Environmental Engineering Reference
In-Depth Information
Iteration time:
The long lead time required between science planning and
execution on-board the platform restricts the science opportunities of a
platform. An alteration of the science plan is required for the mission
group to refocus on the near-term activities.
A great deal of informal communications and negotiations happens bet-
ween the members of the planning groups. Members use a variety of mecha-
nisms to achieve consensus on the high-level science goals. Frequent meetings,
e-mail messages, and telecommunications are used, as well as a variety of
planning and scheduling tools. Normally the science planning group produces
a document that is passed on to the mission planning group. While this is
acceptable when the group is composed of humans, it severely limits the
possibilities for automation of group activities. The informal nature of group
activities imposes severe limitations on the speed at which the group can
reach consensus.
A careful analysis of mission cooperation shows that in some cases, the
wrong type of human cooperation is being applied to a particular level of the
hierarchy. This is especially clear in the mission planning group. Mission plan-
ning is primarily a traditional scheduling problem, dealing with optimizing a
candidate list of activities, resources, and constraints. Ideally, an automated
scheduling system would perform this task and focus on maximizing the sci-
ence output of the mission. The fact that the planning experts are primarily
responsible for the spacecraft's safety suggests that optimizing science out-
put will not be their primary focus. Instead, they spend much of their time
focusing on spacecraft safety and health issues. While spacecraft health and
safety are vitally important, the mission plan should always be optimized for
science output while simultaneously guaranteeing that safety and health goals
are met.
While all these features impose limitations and constraints on mission
effectiveness, the current mission organization has performed reliably for many
NASA missions. The cooperative autonomy model does suggest specific areas
where improvements can be made and these will be the focus of the next
section.
7.4.3 Improvements to Spacecraft Mission Execution
To increase mission science output in the current environment, it is necessary
to insert new technologies that decrease the labor needed in building and
managing spacecraft. This section will examine some technologies supporting
this goal.
The science planning group is responsible for setting goals and interpreting
results. It is one area where it is dicult to eliminate the large investment
in human labor. However, some technologies can be inserted that will make
planning efforts easier and more ecient. Groupware technologies could as-
sist in the planning cycle by making team communication and idea-sharing
