The Mark 14 waverider has evolved from a manned waveriding capsule concept designed to be mated to the top of an Aspire III rocket.
It was realised during the design work on the Aspire III rocket early in 1994, that there would be sufficient capability to loft a manned payload on a sub-orbital flight. The initial design work was carried out by Richard Osborne later on in 1994, and envisaged a small manned capsule with a waveriding lower surface. The design then evolved into a waverider rather than a manned capsule, with a new waverider shape being designed by Rick Newlands. The designation, Mark 14 was then alotted to the vehicle.
Separation of the Mark 14 waverider is designed to occur at apogee, and sub-orbital re-entry at about Mach 8. The Mark 14 waverider is being overdesigned for return from low Earth orbit, following launch on a conceptual rocket booster.
By keeping the wingloading down below 30lb/square foot, and utilising a Waverider's superior lift coefficient of about 0.8 at 50 degrees angle of attack, a waverider can glide high enough up in the atmosphere to perform re-entry at up to Mach 25 at low air densities, and as kinetic re-entry heating depends on density, the temperatures can be kept down to about 1200 kelvin at the worst point (on the nose stagnation point). High altitude gliding in this case refers to altitudes of between 25 miles (40 kilometres) and 40 miles (64 kilometres) high.
Currently, 2 types of landing are being considered, either a landing on a runway, or a simpler and lighter, steerable ram-air parachute, adopted from the Aspire Rocket recovery systems, and deployed at 3000 feet. The initial sub scale vehicle tests will make use of the steerable parachute system rather than landing gear.
The Mark 14 waverider is a small vehicle. This is neccesitated by the capabilities of the Aspire III rocket. The current design measures 4.89 metres long, and is 2.225 metres wide.
Since the Mark 14 waverider re-enters at Mach 8, the design of the heat- shield is relatively straight forward to design. As a Waverider's upper fuselage is at near-vaccuum pressure during high-angle-of-attack re-entry, the heat absorbed by the underside heatshield can be channelled round a hot-metal fuselage and re-radiated off the upper surface. One of the two current design proposals is to build the inner pressurised cockpit and fuselage out of composites such as fibreglass, and insulate the inner pressurised cockpit from the hot, outer hull using either insulated swing-fixtures to allow for thermal expansion of the outer hull, or by adopting the low-pressure 'balloon' cell approach recently suggested for Hotol, where the outer hull is made up of an interlocking network of titanium-foil balloons filled with low-pressure helium. Although this may sound fragile, it works for distributed heat and pressure loads, and as it is semi-flexible, thermal expansion is not an issue.
The nose-cap and wing leading-edges will be conventional pyrolised carbon-fibre, as on the space shuttle.
A series of Mark-14 waverider vehicles are planned, as follows:
The design work for the first sub scale Mark-14A vehicle has been completed, and the first sub scale Mark 14 waverider has been constructed. Wind tunnel testing has been delayed for the moment.
Construction has started on the Mark-14B sub scale waverider.
Detailed design work is still underway on the structural design of the pressurised cockpit. Design of the underside waveriding cavity is also being undertaken by using Computational Fluid Dynamics (CFD) software.
The first test flight on an Aspire II rocket will be as and when an Aspire II rocket is available.
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