"The Landsat Program and Landsat Science"
Presented to the Landsat Science Working Group, Marriott Greenbelt,Greenbelt, Maryland, October 15, 1996
E.J. Sheffner
Johnson Controls World Services
NASA Ames Research Center
Moffett Field, CA 94035
Although it is perhaps a slight to the effort expended by those who designed and built the first Landsat satellite and payload, it is convenient to date the start of the Landsat Program from July 23, 1972, the launch date of Landsat 1. At least one Landsat system has been acquiring and transmitting earth images from space everyday since, 24 years, 3 months and 22 days ago. That record of acquisitions, the longest continuous record of operation by any earth observing system, should have, by now, demonstrated, beyond doubt, the utility of the data and awarded the Landsat Program world wide veneration and a commitment to continued collection, storage and distribution of high resolution, broad area, multispectral data of the land. Such is not the case. The course of the Landsat Program has been tortuous, and will likely remain so. The US government has responded to Landsat as if it were an unusual gift from a wealthy relative - never quite sure what to do with it, irked at the cost of maintaining it, unable to dispose of it, and nagged by the sense it would be better to have more than one. It is remarkable that after a quarter century of service, the construction of 7 satellites and 12 instruments, the acquisition and archival of millions of images and distribution of data to users around the world, the fundamental issues of Landsat remain unresolved. What is the nature of the Landsat Program - is it experimental, operational or something else? How should the program be managed, or, to phrase that question in terms of contemporary issues, what Landsat-type data should the USG procure and how should the USG procure it?
Resolving those issues is not the responsibility of this working group, nor, given the history of Landsat, are long term solutions likely soon. But, near term solutions are emerging, and those solutions will have an effect on your ability to get the data you need. It is worthwhile to review how the Landsat Program evolved regarding the fundamental issues, how the current programmatic environment is affecting availability of data and what is likely to happen with the Landsat Program in the near future. Although you cannot define the nature of the program nor decide how the USG will procure data, you represent the science community, and the interests of that community can and should be considered. To forward those interests, to develop reasonable and effective positions regarding earth observation from space, you need to be aware of the options available to the community and the factors shaping US policy toward earth observations and, especially, toward Landsat.
Initial Landsat Program
The primary causal factor for the uncertainty and periodic shifts in program policy is Landsat's success. The first Landsat satellite was designed, built, launched and operated as an experimental system. It became apparent soon after launch, that the data supplied by Landsat 1, especially data from the Multispectral Scanner System, the secondary instrument on the platform, was popular and potentially applicable in broad range of investigations. Through 1974, Landsat 1 transmitted more than 100,000 images covering 75% of the earth's land surface. More than 300 US and foreign investigators received data. Landsat was a hit The US government was un-prepared for the success of Landsat. An effort to define the nature of the program began in the Administration and Congress in 1973. Was Landsat experimental or operational? The Landsat Program is often compared to the weather satellites. Congress has maintained a consistent policy toward USG acquisition and distribution of weather satellite data, though that policy has been challenged at times. The distribution of weather data was a US government responsibility long before the first weather satellite was launched. Because of that history, weather data is accepted as a part of the national infrastructure like the interstate highways or national parks. A policy toward acquisition and distribution of weather data acquired from space-based platforms flowed directly and easily from the history of the Weather Service. But observation of the land from space was new. Despite the substantial interest shown in such observations in the United States and abroad, despite the technological leadership the US maintained in the field, Congress did not commit in the early 1970's nor since, to on-going, public sponsorship of acquisition and distribution of earth satellite observations. In other words, Congress has never agreed to fund a public, space-based, operational land remote sensing program.
That the first Landsats were built and operated by NASA underscored the ambiguity of the program. NASA is an engineering and science agency. NASA sponsors research that applies data acquired by experimental systems the agency builds and launches; the agency lacks administrative and Congressional mandates for operational systems. But most users of Landsat data are not NASA sponsored scientists, and many, perhaps most, applications of Landsat data are not experimental. NASA involvement with Landsat was then, and is today, an administrative anomaly.
