Glide Phase Interceptor (GPI) Project

May 9, 2024

Amid growing concerns over rivals deploying advanced weapons like hypersonic missiles, Japan is investing in the Glide Phase Interceptor (GPI) Project under joint development with the US.

About Glide Phase Interceptor (GPI) Project:

  • It is a missile-intercepting system under joint development by the US and Japan.
  • By the end of 2032, Washington and Tokyo aim to achieve full operational capability for the system.
  • What is the Glide Phase?
    • With a traditional Intercontinental Ballistic Missile (ICBM), the warhead separates from its booster and continues on a parabolic, gravity driven trajectory to its target.
    • A hypersonic weapon, by contrast, separates from its booster after the peak of its trajectory and accelerates toward the Earth using gravity. It then performs a pitch manoeuvre to begin a flatter trajectory called the glide phase.
    • Unlike typical ballistic missiles, the hypersonic and glide vehicles travel at five times (or more) the speed of sound on an unpredictable trajectory.
  • What is the Project all about?
    • Hypersonic weapons or missiles pose a unique challenge due to their blinding speeds and relatively low altitudes (20 to 80 km) during the glide phase.
    • They can navigate around areas containing known missile defence sensors.
    • These characteristics make it particularly challenging for ground-based radar systems to track them efficiently.
    • The GPI Project aims to provide regional hypersonic missile defence.
    • It will achieve this by launching specially modified missiles from surface warships.
    • These missiles will engage and destroy incoming hypersonic missiles as they glide through the boundary between space and Earth’s atmosphere.
    • The “glide” phase of the missile’s trajectory provides the best opportunity to intercept it before it enters its last high-speed drop.