NASA Earth Science Pushes Up-tempo Mission Schedule

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SAN FRANCISCO — NASA’s Earth Sciences Division is in the midst of an aggressive campaign to reinvigorate its on-orbit fleet. In addition to Soil Moisture Active Passive, a mission scheduled to launch Jan. 29 to produce global maps showing the moisture content of the top 5 centimeters of soil every three days, the division plans to launch as many as 13 missions from 2016 through 2022.

The latest addition to that roster is Pre-Aerosol Clouds and Ocean Ecosystem (PACE), a mission designed to gauge the health of the world’s oceans and monitor atmospheric aerosols. Late last year, NASA Headquarters officials directed NASA’s Goddard Space Flight Center in Greenbelt, Maryland, to begin formulating the PACE mission with a cost cap of $805 million and a launch tentatively scheduled for 2022. The $805 million budget covers the spacecraft, instruments and launch vehicle as well as mission design, engineering, management, science and operations, said Piers Seller, acting director of Goddard’s Earth Sciences Division.

An important feature of the PACE mission will be its ability to observe plankton near the surface of the world’s oceans. “Plankton are the foundation for the food web in the ocean, key players in the carbon cycle and generators of the air we breathe,” Sellers said.

Thanks to advanced ocean-color instrument technology and precise aerosol measurements, PACE will paint a far more detailed picture of plankton distribution and density than is currently possible, Sellers said. “If you know about all the aerosols between the satellite and the ocean surface and can take them out of the picture, you get a better estimate of what’s going on at the surface,” he added.

NASA officials also are eager to obtain PACE’s aerosol information because the space agency’s Glory mission, which was designed to observe the atmospheric particles, was destroyed in a 2011 launch failure.

NASA’s Earth Science Division plans to launch the Stratospheric Aerosol and Gas Experiment (SAGE)-3 mission in 2016. SAGE-3 will measure aerosols, ozone, water vapor and other gases to help scientists better understand Earth’s atmosphere. Credit: NASA Langley/Sean Smith
NASA’s Earth Science Division plans to launch the Stratospheric Aerosol and Gas Experiment (SAGE)-3 mission in 2016. SAGE-3 will measure aerosols, ozone, water vapor and other gases to help scientists better understand Earth’s atmosphere. Credit: NASA Langley/Sean Smith

While the PACE launch remains years away, NASA’s Earth Science Division is making plans to launch two missions in 2016: the Stratospheric Aerosol and Gas Experiment (SAGE)-3, an ozone monitoring instrument, and Cyclone Global Navigation Satellite System (CYGNSS), an Earth Venture-class mission designed to measure GPS signals reflected from the sea surface to examine the evolution of winds in tropical cyclones. In mid-2016, NASA plans to send the SAGE-3 instrument to the International Space Station aboard SpaceX’s Falcon 9 rocket and Dragon capsule. In October 2016, NASA is scheduled to launch the eight small satellites of the CYGNSS constellation on an Orbital Sciences Corp. Pegasus rocket.

The Gravity Recovery and Climate Experiment mission is slated for a 2017 launch. The joint mission involving the United States, the German Research Centre for Geosciences and DLR, the German Aerospace Center, is designed to map Earth’s gravity field.

In 2018, NASA plans to launch the Ice Cloud and Land Elevation Satellite-2 mission as well as Tropospheric Emissions: Monitoring of Pollution, or TEMPO. TEMPO, an instrument being built by the Smithsonian Astrophysical Observatory and Ball Aerospace & Technologies Corp., is designed to operate as a hosted payload on a commercial geostationary satellite.

No missions are currently set for 2019. From 2020 to 2022, however, NASA plans to launch:

  • The joint U.S.-French Surface Water and Ocean Topography altimetry satellite.
  • Two Earth Venture instruments to the space station: the Global Ecosystem Dynamics Investigation and the Ecosystem Spaceborne Thermal Radiometer Experiment.
  • A lightning imaging sensor destined for the space station that is based on an engineering model of an instrument built for the Tropical Rainfall Measurement Mission.
  • A synthetic aperture radar satellite being developed by NASA and Indian Space Research Organisation.
  • Radiation, Ozone, Atmospheric Measurements, a mission designed to make observations that previously were the responsibility of the U.S. National Oceanic and Atmospheric Administration.
  • A successor to the Landsat 8 medium-resolution Earth observation satellite.

That frenetic pace is a significant stretch for the agency, said Michael Freilich, NASA Earth Science Division director.

“We are basically at a point where we can’t support any more solicitations for orbital-type missions at a cadence higher than what we have now without substantially changing the staff of the agency in order to do more reviews,” Freilich said Dec. 18 during the Earth Science Division Town Hall, an annual event at the American Geophysical Union conference here.

Freilich also briefed scientists attending the conference on Landsat 9. In language included with the recently passed 2015 budget, Congress directed NASA to develop a Landsat 8 follow-on but to halt efforts to identify alternatives to the single-satellite architecture that the space agency has relied on since the first in the series of moderate-resolution Earth imaging spacecraft was launched in 1972.

Those efforts stemmed from previous spending bills in which Congress urged the space agency to find less-expensive ways to collect the data. A 2014 spending bill directed the space agency to develop a Landsat 9 project that would provide the same data resolution and frequency as the existing satellite at a cost of $650 million or less. That cost cap was removed in the 2015 spending bill, but Congress is continuing to press NASA to make sure Landsat 9 is less expensive than Landsat 8, a joint NASA-U.S. Geological Survey project that cost about $850 million to build and launch in February 2013.

“The agreement does not endorse any efforts to develop alternative approaches to this data acquisition that would increase the risk of a data gap,” the 2015 spending bill said.

Landsat 8 and the three Earth science missions launched in 2014 are operating well and providing high-quality data used in research and forecasting, Freilich said. The U.S. Naval Research Laboratory, for example, is using sensors flying on the Global Precipitation Measurement mission core observatory, a joint NASA-Japan Aerospace Exploration Agency mission launched in February, to improve its ability to forecast tropical cyclones. Similarly, Rapid Scatterometer, an instrument sent to the space station in September in the cargo trunk of the SpaceX Falcon 9 rocket, proved its utility in early December by measuring wind speed and direction during Super Typhoon Hagupit.