Says 15 000 kg to 300 km LEO, or 11 000 kg to 800 km, out of 350 000 kg launch mass: https://en.wikipedia.org/wiki/Skylon_%28spacecraft%29#Overview https://en.

Says 15 000 kg to 300 km LEO, or 11 000 kg to 800 km, out of 350 000 kg launch mass: https://en.wikipedia.org/wiki/Skylon_%28spacecraft%29#Overview https://en.wikipedia.org/wiki/Skylon_%28spacecraft%29#Overvi... So similar sized as the two-stage Delta IV Medium, with exactly the same mass fraction (23.3 - 23.5): http://www.spaceflight101.com/delta-iv-medium-42.html http://www.spaceflight101.com/delta-iv-medium-42.html