Seeker dome heating is emerging as probably the single largest technical challenge for Israeli missile design house Rafael in developing an air-launched anti-tactical ballistic missile weapon.
Rafael is working on a weapon, dubbed the MOAV, which draws on elements of its Python-4 infra-red (IR) guided short range, air-to-air missile as well as on its still- classified radar-guided AAM, referred to as the Alto or Derby. The aim is to develop a missile capable of intercepting and destroying short range ballistic missiles during the early stages of flight.
Rafael sources say that because of the projected high velocity of the missile, likely to be in excess of Mach 4, seeker dome heating has become a serious technical issue. At these speeds, traditional seeker window materials suffer from thermal washout, rendering the IR detector ineffective.
Rafael is looking at several options in addressing this issue. One solution would be to install a cover that will effectively "blind" the IR seeker until shortly before the terminal intercept phase.
The IR seeker would be uncovered when the MOAV is within acquisition range of the target ballistic missile.
Target information, as well as mid-course guidance updates, would be provided via a Tadiran developed datalink. This is likely to be based on the datalink from the Rafael/MBT active radar-guided AAM.
Another option would be to provide a radar-style nose thermal cover which would be ejected in the final phase of the engagement.
Rafael could also adopt advanced seeker window materials such as single crystal diamond, which can sustain significantly higher surface temperatures.
While the Python-4 has a maximum fly-out range of around 15km (8nm), the projected range for the MOAV is considerably greater, at around 80km. The MOAV would be fitted with the Alto/Derby solid-propellant motor rather than the Python-4 propulsion unit.
The launch platform for the MOAV is an as yet unspecified long endurance unmanned air vehicle being developed by Israel Aircraft Industries.
Source: Flight International
