Orion(2001)

The Orion is a spacecraft included in the add-on World of 2001.

Alternative history

Development of the spaceplane proceeded in two stages. The first stage was to develop the orbiter, which would get to orbit by staging a drop tank. The Lockheed Starclipper was taken as a design starting point, though the final configuration of the Orion II/III was different in many details.

The Titov V was not; it unabashedly shows its origins as the borrowed Starclipper.

Both designs wound up being horizontal takeoff, assisted by a steam catapult. This was driven partly by customer demand – airlines wanted an airplane that could reject a takeoff or return to base at any point, not a flame-belching vertical-takeoff behemoth that needed to get supersonic before it was possible to abort and return to land. This also allowed easier adaptation to the later two-stage concept, as no engines would have to be removed to make that work. The drop tank itself was named Orion I; the cargo shuttle Orion II. The passenger-only version came later, named Orion III.

The Titov used different nomenclature; the drop tank was Blok A (Titov A), the booster Titov B, and the orbiter Titov V (third letter in the Cyrillic alphabet).

Operation

Orion II/III and Titov V operate the same way: the spaceplane is launched with a drop tank or booster stage, catapulted off and up from a steam catapult. A wing-borne flight phase gets the combination above the atmosphere with low drag losses. The engines throttle back to maintain a comfortable acceleration level (3 G's for Orion). Propellants are fed to the upper stage so its engines can help push. The booster / drop tank carries most of the propellant and does most of the work, staging at around Mach 20.

You can switch viewpoint and fly the booster home at this point, making a high-mach 180-degree turn. At the end of this, you'll be much slower; stretch the glide and turn on the airbreathing engines once they are usable. Internal tanks fly the spaceplane the rest of the way to orbit, serve for on-orbit maneuvering, and perform the de-orbit maneuver. The “stage” of the vehicle can be incremented on-orbit, disabling the big engines which are very overpowered for orbital maneuvering. All engines (except the jets) share the same LOX/LH2 propellant tanks; there is no separate RCS or de-orbit tank. Save some! Re-entry is very conventional for the Orion II/III.

Both 2001 spaceplanes use air-breathing propulsion to stretch the glide or perform a go-around. The Orion uses a “ram-wing” concept with small turbopumps for subsonic operation. This allows operation at up to Mach 3.0 and saves mass, though at a cost in fuel consumption. There are some differences between the spaceplanes; as already noted, the Orion can cruise supersonically. The Orion has a dedicated passenger version; the Titov has a single model that drops in a passenger module for passenger service. A dedicated version with windows would make little sense in a lifting-body, where windows would give views of the hydrogen tanks. Both spaceplanes dock with station V using a “virtual” docking port that allows the craft to move into position nose-first but has no physical reality. At Station V, docking arms and cradles (not animated!) would hold the spaceplane in position (or move it to a location off the centerline) and a boarding access arm would snake up to the hatch on the side of the craft. The side hatch is also a legal docking port. The other craft would have to have a flexible collar to mate to the spaceplane's less-than-perfectly-flat exterior face. But this does not seem to be a major problem with 2001 technology. Both spaceplanes are commercial successes, including export sales. China makes Titovs under license; other countries have airlines and sometimes militaries that operate Orions (Western Europe, Australia) or Titovs (Eastern Europe, India).

Keyboard controls

U	Set a launch azimuth for the autopilot (the scenario provides one already)
O	Start the autopilot.
J	Jettison the next stage or payload. Jettisoning the payload only works when the bay doors are open.
	-3 Booster stage only
	-2 Booster stage with orbiter (next stage will skip to Stage 1)
	0 Drop tank and orbiter
	1 Orbiter with main engines
	2 Orbiter, main engines disabled (OMS engines enabled)
	3 Orbiter on airbreathing engines
K	Open/close the payload bay doors
P	Open/close the side personnel hatch
E	EVA from the spacecraft (only if the personnel hatch is open)
G	Lower/raise the landing gear
B	Toggles the wheel brakes
CTRL+J	Join a nearby payload to a suitable attach point. (Only if point is within 20 meters distance and 20 degrees of alignment)