1. Remote-sensing Instruments for the Lagrange Operational Mission
Jackie Davies & The Lagrange Remote-Sensing Consortium

2. ESA SSA Programme ESA’s SSA programme comprises four segments:
NEO : Near Earth Objects,
SST : Space Surveillance and Tracking,
SWE : Space Weather and,
since the start of 2017 (P3), LGR : Lagrange.
The Lagrange segment focusses on developing a pathway to the launch of a space weather monitoring mission to L5 (L1 backup).

3. P2-SWE-X
SSA/SWE Period 2 included an ITT for a pre-phase A study of an “enhanced space weather monitoring system”, comprising missions both on and away from the Sun-Earth line (P2-SWE-X).
Parallel studies were awarded, led by ADS Ge and OHB, each considering missions to L1 and L5.
These P2-SWE-X studies included defining preliminary mission objectives and assessing the required in-situ and remote-sensing payload to achieve these objectives.

4. LGR ITTs
ESA ITT: AO/1-9006/17/DE/MRP : Lagrange Missions Phase A/B1 System Studies (funded through GSP and LGR)
ESA ITT: AO/1-9015/17/DE/MRP : Lagrange Missions In-situ Instruments Phase A/B1 Study & Pre-Developments
ESA ITT: AO/1-9014/17/DE/MR : Lagrange Missions Remote Sensing Instruments Phase A/B1 Study & Pre-Developments (completing negotiations):
PMI : Photospheric Magnetic Field Imager
EUVI : EUV Imager [note different funding model]
COR : Coronagraph
HI : Heliospheric Imager

5. Consortium Activities
Phase
Task A
Support of system study analysis
Instrument requirements analysis
Pre-development activity proposal
Instrument package definition
Detailed sub-systems analysis & design tasks
Ground & flight operation segment definition [DOCS]
Product assurance
Detailed development & verification approach
Schedule, cost estimate & risk assessment
Programme implementation approach B1
Definition of management & product assurance
Consolidation of instrument package design & development
Request for information (RFI) campaign
Pre-dev
Pre-dev activities shall aim to reach TRL6 by end of Phase B. Includes design/manufacture/testing of critical instrument models or components needed for the demonstration of functional/performance requirements where necessary in representative environment and at the highest possible level of representativeness.
Consortium Activities

6. Consortium Roles Role Consortium partner Consortium lead
RAL (Jackie Davies)
PMI
MPS [lead]
OHB
EUVI
CSL/ROB [lead]
PMOD
COR
RAL [lead]
UGOE HI
IPU (Instrument Processing Unit)
ADS-Ge [lead]
Ground & flight operations
Deimos-UK [lead]
Deimos-Ro
Customer requirements
UK Met Office

7. System Block Diagram

8. PMI : Photospheric Mag. Field Imager
Monitoring of magnetic activity on the Sun, includes modelling of background solar wind as input to CME arrival predictions at Earth.
L5 view enables such monitoring of that part of the solar disk yet to rotate towards Earth (improved background)
Monitoring in visible-light (sunspot activity/complexity/development)
Requirements:
Magnetic field map and continuum
Inst type : L-O-S (vector)
FoV : full disk with margin
Spatial resolution : 5 (2) arcsec
Cadence : 30 (10) min
Mass/power : 25 kg/30 W
Telemetry : 15 (40) kbps

9. PMI : Photospheric Mag. Field Imager
STRAWMAN INSTRUMENT : modified Solar Orbiter PHI
PMI team led by PHI lead institute, MPS (PHI flight model delivered April 2017)
PHI obtains the photospheric vector magnetic field of the full disk, with high resolution
PMI is an optically-modified version of PHI HRT:
PMI twice PHI HRT FoV
Reduce aperture size to 75mm
Rescale filtergraph accordingly
Remove FDT
Image stabilizer required? (TBD)

10. EUVI : EUV Imager
Monitor structure and complexity of the solar atmosphere, and its evolution, including prominences, active regions and coronal holes
L5 view enables such monitoring of the solar atmosphere on that part of the solar disk yet to rotate towards Earth
Requirements:
Low coronal images
FoV : full disk with margin
Wavelength : Fe 193 (Fe 193, He 304, Fe 171, Fe 211) Å
Spatial resolution : 5 (2) arcsec
Cadence : 20 (10) min
Mass/power : 8 kg/10 W
Telemetry : 10 (40) kbps

11. EUVI : EUV Imager
STRAWMAN INSTRUMENT : Combines elements of PROBA2 SWAP and ESIO
EUVI team (CSL, ROB and PMOD) work successfully together on Solar Orbiter EUI
ESIO studied to Phase A/B1 via GSTP; SWAP operated successfully on PROBA2 since 2009
Baseline EUVI concept:
Adapted SWAP optical layout
ESIO thermo-mechanical concept [SWAP invar bench too heavy; ESIO titanium base provides lightweight and stiff structure]
Low ESIO mass: duplicate instruments should multiple wavelengths be required (or solution from EUI sought).

