Thread: F-22, stuff you should know

Originally Posted by ARH Gabriel

good job rusky!
There is no more to say !
Just fact for those who have doubdt about russian brains... did you know that the latest atlas rocket flew in space powered by a engine ( rd-180 ) designed by russian scientists about 30 yars ago wich is 40% more powerful than 4 engines used before.

Yes. These engines were created for moon race.... then the program was put to shelves and these engines were swimming in the oil pool for 3 decades.... Until 1990-es when already a private company RKK Energiya remembered about this old project and tendered for Atlas project..... and won. However when they won it was great problem to make upgrades required by Americans...... NOBODY LEFT FROM THE DESIGN TEAM OF 30 YEARS AGO...... So they basically redone a lot from the scratch...... The RD-180 used by Altas today are by half are NEWLY redesigned by RKK Energiya and much better than original designed 30 years ago - lighter and more powerful. That is why RKK has delayed delivery of this technology by 1.5 years. It was basically doing R&D on redesigninin.

Today RD-180 are assembled in US for Atlas. This engine was trying to compete with Shuttle engines for powering new CEV..... RKK Energiya states that it may make further upgrade of RD-180-3 which would HAVE HIGHER TRUST AT LESS WIGHT than what current Shuttle engines may. They require US to fund slightly less than $2bn to achieve this. But politically I don't see any chance of this happening..... NASA is at first American agency and would not order R&D from a designers team located in Korolev town.

Originally Posted by Simullacrum

Another article....
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A number of methodologies to detect stealth aircraft at long range have been developed. Both Australia and Russia have announced that they have developed processing techniques that allow them to detect the turbulence of aircraft at reasonably long ranges (possibly negating the stealth technology).

Passive (multistatic) radars are known to detect stealth aircraft better than receivers connected to the transmitters (active or monostatic radars), since stealth technology reflects energy away from the transmitter's line of sight, effectively increasing the radar cross section (RCS) in other directions, which the passive radars monitor. In addition, it has been suggested that use of low frequency broadcast TV and FM radio signals as the illuminating source produces a much higher RCS than high frequency monostatic radars as the long wavelengths cause whole structural portions of the targets to resonate. Target detection, even at very low Signal to Clutter Ratios (down to –100 dB) is theoretically possible. Target tracking, in three-dimensional position and velocity should be more accurate with a multistatic system than with a monostatic system, using either triangulation or hyperbolic (or both) target location strategies. Wide usage of such broadcast signals (esp. in inhabited regions) means a continuous and reliable coverage and source of energy, that cannot easily be neutralized by an attacker. Researchers at the University of Illinois with support of DARPA, have shown that it is possible to build a synthetic aperture radar image of an aircraft target using passive multistatic radar, possibly detailed enough to enable Automatic Target Recognition (ATR).

The United Kingdom has announced a system that uses the signals broadcast from the huge number of cellular telephone towers to generate a synthetic picture, although it is not clear if this method is actually practical. A general feature of these systems is that they use a large number of low-accuracy radar systems (or signal sources) combined with heavy computer processing to generate tracking information. For this reason they tend to be useful only in the early warning role, and have limited applicability to guidance radars for missile systems, and are rarely portable. The problem of successfully countering stealth aircraft on the battlefield remains essentially unsolved.

Stealth aircraft can also be passively detected from their electromagnetic emissions (terrain-following radar, radio communications, missile guidance communications etc.). Stealth aircraft typically attempt to minimize these emissions (using low probability of intercept radars, satellite communications etc.).

To this date, the only systems that have been shown to successfully detect stealt aircraft are very old, and use long wave radar systems that have a low resolution. The shooting down of an F-117 over Yugoslavia was attributed to the tracking of the vortexes produced by the poor aerodynamic shape of stealth aircraft. The F-117 was also dected by a British ship during the first Gulf War, in this case because the wavelength of the radar was twice the length of the aircraft. This caused the entire aircraft to act as a dipole, leading to a very strong radar return.

detecting is not good enough for fire control and cell phone towers are vulnerable to jamming.