Afraid of a terrorist dirty bomb attack, the U.S. government hired Tony Stark to develop an answer to the radioactive fallout. The goal: a radiation suit for the layman (U.S. government operators) to operate in irradiated areas, primarily for cleanup activities but also for possible armed responses. Fearing that terrorists would soon escalate to a gamma bomb attack, Stark wanted to ensure that his new suit would withstand not just the fallout of a regular nuclear device but also that of the much more potent gamma bomb. To that end, he built the Gamma Armor, Mark I, in Marvel Knights Incredible Hulk #72.

Prior to enlisting Stark’s help, the government found the elements needed to shield the gamma radiation, made constructing a flexible working suit nearly impossible. Remember, gamma photons are not halted by lead or other materials that normally repel atomic particles. But then Stark—something of an expert in the flexible armor field—came along. Working in absolute secrecy, from even most of his employees, Tony built a strong, flexible, and extremly user-friendly suit. (Although the project was not without its failures. Near the end, a researcher on the project, Lisa Cummings, died testing one prototype in secret.) When done, the Gamma Armor, Mark I, withstood both an H-Bomb test and the rigors of gamma radiation well enough. It just wasn’t visonary enough. Enter Dr. Bruce Banner and RG-27.

Banner had the idea that the suit shouldn’t just protect the wearer, it should erradicate the gamma radiation. By infusing the suit with RG-27, Banner helped Stark create an armored suit that could keep the wearer safe while cleaning the environment around the suit at the same time.

RG-27 not only shields gamma radiation, but breaks down the photons, too. And since RG-27 is most potent in gas or liquid forms, the suit is lined with a network of minute irrigation tubes, flowing with RG-27. Behind the reservoir system is a second ultra-thin lining of magnesium oxide, which acts like a magnet, drawing gamma photons into the suit. Gamma radiation is sucked into the suit through microscopic pores. In the end, the Gamma Armor shields the wearer and cleanses the environment at the same time.

This new suit, Gamma Armor, Mark II, worked better than expected—in both tests and the real world. In fact, it withstood a blast six megatons beyond the stated requirements. (Stark tampered with the schematics to make it even more powerful than the government specs.) Unfortunately, there was a downside to this quality.

The Gamma Armor sucked radiation into it as planned, maybe too well. When the irrigation system was compromised, Stark suffered gamma poisoning—he was bombarded by gamma photons. Like his colleague, Dr. Banner, absorbing the gamma radiation made him (and the armor) super powerful. Stark began to hallucinate, experienceing a kind of euphoria, a rush of power. Fortunately Banner and his close friend the Hulk were around to put a stop to Tony’s rampage.

The Gamma Armor featured oversize boots and gauntlets. Red and gold, it also had glowing ports across the armor at key locations. (The exact nature of the ports is unknown, but they may function as lights, repulsors, or even engergy conversion points.) The most notable cosmetic feature is actually the lack of a standard Iron Man feature: his iron briefs. Unlike other armors, the Gamma Armor lacks the key groin segment—the briefs IM is well known for. Instead, the armor’s base is an underlying golden armor suit, which functions as integrated “pants.” There is no need for a separate groin piece.

Armaments: wrist-mounted repulsors.

Early tests and the real world use were all successful—until Stark’s impact with a tunnel wall broke the internal filtering. So, at normal and undamaged, the Gamma Armor would’ve worked. However, the armor’s current status is unknown.