Philae oncomet science: remote sensing by CIVA, Rolis, CONSERT

1
Philae on-comet science remote
sensing by CIVA, Rolis, CONSERT

• Context
• 1. For all of us, this mission has an
  unprecedented potential of discoveries.
• 2. This mission (Rosetta) and our own role
  (Philae) will have a very high visibility, and
  our success is critical far beyond the mere
  science return of our individual investigations.
  It is our responsibility to optimize by all means
  our mission success.

Helsinki, September 5, 2006
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Philae on-comet science remote
sensing by CIVA, Rolis, CONSERT

• Context
• 3. The objective of the proposed exercise is
  not to freeze the on-comet operations. We all are
  well aware that things may and will evolve
  flexibility must be insured to optimize our
  operations. However, securing success and
  optimizing operations requires to build a
  consolidated timeline based on actual figures,
  validated and tested, and to identify and work
  out the relevant actions.
• 4. We have anyhow to load a default sequence to
  be ran entirely autonomously, in case

Helsinki, September 5, 2006
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Philae on-comet science remote
sensing by CIVA, Rolis, CONSERT

• Issues
• 1. Given its challenging status, Philae is
  marginal in all aspects essentially science
  objectives, system, instruments, operations.
  Moreover, the change in comet target has
  contributed to squeeze all margins, possibly
  towards negative values.
• 2. We plan to use at their completion all
  expected resources, which can be viewed as an
  optimized plan (although not necessarily an
  optimized management).
• 3. Only a consolidated tested timeline,
  assessed at system level, can identify issues to
  be worked out. The Philae Project has put in
  place means to perform efficiently this exercise,
  and to sort out the major issues. Some are of our
  own e.g. on board energy instrument modes/data
  processing some requires negotiating with the
  Rosetta Project e.g. release orbit/visibility
  periods.
• We must face and solve all issues. Thus todays
  discussion.

Helsinki, September 5, 2006
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Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• CIVA-P stereo panorama just after landing, for
• - science characterize the surface properties
• - system contribute to landing assessment
• - PR
• ROLIS zoom imaging of the landing site, for
• - science characterize the surface properties
• - PR
• - system contribute to landing assessment
• CONSERT radar sounding, for
• - science unique means to sound the interior
  of a small body, as a pioneering investigation
  of highest value.

Helsinki, September 5, 2006
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Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Driving resources budgets
• CIVA-P telemetry 7 Mbits 14 mn uplink
• ROLIS telemetry 7 Mbits 14 mn uplink
• CONSERT orbit

Helsinki, September 5, 2006
6
Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Issues
• 1) CIVA ROLIS require operation and uplink
  (Orbiter visibility) right following touch-down
  for a minimum of 30 min vs 15 min in the
  present (Wirtanen-based) plan. Negotiation
  required and agreement conceivable (to be
  urgently acted).
• 2) Quick-look data reduction to assess Lander
  landed status prior to actuate any mobile on
  board system (instrument deployment, Lander
  rotation) leaves a 12 hours of operation. This
  is an ideal period (resource-wise and
  operation-wise) to offer CONSERT performing its
  full prime sequence.
• 3) The proposed option does not entirely
  satisfies CONSERT (TBD/TBC), and might not be
  compatible with orbit choice satisfying the
  visibility constraint (ESOC action).

Helsinki, September 5, 2006
7
Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Issues
• 1) CIVA ROLIS require operation and uplink
  (Orbiter visibility) right following touch-down
  for a minimum of 30 min vs 15 min in the
  present (Wirtanen-based) plan. Negotiation
  required and agreement conceivable (to be
  urgently acted).
• 2) Quick-look data reduction to assess Lander
  landed status prior to actuate any mobile on
  board system (instrument deployment, Lander
  rotation) leaves a 12 hours of operation. This
  is an ideal period (resource-wise and
  operation-wise) to offer CONSERT performing its
  full prime sequence.
• 3) The proposed option does not entirely
  satisfies CONSERT (TBD/TBC), and might not be
  compatible with orbit choice satisfying the
  visibility constraint (ESOC action).

Helsinki, September 5, 2006
8
Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Issues
• 1) CIVA ROLIS request operation and uplink
  (Orbiter visibility) right following touch-down
  for a minimum of 30 min vs 15 min in the
  present (Wirtanen-based) plan. Negotiation
  required and agreement conceivable (to be
  urgently acted).
• 2) Quick-look data reduction to assess Lander
  landed status prior to actuate any mobile on
  board system (instrument deployment, Lander
  rotation) leaves a 12 hours of operation. This
  is an ideal period (resource-wise and
  operation-wise) to offer CONSERT performing its
  full prime sequence.
• 3) The proposed option does not entirely
  satisfies CONSERT (TBD/TBC), and might not be
  compatible with a choice of orbit satisfying the
  visibility constraint (ESOC action).

Helsinki, September 5, 2006
9
Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Possible alternatives
• 1) CIVA ROLIS acquire their data as presently
  planned, but the uplink is in part postponed to a
  later visibility period.
• Concerns
• - requires maintaining ROLIS IME ON (tens of Wh
  more)
• - postpones downlink to Earth means to assess
  landing
• - PR
• 2) CIVA acquisition is postponed to the second
  visibility period, to minimize energy (ROLIS off
  after first uplink).
• Concerns
• - postpones downlink to Earth means to assess
  landing
• - PR

Helsinki, September 5, 2006
10
Philae on comet science remote
sensing by CIVA, Rolis, CONSERT

• Actions
• 1) within Philae
• discuss agree with CONSERT a set of acceptable
  solutions
• 2) Philae with Rosetta Project
• discuss release strategy orbit evolution
  taking into account in particular
• - release altitude
• - descent duration
• - visibility windows
• 3) within Philae
• investigate options and re-iterate timelines.

Helsinki, September 5, 2006