Like most ISPs, HughesNet's advertised speeds are their "Up To" maximum burst speeds. They aren't advertised or guaranteed to be any minimum fixed amount, and will vary from moment to moment - mainly due to the number of other concurrent users both inside and outside your residence. It's a dynamic system.
The only way to get a guaranteed fixed Internet speed over satellite is to pay for a dedicated, commercial satellite channel where you are the only user. These cost several thousand dollars per month.
As BirdDog wrote, 660 to 700 ms ping is pretty good for satellite. They're 22,300 miles out in space. A complete circuit from your house out to the satellite, down to the network operations center, and then back up and down to your house is about a 90,000-mile round trip.
Is there some application you're using that isn't working? That's a more relevant test of whether an Internet connection is adequate for your needs.