Landsat 8 (LDCM)

Landsat 8 (LDCM) [OSC]

On December 23, 2005, the Office of Science and Technology Policy (OSTP) issued a memorandum adjusting the LDCM (Landsat Data Continuity Mission) strategy. NASA was instructed to acquire a single Landsat data continuity mission in the form of a free-flyer spacecraft, which will receive the name Landsat 8. The instrument will collect land surface data similar to that of its Landsat predecessors. The data will be delivered to the U.S. Geological survey who will be responsible for mission operations as well as data collection, archiving, processing and distribution.

The most recent, Landsat 7, was launched in April 1999 and continues to collect data. Because its design lifetime is five years, efforts to implement LDCM have been ongoing to minimize risks to data continuity. Early plans called for NASA to purchase data meeting LDCM specifications from a privately owned and commercially operated satellite system. However, after an evaluation of proposals received from private industry, NASA cancelled the Request-for-Proposals (RFP) in Sept. 2003.

In light of the RFP cancellation, an interagency working group was formed (by the Executive Office of the President) to discuss new plans for Landsat data continuity. These discussions eventually lead to the Aug. 13, 2004 OSTP memorandum which directed federal agencies to place Landsat-type sensors on National Polar-orbiting Operational Environmental Satellite System (NPOESS) platforms.

Following an evaluation of the technical complexity of integrating Landsat-type sensors on the NPOESS platforms, the Dec. 2005 memorandum redirected the Departments of Commerce, Defense, the Interior, and NASA to proceed with the NPOESS program without incorporating a Landsat-type instrument.

The LDCM mandated by the most recent OSTP memorandum will collect and archive data consistent with data from the previous Landsat satellites. Expeditious progress towards he acquisition, launch, and operation of the LDCM is anticipated to minimize any possibility of a gap in Landsat data. Landsat 5 and Landsat 7 are still operational, but Landsat 5 is 22 years old and no redundancy remains for most of its mission critical subsystems. Landsat 7, which was launched in 1999, has lost the use of its instrument Scan Line Corrector and has lost gyro redundancy.

The Operational Land Imager (OLI) is being built by the Ball Aerospace and Technologies Corporation. The Ball contract was awarded in July 2007. OLI improves on past Landsat sensors using a technical approach demonstrated by a sensor flown on NASA's experimental EO-1 satellite. OLI is a push-broom sensor with a four-mirror telescope and 12-bit quantization. OLI will collect data for visible, near infrared, and short wave infrared spectral bands as well as a panchromatic band. It has a five-year design life. The graphic below compares the OLI spectral bands to Landsat 7's ETM+ bands.

The Thermal InfraRed Sensor (TIRS) was added to the LDCM payload to continue thermal imaging and to support emerging applications such as evapotranspiration rate measurements for water management. TIRS is being built by NASA GSFC and it has a three-year design life. The 100 m TIRS data will be registered to the OLI data to create radiometrically, geometrically, and terrain-corrected 12-bit LDCM data products.

In October 2007, a Atlas-5(401) was contracted for the launch.

General Dynamics Advanced Information Systems, now Orbital Sciences Corp., has been selected in April 2008 by NASA to build the spacecraft for the Landsat Data Continuity Mission (LDCM). Under the terms of the $116 million delivery order, Orbital will be responsible for the design and fabrication of the LDCM spacecraft bus, integration of the government furnished instruments, satellite-level testing, on-orbit satellite check-out and continuing on-orbit engineering support. Orbital will also provide a spacecraft/observatory simulator.

Orbital will provide a simple, robust and reliable Landsat spacecraft that allows for rapid integration and testing. The company will use mature, qualified, flight-proven components to reduce development time, shorten integration time and improve performance. Orbital will build the LDCM spacecraft in its state-of-the-art satellite manufacturing facility in Gilbert, Arizona.