U.S. now within range of N. Korea’s nuclear weapons 

U.S. now within range of N. Korea’s nuclear weapons 

Context

North Korea said it successfully tested a new intercontinental ballistic missile (ICBM) on Wednesday in a “breakthrough” that puts the U.S. mainland within the range of its nuclear weapons whose warheads could withstand re-entry to the Earth’s atmosphere

Terms to know:

ICBM

• It is a guided ballistic missile – which follows a path – and has a range of 5,500kms.
• They are primarily designed for nuclear weapons delivery but can also carry chemical and biological weapons.
• They were first developed in World War Two
• These missiles can carry a number of separate nuclear warheads – which means a single missile can hit multiple targets
• Speed: An intercontinental ballistic missile constantly changes speed and altitude but the peak speed of an ICBM is about 6-7km/s
• They are like rockets: All ICBMs are large rockets with space for a payload on top. They’re typically smaller than rockets that launch satellites and people into space, but structurally, the missiles aren’t too different – which is why militaries pay close attention to countries that develop human-spaceflight program
• Flies like a football, destroys like a weapon: Most ICBMs don’t enter Earth’s orbit. Instead, they travel in high, arc-like paths, similar to the way a football flies across the field when kicked by the goalkeeper. The difference is that an ICBM “football” touches outer space, can strike a target from thousands of miles away, and is capable ofdestroying entire cities

How an ICBM works?

• 3 stages: To reach high speeds and strike with such precision, ICBMs typically have three (or sometimes four) separate rocket motors, also called stages. This is because smaller rocket motors are easier to make than one big motor
• 1^st stage: The lower, first-stage rocket is sometimes called a booster. Boosters are the largest part of rockets and do most of the heavy lifting. (ICBMs weigh as much as a few school buses, mostly because of the large amounts of rocket fuel they carry
• 2^nd stage: Once the booster has used up its fuel dozens of miles above Earth, it detaches, and the second-stage rocket motor ignites. The same process happens with any subsequent stages
• In-flight adjustments: During flight, ICBMs use several tricks to stay on course, though most adjustments happen during boosting. Flight computers can monitor a rocket’s trajectory and use gyroscopes to help nudge and tweak the missile’s direction. Some ICBMs also use cameras to look at constellations of stars while flying high above the clouds, constantly feeding that information into the flight computer to adjust the missile’s path
• Gravity does its work: At each stage of flight, the missile and its payload move faster and faster, though they coast (moving without power) for some stretches to ensure an accurate strike. All the while, Earth’s gravity pulls the weapon back toward the ground
• Last stage: By the time the last stage has burned out, all that remains is for the payload – a nuclear warhead, chemical weapon , or biological weapon – to deploy

What has happened?

North Korea has successfully tested a new intercontinental ballistic missile (ICBM) in a “breakthrough” that puts the U.S. mainland within the range of its nuclear weapons whose warheads could withstand re-entry to the Earth’s atmosphere

Backdrop

North Korea, which also conducted its largest nuclear test in September, has tested dozens of ballistic missiles under its leader, Kim Jong Un, in defiance of international sanctions

Hwasong-15

The new Hwasong-15, named after planet Mars, was a more advanced version of an ICBM tested twice in July. It was designed to carry a “super-large heavy warhead.” Based on its trajectory and distance, the missile would have a range of over 13,000 km, more than enough to reach Washington D.C. and the rest of the U.S