US Air Force successfully completes test of unarmed Minuteman ICBM

The United States Air Force tested an unarmed Minuteman III, an inter-continental ballistic missile (ICBM), from the Vandenberg Space Force Base in California in the early hours of Wednesday, a military press release said.

Inter-continental ballistic missiles were developed with the singular aim of delivering nuclear warheads thousands of miles away. A typical ICBM consists of three phases; one boost that launches the rocket to an altitude of 100-250 miles (150-400 km), a mid-course phase that can last up to 25 minutes, and takes the missile through a sub-orbital spaceflight.

The reentry or terminal phase starts when the missile is at an altitude of 62 miles (100 km), during which it has a speed of over four miles (7 km) a second and it deploys its warhead. ICBM designs allow them to deploy conventional, biological, as well as chemical warheads. However, none of them have been deployed so far.

The Minuteman III

The Minuteman III is the only land-based ICBM in the U.S. arsenal of nuclear weapons. Development of the ICBM began in the 1950s, and the first Minuteman entered service in 1962 with the capability to strike Soviet cities. The upgraded version, Minuteman II, added range, accuracy, and penetration aids to help beat the anti-ballistic missile system of adversaries.

The Minuteman III was deployed in 1970 and offered a superior ICBM package to the U.S. Air Force. The almost 60-feet (18.3 m) tall missile has an operational range of 8,700 miles (14,000 km) with an accuracy of about 800 feet (240 m). It was also the first Minuteman missile to feature multiple independently targetable reentry vehicles (MIRVs), which basically meant that a single missile could target three locations during its flight.

The ICBM uses an inertial navigation system to make its way to its target and can cruise at Mach 23.

Unarmed Testing of Minuteman

Periodically, the U.S. Air Force tests unarmed Minuteman to "validate and verify their safety, security, effectiveness, and readiness," the U.S. Air Force said in a press release. To this effect, the ICBM was fired from the Vandenberg Space Force Base on September 7 at 1:13 am.

According to the public affairs department, the weapon traveled over 4,200 miles (6,759 km) at a speed exceeding 15,000 miles (24,140 km) an hour to a test range at the Kwajalein Atoll near the Marshall Islands in the central Pacific Ocean. As per treaty obligations, Russia was notified of the plans for the test launch, Defense News said in its report.

This was a routine test that was scheduled well in advance and follows another test conducted on Aug 16, last month. That launch was delayed by a period of 12 days to avoid worsening tensions with China after U.S. House Speaker Nancy Pelosi visited Taiwan last month.

Earlier in March, the U.S. had delayed a similar test launch to calm nuclear tensions after Russia invaded Ukraine.