Reprinted from JANE'S DEFENCE WEEKLY 12 DECEMBER 1992 Written by Bill Sweetman **** HYPERSONIC AURORA: A SECRET DRAWING? **** Further evidence that the US Air Force has secretly produced a high-speed reconnaissance aircraft to replace the SR-71 has emerged. An eyewitness has sketched an aircraft seen over the North Sea in August 1989. A tentative analysis suggests that the aircraft is a manned vehicle, roughly the size of an SR-71. The cruising speed could be as high as Mach 8 (5300 mph/8530 km/h). It is probably powered by a combined-cycle engine burning liquid methane. Oil drilling engineer Chris Gibson told JDW that he saw the aircraft from the rig Galveston Key. The unidentified aircraft was apparently refueling from a KC-135 and was accompanied by two F-111's. While too high to makeout any details, it was directly overhead and silhouetted against high cloud. Gibson spent 12 years with the Royal Observer Corps and was a member of the ROC international aircraft recognition team. Deciding not to take the sketch to the media in 1989, as he was still a member of the ROC, he sent the sketch to JDW consulting editor Bill Sweetman only after seeing a similar design in JDW. The aircraft's planform-a perfect 75 deg swept triangle- corresponds almost exactly to hypersonic aircraft deigned at McDonnell Douglas between the late 1960's and early 1980's, according to Paul Czysz, Professor of aerospace engineering at St. Louis University. Czysz worked on hypersonics at McDonnell Douglas, including the company's National Aerospace Plane (NASP) proposal, and has studied hypersonic technology inside and outside the USA. The sketch, he says, "shows the correct sweep angle for a hypersonic lifting body aircraft." The configuration suggested by Gibson's sketch and the McDonnell Douglas studies resembles another drawing obtained by Bill Sweetman in late 1989. According to the source, it depicts the rear view of an aircraft seen at a USAF flight test base in 1987. The witness who produced the rear-view drawing says the aircraft's engine was making a unique low-frequency, very high-amplitude "pulsing" sound. Such reports have emanated since 1989 from Edwards AFB, Beale AFB, and USAF's secret flight-test centre at Groom Lake in Nevada. The only engines known to make such noises in normal operation belong to a specific class of composite propulsion systems developed since the 1960's for hypersonic aircraft, according to Czysz. The North Sea aircraft appears to be up to 27 m long, with a 14-15 m span. This tallies with the US Geological Survey's analysis of unexplained sonic booms over Los Angeles, which have pointed to an aircraft significantly shorter than the 37 m Space Shuttle orbiter. Dimensions, however, are deceptive. Efficient hypersonic aircraft "are basically air-breathing propulsion systems," says Czysz, "and they virtually design themselves." The wings, unnecessary at hypersonic speed, diminish into movable control surfaces. The result is that the vehicle takes on an all-body, wedge-like shape, more efficient in terms of volume and weight than a conventional aircraft. The North Sea aircraft would have an operating empty weight similar to or greater than the 25 ton SR-71, and a maximum all-up weight between 70 and 80 tons. A hypersonic aircraft needs cooling to withstand the heat generated by air friction at high speeds. This involves using the fuel as a heat sink and circulating either the fuel or a cooling medium (such as helium) through the hottest parts of the structure, i.e. the nose, leading edges, and the inlet lips. The most likely fuel for the North Sea aircraft, according to Czysz, is liquid methane (CH4). Compared with liquid hydrogen, it is three times more dense and easier to handle-inflight refueling has been studied and poses no problems. "If it was a hydrogen aircraft it would be larger," Czysz says. With cooling, most of the structure can be made from titanium alloys with higher temperature limits than standard titaniums, such as the Timet Bet-21S, baselined for NASP. Design studies have shown that a methane-powered vehicle of the size seen over the North Sea could have an unrefueled range of more than 9000 km, with a crew of two, and a maximum cruising speed of Mach 8. At that speed, the aircraft would operate at altitudes between 100,000 ft and 130,000 ft (30,500-40,000 m). Unlike the F-117, the hypersonic aircraft could not be confined to night operations within the USA. Because of its speed and altitude, it will cover a considerable distance during acceleration and deceleration. A realistic operational test would be impossible within the continental USA. Rather, the aircraft could fly to an openwater area close to a suitable tanker base, such as the North Sea, refuel and return. The highly swept leading edges are inherently favourable to stealth-in fact, the shape strongly resembles the original 'Hopeless Diamond' planform which was the starting point for the F-117. Stealth may be of little relevance as it would be virtually invulnerable to any air defence system. The most likely mission is reconnaissance, complementing