What is Sentinel Nuclear Missile?

About Sentinel Nuclear Missile:

• It is an intercontinental ballistic missile (ICBM) being developed by Northrop Grumman, in cooperation with Air Force Global Strike Command, for the US Air Force (USAF).
• It will replace the 400 five-decade-old LGM-30 Minuteman III ICBMs, which have been in service with the USAF since the 1970s.
• The LGM-35A Sentinel will incorporate digital engineering technologies and employ a modular open system architecture, which will provide interoperability and reduce life-cycle costs. 
• It will be equipped with a W87-1 thermonuclear missile warhead.
• It will feature fully integrated launch, flight and infrastructure systems, as well as modern command and control technology and ground equipment.
• The new missile will be launched from silos, whose doors can remain closed during warhead maintenance, eliminating any security threat.
• It is expected to have a range exceeding 5,500km and can reach any target across the world in just 30 minutes post-launch following a parabolic trajectory toward its target.

Q1: What are Ballistic Missiles?

A ballistic missile is a rocket-propelled, self-guided strategic-weapons system that follows a ballistic trajectory to deliver a payload from its launch site to a predetermined target. They are powered initially by a rocket or series of rockets in stages, but then follow an unpowered trajectory that arches upwards before descending to reach its intended target. They can carry conventional high explosives as well as chemical, biological, or nuclear munitions.

Source: Pentagon keeps commitment to Sentinel nuclear missile as costs balloon