14 April 2024 - Mission Day: 10362 - DOY: 105
Science Operations


1. Boundary conditions

a) Orbit, attitude and manoeuvres

- SOHO is upside down (180 degrees).

- manoeuvres

  To the degree possible, manoeuvres take place during the last days of
  34-m keyholes.  Currently proposed or set manoeuvre dates are:

  Aug 11 (TBC)     station-keeping and momentum management
  Aug 13 (TBC)     roll (to approximately 0 degrees)

  Nov 6 or 9 (TBC) station-keeping, momentum management and 
                   roll (to approximately 180 degrees)

b) Communications with the spacecraft

  Graphical DSN schedule: http://soho.nascom.nasa.gov/soc/dsn/

  Keyhole dates for the next 6 months (All keyhole information is available
  at or via http://soho.nascom.nasa.gov/soc/keyholes.html):

* Jul 22-Aug 20 26m Keyhole 
* Jul 29-Aug 13 34m Keyhole

* Oct 27-Nov 13 26m Keyhole
* Oct 31-Nov 9  34m Keyhole

- End-of-pass handling during MDI continuous contact periods

  To avoid problems with transmitter masks at the end of passes during MDI
  continuous, DSN has requested we bring the carrier down 30 min before the
  end of pass.  As a result, the last 30 min of all MDI continuous contacts
  will be TM only.  For ranging passes, the spacecraft will be transitioned
  to record ~1 h before the end of the pass.  The station will drop the
  carrier and re-sweep into receiver 2.  The spacecraft will then be
  transitioned back to VC2 and VC3.

- DSN 26 m antenna decommissioning and the keyholes

  DSN is in the process of decommissioning its 26 m antennae --- the only
  one left is DSS-46. According to current plans DSS-46 is to be
  decommissioned in Aug 2009.

  Since the current high-gain antenna (HGA) position along the unmoved axis
  has been optimized for 26 m antennas, the spacecraft team is
  investigating moving the HGA to a position optimized for D27 and 34 m
  antennae. Such a change would shorten the keyholes (optimization for 34 m
  antennae without the D27 would remove the keyholes entirely), but DSN
  resource allocation issues and possible impacts on MDI and MDI/SDO-HMI
  cross-calibration period need to be addressed. For analyses and details
  see the minutes of Science Working Team meeting number 40 (available at
  http://sohowww.nascom.nasa.gov/operations/SWT/Minutes/swt40.pdf, pages

c) KNOWN submode (SM) dependent activities/submode changes:

* TOO           JOP153/MMOP003 Future Major Flare Watch (SM5 if SUMER
                observes target, SM6 otherwise)
* Jun 1-Jul 10  Sunrise 5-day balloon flight
* Jun 25, Jul 2 EIT shutterless #36
* Oct 8, 15     EIT shutterless #37 (time TBC)
* Jan 7, 15     EIT shutterless #38 (time TBC)

  SUMER campaign dates may overlap with keyholes. Such overlaps shall be
  scheduled only if periods of no SUMER data between passes are acceptable.

  Except for Major Flare Watches, TRACE will be doing full disk mosaics
  if/when EIT is not able to do synoptic sets due to keyhole operations.

d) Instrument maintenance activities

   EIT bakeouts will take place during keyholes. Next bakeout timing is

e) Spacecraft maintenance activities

  Since the FOT staffing (and hence the FOT's resources to implement
  changes quickly) will decrease towards the end of this calendar year, all
  instrument teams are reminded to review not only thermal, but also other
  limits as well as TSTOL procedures and scripts for possible changes.

  The available power from the solar arrays is decreasing. Currently we
  still have sufficient margin, but in the future the decrease per year
  (now ca. 1 A) may increase to 3 A per year.  We have to be prepared to
  reduce our power needs as much as possible. On the spacecraft side
  several adjustments have already been made and there is not much more
  that can be done.  Therefore we are asking the instrument teams,
  especially the 'big' power consumers LASCO/EIT, CDS, UVCS and SUMER, to
  start looking into ways of reducing their power consumption
  (e.g. different operating modes, heater reductions, ...).  Hopefully we
  will not have to use this reduced power mode very soon, but it is better
  to be prepared in case a power reduction is needed.  More details coming

f) Others

  TRACE eclipse season began on 13 Sep 2008 and will be ongoing, except for
  the following predicted non-eclipse period in 2009:

  Jul 28 -- Sep 9

  TRACE will not perform science operations from May 15 - July 20, and
  from September 30 through early December.

