During SOWG#11, we will perform mission level planning of the Cruise Phase, in order to produce the Cruise Phase SAP. Cruise Phase operations are based on the following baseline:
- InSitu payload performs science operations after successful commissioning and characterisation during Near Earth Commissioning Phase (NECP). 3 (~8hr) passes per week are available to downlink the IS data.
- Remote Sensing payload performs calibration and characterisation activities during Cruise, after successful commissioning during NECP. These activities take place during predefined RS Checkout Windows (RSCW). Every 6 months during Cruise a week long window is foreseen. Extra passes will be allocated during or after the window in order to organise a daily data downlink. There is flexibility in the placement of these RSCWs.
As the Feb 2020 trajectory has an exceptional short Cruise Phase of ~18 months, only 3 week-long RS windows are baselined, or 21 days. However there is flexibility in the placement of those and after agreement with MOC these 21 days can be split over 4 windows of 5-6 days duration.
In what follows, SOC did a first analysis of the opportunities and restrictions during the Feb 2020 Cruise Phase and proposes a preliminary placement of the checkout windows. This proposal will form the starting point for the CP mission level planning during SOWG#11 and can be adapted based on the needs of the instrument teams.
Feb 2020 Cruise Phase trajectory
For movies and plots illustrating the trajectory followed during Cruise, see Orbit Plots
SOC proposal for RS checkout window placement
In order to illustrate the SOC's suggestions for the placement of RSCWs in Cruise, given a Feb 2020 launch window, the suggestions have been placed on the plot below. Subject to agreement by MOC that our assumptions are correct, these windows will form the starting point for our discussions with the SOWG in Jan 2018.
On the figure above, you can see the four windows that we're proposing so far, placed on the continuous black curve.
Legend:
- The distances are measured from the spacecraft to the Sun (black curve) and Earth (multi-coloured curve, coloured by Sun-S/C distance so that you can see which periods are warmer/colder on one curve).
- Dashed vertical lines are the start of CP and NMP respectively.
- The suggested RSCWs are coloured, too, according to Sun-S/C distance, and are over plotted on the black curve.
- Orange shading shows VGAMs ±4 weeks’ restriction. Green shading is around the EGAM at the end of Cruise with the same ±4 weeks.
- Grey hatching shows times when Earth-S/C distance is ≥ 1.5 AU (i.e., very poor downlink rates). Black shading is a restriction around solar conjunction.
- Horizontal bands show distance ranges, in NMP covered by perihelion (red), and south (yellow) and north high-latitude (blue) points, so that you can see what kind of conditions the windows represent best.
Note that the actual 10-day-long RS windows during NMP will cover a larger range of distances around the coloured bands, as these only represent points of closest distance to Sun and highest latitudes.
The dates of the centres of these windows are:
- RSCW1 - 5 days around 15 June 2020 – covers distance ranges 0.52 to 0.51 AU, midpoint of window at 0.52 AU. Daily (8h) downlink ~810 Mbytes
- RSCW2 - 5 days around 1 Mar 2021 – covers distance ranges 0.54 to 0.57 AU, midpoint of window at 0.56 AU. Daily (8h) downlink ~375 Mbytes
- RSCW3 - 5 days around 15 Sep 2021 – covers distance ranges 0.58 to 0.59 AU, midpoint of window at 0.59 AU. Daily (8h) downlink ~1490 Mbytes if data comes down after 15th September
- RSCW4 - 6 days around 20 Oct 2021, incl. a dress rehearsal for a RS window in NMP (i.e. with VSTP) – covers distance ranges 0.73 to 0.77 AU, midpoint of window at 0.75 AU. Daily (8h) downlink ~3500 Mbytes
Cruise Phase checkout campaigns of RS instruments
Below the Cruise Phase campaigns for each instrument are listed, based on the available documentation. Campaigns that are proposed to be repeated at each check out opportunity are shaded blue.PHI
source: IUM Iss3.4 Sect. 4.6.4 Table 17 (Aug 15 2017)- PHI will carry out periodic functionality check-outs and instrument re-calibrations
- At least two check-out periods are required during CP: one at 0.7–0.8AU and one at closest possible solar distance (∼ 0.5 AU)
- Each check-out period is expected to last several days, including thermal re-adjustment (relaxation) and data turn-around phases.
