Most of youtube content is not 1080P HD. Broadcast stations were forced to go to digital HD 15 years ago and given a 20Mbs slot of bandwidth in exchange for their previous analog spectrum. That was only enough for a single 1080i (not 1080P) broadcast.
The compression schemes used by satellite and cable companies and internet streaming can fit more resolution in less space, but I think Netflix claims you will need at least 10Mbs. In practice, with all the routing hops and traffic congestion, 10Mbs is nowhere near enough and I run into hiccoughs at 45Mbs where I am.
You might be able to test your download speed here : http://speedtest.dslreports.com/
I’d be interested in your actual HughesNet results.
I tried to download it but it demanded I add it to my homepage etc. Firfox blocked it and I thought that might be a good idea.