  Daytime weekday passes of Mon-Wed are currently automated but
  attended. Thu-Fri passes remain crewed for training and proficiency
  reasons. Date of transition to unattended daytime automation remains TBD.

  NRT during automated passes (both weekend and weekday) is currently
  paused (briefly) regularly for resets of software anomalies. NRT schedule
  (which includes the pauses) for all automated passes can be found at

  The development of a software anomaly detection system (which would pause
  NRT only when needed instead of the current regular pauses) has been put
  on hold due to problems in development.

2. Priorities for the coming month and more

a) Joint observing plans and campaigns

Continuing campaigns:

* 2002/02/25--  JOP136 Default RHESSI Collaborations (#6850),
                POC: Tero Siili
* 2003/05/13--  Default CDS Co-observations with TRACE (#6950)
* 2005/09/20--  JOP153/MMOP003 Future Major Flare Watch (#8008)
* 2007/03/20--  Default CDS/Hinode-EIS co-observations (#7200)

  Campaign #6850 is for "individual instrument studies" selecting an active
  region target [partially] influenced by the Max Millennium target
  selection to maximise chances of serendipitous co-observations.

  EIT supports all with half/full-res 195 A CME watch in submode 5/6. It is
  clear that STEREO-EUVI provides adequate "context" information for RHESSI
  flare observations. Routine EIT submode and resolution switches are
  probably no longer needed.

* Mar 16 - Sep  LASCO C2pB for Tomography Reconstruction,
                  POC: Angelos Vourlidas, Richard Frazin

* Mar 27-       JOP 222 (ToO) Detecting the Origin of Shock-Accelerated Solar
                  Energetic Particles, LASCO/STEREO-SECCHI
                  POC: Angelos Vourlidas

  LASCO is ready to run the JOP, awaiting a target.

* May 15-Jul 20 TRACE not performing science operations

* May 17-Jul 21 MDI 60-day continuous contact

  MDI will run p30vr_fd_c1, a full disk, 1 minute cadence Velocity and
  Continuum campaign during the 60 day CC along with the usual 96 minute
  Full Disk synoptic Magnetograms and Continuum.  The only possible change
  to this observing sequence will be to change to p30vr_fd_m1, a full disk,
  1 minute cadence Velocity and Magnetogram campaign to support the 5 day
  Sunrise balloon flight.

  MDI supported the SUNRISE balloon flight successfully, though
  communication about what has going on with the balloon and required
  observations from MDI were very, very limited.

* Jul 2         EIT shutterless #36, 17-20 UT

* July 21       HERSCHEL sounding rocket launch, 
                  POC: Dan Moses, Lucia Abbo

  HERSCHEL has successfully passed all per-launch testing, and has
  requested launch time (T=0) on Jul 21 at 19:10 UT and the maximum delay
  is not expected to exceed 1 h. The range schedule meeting for the
  HERSCHEL launch will be on Jul 24. The proposed time is chosen for good
  coordination opportunities with observations in conjunction with the July
  22 Solar eclipse. The HERSCHEL observational sequence begins at
  approximately T+65 s and ends by T+500 s.

  The rocket payload consists of a suite of 3 instruments:
  SCORE/Ultraviolet Coronagraph Imager (UVCI), Herschel EIT (HEIT) and
  Helium Coronagraph (HeCor).  The HERSCHEL Sun-Earth Sub-Orbital Program
  is a sounding-rocket payload designed to investigate Helium coronal
  abundance and solar wind acceleration from a range of solar source
  structures by obtaining simultaneous observations of the electron, proton
  and Helium Solar coronae. HERSCHEL will provide the first measurements of
  the coronal He abundance in source regions of the solar wind, thus
  bringing key elements to our understanding of the Sun-Earth connections.