- Data turn-around (ground processing) periods are not time critical, i.e. CP check-out periods can be split into two (or more) sub-periods.
Campaign | TC | science TM (ideal) | Duration | Attitude reqs | Comment |
|---|---|---|---|---|---|
| PHI switch on + HS door opening + thermal relaxation | 0 | 0 | 1 day | Actions only take an hour, relaxation takes rest of the day | |
FDT check-out - part 1:
| 0 | 289282 kibits = 35 MiB | <1 hr (estimated 37min) | ||
FDT check-out - part 2:
| 0 | 351232 kibits = 43 MiB | 1 hr flatfielding + 3 hrs processing | off-pointing mosaic, 9 positions | Duration is assuming 5 mins to repoint and stabilize (and 1 min to take image), processing 160 mins.Off-pointing mosaic is consistent with EUI flatfielding, can be run in parallel. |
FDT checkout - part 3:
| 0 | 244736 kibits = 30 MiB | <1 hr (estimated 25mins) | ||
| Switch to HRT + thermal relaxation | 0 | 0 | 6 hrs | ||
HRT check-out:
| 0 | 665092 kibits = 81.2 MiB | 16 hrs | ideally, the HRT refocus calibration includes 1 off-centre pointing (dwell ~1hr) | |
| Close HS doors | 40 mins | ||||
| Ground processing + SW patch | 512 kibits | 1 day + ?? for SW patch | Duration will depend on time needed for patching SW. Note that the patch will likely need to be scheduled as an engineering activity outside of the RSCW. | ||
| Overwrite look-up tables and switch off | few minutes | ||||
| Total FOR 1 CHECKOUT WINDOW! | 512 kibits | 1644550 kibits | 1 day relaxation + ~ 1-2 days actual operations + x days for analysis and patch | FOR 1 CHECKOUT WINDOW! |
EUI
source: IUM Iss17 Sect. 5.3.1 and 5.3.2 EUI schedules functional and performance tests, both in dark and sunlight during the NECP phase (see Sect. 5.3.1). During Cruise Phase checkouts, EUI's objective is to verify the instrument performances in a hot case and in a cold case, by
- Repeat some NECP performance tests with heat shield and internal doors closed and opened.
- Span wide range of operational temperatures and be most representative of operational conditions: activities around 0.7 a.u. and 0.45 a.u. are desired.
- Data taken in different thermal conditions will be used to validate the thermal model of the instrument. The model will then be used to predict and verify the properties of the instrument during operations.
- The total amount of data expected is equivalent to a few hundred lossless compressed images, i.e. 10 Gbit (i.e. ~310MB per RSCW).
- An update of the onboard science tables (and maybe other on-board software) will be likely needed by the last check-out in CP.
