A Mission to Planet Earth – Global Change and Bretherton’s diagram

Returning from Unispace82, and after the unsuccessful conclusion of the Global Habitability initiative, both James Beggs and Hans Mark, NASA’s Administrator and Deputy Administrator, respectively, concentrated on what was the primary goal of their tenure, the development of the space station programme. President Reagan had already confirmed in a speech on 4 July 1982 that the United States, was working towards “a more permanent presence in space,” mainly due to the recent Soviet activity in space.

Nevertheless, James Beggs was confident that the Global Habitability programme was still viable and asked Dr Burt Edelson, then head of NASA’s Office of Space, Sciences and Applications (OSSA) to quietly keep working on this. But NASA was not the only agency interesting in looking at the Earth. The National Oceanic and Atmospheric Administration (NOAA), through its programme Climate and Global Change, had been developing the next generation geostationary observatory, and the National Science Foundation (NSF) had its own Global Geosciences programme. Both programmes were focused on global change; their purpose was to obtain an advanced and comprehensive knowledge of the Earth system as well as to understand, predict and respond to environmental events and changes such as climate change.

NASA wanted to do better. Learning from previous mistakes, Burt Edelson, an energetic individual and an excellent communicator, who, though, had very little knowledge about Earth Science, thought that the first step towards ‘re-introducing’ Global Habitability, is to create a strong base that could support NASA’s next initiative. He established a department within NASA, the Earth Sciences and Application Division and put Shelby G. Tilford, a researcher from Jet Propulsion Laboratory, as Director. Tilford set up a group of scientists from every aspect of Earth Science, some from NASA but also from other agencies, such as NOAA, NSF, Department of Energy, and the United States Geological Survey (USGS). It was perhaps the first time that different scientific disciplines sat together to discuss the requirements for a comprehensive earth-monitoring programme.  Until then there was very little interdisciplinary communications.

In the summer of 1983, Tilford contacted Dr. Francis Bretherton, and asked him if he would chair the new Earth Science Committee which objectives were, 1) the establishment of the “Earth systems science” (the earth as one system of interacting components) and, 2) the development of an interdisciplinary programme with a broader context than just a NASA programme, and with an emphasis on Global Climate Change as a threat to humanity. Bretherton was trained as an applied mathematician and at that particular time, he was director of the National Center for Atmospheric Research (NCAR). He had published numerous papers in oceans and atmospheric related topics, so Tilford thought he was the right kind of individual to chair the new committee. Francis Bretherton reluctantly agreed to participate and the first meeting of the committee was held early in 1983.

“From the outset, we realized that we had to look at NASA’s role in a broader context than just NASA programs. NASA wasn’t the only, or even the largest, agency looking at the earth. So we set up a liaison program with people from NSF and NOAA.”

Francis Bretherton  quoted in Edelson, Laying the foundation. Mosaic, (1988, p. 7).

The programme was supposed to be a one-year task. But it didn’t finish in 1983, nor in 1984. It had still not finished in 1985 but, at least, it got a name.  As habitability brought memories of failure, NASA was looking for something new and more inspiring. Burton Edelson used the forum of the Science magazine to propose the name “Mission to Planet Earth” and, at the same time, advertise NASA’s new effort.


The Earth System. Image Credit: M. Ruzek

After several meetings and discussions the  committee concluded  that Earth had to be looked as an integrated system from the centre of the core to the top of the atmosphere and emphasised that such a  programme could be successful, only if “a highly integrated suite of new measurements with new instruments” was to be used. They agreed that the best way to do it was “a sustained programme of large space platforms”

Finally, in 1986 and 1988 the committee produced  two landmark  reports entitled   Earth System Science Overview and Earth System Science: A Closer View. As Global Habitability before, the reports highlighted the complexity and the interactions between the planet’s systems and its components parts. They covered almost everything, every element of the Earth system. The effect of the atmosphere, oceans, weather patterns, and land (Bretherton diagram).

But perhaps the most compelling part of the report was an overview of how the Earth system works. Two views were presented. The first one was the view of global change over thousands to millions of years, where processes such as solar variability and plate tectonics are the main drivers. The second view was over decades to centuries, where the important driver for global change are human activities.

