Eihän tuokaan kirje tullut ajallaan vaan monta päivää myöhässä.
The Central Intelligence Agency initiated the Oxcart program, which led to Lockheed's A-12 spy plane, the predecessor of the U.S. Air Force's SR-71 Blackbird, specifically because of concerns that the iconic U-2 Dragon Lady was becoming too vulnerable to Soviet and other hostile air defenses. The aircraft's primary advantages were in its ability to fly extremely high and fast, but it was apparent from the beginning of its development that those capabilities might not be enough to defend against existing and emerging threats at the time.
As a result, the A-12 itself featured then-state-of-the-art stealthy shaping together with radar-evading structures that made heavy use of composites and that were coated in radar-absorbing materials. The CIA undertook further efforts to explore more novel means of reducing the radar cross-section of the planes, including the development of a cesium-laced fuel additive intended to shield its rear aspect from radar waves using a concept called "plasma stealth," which you can read about in greater detail in this past War Zone feature. This same principle also led to the development of powerful electron guns that the A-12 could carry inside its fuselage to create similarly radar-absorbing fields in other directions, according to various declassified documents now available online via the CIA Records Search Tool, or CREST.
Work on the cesium fuel additive, eventually known as A-50, offered one possible method of reducing the radar cross-section of the rear aspect of the aircraft. This was already a problematic area in the radar-evading work because of the jet's massive exhausts and the radar reflective plume from the J58s at full afterburner while flying at above Mach 3.
At its most basic, the general concept of plasma stealth involves using some means to create a cloud of ionized particles, or plasma, which is capable of absorbs electromagnetic radiation, such as radar waves, so they can't reflect back. Burning cesium in the super-heated exhaust stream would do just that at the back of the plane.
The obvious problem was that the exhaust stream only pointed rearward. A-50 could not produce a similar ionized cloud toward the front aspect of the aircraft, which would be most exposed as the aircraft approached the target area at the beginning of its reconnaissance pass. This is also when the aircraft would be most vulnerable.
One option the CIA considered, codenamed Emerald, was to install devices elsewhere in the aircraft that would create "a seeded plasma electric arc," similar to the effect of adding cesium in the exhaust stream, but in other directions. Another idea, codenamed Kempster, was to install electron guns that would emit electrically-charged particles to produce a similar effect.
The U.S. Global Positioning System fleet of satellites provides critical data for navigation apps, banks, power grids, and other commercial and government infrastructure. But for the past decade, it has operated without a safety net, with no backup system in place. Now, two U.S. federal agencies want to change that, and they could select one or more alternatives by September.
Next month, the U.S. Department of Transportation (DOT) is due to deliver the results of a recent demonstration of potential GPS backup technologies to the National Executive Committee for Space-Based Positioning, Navigation, and Timing (PNT). The committee, which is cochaired by deputy secretaries of the U.S. Departments of Transportation and Defense, is expected to use the findings to announce next steps sometime in August. Those steps may include selecting one or more technologies and issuing a request for proposals for companies to develop them.
Eleven finalists participated in the two-week, mid-March demo, in which they showed how their respective PNT systems would perform if GPS went down because of jamming, spoofing, or other problems. The companies, which tested both space- and ground-based systems and include venture-backed startups and industry old-timers, were awarded a total of approximately US $2.5 million to prepare for the demos.
head of the U.S. Army's 11th Armored Cavalry Regiment has offered an interesting and unusually detailed look at the threat that electronic warfare and electronic support measures pose to American troops on the modern battlefield. The likelihood of a potential adversary monitoring friendly movements via electronic emissions and launching electronic attacks, as well as kinetic ones, on those units has only grown in recent years, with Russia, in particular, demonstrating just how effective these capabilities can be in Ukraine and Syria. American forces in Syria, as well as troops in Europe, have been also subjected to Russia's electronic harassment, as well, underscoring these threats.
On May 7, 2020, Army Colonel Scott Woodward, the commander of the 11th Armored Cavalry Regiment, posted an annotated satellite image on Twitter that showed the electronic emissions signature of a battalion-sized element, along with support units, or "trains," during an exercise at the National Training Center at Fort Irwin in California. The 11th is the unit at the NTC that is dedicated to playing the role of enemy troops, or the Opposing Forces (OPFOR), during exercises and has a fleet of modified vehicles and other systems to mimic the capabilities and visual appearance of potential adversaries.