If its been soaked with paint,it's rock hard.If not ,it comes off easily,skim coat and paint.
This is key.^^^^^^^^^
If it has been painted after the initial application the removal is considerably tougher and that goes up exponentially with each subsequent layer of paint.
If there isn't asbestos involved and you do decide to do it yourself be sure to wear a quality (canister style mask) and goggles anyway.
If you get it down to where it can be skim coated, great, but expect to put a couple, if not three applications of skim on before you sand. With mud, the thinner the better. It's easier to mud smooth than sand smooth.
Another approach I've used in the past is to do a fake "knock down". You can take a pole sander and knock down alot of the texture and simply paint over that.
Another approach is to go over it with new drywall. Before you panic it actually can be easier to go this route and you may end up with a better finish in the end. Most municipalities require 5/8 inch drywall on ceilings so I will assume that is what you have. (typically fire codes require this). An added benefit of the 5/8 is it doesn't sag between the ceiling joists over time, or at least not to the extent that say 1/2 inch does, which some contractors try to get away with using. 3/8 inch is never used on a ceiling, or at least none that I've ever encountered.
Enter 1/4 inch
For this application I would consider using 1/4 inch drywall over your existing ceiling. Maybe do a light scrape job then glue and screw the 1/4 inch over the top. (be sure to catch your joists with the screws.) 1/4 inch isn't that heavy so it's easy to work with plus it will give you a finish like a brand new ceiling.
I'm lazy. The first drywall job I ever did was a church out in Simi Valley with cathedral ceilings back in the 70's when nobody screwed drywall, they nailed it. Since then I've tried every trick in the book to make hanging ceilings easier. Slave labor, dead mans, you name it. The best advice I can give you if you do decide to hang it yourself is to go to a "rent all" type place and rent a drywall jack. They're cheap and worth every penny. I've actually hung 12 and 14 foot sheets of 5/8's by myself with them. It will allow you to position each sheet properly and give you nice tight joints to tape. Plus, you can take your time screwing it off, have a sandwich, write a song, whatever.
I don't envy you. Short of having someone else do it you're in for some work any way you look at it. Underline checking for asbestos. Someone else mentioned it hasn't been used since 78 so if your home was built after that you should (emphasize should) be ok.
Good luck.