The committee tried to put together an integrated interdisciplinary research programme that would look at and obtain, through space and in-situ data collection, a scientific understanding of the entire Earth system on a global scale. It recognised the complexity and the difficulty of the suggested proposal but as it was stated, the “new space technology, and quantitative models have now given us the capability to probe the complex, interactive processes of Earth evolution and global change”.

The aim was to collect data and then use the information gained from the observational programme “to guide the development of conceptual and quantitative models of the Earth as a dynamical system that represent the diverse processes and their interactions.”  Computer models regarded as an essential part of this process, not only to simulate global change but also to predict Earth evolution and measure global variables, such as mean atmospheric temperature, atmospheric carbon dioxide concentration and sea-levels. They could also help incorporate specified scenarios of deforestation, industrial development and fertiliser usage in order to gauge the effects of human activities.

Finally, the committee emphasised that present ongoing and operational satellite measurement systems must be continued and improved as required to provide accurate, and timely date. The proposed space observation system was centred to a group of large satellites, flying in a pole to pole orbit.  Using a wide array of advanced sensors would be able to scan the Earth below, and provide continuous, comprehensive and simultaneous measurements of land, oceanic, and atmospheric interactions, and gather detailed information of the entire earth system. [9] It was the same old “System Z” which now had been reappeared as Earth Observing System (EOS) – the initials of its title spelled the name of the Greek goddess of dawn -, a group of even more sophisticated satellites, which scientists believed would enable them to provide more precise and reliable answers about environmental uncertainties and concerns, such as ozone depletion, ocean dynamics and climate change.

An early sketch of “System Z.” Credit: Mark Abbott; Originally published by the Earth Observer. Source: NASA

As in “System Z”, NASA officials were promoting the construction of large platforms in space, arguing that this decision was dictated by the size and the weight of many of the – yet to be constructed – instruments.  Because of the size and cost of the project, NASA tried to attach EOS with the space station project that was still struggling to gain support within the national scientific community.

A few years later, the political situation induced the detachment of these two projects (space station and EOS). With the inauguration of George H.W. Bush in the presidency of the United States the global climate change became top priority and EOS would be paid from NASA’s space science office (OSSA). Yet, in 1986, the reception of the Mission to Planet Earth and EOS was fantastic and the expectations of the programme so huge, that NASA officials hoped it would represent the dawn of a new era for space international programmes.

Sources and References:
  1. Remarks at Edwards Air Force Base, California, on Completion of the Fourth Mission of the Space Shuttle Columbia, 4 July, 1982, https://www.reaganlibrary.gov/sites/default/files/archives/speeches/1982/70482a.htm
  2. Edelson, Laying the foundation. Mosaic, 1988
  3. Earth System Science at 20 Oral History Project, Oral History Transcript, Shelby G. Tilford, Interviewed by Rebecca Wright, Washington, D.C. – June 23, 2009
  4. NASA (1986) Earth System Science. Overview (National Aeronautics and Space Administration, Washington, DC).
  5. NASA (1988) Earth System Science: A Closer View (National Aeronautics and Space Administration, Washington, DC).
  6. W.H., Lambright, Administrative Entrepreneurship and Space Technology
  7. Gary Taubes, “Earth Scientists Look NASA’s Gift Horse in the Mouth” ,Science, Vol 259 (5097), (12 February,1993) 912
  8. Burton I. Edelson, ‘Mission to Planet Earth’, Science, Vol. 227(4685), (Jan. 25, 1985), 367
  9. Earth System Sciences Committee, NASA Advisory Council, “Earth System Science Overview,” May 1986. Document IV-11 inside [J.M Logsdom “Exploring the Unknown: Selected documents in the History of the U.S. Civil Space Program” Volume VI: Space and Earth Science, NASA SP-2004-4407], 536-550
  10. William K. Stevens, Huge space platforms seen as distorting studies of earth.
  11. Featured image source and credits: NASA. Animation that shows the orbits of NASA’s 2011 fleet of Earth remote sensing observatories. https://en.wikipedia.org/wiki/Earth_Observing_System