  The supporting LASCO+EIT observations should complete at least 1 cycle of
  images after the end of the HERSCHEL observing program. MDI 96-min
  cadence magnetograms are requested (and they will be the baseline MDI
  support), but possibilities of being in VC2 will be investigated by the

  The unconfirmed and to-be-negotiated DSN schedule information for the
  timeframe relevant to the HERSCHEL launch is below:

  2009/07/21 D46    0055-0740
  2009/07/21 D27    1540-2345
  2009/07/22 D45    0005-0405
  2009/07/22 D65    0720-0945
  2009/07/22 D27 UL 1810-2130
  2009/07/22 D15 DL 1830-2230

  SOHO is hence expected to be in contact and not in record during the
  HERSCHEL launch. No backup downlink antenna has been requested, since 
  a) SOHO's on-board system will autonomously enable recording (with a
     delay of approximately 30 s) in case of loss of uplink and
  b) HERSCHEL's baseline MDI request does not include high-rate.

  EIT Support will be a four-filter synoptic set binned over the rocket
  flight timing.

  LASCO support will be C2 pB set orange filter binned before and after the
  flight time around the EIT filter set.

  CDS will participate, taking on-disk He I and 2nd order He II
  observations.  Request to add CDS planner to the mailing list.

  TRACE hopes to support HERSCHEL sounding rocket launch, but support
  depends on the scheduled downtime.

  MDI may need to do monthly calibrations, a leg alignment, a tuning load
  and a jitter test on July 20 and 22 (between the end of continuous
  contact and the beginning of the keyhole).  None of these activities
  impact any other instrument commanding EXCEPT the tuning load which is
  done via background queue and care will need to be taken to work around
  other teams doing commanding loads.

  See also section 2b (intercalibration activities) for proposed
  SOHO/STEREO/TRACE/HERSCHEL cross-calibration.

* Jul 22        Total Solar eclipse (around 0236 UT), EIT/LASCO/UVCS,
                  POC: J. Pasachoff, A. Sterling, L. Damé, K. Schenk
                  POC: S. Habbal

  Information on the eclipse itself can be found at URL
  http://eclipse.gsfc.nasa.gov/SEpubs/20090722/TP214169a.pdf. The key
  numbers can be found also at
  http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009iau/TSE2009-fig01.GIF. The
  external/internal contacts of Umbra occur at:

  U1 = 00:51:14.3 UT
  U2 = 00:54:28.4 UT
  U3 = 04:16:10.5 UT
  U4 = 04:19:23.9 UT

  Tentative DSN schedule for the eclipse date and the preceding date is as

  2009/07/21 D27    1540-2345
  2009/07/22 D45    0005-0405
  2009/07/22 D65    0720-0945
  2009/07/22 D27 UL 1810-2130
  2009/07/22 D15 DL 1830-2230

  The week has not been negotiated and there is no guarantee that the
  passes remain as is. If the schedule holds, SOHO is expected to be in
  contact for most of the eclipse. At the request of J. Pasachoff the
  possibilities of backup downlink DSN support(s) are being investigated,
  but the likelihood of obtaining it is low. However, SOHO's on-board
  system will autonomously enable recording (with a delay of approximately
  30 s) in case of loss of uplink.

  Jay Pasachoff's, Alphone Sterling's and Damé/Koutchmy/Kuzin/Nagnibeda
  expeditions will observe the eclipse from Tianhuangping (vicinity of
  Hangzhou), China. Mid-eclipse time will be at 01:37 UT (which almost
  coincides with the 01:36 UT 96-min cadence MDI magnetogram). The team
  would like to have a full set of EIT and LASCO images, one of each type,
  as close as possible to that time and repeating as often as possible +/-
  3 min from mid-eclipse, if it is possible to get more than one image
  during our totality (which is probably not possible). MDI 1-min cadence
  magnetograms are also requested, but their availability will depend on
  the VC2 availability. Since the eclipse tehnically occurs during the
  first day of the 26-m keyhole, the VC2 availability will not be confirmed
  until the keyhole plan is finalized in early July).

