What does radiation hardened mean?

The short answer? That a product can withstand some amount of radiation.

The long answer? Radiation hardened has no real definition in the industry, it means something different to everyone. The term may mean that a product was designed with radiation in mind, or it could mean that a product was run through a series of tests to see if it could survive certain amounts radiation.

The issue of what radiation hardened means is only further muddied by the existence of the term 'radiation tolerant.' Radiation tolerant sounds like a less secure system, maybe one that can survive a little bit of radiation but can't go into geosynchronous orbit where there are larger levels of radiation. It can't be that easy, though, as there are radiation tolerant electronics that are actually better suited to surviving high-radiation environments than some radiation hardened electronics.

So, how do designers know that a product will be able to survive certain environments? There is the actual defined term of radiation hardened assurance (RHA), which guarantees that a product can survive certain amounts of different types of radiation.

Ultimately the ability for a product to survive radiation comes down to different tests and the data they provide. Tests that look at how well electronics can survive TID (total ionizing dose), SEE (single event effects) and ELDR(enhanced low dose rate) conditions. Radiation hardened does not mean a product can survive a specific amount of radiation, it only means that it can survive some radiation.

The term radiation hardened rings hollow as a descriptor, only saying that a product can survive some amount of radiation. Why is this term still used so heavily in the industry when it has no real meaning?