Because Congress had to respond to the success of Landsat, because there was no precedent or existing policy for how an on-going, space-based, earth observation program should be managed, and because of the administrative anomaly of Landsat residing within NASA, the programmatic decisions made in "73 and '74 tended to be ad hoc and subject to change based on ideology, expediency and available funding. That environment for decisions has remained constant through the program's history.
The decision in 1974 was to continue Landsat as an experimental program through 1979. NASA and the Department of the Interior were assigned responsibility for acquisition and distribution of the data. Under those terms, Landsat 2 was launched in 1975, Landsat 3 in 1978.
In 1979, a review of the program by the Carter Administration led to Presidential Directive 54 - a fresh attempt to plan a long term strategy for Landsat. Operation of Landsat was transferred from NASA to NOAA acknowledging that Landsat was an operational system. The directive recommended that Landsat be converted to truly operational status by committing to four additional satellites beyond Landsat 3. The directive also included the recommendation that, as a long term goal, Landsat be transferred to the private sector, even though the Administration conceded that development of a commercially sustainable market for Landsat data was likely to take a decade. The Reagan administration was sympathetic to commercialization and accelerated the process for Landsat. However, it rejected the commitment of its predecessor to an operational program and advocated the immediate end to government funding for Landsat. Efforts to commercialize the program while maintaining data acquisition culminated in the passage of Public Law 98-365 in 1984, the law that established the instrument for commercialization of Landsat system through contract with NOAA. While the legislative machinations were progressing, two new Landsat were launched, Landsat 4 in 1982 and Landsat 5 in 1984. Both included an MSS as the primary instrument and a new higher ground resolution device, the Thematic Mapper, as an experimental instrument. Landsat 5 continues to operate 12.5 years after launch, having exceeded its design life by a factor of 4. (One action this group may wish to take is to suggest that March 1, the annivarsy date for the launch of Landsat 5, be declared a national holiday.)
In 1985, the Earth Observation Satellite Company (EOSAT), a partnership of Hughes and RCA, was selected by NOAA to operate the Landsat system under a ten year contract. EOSAT was assigned responsibility to operate Landsats 4 and 5 at USG expense and build two new satellites, also with USG funds. EOSAT was granted exclusive right to market Landsat data collected prior to the date of the contract through the expiration data (7/16/94) and data collected after the contract date for 10 years from date of acquisition. The primary impacts of the commercialization of Landsat data were a substantial increase in the price and a loss of control of the acquisition policy. Use of data declined with the price increase, and systematic acquisition of data was replaced by a policy of acquiring only data requested.
The 1984 law, and the contract with EOSAT that emerged from it, did not bring peace to the program. The remainder of the decade was marked by annual uncertainty within the USG about appropriating funds to meet the government's commitments to EOSAT and the data user community and to secure the continued acquisition of Landsat data by funding development and launch of new systems. Congress released funding for Landsat 6 in 1988, but operating funds for Landsats 4 and 5 remained hard to come by. Landsat 7
Not until 1992 was an attempt made to address the shortcomings in the program resulting from the 1984 law and plan a future for the program beyond Landsat 6. In February, the Bush Administration issued National Space Policy Directive #5. The motivation for this policy initiative was in part, at least, a desire to address Landsat's on-going problems and uncertainties. Perhaps of greater interest was the desire to ensure the continued availability of Landsat data after it had proved its utility in the Gulf War. The Directive established a management structure and goals for Landsat. It dealt with many issues surrounding the program as it outlined a strategy to: ensure the operation of Landsat 4 and 5 until the launch of Landsat 6,
acquire and launch Landsat 7 before the projected end of life of Landsat 6
foster development of advanced land remote sensing systems and opportunities for commercialization
minimize cost of Landsat data to USG users and in the US global change research program
limit the role of the USG in remote sensing to acquisition of data required for national security, foreign policy and public safety
maintain an archive in the US of existing and future Landsat type data consider alternatives for maintaining data continuity after Landsat 7