  EIT/LASCO acknowledges the support requests and will support. Details of
  support remain TBD --- EIT and LASCO will produce the observation
  timeline approximately 10 days prior to launch. The plan is to support
  all totality timings while also adjusting if needed for EIT instrument
  safety during DSN contact outage.  EIT may not move its sector wheel for
  a 4 filter sequence while in a DSN gap with longer than 2 h until

  UVCS will be supporting.

  SOHO web pages for this eclipse will be set up in June 2009 and linked
  from http://sohowww.nascom.nasa.gov/operations/operations.html.

* Jul 28 (TBC)  SUMI sounding rocket launch, CDS/SUMER/MDI/TRACE, TBC
                  POC: Jonathan Cirtain (TBC)

  The baseline launch time is 19:09:50 UT. The observations begin 100 s
  after launch and will run for 318 s. Launch can slip from tens of minutes
  to hours on the 28th. The backup time on Jul 29 is 19:09:45 UT.

  Tentative DSN schedule for the SUMI launch dates and the following date
  is as follows:

  2009/07/28 1630-2055 D24 (34 m)
  2009/07/29 0640-1040 D65 (34 m)
  2009/07/29 1845-2245 D27/D15 (34 m/70 m)
  2009/07/30 0315-0715 D46/D43 (26 m/70 m)

  The week has not been negotiated and there is no guarantee that the
  passes remain as is. If the schedule holds, SOHO is expected to be in
  contact for the SUMI launch. No backup downlink antenna has been

  High cadence MDI data sould greatly enhance the science return from
  SUMI. It would also provide context for co-alignment with Hinode-SOT and
  thus all of Hinode. 96 minute cadence MDI will significantly inhibit such
  a comparison. High-cadence (1 min) MDI magnetograms are hence requested.

  The nominal launch date is the last day before and the backup date is
  hence the first day of the 34 m keyhole. The timing will very likely
  restrict all, but especially MDI and SUMER supports. In the keyhole the
  magnetogram cadence can be even less than 96 min and some magnetograms
  may not be retrievable at all. SUMER supports will very likely be
  possible only during contacts.

  MDI will support with high resolution magnetograms if VC2 (high-rate)
  will be available at the time of the SUMI flight. Since the SUMI flight
  occurs well within the keyhole, the VC2 availability will not be
  confirmed until the keyhole plan is finalized in early July). Provision
  of VC2 during the SUMI flight (or, as high cadence as feasible) will be
  attempted as part of the keyhole plan.

  TRACE has been asked to support this rocket launch. 

* Sep 23-Oct 10 Coordinated campaign with THEMIS,
                  CDS/EIT/MDI/Hinode-EIS/Hinode-SOT (TBC),
                  POC: Brigitte Schmieder

  Coordinated observations between SOHO instruments during observations at
  the THEMIS vector magnetograph are proposed. JOP 157 is the proposed
  observing programs, and an updated description can be found at but the
  descriptions will need to be updated. At least CDS, EIT and SUMER are
  mentioned in the current JOP descriptions.

  Timing remains TBC.

  MDI has been in touch with the POC re: supporting with full-disk
  observations. Full-disk magnetograms seem to be sufficient, but it may be
  possible after Sep 30 to do High Resolution observations if the JOP's
  require MDI to do so.

  CDS will support.

* Sep 27-Oct 25  JOP 224 Solar Tomography with Minimal Solar Rotation,
                   POC: Russ Hewett

  Proposed STEREO-SOHO co-observations. A unique configuration of the three
  spacecraft is utilized and dictates the timing, but details and timing
  remain TBC.  The optimal configuration occurs on 11 Oct. Draft
  description can be found at

* Sep 30-Dec TBD TRACE not performing science operations

* Oct 8 (TBD)   EIT shutterless #37 run 1

* Oct 15 (TBD)  EIT shutterless #37 run 2

* Oct 26 (TBD)  MDI science roll

  A 360-degree roll with multiple stops and observations is being planned
  and Oct 26 seems to be a good candidate date. The timing remains TBD,
  however. DSN 70-m support will be needed. The duration of the maneuver is
  TBD, but is expected to be of the order of 6-12 h. The Earth-SOHO
  distance, DSN availability, the onset of the November keyhole and the
  proposed JOP 224 are among the timing constraints.

