The Valkyrie is roughly four times the size of the twentieth-century Earth shuttles. Because it uses fusion engines, the Valkyrie can redirect its containment fields for active EMF damping, so it can function very well in the high magnetic field areas of Pandora. It does not rely solely on passive shielding. (Read more)
But its most important mission is the transportation of refined unobtanium from the surface of Pandora back to the orbiting ISV. Without this capability, there would be little or no human presence on Pandora. It is also the only possible ride back to the mothership, and thus the one link with the long highway back to Earth. When the Valkyrie enters the dense Pandoran atmosphere from orbit, the hypersonic speed creates friction that heats the advanced carbon-fiber tiles of the thermal protection system, which covers the nose and leading edges of the delta-shaped wings. As it decelerates in the upper atmosphere, it glides toward its landing site at Hell’s Gate. At 10,000 feet the air-breathing turbojet engines are activated. These provide forward propulsion until the shuttle is on final approach. At that point the engines are vectored for the transition to VTOL mode. The Valkyrie’s powerful fusion power plant can provide energy to the lift engines for hours at a time, which allows the shuttle to function as a low speed aerial platform for exploration and survey roles. As the shuttle approaches landing, it hovers on thrust from the four-poster lift engines, then settles slowly to the ground as thrust is throttled back.
For ascent to orbit the sequence is reversed. The shuttle rises in hover, then the lift engines are vectored aft slightly to begin forward acceleration. The TAV transitions to wing-borne forward flight at 130 knots (in Pandoran atmos) with the engines now aligned longitudinally for forward thrust. It then accelerates to supersonic speed on the turbojet engines. As it approaches Mach 3, the hypersonic inlets open and the TAV goes into scramjet mode. It accelerates at 3G’s to Mach 7, and then transitions to the fusion Orbital Engine for the final burn to orbit.
The Valkyrie rides on a plume from its dual-mode fusion engine so powerful that it is visible at night from Hell’s Gate almost all the way to orbit (though it disappears over the horizon before orbital velocity is reached). Though it reaches orbit in less than ten minutes, the Valkyrie requires an additional six hours to maneuver to rendezvous and hard-dock with the ISV. Despite its size, the Valkyrie's mass is relatively small due to a fuselage fashioned from extremely strong non-metallic composite material. The material has high tensile strength, but only one quarter of the weight of the permalloys used in previous shuttles. The superstructure uses carbon nanotube composite in key locations to maximize stability and help conserve fuel. The two exhaust nozzles of the orbital engines face aft, and the engine nacelles are heavily shielded from the cargo bay. The least radioactive sections of the reactor directly parallel the bay. There is a rear ramp that lowers for the unloading of large vehicles and AMP suits. There are fold-down stools with passive restraints for the individual passengers which line both long walls of the bay. The AMP suit racks are located in the middle of the cargo bay in a double row. The cargo bay is a double deck design which allows the ISV cargo modules to be stacked two-high inside the bay. Cargo modules are transferred from the shuttle to the ISV by a large robotic arm which travels along the longitudinal spine of the starship on a mobile transporter base.