Commercial Rockets

UNHA (은하) ...and SAFIR/QASED (سفیر/قاصد‎), SIMORGH (سیمرغ), NARO (나로호), NURI (누리) — North Korea, 2012

The world’s best-known shorter range ballistic missile is the Russian R-17, known in NATO countries as the Scud. Many countries bought these, but nobody tried to make anything orbital out of it, because it didn’t have anywhere near a useful range. But the North Koreans, having made their own Scud copies which they named Hwasong, decided to see how far they could push the technology, and embiggened the design to a substantially larger scale. The result was a missile called the Hwasong-7, which could reach targets 1000 kilometers away.

As soon as the missile was ready, they promptly exported it to Iran, just as they had done with the classic Scud copies. It appears that the development of the larger version was largely funded by Iranian money, so they got to use the missile almost before its makers did. In Iran it became the Shabab-3 missile, and by 2001 they were building them locally.

This is what the Iranians turned to when they decided they wanted an orbital rocket. Scuds and their derivatives are single stage rockets which burn dimethylhydrazine hypergolically with nitric acid as the oxidizer. By adding one additional stage, the Iranians gave it just enough capacity to get a basic satellite into orbit. They called it the Safir (ambassador). This may not sound like an impressive space program, but the Iranians reached orbit three years before their North Korean friends did, and now have twice as many sats up.

When North Korea wanted a longer range ballistic missile, they continued the basic Scud engine design, but switched the fuel to kerosene, while still using nitric acid as the oxidizer. They then embiggened the booster by simply using four engines. This resulted in the Taepodong 2 ICBM, which got people scared because North Korea now also had a nuclear bomb to put on top of it. It more or less uses a Scud as its second stage. Then they decided that they wanted to boast of having orbital capability, so they added a third stage and came up with the Unha (Galaxy) 3. They got a satellite up on their third try in 2012, but of course claimed to have succeded in earlier attempts, since of all governments on Earth, theirs is the one most utterly dependent on bullshit.

Iran got a piece of this rocket as well, and is now working on a Simorgh (phoenix) launcher based on it, apparently using the Safir booster as a second stage. It’s sometimes just been called the Safir 2. The Simorgh has yet to successfully reach orbit, with four consecutive failures. But in 2020 a new Safir variant named Qased (messenger) did reach orbit. Apparently this version has a solid second stage, and is operated by the military instead of by the space agency.

As of 2021 Iran is shifting further toward solid fuel, announcing a new rocket in the works named the Zoljanah (after a legendary horse), which is also the name used for the giant truck that it will launch from. It has two solid stages and a liquid topper. Not much is known yet, but the target capacity is a few hundred kilograms.

Since it won’t do to be shown up by the North, South Korea then threw together an orbital rocket called KSLV-1 or Naro-1 (after the name of their space center’s location). They tried to make an entirely domestic rocket but then cheaped out in order to finish quickly, and just imported a kerosene/lox booster — an Angara core purchased from Russia. An early Angara prototype, rather — it had a lower trust engine than the final version. Because this booster was larger than originally planned, their solid second stage now seemed undersized on top of it. They then retired it after launching only one satellite in 2013, on the third attenpt. Now that they don’t have to rush to respond to the North, they’re developing a KSLV-2 or Nuri (“world”) which will be all domestic, and openly takes inspiration from the Falcon 9. The design has four engines on the hopefully reusable booster, then one on the second stage, and a little one on the third stage, all burning kerosene with lox. They’re aiming for a capacity of 2.6 tons. In 2020 the former head of their space agency was grumbling that the rocket will cost an enormous amount without producing anything commercially competitive, but it looks like they will be launching it in 2021. After that they want to privatize the technology.

Meanwhile, a small South Korean company called Perigee Aerospace is trying to beat the government to orbit by building a rocket so tiny that it weighs barely over two tons. See the Blue Whale article.

Safir-1: mass 26 t, diam 1.25 m, thrust unknown, imp ~2.5 km/s, type Gd, payload 0.05 t (0.2%), cost unknown, record 6/2/2?

Unha-3: mass 90 t, diam 2.4 m, thrust 1200 kN, imp 2.5 km/s, type Gk*, payload ~0.35 t (0.4%), cost unknown, record 2/0/2.

Simorgh: mass 87 t, diam 2.5 m, thrust 1300 kN, imp 2.5 km/s, type Gk*, payload 0.15 t (0.2%), cost unknown, record 0/1/4.

Naro-1: mass 140 t, diam 3.0 m, thrust 1700 kN, imp 3.3 km/s, type ZOk, payload unknown, cost unknown, record 1/0/2.