Process for Constructing a New Cycle LRP

INTRODUCTION

Building a new cycle LRP has a number of phases, some of which are iterative. The general idea that has been used in Cycles 7, 8 and 9 (at least) is to build an LRP based upon the existent dynamic LRP all at once (as opposed to letting visits dribble into the plan as they become ready for long range planning). Such an "all up" plan is necessary to minimize conflicts between visits which could arise in a number of ways. An example of one way would be a very restricted visit coming into the LRP targeted for a time where the plan has already become full. This situation is not unique to cycle start-up and is a continual problem throughout the year, but by planning as many visits as can be had at once, conflicts can be minimized.

To execute the approach of planning as many visits at once as possible, with allowance for a continual influx of 'ready' visits, the ideal situation is to create and release a plan as late as possible within the constraints of cycle LRP release deadlines, dropoff in subscription of previous cycle visits within the LRP, and the natural ramp-up in opportunities for the more restricted visits within the new cycle.

What follows is an outline of a series of steps and actions that need to be taken as a part of the new Cycle planning process. It is not a detailed procedure, but an overview. For a practical guide to which tools and commands are used in the process of building an LRP (in Cycle 9), see the accompanying document. For a more up to date practical guide (detailing step by step what occurred) see the Cycle 17 documentation.

PRE-TAC ORBIT ACCOUNTING & MANAGEMENT RECOMMENDATIONS

An important phase of building a Cycle LRP begins months before the actual release of that LRP. An accurate accounting of orbits unexecuted, and orbit execution rates are necessary. The orbit accounting is done at a later stage as well, prior to the actual Cycle LRP Build stage, to update the accounting.

The earlier phase of orbit accounting can start 7-8 months prior to the nominal end of cycle and timing is driven by when the TAC occurs.

Orbit Accounting

• Orbits remaining to be executed.

  ToOs

  SAA-free consumers

  CVZ visits in high-interest areas (LMC, SMC, HDFN, HDFS, etc).

• Historical execution rate.

  Overall

  Calibrations

• HOPR Rate

• DD Tally

• ... Any other items.

For a more detailed explanation of the algorithm and the logic behind it, see the accompanying document.

Appropriate adjustments for Safings or other down-times may need to be made to execution rates, as often Safing victims are not subject to HOPRs and are merely replanned for later times.

TAC & MANAGEMENT ORBIT RECOMMENDATIONS

The findings from the previous orbit accounting are used as direct input for determining TAC recommendations. Recommendations need to be made to the TAC and HOD Management on a number of possible issues:
• On the number of orbits that can be granted to GOs for a given Cycle-end date.

• On the percentage of MAMA orbits that can be granted to GOs for a given Cycle.

• In Cycle 8, 47-Tuc/SMC, HDFN, and LMC CVZ orbit limit recommendations were made.

• In Cycle 10, other issues will raise their head:

  The ACS SBC-MAMA will require SAA-free half of the day.

  NICMOS return ... Camera 3 campaigns?

  Need enough STIS/WFPC to execute during commissioning phase of new instruments.

  Commissioning schedule for various ACS & NICMOS modes --> USC generators.

  STIS NUV/MAMA 'cold' campaigns.

  Increased number/percentage of NICMOS visits requiring non-SAA-intersected orbits.

  Servicing Mission Impact

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MONITORING INGEST PROGRESS & PRE-BUILD ACTIVITIES

A valuable step in building a Cycle LRP is to monitor the progress of visits being made available for assimilation into a Cycle LRP and allow update of SPIKE products to help PCs determine any problems with ingested proposals.

Activate a special markers/unschedulables nightly SPIKE run to allow:

Update of visit constraints.

Note: The mechanics of this procedure need to be reviewed and overhauled--a shortcoming of the current procedure is that it does not guarantee updating of the constraints because a clone of the batch-LRP script (which does not update cv-descs nor CWs) is used as opposed to the batch markers (which does update cv-descs, but does not write out plan_window_status or unschedulable records).

