The government may be headed for a shutdown at midnight Monday, but according to Health and Human Services Secretary Kathleen Sebelius, it will have no effect on the next phase of the Affordable Care Act, the opening of the new health insurance marketplaces, which are set to launch at 8 a.m. Tuesday morning.

"Shutdown or no shutdown, we are ready to go, to start enrolling people tomorrow," Sebelius said at a news briefing today. "We are about to make some history and some very positive history for lots of families around the country."

Sebelius said about 52 percent of HHS employees will be deemed unessential and furloughed, but that will not affect any workers in the call centers or "navigators" tasked with helping people to sign up. Most of the funding for the Affordable Care Act, aka Obamacare, was provided in the law so it would not be affected even if the federal government shuts down.

Sebelius did say it was "hard to tell" how a prolonged shutdown could affect implementation of the law down the road, though.

"That begins to look more serious the longer it takes," Sebelius said, noting that much of HHS' operations will be covered under "mandatory money."

She also acknowledged that there were bound to be "glitches" when the new insurance marketplaces come online Tuesday morning, and people begin to sign up. HHS is running all or part of the marketplace exchanges in 36 states; the others will be handled by each state individually. She compared that possibility to Apple's latest software upgrade, which asked users to download an additional update to fix problems with the initial update.

"No one is calling on Apple to not sell devices for a year, or to get out of the business because the whole thing is a failure," Sebelius said. "Everybody just assumes, 'Well, there's a problem, they'll fix it, we'll move on.'"

Sebelius continued, saying, "We're likely to have some glitches. We will fix them and move on. Is this a sign that the law is flawed and failed? I don't think so. I think it's a sign that we are building a piece of complicated technology."

Tips for finding the most affordable plan in your state's exchange.

Individuals and their families can begin to sign up for health insurance in these marketplaces Tuesday, but insurance does not kick in until Jan. 1. The deadline for purchasing coverage is Dec. 15. Although there is some confusion, with some people believing the insurance begins Oct. 1, the Affordable Care Act has many start dates for various parts. The portion of the law that allows young adults up to age 26 to stay on their parents' insurance is already under way.

Since there is a six-month window where the public can enroll in coverage, HHS officials said this period will allow them to work out any problems that emerge. "Oct. 1 is not the end of anything, it is the beginning," said Sebelius.

Sebelius and the other senior HHS officials at the briefing said after Tuesday they would ramp up their promotional campaign, which will include "turning up the volume on our educational efforts," Sebelius said, and reach out "to people in person, on television, on social media and traditional media."

She also said that with this campaign many Americans "will be learning what the law means to them" for the first time, and they won't be relying on "conversations inside the beltway, but conversations in their own community" from people including clergy, media personalities and even celebrities."

Last month, singer Katy Perry retweeted a tweet from the president that said, "If you're one of millions of young Americans without health insurance, you can get affordable coverage starting Oct. 1."

Today, HHS officials noted there would be others, but they wouldn't name any other names. (Jennifer Hudson and Amy Poehler have already expressed support.)

The briefing also included a demonstration from HHS officials on how to apply for coverage through the federally run health insurance exchange on healthcare.gov. They said they took into account that some users prefer graphics while others want "simple" text, so the site includes both. Sebelius called the system "user-friendly" and said it was a "gazillion times faster" than signing up for private health insurance. She noted the call centers can help customers in 150 languages.

There is also a Spanish language site: CuidadoDeSalud.gov, Spanish-language users that will launch Oct. 21 as part of a National Week of Action to "raise awareness with Latino consumers" about the health care law, according to HHS.

Healthcare.gov is designed to help individuals and families buy insurance or determine if they qualify for Medicaid or for tax subsidies to help buy that private insurance. Plans can be compared side by side, and will list monthly premiums and out-of pocket-costs. The exchanges will not handle the final step of enrollment. Once customers have chosen the plan they want, they will then contact the insurance companies themselves to sign up.

Neither Sebelius nor the HHS officials would answer specifically what would constitute success for the marketplaces, but Sebelius said the health care law opponents were "desperate for anything that could go wrong."