Dongtaijinai’er Salt Lake, China – May 3, 2016

Operator Sanity via AutomationThe Systems Behind Flock 3p/Flock 2k Commissioning

Nate Parsons, Alex Paul, Lawrence Leung ({nate,apaul,lawrence}@planet.com)

Jeddah, Saudi Arabia

Introduction

• Planet Mission 1: image the entire Earth’s landmass every day• Dove Launches, 2017

￮ Flock 3p - 88￮ Flock 2k - 48￮ Flock 3m - 4

• Operations Philosophy: automate as much as possible, see“Commissioning the World’s Largest Satellite Constellation”†

• Until 2017, ADCS commissioning was manual

† https://digitalcommons.usu.edu/smallsat/2017/all2017/138/

Shallow Seas, Bahamas – February 4, 2016

CommissioningProblem: ADCS Commissioning

CommissioningTimeline of events

Launch

Initial Checkout

Detumble, Panel

Deploy

Calibration Maneuver 1

Calibration Maneuver 2

... Nominal Operations

Calibration Maneuver N

Tylihul, Estuary, Ukraine

• Scheduling maneuvers￮ After software updates￮ Within orbital constraints￮ Around contact plan

• Waiting for data• Handling bad data• Tracking progress• Dozens of heterogeneous satellites

CommissioningChallenges

London Array Wind Farm, United Kingdom – April 17, 2016

Solution: The Sequencer

Sequencer: Goals

• Handle each maneuver• Execute deterministically• System state: easy to determine, understand, communicate• Allow manual intervention• Configurable• Utilize existing infrastructure

￮ Automated contact scheduling￮ Scheduling API￮ Asset config service￮ Batch processing system￮ Alerts (Slack)

Sequencer: DesignCommissioning Events Sequencer State Machine

Schedule Maneuver

Uplink Schedule

Execute Maneuver

Downlink Telemetry

Process Telemetry

Uplink Calibration Parameters

Ground Space Init

Take

Check

Apply

Success

Cancel

Failure

scheduleitems.py

Sequencer: Architecture

• Sequencer - command line interface• State Machine

￮ Determined via asset config service￮ State objects: when invoked, return action items

• Action Items￮ Set config value (to set state)￮ Skip schedule item￮ Take schedule item￮ Start processing job￮ Apply configuration params

• Schedule Items￮ Objects: know how to take and skip themselves

• Maneuver Modules￮ Scheduling constraint logic￮ Telemetry Validation/Processing￮ Determine when to retry maneuver vs fail and alert

statemachine.py

actionitems.py

sequencer.py

maneuver interfaces

maneuver definitions

Central Pivot Irrigation, Saudi Arabia

● Manager○ For manual intervention○ Request/cancel/retry/apply/reprocess any sequence

● Kickoff Processes (runs every 2 hours)○ For each sequence,○ if it can advance,○ kicks off state processing

● Process State○ Invoke a single state per run, ○ execute the resulting action items

● Commissioning Report○ Gathers state of all sequences,○ stores in metrics system

Sequencer: UsageServices Deployed

Kashaga, Oil Field, Kazakhstan

Sequencer: Testing

1. Unit tests on state machine logic2. Manual tests of action items3. Regression tests on processing of past data

○ Pro: Exercised Sequencer/ADCS code interfaces○ Con: Require satellites with similar hardware

4. Piecewise with virtual satellites○ Pro: real mission control○ Con: no physics model

5. End-to-end retired satellites in space○ Pro: High fidelity○ Con: Hardware mismatch

6. End-to-end with production satellites in space○ Pro: Highest fidelity○ Con: Acceptable loss in production imagery

“All the testing”

Muir Woods & Mt. Tamalpais, California, USA – December 23, 2015

Results

Results

● All goals met● Satisfied operators● Stable architecture● Reduced ADCS commissioning time● Things to improve

○ Adapt for nominal operations○ Alert on “stalled” sequences○ Reduce scheduling latency

† https://digitalcommons.usu.edu/smallsat/2017/all2017/138/

Success!

Mercator Projection

Thank You Flight Software Workshop 2017Visit us at www.planet.com

Nate Parsons | Missions Software Team | nate@planet.com