12. COR : Coronagraph Earliest definitive confirmation of CME launch
L1 confirms Earth-directed CME, while L1/L5 resolves ambiguity between radial distance and angular width
Basis of CME parameterization for most CME arrival predictions
Requirements:
Visible-light images of the K-corona
FoV (radial) : 3 – 22 (2.5 – 30) RSun
FoV (azimuthal) : 360°
Wavelength : 500 – 900 nm
Spatial resolution : <2 arcmin
Cadence : 10 (5) min
Mass/power : 20 kg/25 W
Telemetry : 12 (24) kbps

13. COR : Coronagraph STRAWMAN INSTRUMENT : SCOPE
Currently under Phase A/B1 study via GSTP
Various potential orbits: LEO, GEO, L1/L5
RAL Space [lead] : requirements; flight instrument design
UGOE : design/manufacture of optics bread-board (OBB)
CSL : straylight testing of OBB
ADS Ge : DHU H/W & S/W; environmental assessment
ROB : image processing software
Design : direct-imaging instrument (like STEREO/HI)
Stack of 5 disk occulters (separated by 50mm)
Side baffles and conical baffles
Straylight rejection to 20% of F-corona
Single shot door/protection shutter
CCD-based detector system
Status : Manufacture of OBB; recent CDR

14. HI : Heliospheric Imager
Fills under-sampled region between corona and 1 AU to mitigate deficiencies in modelling CME arrival based on near-Sun observations
L5 provides clearer side-on view of Earth-directed CMEs out to Earth
Provides additional information on background solar wind
Requirements:
Visible-light images of the heliosphere
FoV (radial) : 10 – 40° (4 – 60°)
FoV (azimuthal) : Towards Earth
Wavelength : 500 – 900 nm
Spatial resolution : ~4 arcmin
Cadence : 60 (30) min
Mass/power : 20 kg/22 W
Telemetry : 15 (30) kbps

15. HI : Heliospheric Imager
STRAWMAN INSTRUMENT : STEREO HI
Built by UK-led European consortium
Over 10 years of successful operation
Modification of FoV to reflect view from L5
Threshold FoV : single camera
Goal FoV : two cameras (as STEREO HI)
Improved H/W and S/W resilience (addition of a protection shutter in case of off-points)
HI-1
HI-2
To Sun
HI-2
HI-1

16. Mass/Power/Telemetry
Mass (kg)
Power (W)
Telemetry (kbps)
Threshold
Goal
Sensor unit
PMI
21.5
13.8
15.0
40.0
EUV
8.0
3.6
3.5
COR
12.0
7.0
28.0 HI
16.3
18.0
10.0
14.0
Processing unit
PMI electronic unit
6.0
19.7
N/A
IPU
10.8 27
Harness
PMI harness
0.9
Harnesses (excl. PMI)
5.8
Total
81.3
97.1
37.5
122.0
Requirements
<80
<100
<60
<150

17. IPU

18. IPU The purpose of the IPU is to provide:
power to the FEE of each RS instrument
thermal control for each instrument
commands to control operational modes
communication link between FEE and S/C
data processing for the RS Instruments, except PMI
Potential benefits of a common IPU:
to facilitate data processing
reduced mass /power
Main trades:
number of processing units
redundancy concept of the IPU
choice of TM/TC and data busses (aim to standardize I/Fs)
inclusion of mass memory (depends on DOCs, central mass memory)

19. Ground & Flight Ops Analyse the impact of the RS instruments on:
the operations concept;
the flight operations ground segment;
This feeds into the mission studies.
Analyse the impact of the operations concept on instrument definition/design.
For each of the instrument processing chains:
identify the elements in the processing chain up to Level-1b;
produce the Algorithm Theoretical Baseline Document (ATBD).

20. Ground & Flight Ops
An End-to-end (E2E) Mission Performance Simulator Architecture simulates the E2E data flow of a mission, from observed scene to final products.
Space and ground segment are modelled, with relevant noise/errors
An E2E simulator will support activities such as:
performance consolidation on mission level, by assessing observation capabilities vs. performance of processing algorithms;
quantification of the impact of technical trade-offs, by simulating possible scenarios or by instrument sensitivity analysis;
consolidation of system specification and early preparation of user community for mission exploitation.
We will use a standard approach built on the Space Science E2E Mission Performance Simulator Reference Architecture.

21. Pre-development Activities
PMI etalon development : PHI is based on a Lithium Niobate (LiNb03) etalon, enabling a lightweight and compact instrument. The producer of the PHI etalons has discontinued production, hence a pre-development activity is required to secure a replacement supply.
COR optics breadboard : A proposed pre-development activity is to build a further breadboard, thermo-mechanically representative of COR, and measure the straylight rejection in vacuum and in a representative thermal environment.
“Cosmic ray” scrubbing : It is critical for space weather instruments to operate effectively during period of high SEP flux. A proposed pre- development activity is development of an efficient scrubbing algorithm for COR and HI to test in a relevant environment (e.g. running on a software emulator of the baselined processor).

22. Design Considerations
As an operational mission, consideration must be made of:
The need for continuous synoptic observations;
Robustness/redundancy [of hardware and software];
Operation under extreme space weather conditions [of hardware and software];
Cost savings driven by commonalities vs loss of heritage;
Future-proofing to ensure that the operational system can benefit from future improvements in understanding/data analysis/modelling.

23. Thank you for listening.