Mission Planning for MOMS-2P

Martin Wickler, German Zoeschinger
martin.wickler@dlr.de
DLR / GSOC

Abstract

The spatial high-resolution Modular Optoelectronic Multispectral Scanner 
(MOMS-02) operating  outside the PRIRODA-module of the Russian space 
station MIR will provide digitized high-resolution images of the earth, 
suitable for thematic and three-dimensional topographic mapping. MOMS-2P 
(MOMS-02 on PRIRODA) is a co-operative project between Russia and 
Germany, the operational phase of which is expected to last 18 months 
starting in summer 1996. 

The control of and planning for the MOMS-2P camera is done by DLR/GSOC 
in Germany in co-operation with the PRIRODA group at the Russian control 
center ZUP near Moscow.
The user community, consisting of Germans and Russians, has highly 
demanding requirements, which range from imaging whole continents to 
performing repetitive data imaging over small earth targets under 
certain seasonal and lightning conditions.
On the other hand a set of operational constraints limits the possible 
data take opportunities (e.g. not more than 10 minutes data imaging per 
day are available, tape for data recordings has a capacity of 
60 minutes, data dumping conflicts with recording).
This calls for a sophisticated planning concept to exploit the assigned 
resources efficiently.

This paper describes the planning concept, developed for MOMS-2P, which 
profits from experience gained by MOMS-planning at GSOC during the Space 
Shuttle mission D-2.
The concept is based on a distributed planning approach. It makes use of 
the so-called "envelope method", which in this case regulates the 
exchange of requirements and resource availabilities between GSOC and 
ZUP, and ensures that the MOMS-planning at GSOC is harmonized with the 
overall PRIRODA-planning at ZUP.

The planning is carried out in three stages with an ever increasing 
level of detail. 
In the top level plan, covering a period of three months, a subset of 
targets is selected taking into account seasonal constraints and user-
defined priorities. 
The so-called two week plan reflects an observation timeline, which is 
optimized for data takes and dumps, using statistical weather 
information to prefer target areas with expected low cloud coverage in 
this time frame. 
Finally a one day plan allows for consideration of actual weather and 
any off-nominals.
The concept is realized using the GSOC mission planning system with 
tailored add-ons developed for MOMS-2P, especially focussing on 
visualisation of groundtracks and scheduling of a large number of 
activities.

In summary the MOMS-2P planning is an example for an optimizing planning 
concept for any kind of future earth observation missions.

Key Words: earth observation missions, activity scheduling, 
(distributed) mission planning, envelope method