The international Earth observation community faces a serious challenge. As we contend with climate change and other environmental concerns, our need for data to better understand the complex interactions between humans and the planet has never been greater. At the same time, governments around the world are grappling with budgetary pressures that limit the public resources available for deploying new space-based sensor platforms. There is a serious danger that we will experience significant gaps in the collection of critical climate observation data sets, a blow not only to the scientific community but to society at large.

The international community needs to come together and creatively fill this emerging gap in climate observations and utilize new cost-effective alternatives to Earth observation and remote sensing. One such alternative deserving serious consideration is public-private partnerships in which Earth observation payloads are hosted on commercial satellites.

A program known as Iridium Next came to the attention of the Group on Earth Observations (GEO) in 2007. It is a good example of how a public-private partnership can assist in filling this need. Iridium Next, a constellation of 66 cross-linked satellites in low Earth orbit (LEO), is slated for deployment by 2016; therefore, to take advantage of this opportunity, the time to act is now.

Since 2005, GEO, a partnership of governments and international organizations, has been facilitating discussions on how to meet these challenges. GEO’s main mission is to coordinate development of the Global Earth Observation System of Systems (GEOSS). The goal of GEOSS is to integrate data sets collected by space and ground sensors, making it easier for people to make connections on how climate affects the water they drink, for example, or how rain patterns affect energy supplies, or how biodiversity changes and ecosystems alteration affect their health.

Experience has shown that hosted payloads on commercial satellites offer a cost-effective supplement to dedicated space platforms, with a much shorter time from drawing board to deployment. NASA and  the U.S. National Oceanic and Atmospheric Administration (NOAA), for instance, used the commercial option to successfully launch the Sea-viewing Wide Field-of-view Sensor, while the U.S. Coast Guard and the Federal Aviation Administration are using sensors on commercial satellites to improve air safety and maritime domain awareness.

GEO has been working directly with Iridium to facilitate the use of its Next constellation for hosted payloads. The company, operator of the world’s largest commercial mobile satellite network, is designing and developing Next to replace its current constellation of 66 LEO space vehicles. Iridium officials expect to begin launching the first of the polar-orbiting replacements in 2014 and to have the new network operational by the end of 2016. This satellite replenishment program offers an excellent opportunity for getting Earth observation payloads into orbit quickly in a relatively low-cost and low-risk manner. It will not be repeated at this scale for many years.

GEO recognized this unique opportunity two years ago and engaged the Earth observation community to explore the possibilities of using Iridium Next to host climate- and weather-monitoring payloads. In January 2008, GEO convened a meeting at the Royal Society in London that brought together representatives from Iridium, the international environment and climate science communities, U.S. and European weather and space agencies, and the aerospace industry. The consensus was that the LEO constellation, with its global coverage, low latency and cross-linked satellite network architecture, could offer truly impressive temporal and spatial coverage for monitoring critical variables in climate and environment change in a very cost-effective manner.

Since then, a series of detailed, independent studies — conducted by such groups as the NASA Jet Propulsion Laboratory, Britain’s Rutherford Appleton Laboratory and the French space agency, CNES — have validated the feasibility of utilizing the Iridium Next satellites to host a wide range of Earth observation and remote sensing payloads. Specific feasibility studies have examined radar altimeters for monitoring the height of sea surface, waves and ice; broadband radiometers for measuring Earth’s radiation budget; multi-spectral imagers to detect ocean color and land imaging, key measures for monitoring deforestation, desertification and agricultural crops; and GPS radio occultation measurements to provide data on atmospheric humidity and temperature profiles. Other potential mission areas include ozone profile monitoring, solar irradiance, polar wind observations and forest fire detection. Several national weather and climate agencies have also conducted feasibility studies for specific mission payloads on Iridium Next. It is important that all of these missions support the aims and objectives of GEOSS, which emphasize international cooperation, data sharing and informed decision-making for the benefit of the public as well as the private sector.

This is an unprecedented opportunity for the Earth observation community, and there is a need for immediate action. For payloads to be deployed with the planned first round of launches in late 2014, optimally commitments must be made by 2011. If we act fast, we can be collecting sensor data as early as 2015, which clearly could not be accomplished with any dedicated space platform.

By leveraging commercial satellite assets, mission payloads can be sent into space at a fraction of the capital and operational costs associated with developing and deploying mission-specific dedicated satellites and the infrastructure required to support them. A study by Futron Corp. compared annualized costs for various sensor missions flown in the past with what they might cost as a hosted payload on Iridium Next. The bottom line showed that the average costs of using the commercial satellites were less than 25 percent of the expense for a dedicated mission. This cost-effective method of accessing space will allow climate and environmental agencies to focus on obtaining better data rather than building communications infrastructure.

In today’s complex world, this creative, constructive engagement is essential to ensure the public has the information it needs to make intelligent decisions about the future of our planet. This unique public-private partnership opportunity can augment the work of other Earth observation programs to monitor our changing planet, allowing us to pursue economic growth and development while minimizing social and environmental risks. 


José Achache is executive director of the Group on Earth Observations.