  Information on a similar earlier maneuver can be found at
  http://sohowww.nascom.nasa.gov/soc/timeline_roll2001 and
  http://sohowww.nascom.nasa.gov/soc/timeline_roll2001.detailed. The
  details (such as number of stops and dwell times) will most likely be
  different this time.

  Other instruments are invited to take advantage of this maneuver.

  CDS will use the multiple stops during the roll to verify the instrument
  point spread function.

* Jan 7 (TBD)   EIT shutterless #38 run 1

* Jan 15 (TBD)  EIT shutterless #38 run 2

b) Intercalibration activities

  Last ICAL was: May 21

  ICALs are normally performed monthly. Below is a SOC proposal for ICAL
  weeks for the next six months. Baseline will be to schedule it for
  Thursday during contact.

* Jun 25        ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

  Timing is 12 UT.

* Jul 13-17     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

* July 21 (TBC) ICAL14 SOHO-STEREO-TRACE-HERSCHEL radiometric 
                  cross-calibration (TBC),
                  POC: Lucia Abbo

  A radiometric cross-calibration between SOHO, STEREO, TRACE and the
  HERSCHEL sounding rocket has been proposed. A preliminary draft of the
  ICAL proposal can be found at
  http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf. For timing and
  details of the HERSCHEL launch see section 2a above.

  TRACE hopes to support HERSCHEL sounding rocket launch, but support
  depends on the scheduled downtime.
* Aug 17-21     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

  NOTE: the Aug 2009 keyhole ends on 20 Aug 2009, hence this run should be
  possible during the proposed time, but may also be postponed to the
  following week.

* Sep 14-18     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

* Oct 12-16     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

* Nov 16-20     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

* Dec 14-18     ICAL01 (#7113), CDS/EIT/STEREO/Hinode-EIS(TBD)/Hinode-SOT(TBD)

  Proposed compiled ICAL scheduling criteria, constraints and guidelines
  (see also campaign #7113):

  1) EIT/CDS are the primary participating instruments

  2) STEREO-EUVI observations are included when possible. ICALs are
     attempted to be scheduled not to coincide with STEREO manoeuvres or
     other interruptions in observations (see

  3) EIT: ICALs OK at all other times except the weeks of shutterless

  4) Dates, details and confirmation will be determined by the planners
     with support from the SOHO SOCs.

  5) Neither Hinode-SOT nor Hinode-XRT have current interest in
     participating in ICALs. Hinode-EIS will from time-to-time perform its
     sensitivity calibration exercise, but has no need to perform this
     regularly as part of the SOHO ICAL. When it is convenient for
     Hinode-EIS (given Hinode's constraints), SOHO will be informed ahead
     of time of when the sensitivity calibration is to be performed. It
     will then be up to SOHO whether to follow Hinode-EIS' pointing and

  CDS OK. If Hinode-EIS can suggest convenient date & time, CDS can usually

c) Individual instrument plans


  See section 2a for MDI continuous contact periods.

  MDI may reduce the ALT cadence during Keyholes to be less than 15 ALT
  magnetograms per day if the lack of high rate telemetry is such that we
  will lose all or almost all of the 15 ALT Magnetograms each day.  The ALT
  cadence will be decided on an individual Keyhole basis and even a daily
  basis during each Keyhole depending on the 70 m antenna availability at
  the time.  MDI may also down-link select magnetograms in the 5 kbps
  telemetry if no 70 m passes are available at least every 2 days for Mag
  dump in the 160 kbps telemetry.

  All requests for MDI support need to be made several months ahead of time
  and sent to mdi-ops(at)mdisas.nascom.nasa.gov.  Even outside keyholes,
  MDI can only do 1-minute cadence observations when we have contact and
  there is no recorder dump in progress.

