There are a few issues with building an orbital aircraft to launch satellites. We need more than one stage, so do we put the stages under or on top? Under threatens ground clearance but offers a drop. Even a drop may be driven back into the carrier by air currents. On top has the same issue plus gravity resisting that separation. I can see that I am not alone in considering in-line staging on horizontal applications. Does anyone know what this is? I don’t. The only use I see is space launch, but does it work?
A REAL DARK HORSE
Boeing has an in-line application brewing too. No fear of structural issues here!
HYPERSONIC TO SPACE
Actually in-line staging has already been flown for an X-plane. The X-43 was mounted on a Pegasus winged rocket for its testing flights.
TECHNICALLY THIS IS PARTIALLY ON TOP OF THE PEGASUS
IF THE FIRST STAGE IS HIGH PERFORMANCE, THE UPPER STAGE CAN BE SMALL
BUT NOT ALL THAT SMALL!
So I don’t feel too bad about keeping my concept alive. There are aerodynamic advantages in the HILLS blended wing bodies that these earlier examples are missing. Expect to see more development of our concepts.
Staging and aerodynamics are not the only issues here. Early space planes were fond of their metal structures, but we are seeing more composites now. The Dream Chaser and the Xcor Lynx showcase 21st century structures. I see pressure vessels and tanks as part of the structural consideration. They can help with lateral loads and rocket engine linear thrust loads. Airframes can lose weight with carbon fiber and optimized analysis. We may not reach the goal with older airframe designs, so we move on.
EVOLUTION IN STRUCTURES
REDUCED METAL CONTENT AND HYBRID PROPULSION HERE
COMPOSITE BULKHEADS AND SKINS
SKINS OVER STRUCTURE AND PRESSURE VESSELS
WING MASS PENALTY OFFSET BY MATERIALS AND METHODS
XCOR LYNX TANKS AND CABIN COMING TOGETHER
SKINS ARE NOW MORE STREAMLINED THAN EARLY IMAGES
XCOR RARELY SHOWS YOU CURRENT IMAGES SO SAVOR THESE!
We see problems and solutions as we move into a design project. These ventures share the same technology availability except for the unique solutions we can each add. I look ahead to lots of work and lots of paychecks for the innovators and problem solvers.