The boost phase is the portion of the flight of a ballistic missile or space vehicle during which the booster and sustainer engines operate until it reaches peak velocity. This phase can take 3 to 4 minutes (for a solid rocket shorter than for a liquid-propellant rocket), the altitude at the end of this phase is 150-200 km, and the typical burn-out speed is 7 km/s. Boost-phase intercept is a type of missile defense technology that would be designed to disable enemy missiles while they are still in the boost phase. Polish missile wz. ... The Space Shuttle Columbia is initially launched using solid-fuel boosters Solid rockets are rockets with a motor that uses solid propellants (fuel/oxidizer). ... The highest specific impulse chemical rockets use liquid propellants. ... hi mom ... Missile Defense is a term referring to systems, weapon programs, or technology involved in the defense against a missile. ...