Veterans who served at secret base say it made them sick, but they can't get aid because the government won't acknowledge they were there

In the mid-1980s, Air Force technician Mark Ely's job was to inspect secretly obtained Soviet fighter jets. 

The work, carried out in hidden hangers known as hush houses, was part of a classified mission in the Nevada desert, 140 miles outside of Las Vegas at the Tonopah Test Range — sometimes referred to as Area 52. The mission was so under wraps that Ely said he had to sign a non-disclosure agreement.

"Upholding the national interest was more important than my own life," Ely told CBS News, and that's not just talk.