Two possible fixes:

Have the regular batch markers use a modified proposal input list to pick up new Cycle proposals (which would require modifying the way the batch proposal query is set up), and

Clone the batch markers as well to run on the new Cycle proposals

Update of unschedulables/processing error statuses by generating special New Cycle LRPs which do not contain plan windows.

At some point, OPRs should be filed to allow PCs to query these special LRPs and obtain information about their new visits.

Run the find_early_in_cycle tool early and often

This tool identifies visits whose constraint windows end before a given date (e.g., the beginning of the cycle).

Software development

An early start is required for any tools needing to be written for building and evaluating the Cycle LRP. Software development may be required in any number of important areas:

SPIKE

Proposal Processing

LRPG tools.

Evaluate impact of special proposals and events on the new Cycle planning process.

The basic ground rules for planning observations change from cycle to cycle. For example:

• During one of the Cycle 7 replans (early NICMOS cryodeath), tests of where to place NICMOS Camera 3 campaigns were done. Similar tests for NIC3 campaigns were done in Cycle 7.5.
• During Cycle 8, a 100+ contiguous orbit proposal had several opportunities throughout the Cycle. Test LRPs using SPIKE were generated evaluating the impact of placing that proposal at various times (along with impact of SM3A).
• At the end of Cycle 6 and the middle of Cycle 8, Servicing Missions occurred. A Servicing Mission (SM3B) is planned for the beginning of Cycle 10 (as of 00-05-18). Impact of nominal launch and planning for several month launch slips should be done.

Identification of ToO proposals and ensuring limited_resource_track is correct and up-to-date.

Resource Evaluation

Neither management nor the TAC is bound by the recommendations made by OPT planners. An assessment of the differences between OPT recommendations and management/TAC decisions that result should be made to understand if there are important changes or issues that need to be addressed either before or during the CYCLE LRP build.

Historically, this has not been a crippling problem, however, for example, during Cycle 8, the percentage of orbits granted which were MAMAs was at the upper limit of what was recommended by the planning group, and as a result, as Cycle 8 draws to a close, an excess of MAMA visits has accumulated. To be fair, this is a result of not making a conservative enough recommendation.

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BUILDING THE NEW CYCLE LRP

The active phase of building an LRP proceeds after the Phase IIs are in house and processed through the phase of being 'lrp ready'. Each of Cycle 7, 7.5, 8, & 9 LRP builds has proceeded in a slightly different fashion in the sense that different software tools have been used to help compile lists of visits and proposals as input to SPIKE. SPIKE, however, is a common critical tool for building an LRP regardless of the cycle.

Compile a list of proposals within the 'existing' released LRP.

Compile a list of proposals in the new Cycle.

Compile a list of visits in the new Cycle.

Classify the new Cycle visits by the severity of constraints inherent to them.

• A primitive implementation (MAMA/non-MAMA) was done in Cycle 7.
• A less crude implementation of this was done in Cycle 8 (CVZs category added)
• A more advanced and detailed scheme was implemented in Cycle 9.

Build a SPIKE script, or set of scripts to plan the new Cycle.

Set up control files.

Adjust resource levels.

Set up constraint sets.

Implement new constraint set if so decided.

Set up criteria files.

Adjust and activate/deactivate weights of criteria.

Execute the SPIKE script sequence.

Evaluate the output products of the SPIKE script. Issues to examine:

SAA-free consumption.

MAMA subscription.

Overall 'levelness' of subscription rate.

Large-orbit visit distribution.

The following are also issues, but of secondary importance and can be deferred to the Repair or post-release maintenance phases where adjustments can be made as necessary.

Artificially small or choppy PWs.

Tight Link-set distribution.

SAA-hiding visit PW assignation.

CVZ crowding.

Iterate if necessary (some of the above steps may be deferred to the post-release maintenance phases).

"Repair" the LRP which is judged to be acceptable from previous steps.

Release the repaired LRP.

Pre-Maintenance Adjustments:

Tight-tolerance linkset "nailing".

Tailoring PWs of large GROUP WITHIN linksets.

Conflict hunting.