NASA Landsat 8 Satellite Launch This Monday!


LDCM Decal1

Here is my latest post on

NASA Landsat 8 Satellite Launch: Where It’s Going and What It Could Mean For the Future

And my Q&A with NASA Project Scientist Dr Jim Irons?

1.   After reading the pieces in Wired and Nature this evening it is clear the continuity of this mission is crucial to the mapping of landscape and land usage but what would it mean to not have that coverage post-2016 when Landsat 7 runs out of fuel?

With both Landsat 7 and Landsat 8 in operation, one of the satellites will fly over any parcel of land once every eight days.  This is particularly useful for those who wish to observe the seasonal phenology of vegetation canopies, for example, those who use Landsat data to track crop development during the growing season.  If cloud cover intervenes, the eight day coverage is just barely sufficient for those sorts of applications and many wish for even more frequent Landsat coverage.  When Landsat 7 is decommissioned, those sorts of applications will become problematic with only the 16 day coverage afforded by a single Landsat 8 satellite.  Part of the research agenda in the near future will be to learn to use Landsat data in concert with data from other satellites, such as the ESA Sentinel-2 satellites, to obtain more frequent temporal coverage of an area.


2.   Other than the landscape mapping of Earth, what other information does the Landsat offer to the general public and does the improved technology offer any other insight into global patterns such as population data for human geographers?

The Landsat sensors basically measure the amount of light reflected or emitted at multiple wavelengths from the surface of the Earth for every pixel in an image.  All manner of information is derived or inferred from these measurements.  In many cases, the information is derived from several sources of data and Landsat images are just one, often important, part of the analyses.  For example, in recent years researches have develop models for measuring evapotranspiration rates using Landsat data in concert with meteorological data.  In another interesting application, penguin populations in Antartica have been estimated from Landsat observations of the extent of guano stains on the ice and that requires some other knowledge of the density of penguins per unit area in their rookeries.  The Landsat satellites cannot directly measure population densities of humans and images can be used to observe and measure the expansion of urban development, for examples, and human geographers can estimate population if they know the number of people per unit area, kind of like penguins.

3.   What are the fields of science that will most and best use the data that will be coming in?

Similar to the answer above, a wide scope of Earth science fields will use LDCM data.  I am not prepared to state that one or two fields will best use the data.  Climatologists were certainly look at the impact of climate change on the land surface and how those changes feed back to the climate system.  Forestry, agronomy, hydrology are obvious examples of the fields that will use the data.  The cryospheric sciences and even marine science will find uses.  The scope of fields that will use LDCM data is broad and diverse.


4.   You have said it probably wont live as long as some of its predecessors, but what would be your best estimate and how long would you hope to have a functional Landsat 8?

Every satellite component has a design life.  The design life of Landsat 5 was five years and that satellites remarkably remained in operations for over 28 years.  The design lives of the LDCM spacecraft and the OLI are five years.  The design life of TIRS is three years.  The spacecraft will contain enough propellant to maintain it’s operational orbit for at least 10 years.  We are obviously hoping that the satellite and instruments exceed their design lives.



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