To implement this strategy, DOC was instructed to complete and launch Landsat 6 and to maintain, through EOSAT, operation of Landsats 4 and 5 until Landsat 6 became operational. Responsibility for Landsat 7 and beyond was assigned to DoD and NASA. The two organizations were instructed to develop and launch Landsat 7 with performance capabilities at least equal to Landsat 6,
In March 1992, DoD and NASA signed a management plan for Landsat 7. DoD accepted responsibility for the space segment and NASA assumed responsibility for the ground segment. A budget or $880M for the life of the program was established. In response to the management plan, DoD issued a Request for Proposals (RFP) for Landsat 7 in May 1992. The RFP specified performance requirements, it did not specify an instrument or instruments. The performance requirements included capabilities equivalent to Landsat 6 with the addition of TDRSS. The RFP also included, for potential bidders to consider adding to their proposals, "prioritized enhancements" and "lower priority enhancements." The former included improved spatial resolution, improved absolute calibration and stereo mapping capability. The latter included additional spectral bands, cross-track pointing, improved radiometric sensitivity and improved line of sight (LOS) accuracy. The award for Landsat 7 was given to General Electric (subsequently sold to Martin Marietta, subsequently to merge into Lockheed Martin) The winning proposal called for two instruments - The Enhanced Thematic Mapper Plus (ETM+) as the "continuity" instrument (including the enhancement in LWIR ground resolution and absolute radiometric calibration noted above), and the High Resolution Multispectral Stereo Imager (HRMSI) as an instrument that addressed many of the other performance enhancements described in the RFP. HRMSI performance characteristics included 4, 10 meter VNIR bands, a 5 meter panchromatic band, stereo imaging capability and off track pointing. The contract for Landsat 7 accepted the two instrument concept, but HRMSI was included as an option to be exercised, i.e., selected or rejected, by February, 1994. The option arrangement was necessary because neither DoD nor NASA had anticipated a second instrument on the platform or included funding for a second instrument in the budget for the baseline program defined in the management plan. Exercising the HRMSI option was dependent on both agencies securing additional funding to cover the anticipated additional cost.
Land Remote Sensing Policy Act of 1992
The award for Landsat 7 brings us to October, 1992 and enactment of the Land Remote Sensing Policy Act. That legislation contains the most recent directives from Congress on how the Landsat Program should proceed, and implementation of the provisions of the law have brought us to this meeting.
The 1992 law conformed to the history of the program It marked another shift in the philosophy of Landsat returning control of the program to the government sector, at least through Landsat 7. It recognized officially the importance of data continuity by authorizing Landsat 7, but it left undefined the program after Landsat 7. The law was another attempt to bring order and consistency to the program; but it did not resolve the fundamental policy issues.
More specifically, the law ratified the actions and followed the recommendations of National Space Policy Directive #5. It created an entity called Landsat Program Management consisting of DoD, NASA and any other agency the President selected to serve on it. LPM was directed to establish a management plan (it already existed) authorized to build, launch and operate Landsat 7, maintain the Landsat system, provide data to the user community at the cost of fulfilling user requests, place copies of Landsat 7 data in the National Satellite Land Remote Sensing Data Archive at EDC, negotiate a new data policy for Landsat 4-6 with EOSAT, assume Landsat 6 program responsibilities from NOAA following launch of the system, initiate a Landsat Advisory Process; conduct a technology demonstration program, and assess options for a land remote sensing system after Landsat 7. All provisions of the law have been or are currently being implemented. Landsat Program Since 1992
Two major events affected the Landsat Program after passage of the 1992 law. Both occurred in the fall of 1993. First came the loss of Landsat 6 in early October. Second was the decision of DoD in December to withdraw from the program. The loss of Landsat 6 led to a review of the program by OSTP. DoD's withdrawal from the program while the OSTP review was underway broadened the scope of the review and led to a reorganization of the program. The re-organization was announced officially in Presidential Decision Directive/NSTC #3 in May, 1994. The Administration directive defined the Landsat 7 project as it is now constituted. NASA, assigned in the original management plan responsibility for the Landsat 7 ground segment only, assumed responsibility for the space segment as well. NOAA and USGS were officially added to Landsat Program Management. NOAA was assigned responsibility for operation of the satellite and ground system; USGS was to operate the ground system under NOAA's direction and archive