Introduction - Autonomous and Autonomic Systems - page 13

Table 1.3. Ratio goals for people controlling spacecraft
Number of people Current Goal
Number of to operate with people: people:
Year Mission spacecraft current technology S/C S/C
2000 WMAP 1 4 4:1 -
2000 Iridium 66 200 3:1 -
2000 GlobalStar 48 100 2:1 -
2007 NMP ST5 3 12 - 1:1
2012 MC 30-40 120-160 - 1:10
WMAP Wilkinson Microwave Anisotropy Probe; NMP New Millennium Program;
MC magnetotail constellation

The figure also shows the operator-to-spacecraft goal for the future missions.
Missions capable of performing the desired science will achieve the operator-
to-spacecraft ratio goals only if designed to operate without intensive control
and direct commanding by human operators. Clearly, a combination of au-
tomation, autonomy, and autonomicity will be needed . 1
In many cases, multispacecraft missions would be impossible to operate
without near-total autonomy. There are several ways autonomy can assist
multispacecraft missions. The following section describes some of the ways by
which autonomy could be used on missions to reduce the cost of operations
and perform new science.

1.3.1 Multispacecraft Missions

Flying multispacecraft missions can have several advantages, including:

• Reducing the risk that the entire mission could fail if one system or in-

strument fails

• Making multiple observations of an object or event at the same time from

multiple locations (giving multiple perspectives or making the equivalent
of a large antenna from many small ones)

• Reducing the complexity of a spacecraft by reducing the number of

instruments and supporting subsystems

• Replacing or adding an instrument by adding a new spacecraft into an

already existing constellation or swarm

The Wilkinson Microwave Anisotropy Probe (WMAP) mission, launched
in 2001, was forecast to use an average of four people to operate the mis-
sion (Table 1.3 ) . This mission consists of a single spacecraft and utilizes a
small number of people for operations. The Iridium satellite network has 66

1 To simplify, in the remainder of this topic, since autonomicity builds on auton-
omy, we will simply refer to the combination of autonomous and autonomic systems
simply as autonomy, except where explicitly noted.