- 1 raw HRI image accounts for 6.8MB, losslessly compressed this probably means 3.4 MB per HRI_LYa or HRI_EUV image
- 1 raw FSI images accounts for 15.3 MB, losslessly compressed this probably means 7.8 MB per FSI image
Campaign | TC | science TM | Duration | Attitude reqs | Comment |
|---|---|---|---|---|---|
Performance tests - Dark - Hot case:
| ~150 MB assumed (TBC) | ~3 days | none | Duration may be shorter than the 3 days assumed for NECP (this is a repetition of the NECP campaign but in warm conditions) | |
Performance tests - Sunlight - Hot case - Part 1:This test primarily includes the following steps (there may be more):
| 250 MB (TBC)Few tens to hundred images, all 4 channels. | ~4 days | Step 1 could be part of a common alignment campaign with other instruments, preferably including a reliability test of the PHI jitter service. | ||
| Analysis of data and Update of onboard tables | TBD | 0 | It is not clear yet how to accommodate for this feedback loop during the same RSCW -> to be checked with MOC whether uplink and campaign part 2 can be organised as engineering | ||
| Performance tests - Sunlight - Hot case - Part 2:Test all the science operations modes, low latency and calibration campaigns, data prioritisation and transfer to the S/C queue (without necessarily telemeter the data to the ground) | TBD, if any | TBD | To be discussed with EUI whether this part 2 can be run in next hot case RSCW. Otherwise, it is not clear how the feedback loop can be organised. | ||
| Performance tests - Sunlight - Cold case:Repetition of performance tests in sunlight - hot case. | TBDCurrently assumed to be ~300MB. | 5 days | To be discussed with EUI whether this campaign also needs two parts as in the hot case above. | ||
Calibrations during offpoints:
| 70 + 61 = 130MB (TBC) | 1 hr (see PHI) | off-pointing mosaic | Off-pointing mosaic is consistent with PHI flatfielding so can be run in parallel with PHI campaign. TM needs estimated using assumption of 1 FSI image resp. 2 HRI images per off-pointing step: 9 * 7.8 = 70 MB for FSI FF and 9 * (2*3.4) = 61MB for HRI FF | |
Calibrations during rolls:
| TBD Currently assumed to be ~50MB. | few hours TBC | rolls | No strict roll requirements, can be run during SoloHI/Metis rolls (TBC) | |
| Total | uploads before each RSCW | 300-400MB per RSCW (TBC) | at least ~5 days per RSCW | Roughly Estimated Total for Cruise characterisation is 10Gbits |
STIX
source: TBW (input below comes from old documentation at time of PDR and CDR)Campaign | TC | science TM | Duration | Attitude reqs | Comment |
|---|---|---|---|---|---|
Performance verification:
| at start of each new checkout | 0.7 kbps datarate (TBC)= 53 MB per RSCW | 4 * 7 days at least | none | STIX need to acquire as much data as possible to construct the background. They also would like to catch at least 2 flares. Current approach is: switch them on during each checkout window. |
| Review HK, LL, science TM Adjust parameters as needed before next campaign |
SPICE
source: IUM 11.0 and Private communication from RAL post-SOWG 10.Campaign | science TM | Duration | Attitude reqs | Comment |
|---|---|---|---|---|
Thermal / Mechanism functional check
| HK only?2.2 MB | 2 hr | doors closed | "Once per orbit" |
Dark level calibration:This response is expected to change during life. Therefore the dark field maps are planned to be made during near-earth commissioning, during cruise phase check-out, and in NMP operational phase it is to be made prior to each RS window. The procedure and analysis is as per the on-ground test.For the zero-light level case the measurement is constrained as it relies on the ability to have the SPICE Door in the closed state.This calibration involves collecting dark images for the detectors in several cases. These are, with no UV light incident on the detectors, i.e. SPICE door closed :
| 40 MB | 0.5 hr | ||
| First light | 56 MB | 0.2 hr | ||
| Dark subtraction | 14 MB | 0.1 hr | ||
Telescope FocusThis calibration is to determine the optimum telescope focus as a function of the temperature of the instrument. This will have been measured during ground testing, however, it will have to be repeated when in flight. This calibration is executed as a SPICE Study with the following tasks:
| 6.3 MB | |||
PointingThis calibration is that of the pointing responses of the instrument:
| 19.6 MB | 1.2 hr | ||
Spectral responseObservation to record spectral lines of known wavelengths, chosen near band edges. Use narrow slit to improve resolution. Use long exposure time as needed to remove time variability of solar source and give high SNR in line signals.
