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| {{Image|SR-71 over mtns.jpg|right|250px| SR-71B loaned from the U.S. Air Force for use in high-speed, high-altitude research at the NASA Dryden Flight Research Center, Edwards, California.}} | | {{:{{FeaturedArticleTitle}}}} |
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| The '''[[Lockheed SR-71]]''' (known unofficially as the '''Blackbird''', and by its crews as the '''Habu''' or the '''sled''') was an advanced, long-range, Mach 3 strategic reconnaissance aircraft developed from the Lockheed YF-12A and A-12 aircraft by the Lockheed Skunk Works. The SR-71 line was in service from 1964 to 1998, and it was the world's fastest and highest-flying operational manned aircraft throughout that entire period, an unparalleled achievement in aviation history. The aircraft flew so fast and so high that if the crew detected a surface-to-air missile launch, the standard evasive action was simply to accelerate. Thirteen aircraft are known to have been lost, all from non-combat related reasons.
| | ==Footnotes== |
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| | {{reflist|2}} |
| The SR-71 included many novel and advanced technologies in order to achieve that performance; in particular, due to extensive frictional heating from its high speed, almost everything in the aircraft had to be specially produced; the airframe was built almost entirely of titanium, as operating temperatures were too high for aluminum. It was also one of the first aircraft to be have been built with a reduced radar cross section; however, the aircraft was not completely stealthy, and still had a fairly large radar signature. The chief designer, Kelly Johnson, was the man behind many of its advanced concepts. After his retirement, Ben Rich ran the program.
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| ====History====
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| While the U-2 Dragon Lady reconnaissance aircraft produced immense value when it began to overfly the Soviet Union in 1956, it was accepted that this subsonic, nonstealthy aircraft eventually would be vulnerable to the Soviet air defense network. Indeed, one was shot down in May 1960, ending manned reconnaissance overflights of the Russian landmass. Overhead reconnaissance of the Soviet Union was taken over by satellites, but the SR-71 was already in development.
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| =====Predecessor models=====
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| The A-12 Oxcart, designed for the CIA by Kelly Johnson at the Lockheed Skunk Works, was the precursor of the SR-71. Lockheed used the name "Archangel" for this design, but many documents use Johnson's preferred name for the plane, "the Article." As the design evolved, the internal Lockheed designation went from A-1 to A-12 as configuration changes occurred, such as substantial design changes to reduce the radar cross-section. The first flight took place at Groom Lake, Nevada, on April 25, 1962. It was 'Article 121,' an A-12, but it was equipped with less powerful Pratt & Whitney J75s due to protracted development of the intended Pratt & Whitney J58. The J58s were retrofitted as they became available. The J58s became the standard power plant for all subsequent aircraft in the series (A-12, YF-12, MD-21) as well as the follow-on SR-71 aircraft. Eighteen A-12 aircraft were built in four variations, of which three were YF-12As, prototypes of the planned F-12B interceptor version, and two were the M-21 variant (see below).
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| The Air Force reconnaissance version was originally called the R-12 (see the opening fly page in Paul Crickmore's book ''SR-71, Secret Missions Exposed'', which contains a copy of the original R-12 labeled plan view drawing of the vehicle). However, during the 1964 presidential campaign, Senator Barry Goldwater continually criticized President Lyndon B. Johnson and his administration for falling behind the Soviet Union in the research and development of new weapon systems. Johnson decided to counter this criticism with the public release of the highly classified A-12 program and later the existence of the reconnaissance version.
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| ===== Name and designation =====
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| The USAF had planned to redesignate the A-12 aircraft as the B-71 as the successor to the B-70 Valkyrie, whichhad two test Valkyries flying at Edwards Air Force Base, California. The B-71 would have a nuclear capability of 3 first-generation SRAM's (Short-Range Attack Missiles). The next designation was RS-71 (Reconnaissance-Strike) when the strike capability became an option. However, then USAF Chief of Staff Curtis LeMay preferred the SR designation and wanted the RS-71 to be named SR-71. Before the Blackbird was to be announced by President Johnson on February 29, 1964, LeMay lobbied to modify Johnson's speech to read SR-71 instead of RS-71. The media transcript given to the press at the time still had the earlier RS-71 designation in places, creating the myth that the president had misread the plane's designation.
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| ''[[Lockheed SR-71|.... (read more)]]''
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Latest revision as of 10:19, 11 September 2020
Nuclear weapons proliferation is one of the four big issues that have held back worldwide deployment of peaceful nuclear power. This article will address the proliferation questions raised in Nuclear power reconsidered.
As of 2022, countries with nuclear weapons have followed one or both of two paths in producing fissile materials for nuclear weapons: enrichment of uranium to very high fractions of U-235, or extraction of fissile plutonium (Pu-239) from irradiated uranium nuclear reactor fuel. The US forged the way on both paths during its World War II Manhattan Project. The fundamental aspects of both paths are well understood, but both are technically challenging. Even relatively poor countries can be successful if they have sufficient motivation, financial investment, and, in some cases, direct or illicit assistance from more technologically advanced countries.
The International Non-proliferation Regime
The International Atomic Energy Agency (IAEA) has a vigorous program to prevent additional countries from acquiring nuclear weapons. The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is the cornerstone arrangement under which strategic rivals can trust, by independent international verification, that their rivals are not developing a nuclear weapons threat. The large expense of weapons programs makes it very unlikely that a country would start its own nuclear weapons program, if it knows that its rivals are not so engaged. With some notable and worrying exceptions, this program has been largely successful.
Paths to the Bomb
It is frequently claimed that building a civil nuclear power program adds to the weapons proliferation risk. There is an overlap in the two distinct technologies, after all. To build a bomb, one needs Highly Enriched Uranium (HEU) or weapons-grade plutonium (Pu-239).
Existing reactors running on Low Enriched Uranium (LEU, under 5% U-235) or advanced reactors running on High Assay LEU (HALEU,up to 20% U-235) use the same technology that can enrich uranium to very high levels, but configured differently. Enrichment levels and centrifuge configurations can be monitored using remote cameras, on-site inspections, and installed instrumentation -- hence the value of international inspections by the IAEA. Using commercial power reactors as a weapons plutonium source is an extremely ineffective, slow, expensive, and easily detectable way to produce Pu. Besides the nuclear physics issues, refueling pressurized water reactors is both time-consuming and obvious to outside observers. That is why the US and other countries developed specialized Pu production reactors and/or uranium enrichment to produce fissile cores for nuclear weapons.
Future Threats and Barriers
Minimizing the risk of future proliferation in states that want to buy nuclear reactors or fuel might require one or more barriers:
1) Insisting on full transparency for all nuclear activities in buyer states, including monitoring and inspections by the International Atomic Energy Agency (IAEA).
2) Limiting fuel processing to just a few supplier states that already have weapons or are approved by the IAEA.
3) Ensuring that fuel at any stage after initial fabrication has an isotopic composition unsuitable for weapons. "Spiking" the initial fuel with non-fissile isotopes, if necessary.
4) Limiting the types of reactors deployed to buyer states. In general, breeders are less secure than burners. Sealed reactor modules are more secure than reactors with on-site fuel processing.
5) Providing incentives and assurances for buyer states to go along with all of the above.
6) Application of diplomatic pressure, sanctions, and other economic measures to non-compliant states.
7) Agreement that any reactor declared rogue by the IAEA will be "fair game" for any state feeling threatened.