The Myth of the Data-Constrained Mission: Ten Years of Data Management Onboard the Curiosity Rover

Eleven years have passed since the Mars Science Laboratory (MSL) Curiosity rover touched down on the surface of Mars in August 2012. The mission has returned considerable science despite the serious constraints placed on operations by limitations in hardware, software, and the punishing radiation and weather on the surface of Mars. In fact, the main constraints for mission planning are power, plan complexity, and how much data can be returned; and these constraints affect the scope of operations for the Curiosity rover and result in conservative operations and data handling.Behind the data is the data management subsystem, tasked with assessing the health and safety of the rover's onboard storage, including its non-volatile memory partitions, and commanding onboard maintenance activities including retransmission and reprioritization of data products. This team tracks partition mount times; data product creation, downlink, and deletion; completeness of received data within a downlink; the amount of unused space within a downlink; and other data-product related metrics. They also enforce flight rules about file system utilization so as not to run into undesirable autonomous behavior or slow mount times. Understanding these trends helps to improve ground assessment of onboard functionality, and process improvement leads to more efficient and lossless data transfer from Mars.Retrospective analysis of data management metrics showed that data constraints had lifted mid-mission. While downlink data volume was indeed constrained in early mission (to sol 2043), in mid-mission (sol 2230–3950) only 76% of the available downlink envelopes was fully utilized. File system utilization was 60% in early mission, and just 20% in mid-mission of the guidelines-allowable. Overall, mission volume exceeded 3,279 GB down-linked from Mars, equivalent to the content of more than 1000 Marvel movies at 1080p resolution.This paper presents highlights from over ten years of data collection on the Curiosity mission and presents evidence to dispel the myth that the Mars mission is still data-constrained. The paper then presents suggestions to current and future missions with similar resources, with the aim to bring back more science.