energy away from its source it was still possible to detect it using passive receivers located at different angles from the radar source additionally its shape was so critical to its stealth that opening the weapon bay doors and not retracting antennas on the surface of the aircraft would significantly increase its radar cross-section because of this operational tactics played a large part of the stealth equation missions were designed around avoiding known vulnerabilities this reliance on tactics to mask its flaws would prove disastrous on March 27th 1999 during the NATO bombing campaign of Yugoslavia during sorties f-117 would routinely perform checks of weapon bay doors as they ingress to their targets because opening the weapon bay doors would increase the radar cross-section momentarily this was noted by Yugoslavia and army air defense operators with this knowledge anti-aircraft missile batteries were place at advantageous positions and their radars configured to use longer wavelengths than the f-117 were designed for the combination of these factors allowed for the successful detection and subsequent shooting down of one of the stealth aircraft because the aircraft crashed mostly intact the event was a blow to the u.s. stealth advantage as the wreckage was reportedly sent to both Russia and China for reverse engineering by 2008 the f-117 was eventually retired due to its aging design costly upkeep and being superseded by newer generation of stealth aircraft as the have blue program progressed Northrop began working on a technical demonstrator of its own known as tacit blue tacit blue attempted to demonstrate a series of then advanced technologies including forms of stealth that employed curved surfaces and the use of less radar reflective composite materials during the late 1970s due to the success of the have blue and tacit blue programs momentum was building for the development of a deep penetrating stealth bomber by 1979 the highly secretive advanced tactical bomber program was started under the codename of Aurora with the recent development of more advanced supercomputers superseding what was available during echo ones development more complex radar cross-section calculations could be performed allowing for the design and analysis of blended curved shapes Northrop would eventually win out as the best design choice with their flying wing design with no protruding vertical surfaces the flying wing design forms a near-perfect Stealth shape offering no angles to reflect radar with an added benefit to this design is the inherently small visual silhouette of the airframe creating visual stealth as well adding to this the majority of the aircraft was made of radar absorbing carbon graphite composites with parts being covered in radar absorbing materials internal structures of the airframe are also designed to trap radiation similar to the f-117 the engines were buried deep within the frame hiding highly reflective rotating engine opponents to reduce its infrared signature the engines are mounted above the wings masking the exhaust additionally cool air is injected into the exhaust flow further reducing its heat signature circulating cool fuel is also used to cool exhaust sections of the aircraft as well as leading surfaces of the aircraft that are heated by air friction additives are also dispensed into the exhaust stream in certain conditions to eliminate contrails designated as the b-2 spirit this flying wing design also offered efficient aerodynamics giving it a range of 6,000 miles however with no vertical surfaces it requires fly-by-wire computer control to maintain stability the b2 became fully operational in 1997 with its combat debut occurring in 1999 during the Kosovo war its stealth an incredible range has allowed the b2 to take part in some of the longest bombing missions ever during Operation Enduring Freedom with some exceeding 70 hours of flight time spanning the planet to this day it remains the stealthiest aircraft ever produced while the f-117 was designated as a fighter both it and the b2 were exclusively penetrating bombers with no air-to-air capability this narrow use of stuff technology would soon change during the early 1980s the Air Force would put forward a request for a new generation of air superiority aircraft with stealth being a priority on the list of requirements unlike a bomber the demands of a fighter aircraft are more intensive they require speed maneuverability and powerful radar and sensor packages these requirements all compete against stealth within a fighter design because of these compromises stealth implementation and a fighter isn't about complete stealth but rather being the first to detect and fire on a target the f-22 was designed to be fast and extremely agile in air-to-air combat utilizing powerful supersonic capable thrust vectoring engines and traditional control surfaces it carried over low radar cross-section design cues from previous stealth programs utilizing edge shape refinements a coated canopy buried engines with masked Inlet design composite construction radar absorbent materials and internal weapons base low radar cross-section was given a higher priority at angles in which it would face off against other aircraft hindering easy detection and missile tracking in addition its stealth surfaces were designed to evade the smaller wavelength radar used by other aircraft it also relied less on radar absorbent material due to their higher maintenance requirements tactically the f-22 makes use of sensor fusion linking battlespace data from other aircraft and non emitting sensors to avoid giving away its own position by radar emission overlapping with the f-22 program work started on the f-35 stealth fighter in 1992 design cues and technology from the f-22 made its way to the f-35 similar techniques were employed for reducing radar cross-sections notable differences are the use of stealthier tines instead of leading-edge extensions for enhanced maneuverability a engine Inlet that masks rotating components and the use of more durable radar absorbing materials similar to the f-22 more focus was given to the radar wavelengths used by other aircraft and missiles with the success and dominance of the u.s. stealth program the technology has worked its way into other applications the canceled Comanche rah-66 reconnaissance helicopter for example was an attempt to employ stealth on a rotary wing aircraft other examples include naval programs such as the sea shadow and the USS Zumwalt with unmanned aviation becoming the next frontier of combat aviation stealth technology is also being incorporated into the next generation of unmanned air combat vehicles as seen by the Grumman x-47b with heavy air defense research being funneled into the tection of stealth aircraft and the emergence of competing stealth platforms on the world stage the constant battle to stay one step ahead of detection will always be coupled to combat aviation you [Music]

Channel: New Mind

Views: 845,922

Rating: 4.8216562 out of 5

Keywords: how stealth technology works, how stealth works, how stealth planes work, how the b2 bomber works, how fast is the b2 stealth bomber, how the f 117 was shot down, how does stealth technology work, how good is the f22, how the f 35 works, f22 in combat, f 35 fighter, f 35 program, f35 plane, f117a stealth fighter, f117a stealth fighter documentary, f 117, radar how it works, radar technology, stealth, stealth technology, b2 stealth bomber, how b2 stealth bomber works

Id: 5ji7H1PnuTo

Length: 20min 58sec (1258 seconds)

Published: Sat Feb 23 2019

Reddit Comments

[u/InadequateUsername]

Omg a video thats interesting and over 5 minutes in length, thank you!

[u/bendrigar]

This was a neat watch.

SubSEEquently

Woof.

[u/H0boHumpinSloboBabe]

Que? Fiirst used in Desert Storm?

The F-117 has been used several times in war. Its first mission was during the United States invasion of Panama in 1989.[45] During that invasion two F-117A Nighthawks dropped two bombs on Rio Hato airfield.

https://en.wikipedia.org/wiki/Lockheed_F-117_Nighthawk

https://youtu.be/WrjwaqZfjIY

[u/Diesel_Doctor]

Did not see that comin.

[u/laxking77]

Very technical and very informative. Got the sense that there haven’t been any landmark developments in the 21st century though, just incremental improvements?

[u/thisimpetus]

It’s super interesting but the narration is challenging to listen to for that mich time.

I heard him say “sub-SEE-quent” and then had to stop; if you’re just going to read a paper to me, put up the text if you don’t have any capacity to narrate.