“Fordow is gone,” said US President Donald Trump after America bombed Iran. It deployed its B-2 Spirit stealth bombers to carry out precision strikes on Iran’s Fordow fuel enrichment plant, which Trump has described as the “crown jewel”. The United States used these bombs to target Fardow, as it is built into the side of a mountain and is reportedly half a kilometre below the Earth. What makes these bombers even more dangerous is that they can go undetected into the airspace, carry out precision airstrikes, and return.

The strike comes days after the US military jets were spotted in Iranian skies, and President Trump said that they now have complete control of the country’s airspace. When asked if the US would side with Israel in the ongoing conflict in the Mideast, Trump told reporters that he may or may not join the war, adding that nobody knows what he’s going to do.

What is B-2 Spirit bomber?

The B-2 Spirit bomber is built in a bat-like design with radar-absorbing materials. So, on radar, the aircraft operated by a two-pilot crew appears like a small bird. The aircraft was developed by Northrop during the Cold War, which later became Northrop Grumman. Each unit costs around $2.1 billion, as per a report by Reuters. The outlet further reported that only 21 such aircraft have been built after the Soviet Union collapsed.

B-2 was armed with a GBU-57 A/B Massive Ordnance Penetrator bomb, which is a 30,000-pound (13,600-kilogram) bunker buster bomb, to strike Iran’s Fordow nuclear plant. Since the bunker buster bomb is heavy, each aircraft can carry only one or two per mission.

“Bunker buster” is a term used to describe bombs that can penetrate deep below the surface before exploding. It’s believed to be able to penetrate about 200 feet (61 meters) below the surface before exploding, and the bombs can be dropped one after another, effectively drilling deeper and deeper with each successive blast. As per reports, the US dropped as many as six MOPs on Fordow.

Why does the US need to be involved?

Although the GBU-57 A/B could be dropped by any bomber capable of carrying the weight, only America has configured and programmed its B-2 Spirit stealth bomber to deliver the bomb, according to the Air Force. B-2 is only flown by the Air Force.

According to the manufacturer, the B-2 can carry a payload of 40,000 pounds (18,000 kilograms), but the US Air Force has said it has successfully tested the B-2 loaded with two GBU-57 A/B bunker busters, which means a total weight of some 60,000 pounds (27,200 kilograms). Additionally, it can include both conventional and nuclear weapons. It can deliver up to 16 B83 nuclear bombs as part of the US nuclear triad.

The strategic long-range heavy bomber has a range of about 7,000 miles (11,000 kilometres) without refuelling and 11,500 miles (18,500 kilometres) with one refuelling, and can reach any point in the world within hours, according to Northrop Grumman.

It can also carry GPS-guided bombs capable of carrying out precision strikes, glide bombs to engage targets from outside the range of enemy air defences and long-range cruise missiles that can strike from up to 500 miles (805 km) away.

It remained unclear early Sunday how much damage had been inflicted upon Fordow. With the US siding with Israel in the ongoing conflict, it also means that the deal between Iran and the US, which Trump said was going in a “positive direction”, before it derailed, is of the table now.

How tough a target is Fordow?

Fordow is Iran’s second nuclear enrichment facility after Natanz, its main facility, which has already been targeted by Israeli airstrikes. The IAEA says it believes those strikes have had “direct impacts” on the facility’s underground centrifuge halls.

Fordow is smaller than Natanz, and is built into the side of a mountain near the city of Qom, about 60 miles (95 kilometres) southwest of Tehran. As per reports, the site’s construction is believed to have started around 2006, and it became operational in 2009, the same year Tehran publicly acknowledged its existence.

In addition to being an estimated 80 meters (260 feet) under rock and soil, the site is reportedly protected by Iranian and Russian surface-to-air missile systems. Those air defences, however, likely have already been struck by Israel.

Israeli Prime Minister Benjamin Netanyahu has said the goal of attacking Iran was to eliminate its missile and nuclear programme, which he described as an existential threat to Israel, and officials have said Fordow was part of that plan.

“This entire operation … really has to be completed with the elimination of Fordo,” Yechiel Leiter, Israel’s ambassador to the US, told Fox News.

(With inputs from agencis)