| 3.2 MB | 1 hr | ||
Radiometric Calibration & Flat-fieldThis calibration involves collecting sufficient counts to be able to determine the relative pixel-to-pixel response of the detector. Scan of raster-FOV and averaging of the data on the ground in X, to blur out the features in the image of the Sun, thus providing an effective uniform illumination.The calibration is executed as follows:
| 4.2 MB + 13.0 MB (17.2 MB) | 0.3 hr + 0.9 hr (1.2 hr) | ||
Compression testCompression settings verification.The calibration is executed as follows:
| 116 MB | 4.2 hr | ||
| Functional test | 2.2 MB | 2 hr |
SoloHI
source: IUM Rev E Sect. 4.6.4 (Feb 2017, part of FM delivery datapack)The SoloHI one-shot door will be closed during most of the cruise phase. Periodically an aliveness check will be performed, in which a few dark and LED calibration lamp images will be taken.
Campaign | TC | Science TM | Duration | Attitude reqs | Comment |
|---|---|---|---|---|---|
Aliveness Check
| 8 MB (+ HK) | 1 hr | n/a | This campaign is to be repeated as often as possible during Cruise (each RSCW). | |
Door opening
| (HK only) | 3-12 hrs | disk centre | Only for end of Cruise (not during E2E test period)This is likely to be performed as an engineering test, led by MOC, prior (and thus not in) one of the last RSCWs. This gives SoloHI the chance of doing first light campaigns in the RSCW and participate in the E2E test for NMP that will take place during one of the last RSCWs. | |
Door-open commissioning:
| 190 MB (total)= 108 MB + 32 MB + 0 MB + 50 MB | ~30 hrs (total)= 3 hrs + 2hrs + 12-24 hrs + 3hrs | disk centre | This could possibly be run, at least partially, during the RSCW. To be double-checked with SoloHI.Current assumption: NECP repetition as part of the door opening engineering activity, rest in RSCW.Question to SoloHI: Does the post-annealing calibration need a roll to 90º, like in NMP? | |
Offpoints - with door open!
| few images | TBD | spacecraft off-points in 4 cardinal directions in small steps up to 1 solar radius | Offpoints done in steps around nominal pointing at the scale of HS alignment requirement, then 20 arcmin steps up to max (1 radius). | |
| Calibration Rolls - with door open!Straylight evaluation (20 mins dwell time) | 15 MB | 1 hr | Roll to 90º and back | A roll of 90º to point the instrument to the north or south ecliptic pole at about the same frequency of the annealing (once per orbit) would be useful to evaluate the evolution of stray light in the instrument. | |
Straylight at Sollar Array anglesStraylight depends on Solar Array Aspect angle SAA.
| 90 MB (all SAA) | ~1-2 hrs per campaign | As we cannot do a specific campaign at 1 solar distance, trying out all SAA angles, we will alternatively allow SoloHI to take some observations before and after a SAA change in CP (limited to end of Cruise due to door opening restrictions). |
Metis
source: IUM Iss 3.0 2016/05/16Campaign | Science TM | Duration | Attitude reqs | Comment |
|---|---|---|---|---|
| Characterisation & Performance Verification Block #1 | This block should occur at least twice in Cruise, i.e., in ≥2 RSCWs, with opposite thermal conditions | |||
| Open external door | ||||
| IOM position check (check IO position and eventually realign it) :VL_IOM or UV_IOM | 3.37 x TBD < 250 Mbit = 31.3 MB | 1 hr (TBC) | "During planned rolls"(Could be combined with rolls of VL_POL, SL1, and SL2 if PCH is visible – assume it is for worst case). | Choice of UV or VL for alignment check depends on degree of misalignment detected.l |