USAF's constellation of satellites. Satellites are economical for long-term, repeated coverage and can mount superb optical sensors. An aircraft is more responsive. The satellite system is believed to be capable of producing imagery with 24 hours of a request. At Mach 8 the flight time to any point on Earth is under three hours. Unlike a satellite, the aircraft can pass over a target at any time of day. The aircraft also gives the defences less warning time than a satellite. Although slower, it flies lower. The aircraft's engines can also generate power for an active radar, used for reconnaissance at nigh or in adverse weather. USAF has a radar reconnaissance satellite, Lacrosse, but the need to power the system for nocturnal reconnaissance (in the shadow of the earth) are design challenges. Each reconnaissance aircraft could cost as much as $1 billion. This is equivalent in price to a satellite, but the aircraft is more durable - SR-71's operated for more than 20 years, while no satellite has lasted longer than five years. It is likely that Lockheed Advanced Development Co. (LADC) - the Skunk Works - is prime contractor for the new aircraft. Quite apart from the Skunk Works' reputation for advanced technology, Lockheed's financial figures have indicated a continuing, large flow of income for "classified" and "special mission" aircraft. The propulsion contractor will have been a major partner in the programme. The Rocketdyne division of Rockwell International may well be involved. The combined-cycle engine, which appears to match the reported characteristics of the unidentified aircraft, is closer to a rocket than to a turbojet. The North Sea sighting and the SR-71 retirement in early 1990 suggest the new aircraft became operational in 1989. If so, the first flight probably took place in 1985 or 1986, placing the start of full-scale development in the early years of the Reagan Administration, in late 1981 or early 1982. The new spyplane programme would have been launched at about the same time as the B-2. Surprisingly, that contract went to Northrop, Boeing, and Vought. The losing team, interestingly, was Lockheed and Rockwell. The existence of a hypersonic follow-on to the SR-71 would explain a number of anomalies. The most glaring is the retirement of the SR-71. The ostensible reason was to save money, but the annual cost of between $200 million and $300 million was only 5-7 percent of what USAF appears to spend each year on reconnaissance satellites. It was also the only occasion in USAF's history that the service voluntarily relinquished a manned mission in favour of unmanned vehicles. Lockheed's lobbyists -uncharacteristically- did not fight the decision. The hypersonic aircraft also explains some aspects of the NASP programme. NASP research focused from the outset on the Mach 8-plus regime, even though there was an almost equal lack of validated data from Mach 4 to Mach 8. Also, while the NASP programme has been run in the open, the low-speed portion of the propulsion system has been secret. Both these observations are consistent with the hypothesis that NASP was conceived as an outgrowth of the hypersonic reconnaissance programme, using a higher-energy fuel (slush hydrogen), more advanced materials, and a modified propulsion system with scramjet and rocket modes. *************************************************************** **** DISGUISED BY NASP **** Has the National Aero-Space Plane -NASP- provided a disguise for Aurora? At a conference in Orlando last month Heinz Pfeffer, head of the European Space Agency's directorate for space transportation systems, told JDW: "NASP is a cover for Aurora." There's no other reason that the industry would put $900 million into NASP. "Aurora has achieved its goals and NASP can be allowed to fizzle out." NASP's future is in doubt because Congress has not approved funds for developing a prototype. *************************************************************** **** RADICAL ENGINE TECHNOLOGY **** The hypersonic aircraft may be powered by a type of combined-cycle engine, studied in the 1960's by Dr. Fred Billig at the Applied Physics Laboratory of John Hopkins University. The Billig-cycle engine uses cryogenic fuel and combines features of a ramjet, a rocket, and a turbine engine. It is lighter than a classic turbo-ramjet and, unlike a rocket/ramjet combination, it can operate efficiently across the entire speed range. The engine is based on a ramjet duct, which incorporates both a fuel injector and a group of small rocket-type nozzles, and a turbine-driven compressor. The methane fuel drives the turbine as it expands from a liquid to a gas, and both the high-pressure air from the compressor and the methane from the turbine are delivered to the rocket-type nozzles in the ramjet duct. Liquid oxygen (LOX) can be added to the rocket nozzles. To start the engine, methane is pumped through the aircraft's skin, where it is heated to ambient temperature. The methane expands through the turbine, spinning the compressor and pumping air into the rocket nozzles, where the