Great! I've been interested in Skylon and the Sabre engine for a long time. It'll be amazing to eventually see it in action! *This* is truly the future of both ordinary flight and spaceflight - a 100% reusable vehicle with incredible speed.

Of this I approve for now. Global interactive approval should be offered on an item by item basis - this ensures the people who will ultimately benefit will have a part to play - this leads to global co operation and several possible side effect designs become available

Thunderbird One is go!

This will be the first "truly green" space launcher!!! We need it!

60 million? it's a Kit model? :D

Some people never learn. Starting around the speed around mach 5 the system will switch to conventional rocket propulsion, yet it will have only around 5% of the kinetic energy to enter on low earth orbit. This design will have the drawback of accelerating to orbital speed with a heavy turbo-machinery and an over-sized frame. Also the design is forcing the usage of "classic" propellant combination, liquid oxygen and liquid hydrogen, when other cheaper combinations might result in better designs (http://www.dunnspace.com/alternate_ssto_propellants.htm). After spending a fortune on HOTOL they keep on pushing in the wrong direction. Two stage to orbit is the way to go.

The real attraction to me is for international passenger flights. The PanAm 747s that flew me to Asia and back to the US in the 70s have barely changed. 2 hour flights to anywhere on the globe would change our lives in incredibly beneficial ways.

A scramjet is a Supersonic Combustion ramjet meaning that the relative airspeed through never drops below supersonic velocities; it is a neat trick keeping a fire burning under control in a 700+mph breeze a little like keeping a candle lit in a hurricane. The SABRE does not do this it condenses the oxygen out of the air and pumps it into a rather conventional liquid rocket engine. It is also a neat trick and I hope Skylon works but I don't think it will.
I would go with a large high lift low drag blended wing aerospace plane burning a noncryogenic fuel that is stored in the wings and super chilled LOX. This craft is towed to high altitude by another plane that looks like a Photoshopped joke of too many engines on an airliner.

Elon Musks Hyperloop will get us around the surface of the planet in vastly greater numbers and at a fraction of the cost. Space elevator for the low earth orbit stuff.

What worries me is that it is just another engine The obvious offshoot for this is war applications - otherwise why do we need to go into space? We should be investing this money in sustainable technologies to pass cost savings onto the needy and make our country free from fossil fuels. Example Rolls Royce - who work and live in the UK but manufacture in the US and have been reported for avoidance of paying UK taxes - what is the point of this company or similar companies if they support weapons of destruction and think that they can play games with their social responsibilities?