Artists rendering of the International Space Station (ISS) after installation of the U.S. Laboratory Destiny and its nadir-viewing optical quality window during Space Shuttle Mission STS-98/Station Mission 5A in February 2001 (Image JSC2001e00360).
With much of their time committed to construction of the International Space Station, astronauts and cosmonauts are also beginning their first scientific studies. The Destiny Laboratory just joined to the International Space Station includes the best optical quality window ever flown on a human-occupied spacecraft. The window will eventually host a number of remote sensing experiments that will use a special rack system, the Window Observational Research Facility or WORF, for mechanical and electrical support (Eppler et al. 1996). Until the WORF is complete in June 2002, astronauts are photographing the Earth’s surface as part of an early project, Crew Earth Observations.
Since early space missions in the1960s, astronauts have photographed the Earth below, observing the world’s geography and documenting transient events like storms, floods, fires, and volcanic eruptions. The early photography formed a foundation for Landsat and other Earth observing satellites. Even as such satellites have become the most common way for scientists to collect data from orbit, humans have continued to look out the windows of spacecraft and to record what they see with cameras. For the early Space Station expeditions, 70- and 35-mm film cameras and electronic still cameras will be used to capture images of the Earth.
Astronauts have documented human impacts on the Earth—city growth, agricultural expansion, and reservoir construction. Today, images of the world spanning more than 30 years provide valuable insight into Earth processes and the effects of human activities on the planet. Photographic images taken by astronauts serve as both primary data on the state of the Earth and as secondary data to be combined with images from other satellites in orbit. Through their photography of the Earth, ISS astronauts will build on the time series of imagery started 35 years ago, insuring that this continuous record of Earth remains unbroken.
As a formal project or “payload” on the International Space Station, Crew Earth Observations will focus on some of the most dramatic examples of change on the Earth’s surface. Target sites selected by an interdisciplinary group of scientists are some of the most dynamic regions of the Earth that could be observed under the tight time constraints of the early phases of Space Station construction. These sites include major deltas in south and east Asia, coral reefs, major cities, smog over industrial regions, areas that typically experience floods or droughts triggered by El Niño cycles, alpine glaciers, tectonic structures, and features on Earth, such as impact craters, that are analogs to structures on other planets.
Image courtesy Johnson Space Center Office of Earth Sciences