Task Definition

1
Task Definition

• Realistic assessment of strawman payload
• Mass, size, power requirements
• Demonstrate feasibility
• Task is NOT to provide complete instrument
  designs
• Uncover any items which will drive system design
  for S/C
• Input for Payload Definition Documents (PDD),
  which will be prepared by ST before industrial
  S/C studies get underway
• Identify key problem areas arising as a result of
  the extreme thermal and radiation environment
• Identify necessary technological developments to
  cope with these challenges
• Studies and tests to be initiated
• Identify operational concerns and devise plans
  how to tackle them

2
Product of Study

• Study Report to ESA
• Recommendations for tests/investigations/strategy
  etc..
• Anything we feel is appropriate

3
Agenda Splinter Session

• Intro Approach / Brainstorm
• Revisit Instrument List
• Taking Stock
• What are people working on?
• What development work/tests are planned at
  national laboratories?
• What should be initiated/coordinated through ESA?
• Instruments
• Identify, for each instrument, key areas
  requiring development or test activities
• Environmental and spacecraft issues
• Operations / S/C
• Identify next steps

4
Status of the Project - Background

• Tenerife Crossroads Workshop (March 1998)
  Resolution
• Launch a Solar Orbiter, as ESAs F2 mission,
  with possible international participation, around
  2007 there are two main candidates for this,
  namely a mission approaching the Sun to 30 solar
  radii, and a polar orbiter at about 0.5 AU.
• ESA Pre-Assessment Study conducted in 1999
• Solar Orbiter proposed as a Flexi-mission in 2000
  by E. Marsch et al.
• ESA delta-Assessment Study conducted in 2000
• Solar Orbiter selected by ESAs SPC in October
  2000 for launch after BepiColombo (2008-2013
  timeframe)
• Solar Orbiter recommended by ESAs SSAC in May
  2002 for implementation with BepiColombo as a
  single project in 2011/2012
• ESAs SSAC also encouraged further international
  collaborations, specifically involvement of NASA
  in Solar Orbiter as part of the ILWS program,
  linked to European participation in other LWS/STP
  elements.
• Industrial study to start in fall 2002, tightly
  coupled to BepiColombo

5
SSAC Recommendation
103rd Meeting, 2-3 May
2002, ESA/SSAC(2002)1 - excerpts

• The SSAC recommends a scenario which rests on
  the following assumptions
• The implementation of BepiColombo and Solar
  Orbiter as a single project under a cooperative
  arrangement, leading to significant savings.
• the SSAC reommends to the SPC the following
  scenario for approval
• . 2011/12 BepiColombo/Solar Orbiter
• elements of flexibility and uncertainty, which
  should be exploited to the best advantage of the
  overall programme
• Within each combined set of missions (
  BepiColombo/Solar Orbiter) the launch sequence
  can be optimised.
• Further international collaboration on mission
  and payloads is encouraged. Specifically a
  significant contribution from NASA on Solar
  Orbiter as part of the ILWS programme may be
  linked to European participation in other
  elements of the LWS/STP programme.

6
ESA/NASA Collaboration

• Several meetings between ESA and NASA to discuss
  collaboration within ILWS programme
• ILWS signed at IACG meeting in Padua, January
  2002
• Last ESA/NASA meeting 15 April
• US participation in Payload Working Group
  endorsed and supported by NASA
• Agreed to form Joint ESA/NASA Solar
  Orbiter/Solar Sentinels Working Group
• Memo to ESA SPC delegates with well grounded
  confidence that the US will be able to contribute
  to the Solar Orbiter payload in a substantial way

7
Joint Solar Orbiter/Solar Sentinels WG

• Discussed at ESA/NASA bi-lateral in Villafranca
  von 15/16 May
• Kick off planned for fall 2002, after new NASA
  Roadmap and NAS Decadel Survey have been issued
• 5-6 members each from European and US community
• Charter
• Study how to modify existing concepts of the
  Solar Orbiter and Solar Sentinels to more
  effectively achieve their combined science goals
  by looking for synergies and complementarities
  between the two programs
• (1)    Synthesize the goals of the Solar Orbiter
  and Solar Sentinels as presently defined to
  determine a prioritized set of science objectives
  that will enable the LWS and ILWS programs to
  achieve their stated goals.  
• (2)    Optimize the scientific cost benefit by
  devising an implementation strategy that combines
  NASA and ESA resources.
• (3)    Identify key science objectives that can
  only be accomplished jointly, but not separately.
• (4)    Suggest combined mission scenario options
  to accomplish the ILWS goals.

8
Solar Orbiter Schedule
9
Heliospheric in-situ Package
10
Remote-sensing Instruments

Hard X-ray imager Gamma-ray instrument
11
Instrumental Challenges

• Thermal (up to 34 kW/m2 on surfaces exposed to
  full disk)
• Long external baffles to limit FOV
• Grazing incidence primary optics
• Radiation Environment
• up to 25 higher particle flux
• Aging
• Limited S/C resources
• Mass
• Telemetry
• Power
• Balance in-situ/remote sensing
• Mass - 24105
• Telemetry - 12.562.5