After nearly nine years of planning, preparation, and even once being slated for cancellation entirely, NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Earth-observation mission is set for launch. Initially conceived in 2015, PACE will finally reach orbit and begin its planned 3-10 year mission on a launch currently slated for February 6, 2024 at 1:33 AM.
Controlled by the Ocean Ecology Laboratory at NASA’s Goddard Space Flight Center, PACE will enter orbit with two primary science objectives – to further build upon more than 20 years of NASA’s extensive record of previous climate studies (ocean color, aerosol and cloud data), and to explore new questions about our planet and its ecosystems with state-of-the-art instruments.
Once launched, PACE will enter a sun-synchronous orbit with Earth, meaning it will be passing over any given point above the planet at the same local solar time. This type of orbit is crucial for Earth-observation satellites to ensure there is consistent lighting and shadows each time the satellite passes over a given area. The primary instrument aboard PACE is the Ocean Color Instrument (OCI), a spectrometer that will measure the color of Earth’s oceans across the electromagnetic spectrum in ultraviolet, visible light, and several shortwave infrared bands.
The most advanced instrument of its kind, the OCI will provide NASA with never-before-seen insights into the interactions between sunlight and the substances that make up our oceans, like chlorophyll from sea-dwelling phytoplankton. OCI’s co-passengers aboard PACE will include two polarimeters (HARP2, designed by University of Maryland, Baltimore County, and SPEXone, being contributed to the mission from SRON Netherlands Institute for SpaceResearch and Airbus Defence and SpaceNetherlands) that will study how sunlight’s polarization is changed as it passes through Earth’s atmosphere and the aerosols and clouds within it. In addition to using state-of-the-art technology to beam data back to Earth via downlink, PACE will also have an onboard memory capable of collecting nearly 1.7 terabytes of data.
Aside from environmental and scientific insights gleaned from PACE, a more intimate understanding of Earth’s oceans is crucial when so many economies and societies depend on them for food and overall well being. The data provided by PACE will help predict “boom and bust” cycles that fisheries experience as well as the appearance of harmful algae blooms. In the skies, the data sent back to Earth from PACE can help improve air quality reports as well as weather predictions as it studies how the exchange of carbon dioxide in ecosystems can create population booms in phytoplankton and how the particles released by those phytoplankton play a role in the formation of clouds.
At its core, PACE will open the door to new oceanic and atmospheric discoveries and unlock secrets about our world unattainable by previous observation satellites. With rapidly changing environments and potential instability that comes due to both natural and man-made activities and disasters, it is becoming increasingly crucial to have not just up-to-date information about the water and air that sustains our planet, but to be able to predict what it may be like in the future too. Ultimately, the knowledge provided from PACE will be not just instrumental to mitigating future harm to societies and economies, but even preventing it.