The largest truss framework aircraft I know of is the Messerschmitt Me 323 Gigant but I would not cite that as technology heritage.
I had forgotten about the Me323. It's *huge*. It's too bad that it's proportions are very different from Skylon's.
Thank you for continuing to post to this thread. The announcement on the 1st phase of the pre-cooler costs was very positive.
In regard to funding I am unclear but was the next stage of funding conditional on passing this phase, the 2nd phase that's starting or all 3 test phases of the pre-cooler?
It was my impression that even in phase 1 the outlet from the pre-cooler would already be below zero and frost control would have to be working or the structure would be seriously damaged, which seemed to be the decision gate for releasing the £200m block.
aero “I'm wondering why it costs $10 billion to get something flying.”
Because it doesn’t - $10 billion includes the qualification programme to get the plane into operational service not just the first flight. It is comparable to the cost of a large civil jet program such as the Airbus A380 for pretty much the same reasons.
I think this is a point (along with the fact Skylon gives you ELV payload fraction in an SSTO vehicle) that should be better emphasized.
People who are not familiar with the project see that figure and wonder why it's so much bigger than say the EELV programme for either Delta or Atlas.
They see the cost to get to the 1st LV *rather* than including the full cost of qualification launches, and the substantial post flight analysis (and any associated modifications that analysis shows to be necessary) and the re-flights to confirm the changes. This also disregards the cost of funding from commercial lenders.
I understand that including a *full* test programme in the cost estimate REL is demonstrating to lenders there are no hidden "extras," that in reality you would have to get funding for down the line to get type approval. Would it be possible to *publicly* give a figure for how much it would take to get to the 1st orbital capable vehicle? Not for sale (and possibly not full sized) but to fly the full envelope and demonstrate HTOL SSTO from takeoff to orbit to landing.
I believe that ability to deliver down mass is another significant part of its appeal. A one way demonstration trip to orbit would not be sufficient.