  MDI's REQUEST page is at http://mdisas.nascom.nasa.gov/coordination.txt
  NOTE: Listing of a study on that page means *only* that a request has
  been received, not that it will necessarily be supported.

  A description of MDI Observing Modes most used for JOPs and campaigns (FD
  vs. HR) can be found at http://mdisas.nascom.nasa.gov/Collaborate.
  Anyone requesting MDI observations is encouraged to read this page in
  order to have a better idea of what observing modes would be best suited
  for a particular study.  More detailed information about how MDI
  operates, observational constraints and telemetry information can be
  found at http://mdisas.nascom.nasa.gov/MDI_Collaboration_Details.

  MDI has switched to Focus 5 (best focus for full-disk observing) on Oct
  23, 2008.

  MDI will do Full Disk Velocity observations for March and September 2009.
  These FD Velocity observations are reserved specifically to collaborate
  with Hinode-SOT.  MDI also reserves the March (28-30) continuous contact
  for FD Helioseimology studies with Hinode-SOT.

  A 360-degree roll with multiple stops and observations is being planned
  --- see October entries of section 2a above.

  Tentatively planning a jitter test July 20, 21 or 22 and then one in
  October as well.  Will coordinate that around the 360 degree roll and the
  Themis campaign Sept 23 - Oct 10.


  For weekly plans, see the SOHO calendar and the UVCS planning page:


  For details see http://solar.bnsc.rl.ac.uk/scientificops/request.shtml.


  EIT: 195 A CME watch plus synoptics at 6-hour cadence, as usual. Full-res
  CME watch whenever we're in submode 6. Hope never to change until the
  Bogart mission.

  EIT and LASCO will perform the annual full calibration set Jun 22-24,


  See section 2a for details.

  SUMER has plans for another campaign after SDO commissioning. SUMER team
  needs to finish investigating the status of the detector and the azimuth
  drive (expected to be done within a few days) before definitive campaign
  dates can be given.


  NOTE that TRACE in general reserves the right to withdraw support from
  agreed, existing collaborations if a sufficiently "good active region" is
  called by the Max Millennium group.

  For TRACE summer eclipse season see section 1f.

  TRACE will not perform science operations from May 15 - July 20, and from
  September 30 through early December. See also

3. Any other business

* Tentative SPWG meeting times for next six months (only the next one will
  be decided in this meeting). Meetings take place as a baseline on Fridays
  after the daily and weekly meetings.

  Jul 24
  Aug 21
  Sep 25
  Oct 30
  Nov 20
  Dec 18

The rest are FYI items:

* In the future SOHO's DSN contacts will grow shorter as we lose 26-m
  antenna support and other, new missions get higher priority. The
  instrument teams are therefore requested to look at the NRT commanding
  that is done (especially for emergencies and recoveries) and see what can
  be converted into TSTOLs that the FOT can run (even without explicit
  instrument or SOC direction).

* MDI high-rate support requests: no change, see URL

* DSN support requests: preferably at least 6 months in advance.  Keep this
  in mind for: ground-based collaborations that require MDI support,
  stellar/shutterless observations that require NRT, etc.

* Future Mercury and Venus transits: no change, see URL

* Hinode operational and planning information and guidelines: no change,
  see URL http://sohowww.nascom.nasa.gov/operations/SPWG/spwg-20080118.html
  and http://sohowww.nascom.nasa.gov/soc/JOPs/jop-submit.html

* STEREO operational and planning information: no change, see URL

* The SOHO JOP/ICAL database and the web pages are now the Solar JOP/ICAL
  database and web pages. This is due to anticipated increased
  contributions by and collaborations as well as intercalibrations with
  STEREO and Hinode.

* New JOP vs. modified existing JOP rules-of-thumb: no change, see URL

* SOHO calendar email notifications: no change, see URL

• European Site • US Site


Feedback & Comments: SOHO Webmaster

Last modification: July 27, 2020

SOHO is a project of international cooperation between