Some very interesting reading for those who are interested in doing so...
Why did we turn away from the progress that was being made by test projects such as the X-15? David Ashford goes into detail in his article posted on Spacefuture.com.
Quote: Present designs are sub-orbital in that they can fly fast enough to zoom up to space height for a few minutes but not fast enough to stay in orbit. Orbital spaceplanes need some six times the speed of sub-orbital ones and will cost some ten times more to develop. This cost is at present beyond the means of the private sector. The best way ahead is probably a public-private partnership. Government would pay for developing prototypes adequate for their own purposes. The private sector would then take over commercial exploitation. Governments would save money on present space programmes alone. Their reluctance to become involved in such a programme is little short of scandalous. End quote.
David Ashford goes on with the projects that are underway in Great Britain such as the Ascender. For more details,please visit both website articles listed below.
1. Spacefuture.com. "The Great Space Scandal" by David Ashford. March 7, 2010.(http://www.spacefuture.com/journal/journal.cgi?art=2010.03.07.the_great_space_scandal).
2. Bristol Spaceplanes Limited website. "Ascender" by David Ashford(http://www.bristolspaceplanes.com/projects/ascender.shtml).