NASA PACE, a new view of the ocean from space

Despite some delay accumulated on previous milestones, NASA announced that the PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) spacecraft is finally assembled and ready for launch next year. According to the current plan, a SpaceX Falcon 9 will send the observatory into a sun-synchronous orbit in January 2024 from Cape Canaveral, Florida.

This advanced Earth Observation satellite will investigate the contribution of the ocean to the carbon cycle, continuing NASA’s twenty-year research work in this field.

NASA studies phytoplankton in different ways with satellites, instruments, and ships. Upcoming missions like Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) – set to launch Jan. 2024 – will reveal interactions between the ocean and atmosphere. https://t.co/zZcYWty2C3 pic.twitter.com/qF99PTLYbj
— NASAOcean (@NASAOcean) June 8, 2023

Three special instruments to uncover carbon cycle secrets

As stated in his name, PACE will observe the ocean, the atmosphere, and their interactions. In particular, it will collect detailed data about phytoplankton at the ocean surface and provide deep insights into how these microscopic algae react with atmospheric aerosol and carbon dioxide, thus playing a fundamental role in the carbon cycle.

To accomplish its mission, the observatory will use three innovative scientific instruments:

Ocean Color Instrument (OCI), the primary science sensor, is an advanced optical spectrometer working on a wide range of frequencies, from ultraviolet to shortwave infrared; it allows to capture the color of the ocean at a higher wavelength resolution than previous satellite detectors.
Spectro-Polarimeter for Planetary Exploration (SPEXone) is a multi-angle polarimeter aiming to collect data about the linear polarization of sunlight reflected by ocean and land surfaces and the atmosphere; it provides accurate characterization of airborne aerosol.
Hyper-Angular Rainbow Polarimeter #2 (HARP2) is a wide-angle imaging polarimeter, that will provide additional information about the atmospheric aerosol from different spectral bands and angles of linear polarization, including the particle shapes, size distribution, and amount.

Technicians crane the Ocean Color Instrument onto the Thermal Vacuum Chamber (TVAC) cart. Credit: NASA GSFC — *Technicians crane the Ocean Color Instrument onto the Thermal Vacuum Chamber (TVAC) cart. Credits: NASA GSFC*

Instruments are integrated into the spacecraft bus, built by NASA Goddard Space Flight Center (GSFC), as well as the solar panels, the S-Band communication system for command and telemetry, and the Ka-Band for science data.

Lifting PACE Structural Verification Unit for engineering tests. Credit: NASA GSFC — *Lifting PACE Structural Verification Unit for engineering tests. Credits: NASA GSFC*

January 2024 launch is no longer a mirage!

Passing the critical review last April, the PACE spacecraft moved to the final integration and testing stage at GSFC. During this phase, the equipment will undergo vibration, acoustic, and thermal vacuum tests to ensure its resilience to the launch stress and the harsh space environment. Finally, it will be packed and transferred to Kennedy Space Center, where the launch vehicle will wait for the payload integration.

Large algal blooms after Australia wildfires spotted by satellites. Credit: NASA/Jeff Schmaltz, LANCE/EOSDIS Rapid Response — *Large algal blooms after Australia wildfires spotted by satellites. Credits: NASA/Jeff Schmaltz, LANCE/EOSDIS Rapid Response*

From its planned 676.5 km orbit, the spacecraft will provide the new measurements necessary to increase understanding of the carbon cycle and support new scientific evidence on climate change.

“I’m energized for this opportunity for discovery that this observatory is offering. I have every expectation the world is going to do great things with these data.”
— Jeremy Werdell, PACE mission project scientist