The Airborne Science Program uses aircraft-based platforms to test, refine and calibrate instruments and algorithms ultimately intended for space-based operations. At the same time, they can make high-resolution measurements that are valuable either on their own or coupled to satellite observations to improve understanding of global systems.

Data from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation mission is combined with that of CloudSat for 3-D perspectives of how clouds and aerosols form, evolve and affect weather, climate and air quality. NASA’s partner in CALIPSO is France’s space agency, CNES, which operates the satellite.

The Cloud-Aerosol Transport System instrument uses lidar (like radar but with a laser) to measure the coverage and properties of clouds and aerosols, improving knowledge of their impact on Earth’s climate. CATS is mounted on the International Space Station, whose orbit permits observations that standard satellite orbits can’t offer.

CloudSat’s radar, 1,000 times more sensitive than weather radars, penetrates clouds to reveal their vertical structure. Its data is coupled with that of CALIPSO for 3-D perspectives of how clouds and aerosols form, evolve and affect weather, climate and air quality. It was developed with the Canadian Space Agency.

The New Millennium Program’s Earth-Observing 1 program validates advanced instrument and antenna technologies, and software that integrates sensors and increases autonomy in imaging events such as wildfires, volcanic eruptions, floods and ice breakup. Images are sold through a partnership with the U.S. Geological Survey.

The Global Precipitation Measurement mission comprises an international network of satellites that measure rain and snow worldwide, using a core satellite with an advanced radar/radiometer system as a reference standard. The mission advances understanding of the water and energy cycles and improves forecasting of destructive storms.

The Gravity Recovery and Climate Experiment measures with exquisite precision the varying distance between twin satellites as one follows the other around the planet. This enables scientists to calculate changes in gravity distribution over Earth’s surface and infer the movement of large masses of water and ice.

ISS-RapidScat bounces microwaves off the ocean surface and measures the return pulses. Stronger signals mean rougher seas, caused by stronger winds. Ocean-wind data are critical for short- and long-term weather forecasts, tracking storms, analyzing climate trends and understanding the interplay of wind, ocean and sea life.

Jason-3 is the fourth U.S.-European satellite mission to measure variations in ocean-surface height, continuing the study begun in 1992. Measurements over this lengthy period will improve understanding of ocean circulation patterns, global and regional sea-level changes, and climate change.

The two Laser Geodynamics Satellites provide stable orbital positions against which to measure Earth’s surface. Each is studded with 426 reflectors that return a laser pulse to its source on the ground. Measuring the laser’s round-trip travel time permits very accurate distance measurement for studies of Earth’s shape and continental drift.

Landsat 7 continues the Landsat Program’s groundbreaking series of repetitive imaging of Earth’s land at a spatial resolution that shows human interaction with the environment. A joint initiative of NASA and the U.S. Geological Survey, it informs decisions worldwide about urban growth, natural disasters, agriculture and many other issues.

Launched in 2013, this latest Landsat satellite carries sensors much more sensitive than those employed earlier in the series. Its images are available without charge and are used to track urban expansion, forest loss and regrowth, glacier melting, changes in farmland and other land use, and water use by crops.

Orbiting Carbon Observatory 2 is the first operational spacecraft dedicated to studying atmospheric carbon dioxide, which is linked to global warming and climate change. The mission’s goal is to improve understanding of the carbon cycle and the processes that regulate atmospheric CO2 concentration so scientists can better predict CO2 increases and their impact on Earth’s climate.

The Ocean Surface Topography Mission on the Jason-2 satellite measures ocean height by timing how long microwave pulses take to travel from the spacecraft to the ocean and back at the speed of light. This enables scientists not only to monitor sea-level rise, but also to see how the ocean stores and transports heat—an important factor in understanding climate change and forecasting hurricanes and other weather events.

The Soil Moisture Active Passive mission used both active (radar) and passive (receiving natural microwave emissions from the ground) techniques to measure soil moisture and detect where soil is frozen or thawed. Though the radar has stopped working, the mission continues. SMAP increases understanding of the links between the water, energy and carbon cycles and improves the ability to monitor and predict floods, droughts and crop yields.

The Solar Radiation and Climate Experiment provides continuous measurement, at each of several groups of wavelengths, of the total amount of sunlight that reaches Earth and how the sun’s output varies over time. SORCE data helps scientists understand the sun’s impact on Earth’s weather and climate systems.