Exploring the Unknown - NASA's History Office

Although we are in the early stages of assessing options, initial indications from
EOSAT, the system’s operator, are that Landsat 5 could continue to operate for several
more years even though it is already 9 years old and well past its design life. Consequently,
the likelihood of a significant data gap may not be as great as originally anticipated, assuming
that Landsat 7 is launched on schedule. However, we do have serious concerns with
the coverage of the earth and the site revisit time of Landsat 5. Landsat 6 would have
addressed these concerns and added some additional capabilities that would have further
increased the competitiveness and utility of the Landsat system.
OSTP in conjunction with the DOD, NOAA, and NASA is carefully considering
options to address both the loss of Landsat 6 and the cost and risk of the Landsat 7 program.
These two items are linked because the availability of Landsat 7 directly affects when
or if a replacement spacecraft for Landsat 6 should be launched. As you are aware the current
budgetary environment has made it necessary to examine options in terms of their
cost and risk; therefore, I want to assure you that any alternatives to the current program
will undergo careful interagency review in order to evaluate potential impacts relative to
the Landsat program’s diverse requirements and users. [2] Further, I would like to assure
you that any proposal for responding to the loss of Landsat 6 or for significantly modifying
the current Landsat program will address data continuity; impacts on agency budgets;
schedule impacts; the acquisition, launch and operation of the necessary satellites and
instruments; and the needs of the user communities.
The necessary interagency review will be expedited to meet the needs of FY95 budgetary
decision timetables. However, it is important to make clear that no decision on program
alternatives has been or will be taken prior to the completion of this review.
I look forward to working with you on this important issue and will provide a more
detailed discussion of the alternatives being considered in the near future.
The Honorable George E. Brown, Jr.
Chairman
Committee on Science, Space and Technology
U.S. House of Representatives
Washington, DC 20510
EXPLORING THE UNKNOWN 371
Sincerely yours,
[hand-signed: “Jack”]
John H. Gibbons
Director