Small Satellite Reliability · 2017-03-03 · © Planet - Proprietary & Confidential Lake Saint...
Transcript of Small Satellite Reliability · 2017-03-03 · © Planet - Proprietary & Confidential Lake Saint...
© Planet - Proprietary & ConfidentialLake Saint Pierre, Canada APR 14, 2016
Small Satellite Reliability
Small Satellite Reliability TIMCalifornia Institute of TechnologyPresenting: Michael T. Rubel2017/02/14
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About Planet
• Private SF-based Earth-imaging company, founded 2010• Design/build/operate our own 3U “Dove” satellites, 118 deployed to date;
>12 launches since 2013; also Rapid Eye and (pending) Terra Bella• Goal is to image the whole world every day
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Eighty-eight of our Dove satellites are due to launch on a single rocket tonight.
But sure, we have a totally rational* risk posture.
• Keep fingers crossed• Pancakes
*N.B.: I rode here today on a motorcycle.
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Agile Aerospace
Iterate rapidly to increase capability, even if it impacts reliability
90% of 100 > 99.9% of 5
Key factors:
● Fast Hardware / SW iteration● Redundancy at the spacecraft, not component, level● Regular launches (easier said than done)● Integrated organization: everything but the rocket● Tolerate but contain failures● Keep complexity on the ground if possible● Extensive automated ground testing● Refine with on-orbit experiments
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Mission 1-Launch History
Dove 1&2 - April 2013Dove 3&4 - November 2013Flock 1 - Feb 2014 (28 satellites, ISS)Flock 1b - July 2014 (20 satellites, ISS)Flock 1c - June 2013 (12 satellites, SSO)Flock 1d - October 2014 (Antares launch failure)Flock 1d’ - March 2015 (2 satellites, ISS)Flock 1e - April 2015 (14 satellites, ISS)Flock 1f - June 2015 (Falcon 9 launch failure)Flock 2b - August 2015 (14 satellites, ISS)Flock 2e - December 2015 (12 satellites, ISS)Flock 2e’ - March 2016 (12 satellites, ISS)Flock 2p - June 2016 (12 satellites, SSO)Flock 3p - January 2017 (88 satellites, SSO)
118 Doves deployed, ~60 still in orbit, 88 more on the way tonight
Mission 1 final population: >100 operational satellites
Also ~30 antennas at ~10 ground station sites around the world
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Planet Spacecraft Engineering
Planet design, manufacturing, test, and operations under one roof
Around 50 staff total in spacecraft group (excl. mfg/test and product)
Loose team boundaries and lots of interaction
Focus on rapid iteration and low friction
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Risk Posture for Software
● Targeted 15% device failure rate in early builds○ Measurable risk-posture○ Keeps development velocity high
● Experimental Fleet○ Utilize broken assets
■ ex. Broken Camera == Great for testing battery heater SW○ Satellite “checkout”
■ Developer can have full access to an asset for experimentation■ Operators help triage on-orbit experiments
● Capabilities added when needed, even post launch○ Ranging added to radios when we realized that JSPoC orbits weren’t
accurate○ Conops has changed due to lessons learned, launch slippages, GS
procurement, etc
Dozens of Cheap Satellites
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Fast Iteration: Enablers
● Risk tolerant mission design○ For us: Quantity, cadence
● Low friction updates○ Automate testing and rollout○ Be able to rollback ○ Tolerate transient failures/outages
● Small, flexible team + Agile planning● Code review● Automated code builds, unit tests, integration tests
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Questions?