Comet Phase Operations Study

1
Comet Phase Operations Study
LOWG8

• J-F Fronton CNES / SONC
• MPS, Lindau April 2005

2
Context

• Over the three identified operation phases
  Descent and First Operations Sequence On
  primary batteries
• Based on document established in 2001-2004
• Definition of the Lander First Scientific
  Sequence for the On Comet Phase (J.Biele,
  D.Moura)

3
Approach / Objectives

• Analysis and modelling on Most of descent first
  sequence (55 hours)- definition of the
  dimensional constraints (inventory,
  classification, constraints clusters,
  validation) - nominal sequence optimisation
  validation vs. science expectations plus
  constraint coverage - proposal of alternative
  sequences - analysis to limits (resource
  mission constraints)- internship Anne Vigne

4
Initial proposed sequence (1)
5
Initial proposed sequence (2)
6
Initial proposed sequence (3)
7
Initial proposed sequence (4)
8
Alternate Comet Operations

• Possible sequenceSESAME as background (except
  when CONSERT, APXS)

9
Constraints inventory

• Environmental constraints- comet day / night
  cycles- lander / orbiter visibility- orbiter /
  earth visibility- landing site impact
• Lander constraints- power / temperature- memory
  management- data processing transmission rates
• Scientific constraints- incompatibilities
  between experiments- non formal non expressed
  constraints

10
Operations modelling

• Sequence modelling with Most- taking into
  account the variation of the constraints
  (clusters)- establishment of three case study
  scenario for each phase
• worst case
• nominal case
• best case

11
Remaining activities

• ActionsFor experiments- constraints
  validation - individual activities description-
  general scenario - general scheduling (Most)-
  instrument modelling (Most)- modelling
  validation (GRM HK data) For subsystems-
  modelling (Most)- modelling validation