the data. Under that management structure, the Landsat 7 project has gone foward as is doing well as you well hear later this morning. When NASA took on responsibility for the Landsat 7 space segment, it made the ETM+ an EOS instrument and Landsat 7 became part of the EOS program. That decision was ratified by the EOS payload panel, because, as the panel stated, the availability of Landsat type data was assumed when the EOS payloads were selected. If a source for such data was not assured, then an instrument to collect Landsat type data should be included in EOS. The decision had no effect on Landsat 7 but it did have an impact on EOS as space was reserved on the AM-2 platform, scheduled for launch in 2004, for a Landsat/ETM+ type instrument. The 1992 law has remained unchanged since its enactment, but the 104th Congress, just adjourned, came very close to changing and amending it and it is likely an attempt will be made again in the 105th regardless of the outcome of the election next month. On September 17 the House passed the "Space Commercialization Promotion Act of 1996" and sent it on to the Senate where it died short one vote as the legislative clock ran out. That bill included a section of changes to the 1992 Land Remote Sensing Policy Act and another section that addressed directly acquisition of Earth remote sensing data. The changes proposed in the 1992 law had no direct impact on Landsat 7, but they offer evidence of what Congress may be willing to accept in a post Landsat 7 system. For example, the finding in the 1992 law that reads "Full commercialization of the Landsat Program cannot be achieved within the foreseeable future, and thus should not serve as the near term goal of national policy on land remote sensing; however, commercialization of land remote sensing should remain a long term goal of United States policy," is stricken and replaced by "Commercialization of land remote sensing is a near-term goal and should remain a long term goal of United States policy." In section 301 of the 1992 law, on continued federal research and development, to the sentence that reads, "The Administrator (NASA) is authorized and encouraged to...develop remote sensing technologies and techniques, including those needed for monitoring the Earth and its environment," the words "that are not being commercially developed" are added. At the conclusion of that section the following paragraph is added: "The federal government shall not undertake activities under this section which duplicate activities available from the commercial sector, unless such activities would result in significant cost savings to the federal government." Section 303 of the 1992 law authorizing the President to conduct a technology demonstration program is stricken in its entirety. That section is part of, at least, the justification for NASA's New Millennium Program under which the EO-1 instrument, a potential precursor for a Landsat 7 follow-on, is being built. Section 202 of the Space Commercialization Promotion Act addresses earth remote sensing. The first paragraph states, "For purposes of meeting government goals for Mission to Planet Earth, the Administrator shall, to the maximum extent possible and while fully satisfying the scientific requirements of the National Aeronautics and Space Administration, acquire, where cost effective, space based and airborne remote sensing data, services, distribution and applications from the private sector. " The administrator is also called upon to undertake a study, due 9 months after enactment of the law, to determine the extent to which the baseline scientific requirements of Mission to Planet Earth can be met by the private sector and how the Administrator will meet those requirements which cannot be met by the private sector. What I have just described is not law...yet, but it is an indication of the mood of many in Congress to regard commercialization, i.e. acquisition of data from the private sector, as the preferred solution for government data acquisition requirements. Prospects for Landsat 8
However, regarding post Landsat 7 systems, that preference is also stated in the 1992 law. References in the law to post Landsat 7 systems are contained in Title IV, "Assessing Options for Successor Land Remote Sensing Systems" The law calls upon Landsat Program Management to report to Congress by October 1997 on options for a follow-on to Landsat 7. The report is required to include a "...full assessment of the advantages and disadvantages of 1) private sector funding and management of a program; 2) creating an international consortium for a follow-on system, 3) funding and management of the system by the US government, and; 4) build and operate a system through a cooperative effort between the US government and the private sector." The criteria for evaluating the options are also stated in the law as goals for the system. The follow-on to Landsat 7 should : 1) serve adequately the civilian, national security, commercial and foreign policy interests of the United States; 2) maintain data continuity with previous Landsats, and 3) include system