| VL alignment (determination of boresight) :VL_ALI | 0.84 Mbit x 42 = 4.4 MByte | 14 hr TBC (15 mins slew + 5 min per image) | S/C slews required, in both E-W and N-S directions between 1 R? and βmax | Default assumption is N = 10, that M = 2(2N+1) positions are taken in both EW and NS directions, and therefore M = 42 images are taken. |
| VL polarisation curvecharacterisation:VL_POL | 54 Mbit =6.8 MB | 2 hr TBC | S/C rolls: 0º, 45º, 90º, 135º | |
| VL diffraction characterisation:VL_SL1 | 6.76 Mbit = 0.85 MB | 1 hr TBC | S/C rolls: 0º and 180º | Assessment of the diffraction pattern off the inverted external occulter as a function of the angular size of the Sun, for different S/C-Sun distances; |
| VL background characterisation:VL_SL2 | 6.76 Mbit = 0.85 MB | 1 hr TBC | S/C rolls: 0º and 90º (if CH is in north), or 0º and -90º (if CH in south)Also 0º, 180º (Section 4.6.5.1.14 – additional, or at odds with above?) | Depends on the presence of at least one large polar coronal hole.Assessment of the visible-light (VL) and UV stray-light background as a function of different solar angular sizes. |
| Close external door | ||||
| Total for Characterisation Block #1 | 44.2 MB | ~5 d | Rate: 819 b/s | |
| Characterisation & Performance Verification Block #2 | ||||
| Open external door | ||||
| UV_RC1 | combined with below | UVDA analogue calibration | ||
| UV_RC2 | 27 Mbit= 3.38 MB | Typically 3 d (together with UV_RC1) | Calibration star required (slight off-pointing up to βmax; VLD is therefore also on) | UVDA photon-counting calibration |
| Close external door | ||||
| Total for Characterisation Block #2 | 3.38 MB | 3 days (TBC) | Rate: 104 b/s | |
| Characterisation & Performance Verification Block #3 | ||||
| Open external door | ||||
| VL_RC1 | combined with below | NPOL=2 | ||
| VL_RC2 | 27 Mbit= 3.38 MB | Typically 3 d (together with UV_RC1) | NPOL=4 | |
| Close external door | ||||
| Total for Characterisation Block #3 | 3.38 MB | 3 days (TBC) | Rate: 104 b/s |
Rough, preliminary skeleton of activities per RS checkout window
| Checkout 1 ~Warm (0.51-0.52AU) | Checkout 2 Cold (0.54-0.57AU) Low TM | Checkout 3 Cold (0.58-0.59AU) | Checkout 4 Extra-cold (0.73-0.77AU) + RSW rehearsal (high TM) | |
| EUI |
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| Metis |
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| PHI |
| Full performance checkout | Full performance checkout incl. FDT flatfield (off-points) |
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| SPICE |
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| SoloHI | Aliveness Check | Aliveness Check |
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| STIX | 5 days NOMINAL (TBC by STIX whether 5 days is sufficient) | 5 days NOMINAL (TBC) | 5 days NOMINAL (TBC) |
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| Common |
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First crude estimates on TM volume needs of RS payload during Cruise Phase - Feb 2020
| TM vol [MB] excl. HK | Checkout 1 Warm | Checkout 2 Cold | Checkout 3 Cold | Checkout 4 Extra-cold |
| EUI | ~400 MB + 60 MB | ~300 MB | ~430 MB | ~350 MB + 60 MB |
| Metis | 45 MB | 20 MB | 20 MB | 45 MB |
| PHI | 200 MiB* + 20 MB | 200 MiB* | 200 MiB* | 200 MiB* + 20 MB |
| SPICE | >406 MB (to be recalculated) + 15 MB | 70 MB | 214 MB | 56 MB + 15 MB |
| SoloHI | 10 MB | 10 MB | ~230 MB | ~185 MB + 20 MB |
| STIX | 50 MB** (7d) | 50 MB** (7d) | 50 MB** (7d) | 50 MB** (7d) |
| Common | separate contribution estimates in italic above | |||
| Total excl. HK | 1210 MB | 650 MB | 1145 MB | 1005 MB (+ RSW rehearsal) |
| Downlink volume (3 passes)*** | ~2430 MB | ~1125MB | ~4450 MB | ~10500 MB |
| Min Number of 8h passes needed | 2 | 2 | 1 | 1 |