                               Concept : Space

 Space shuttles are high-tech, manned, navigable satellites.  Unlike expensive
one-shot  satellites  however, shuttles are reusable.  Also, while the initial
construction cost of a shuttle is high, each launch of  the  same  shuttle  is
relatively inexpensive at around $500 per shot.

Unlike satellites, which stay in a fixed orbit, shuttles can be maneuvered  to
various  altitudes and can even change orbital direction. Altitudes range from
0 (on the ground) to 127 (the threshold of space).   The  planet's  atmosphere
extends  up  to  about altitude 32; it is beyond this point that shuttles best
function.

ORBITAL VELOCITY AND DIRECTION

Orbital velocity varies linearly with altitude.  Each update,  a  shuttle  (or
satellite) will move zero distance if in the geosynchrous parking orbit at the
threshold of space (altitude 127); a distance of ETU sectors if at the edge of
the  atmosphere  (altitude  32);  appropriately larger or smaller distances at
other altitudes.  The direction of movement generally is set by the  direction
in  which a shuttle (or satellite) is launched; although you can use the `nav'

                               Concept : Space

command to maneuver a shuttle in any direction as it  flies,  it  will  always
continue in its current orbit at the update.

The only way to alter the orbital direction is to first ascend to altitude 127
(the zero-velocity geosynchronous parking orbit), and then `navigate' in a new
direction.  The last direction in which you move will become the  new  orbital
direction if you then descend to a lower altitude.

With increased altitude, a shuttle's radar and viewing range increase.  Report
accuracy,  however, decreases.  Shuttles themselves are visible only to ground
radar (they show up on the map as a '$')  and  to  other  shuttles  in  nearby
orbits.

LIMITED O2, ORBIT DEGRADATION, AND OTHER INTERESTING STUFF

Like submerged submarines, shuttles have limited  oxygen  for  the  crew.   To
replenish  oxygen, you must land the shuttle.  In any sector capable of build-
ing a shuttle, cabin O2 automatically refills completely  during  the  update.
Aloft, O2 depletes at the same rate as aboard submarines.

                               Concept : Space

All orbits below 127 degrade somewhat with  each  update,  with  low  altitude
orbits  suffer greater degradation than high altitude orbits.  The only excep-
tion is the parking orbit at altitude 127, which suffers  no  loss.   Altitude
loss  in  other  orbits  varies  linearly  through the following points: 1 per
update at altitude 126; ETU/2 per update at altitude 32 (edge of  atmosphere).
Any  descent that ends up in the atmosphere with a vertical velocity exceeding
ETU/2 has catastrophic consequences.

Shuttles can land only in airfields.  You will be informed if  a  sector  does
not offer an suitable landing area.

Shuttles can be loaded, unloaded only while on the ground in airfields.   Once
aloft,  shuttles  cannot be boarded, and can be tended only by another shuttle
in the same orbit (both altitude and direction must match).

You use the `nav' command to move shuttles once they  are  airborne.   `Radar'
and  `look' range increases with altitude, but at the price of decreased reso-
lution.  From the ground, a shuttle in orbit can be seen only by radar.

If you wish to move a shuttle while it is on the ground,  you  can  do  so  by

                               Concept : Space

using the `transport' command.

See also : build, cargo, fleetadd, navigate, load,  lookout,  scrap,  upgrade,
transport, shuttle