compressed air/methane mixture is ignited. The high-velocity rocket exhaust acts as an ejector, drawing air through the ramjet. At idle and low speeds, however, the ramjet duct is too large for the airflow. The flow becomes discontinuous, with a cyclic build-up and release of pressure in the duct, producing the distinctive noises associated with these unidentified aircraft. The Billig engine needs more thrust for take-off, climb, and transonic acceleration, so LOX is added to the rocket nozzles. This increases exhaust velocity, draws additional air through the ramjet and increases the pressure ratio to the point where more methane can be added (through the fuel injector) and burned in the duct. The engine becomes an air-augmented rocket, ducted rocket or ram-rocket. The engine needs less oxygen as the vehicle accelerates, firstly because more air is flowing into the ramjet duct; and secondly, increased skin friction means that the methane driving the turbine has more energy, so the compressor is delivering more air pressure to the rocket nozzles. The LOX flow is gradually reduced, reaching zero at about Mach 2.5. At higher speeds, the methane supply to the rocket nozzles may be shut down and fuel delivered through the fuel injector. The compressor exhaust can supercharge the ramjet until Mach 6, when the compressor inlet closes and the strut with the rocket nozzles retracts to reduce drag. The engine can then run as a pure ramjet to Mach 8. *************************************************************** ****DENIAL AND DISINFORMATION **** Despite political moves to acknowledge more programmes, USAF and Congressional leaders continue to fend off questions on the hypersonic aircraft, while avoiding direct, unambiguous denials that USAF is operating a secret high-performance aircraft. USAF Secretary Donald Rice brushed off reports of unidentified high-speed aircraft in a press conference in Los Angeles on 30 October. "The system that has been described in those articles does not exist. We have no aircraft programme that flies at six times the speed of sound or anything close to that," Rice told reporters. He cast doubt on "the kind of descriptions laid out in some of those articles" which "would take an aircraft of such proportions and capabilities that there wouldn't be a snowball's chance in you know where of hiding it." The most specific denial concerns a Mach 6 aircraft, but -according to Czysz- "Mach 6 is exactly where you don't want to fly," because it is a transition point between different modes of any likely propulsion system. USAF has been casting doubt on the seismographic evidence collected by the US Geological Survey, which indicates that unidentified supersonic aircraft have been crossing southern California. Under contract to USAF, Massachusetts Institute of Technology's Lincoln Laboratory analyzed one of these readings and concluded that it was caused by a US Navy fighter on a flight-test evaluation. That does not explain repeated readings from sensors more than 130 km inland, unless pilots have been routinely violating the ban on supersonic flight over metropolitan areas. The USAF Flight Test Center states that the boom carpet of an aircraft at 50,000 ft extends 40 km on either side of the flight path. Witnesses describe the booms as a "rumbling" sound rather than the pop-thud of a fighter boom. USAF's credibility is undermined by the fact that the DoD authorizes disseminating misleading information. Steven Aftergood, Editor of the Secret & Government Bulletin for the Federation of American Scientists, said: "Once we know that the DoD practices this kind of deception, it became harder to discern what's real and what is not." JDW asked Senator Sam Nunn, Chairman of the Senate Armed Services Committee, about the California booms at a press conference in Dayton earlier this year. Also present was Ohio Senator John Glenn, a senior member of the Senate Intelligence Committee. As SASC Chairman, Nunn is briefed on Special Access Programs (SAP's). Normally, the full SASC and intelligence committees get the same briefing. Aftergood has reported the existence of a subset of SAP's called "waived programmes", in which the Secretary of Defense waives the requirement to notify the full committees, and briefs only the chairman and senior minority members of each committee. If the hypersonic aircraft is a waived programme, Nunn would be briefed and Glenn would not. Nunn's response to the question was to refer it to Glenn, without expressly declining to comment. Glenn's response was: "First, I don't know. Second, no comment." *************************************************************** **** THE END **** _____ __ _____ __ __ ______ _____ _____[ß] ThE-/. \--/. \-/. \-----/. \/. \-/. \-/. \--/. \- ...// / _/.// /// / /....// // /_\\_/ /// / _/.// / /. ::/ \:/ // /__/::::/ __ // // \:/ / /:: / / // // / /¯ / / // / // / // / / -\______/-\__/-\______/----\__/\__/-\______/-\__/\__/-\______/-ONE THE BIG HARD ONE oO-NFA WHQ-Oo 0116 2661610 DOWN AND OUT oO-NFA UKHQ-Oo 0192 5234981 This is part of the ever growing NFA Empire.