Explainer: Is ‘Khorramshahr-5’ poised to become Iran’s first intercontinental ballistic missile?

By Yousef Ramazani

The growing speculation about the Khorramshahr-5, Iran's potential first intercontinental-range ballistic missile (ICBM), suggests that the country could soon join the small circle of countries with such weapons.

In recent days, reports have been circulating about the Khorramshahr-5, an ICBM with extremely high capabilities. It reportedly has a range of 12,000 kilometers, a speed of Mach 16, and a 2-ton warhead.

Unlike previous official unveilings of major Iranian military achievements, which are usually announced by the Ministry of Defense or the Aerospace Force of the Islamic Revolution Guards Corps (IRGC), the news of the Khoramshahr-5 originated from unofficial sources.

Some media outlets falsely reported that a missile test had been conducted, sharing footage of the Khorramshahr-4 test from 2023. However, the possibility that the missile is ready cannot be ruled out.

Iran has always maintained that its missile program is defensive, adhering to a self-imposed range limit of 2,000 km, as stated by senior officials in 2015 and reaffirmed in subsequent years.

Iranian leaders, including those from the IRGC, have in the past denied pursuing ICBMs, arguing that existing missiles are sufficient to neutralize threats from the Israeli regime and US bases in the region.

Following recent changes in regional dynamics and the unprovoked Israeli-American aggression against the Islamic Republic, there is a possibility that the long-standing stance could be revised.

What is an intercontinental ballistic missile (ICBM)?

An intercontinental ballistic missile (ICBM) is a long-range guided missile designed to deliver different types of warheads across continents, with a minimum range of 5,500 kilometers.

With reduced warhead mass, some ICBMs can have a maximum range of up to 16 or even 18 thousand kilometers, covering almost every land location on Earth.

ICBMs are two-stage or three-stage and usually large in size, 20 to 30 meters high and 2-3 meters in diameter, although there are also advanced miniature versions with almost half that size.

Explainer: What does Iran’s newly-unveiled largest subterranean ‘missile city’ reveal?

With its largest missile city unveiled, Iran sent a strong message to adversaries about its growing military prowess.

These missiles are launched from silos, mobile launchers, or submarines, and use a first stage, sometimes with rocket boosters, to exit the atmosphere.

Traveling through space in a parabolic arc, they can reach speeds of Mach 20+ (over 24,000 km/h) and release multiple warheads (MIRV) or decoys to evade defenses.

Warheads descend at extreme speeds (15,000–24,000 km/h), protected by heat shields. Precision guidance systems like inertial navigation and GPS ensure target accuracy. Typical full-range flight time is 30–40 minutes.

The primary strategic role of active ICBMs in the service of world powers is to deliver nuclear weapons, as one element of the nuclear triad, along with bombers and submarine-launched ballistic missiles (SLBM).

Although rarely used so far, ICBM warheads can be conventional or contain hypersonic glide vehicles (HGV) that can maneuver and glide at hypersonic speed.

ICBMs are among the most powerful weapons ever created, reshaping global geopolitics since their Cold War debut. Modern air defense systems can shoot them down, but intercepting ICBMs mid-flight remains highly challenging.

What are the specifications of Khorramshahr-5?

According to some media reports, the Khorramshahr-5 is an ICBM with an operational range of up to 12,000 kilometers, a distance that covers the entire mainland United States.

This figure is much higher than Iran's current longest-range ballistic missiles, specifically the Khorramshahr (1-4), which is estimated to have a range of up to 4,000 kilometers.

The Simorgh carrier rocket would also have a similar range if converted to a ballistic missile, and the intercontinental range would be reached by the converted Soroush-1 and Soroush-2 carrier rockets, both currently under development, with payloads 10 to 20 times greater than the Simorgh, respectively.

However, it is unlikely that a potential ICBM would be based on these civilian carrier rockets, which are bulky, slow to load with fuel, and thus easy targets for an enemy in the event of an all-out war.

The Khorramshahr-5 missile's speed has been reported to be Mach 16 (approximately 20,000 km/h), typical of ICBMs in mid- or terminal flight.

Such speeds require a reentry vehicle (final stage) capable of withstanding the extreme heat and forces of atmospheric reentry while returning to Earth, delivering the payload accurately to its target.

Iran has already demonstrated this technological capability by testing hypersonic Fattah missiles that reach speeds of Mach 15, have special resistant materials, and complex guidance.

The third interesting feature of the Khorramshahr-5 ICBM is, as per reports, its two-ton warhead payload, which is said to be comparable in power to American bunker buster bombs.

It is not clear what particular range this figure refers to, since payload is inversely proportional to range and can drop tenfold from minimum to maximum range.

Regardless of whether it refers to 5,500 or 12,000 kilometers, Iranian Defense Minister Brigadier General Aziz Nasirzadeh reported in June that a record-breaking two-ton warhead had been tested at hypersonic speeds.

However, he did not mention these warheads in the context of intercontinental ballistic missiles, but said that they could be used for existing medium-range (MRBM) and intermediate-range ballistic missiles (IRBM), such as the Emad and Khorramshahr.

Other features reported in the media, such as a height of 12 meters and a mass of 14-15 tons, are not reliable because they are not congruent with claims of liquid fuel propulsion and a two-ton warhead.

Press TV’s website can also be accessed at the following alternate addresses:

www.presstv.co.uk