Months before the planned launch of the open enrollment process for President Obama's health care law, a top official at the Centers for Medicare and Medicaid Services expressed fear that the federal health care website would "crash," according to an internal email, even as he publicly testified to Congress that it would be up and running on Oct. 1.

As the deputy chief information officer at CMS, Henry Chao helped oversee the development of the troubled website. In a July 16 email unearthed by the House Energy and Commerce Committee, responding to a request for more money from contractor CGI Federal, Chao wrote, "I just need to feel more confident that they are not going to crash the plane at take-off, regardless of price."

The next day, he and CMS chief Marilyn Tavenner testified before Congress that the website would meet its Oct. 1 target.

"CMS has already completed the majority of the development of the services required to support open enrollment beginning on Oct. 1, 2013, for coverage beginning on Jan. 1, 2014,” Tavenner testified.

On July 20, Chao emailed a link of the hearing to the tech team working on the Obamacare launch.

"I wanted to share this with you so you can see and hear that both Marilyn and I under oath stated we are going to make October 1st," he wrote. "I would like you [to] put yourself in my shoes standing before Congress, which in essence is standing before the American public, and know that you speak the tongue of not necessarily just past truths but the truth that you will make happen, the truth that is a promise to the public that millions of people depend on for us to make happen."

Read this and other emails released by the committee here.