enhancements that make the system cheaper to build and operate and more responsive to user data requirements. Section (c) of Title IV reads, "Preference for Private Sector System - If a successor land remote sensing system to Landsat 7 can be funded and managed by the private sector while still achieving the goals [stated above] without jeopardizing the domestic, national security, and foreign policy interests of the United States, preference should be given to the development of such a system by the private sector without competition from the United States Government." NASA, as part of LPM, is implementing Title IV of 1992 law and will make recommendations on a successor to Landsat 7 by October, 1997. To begin addressing the mandate of Title IV, NASA commissioned an assessment of options for "Landsat 8" based on the current state of land remote sensing from space and the stated plans for new commercial and government sponsored systems The report found that the primary demand for Landsat data, in terms of number of scenes, came from the global change science community. In the next five years, a number of systems will provide data similar to ETM+. That data may be more than adequate not only for the needs of the science community but for all users of Landsat data. The report recommended that the US government pursue purchase of data from the private sector to meet the need for Landsat-type data. If that option was not viable, the purchase of a commercial instrument for operation by the government combined with a commercially operated ground system and an international consortium to share data would likely be the most efficient way to proceed. Regardless of the option chosen, the report recommended that NASA return to its role of advanced technology development and retire from the responsibility of maintaining an operational remote sensing system.
The report was one element of a comprehensive strategy toward fulfilling the requirements of the law. (Other actions taken by NASA regarding a follow on to Landsat 7 will be described on Thursday.) The report's recommendations have neither been adopted, nor dismissed. The viability of commercial systems has yet to be demonstrated. A data purchase has attractive features, but that type of program has no successful precedent at any scale, let alone the quantity of data a Landsat-type data purchase may entail. A crucial element in any data purchase will be the data policy, i.e., the rules for sale and redistribution of data after purchase. Who will have access to the data purchased by the government? What will it cost? How can it be used? The 1992 law found that commercialization of Landsat data was a failure because, in part, the cost of the data impeded distribution. What are the obligations of the US government to supply "low cost" data, to what elements of the user community, and at what level of data processing? Should the concept of COFUR, explicit in the Landsat 7 data policy, as required by law, be extended to the Landsat 7 follow -on? These issues will be addressed, directly or by default, in any option selected for a post Landsat 7 system. Final Words
Four years after passage of the 1992 law, a robust, consistent policy for Landsat remains as elusive as ever. Nevertheless, the commitment to Landsat 7 remains intact. Currently, there are no initiatives in Congress or the Administration to alter the manner in which Landsat 7 will collect, process, archive and distribute data. The picture after Landsat 7 is murky. Congress appears to favor a data purchase agreement or some solution that obviates the need for the government to build and operate new satellites. The dream of commercially available, Landsat like, earth remote sensing data is alive but unfulfilled. No fully commercial, space-based, earth observation system of any type has yet been built, launched and operated successfully. But there are other Landsat type instruments now acquiring data. Others are planned. Those systems may provide all or part of a solution. The EOS program continues to plan for an instrument on AM-2 with ETM+ capabilities, but the nature of the instrument is undefined, and the promise of AM-2 may be another unfulfilled dream. The report prepared for NASA on post Landsat 7 systems also recommended for further study establishing a process for refining and quantifying the science requirements for a global land change archive and developing a plan for a global land change science institute. The recommendations were made to help define the acquisition requirements for Landsat-type systems and to establish an independent entity to assess how best to meet the requirements.
Those are two issues that may fall within the purview of this group. Unambiguous direction from the science community regarding collection of global data and evaluation of the interoperability and/or utility of data from the public and private land remote sensing systems on orbit or planed for operation in the next five years, would be a positive contribution toward a coherent, sustainable US policy for earth observations.
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