NASA Lays Groundwork to Include Thermal Sensor on Landsat Mission

WASHINGTON — Several bills moving through Congress this year would require NASA to add a thermal-infrared sensor to the Landsat land-imaging satellite now in development even if that means delaying its planned mid-2011 launch.

Rather than fight the provisions included in NASA authorization and appropriations bills now before the House and Senate, the space agency appears resigned to adding the thermal- imaging capability to the Landsat Data Continuity Mission (LDCM) whether or not the bills become law.

A senior NASA official told Space News the agency’s Science Mission Directorate has been told to bank on adding the sensor and not to await formal legislative direction from Congress to get moving on the change.

In a July 16 interview, another official – Steve Volz, associate director for flight projects in NASA’s Earth Sciences division – said the LDCM team has not been given the go ahead to start work on a new instrument. But he said NASA’s , the , facility leading the LDCM development, is actively studying what it would take to add a thermal imaging capability to the satellite.

“I would not want to say whether we would get ahead of congressional direction and actually start building a flight instrument,” Volz said. “But I think we are doing everything feasible, everything reasonable, and everything possible to make this capability available for LDCM on the launch date we arrive at when we get through our mission confirmation.”

For now, NASA is holding to the July 2011 launch readiness date and $555 million budget – roughly a fifth of which already has been spent – advertised in the 2009 budget request the agency sent to Congress in February. The LDCM’s mission confirmation review – a major decision point that marks NASA’s formal commitment to a project’s budget and schedule – is slated for early next year.

Adding a thermal imaging capability to the LDCM is feasible, but would increase the amount of time and money needed for the satellite project. Landsat thermal- infrared data is currently used to remotely measure water consumption by crops and natural vegetation. Western U.S. states including , and others also rely on the data to administer existing water rights and interstate water compacts.

Volz said the spacecraft platform, or bus, being built by General Dynamics Advanced Information Systems of Gilbert, Ariz., under a $116 million fixed-price contract awarded in April, has been designed to accommodate up to two instruments in addition to its main instrument, the Operational Land Imager (OLI). That instrument is being built under a separate $127.9 million cost-plus-award-fee contract awarded to Boulder, Colo.-based Ball Aerospace and Technologies Corp. in July 2007.

Ball spokeswoman Roz Brown said adding a thermal imaging capability to the LDCM is expected to have minimal impact on the OLI since the thermal capability is envisioned as a separate instrument. “It might have an effect on our thermal environment – in that it would be located next to OLI on the bus – but we don’t anticipate the impact would be significant,” Brown said.

General Dynamics spokesman Mike Greenwood deferred to NASA on questions about the feasibility of adding a thermal sensor to the mission.

While a thermal band could be added to the OLI given enough time and money, Volz said it would make more sense to build a separate instrument since the OLI passed its preliminary design review earlier this year and Ball’s work on the sensor remains on schedule and under budget.

Given the LDCM’s relatively tight development schedule, Volz said, NASA likely would skip a competitive procurement for the thermal sensor and build it in-house at Goddard or under a sole-source contract to industry.

Volz would not discuss how much adding a thermal instrument would cost or how long it might delay the LDCM’s launch. A Landsat source told Space News that NASA previously estimated that including the thermal sensor would add a year to the LDCM’s development timetable.

At a Landsat Science Team meeting the week of July 14 at the U.S. Geological Survey’s headquarters in Reston, Va., attendees were told that the LDCM’s launch readiness date could slip as much as a year independent of any thermal sensor decision in order to comply with more conservative cost- and schedule-estimating practices ordered by NASA Administrator Mike Griffin, according to a source who was present.

Volz did not attend the meeting, but told Space News in a follow-up e-mail that by following ‘s new 70-percent confidence requirement for flight project cost and schedule estimates, LDCM program officials will reduce their chances of running afoul of cost control rules put in place by the 2005 NASA Authorization Act.

“By planning to the 70 percent confidence level, and managing our mission development carefully, NASA should not exceed the cost and schedule thresholds identified in the Congressional legislation,” Volz said.

While at least one attendee at the Landsat Science Team meeting came away with the understanding that NASA considers the addition of a thermal sensor a foregone conclusion, Volz disagreed with that characterization.

Volz said the NASA official who spoke at the meeting, LDCM Program Executive Ed Grigsby, told the attendees that the agency was taking measures to minimize the impact of adding the thermal-infrared capability to the mission.

“In parallel NASA has in the past and is continuing to investigate in detail fruitful thermal band instrument options,” Volz said.

These options include traditional actively cooled sensors as well as newer approaches involving microbolometers and quantum well infrared photodetectors that were not considered realistic options when NASA was building Landsats 5 and 7, both of which had thermal bands incorporated into their primary mapping instruments .

Volz said the thermal channels on Landsats 5 and 7 were considered an experimental capability at the time and were not included as part of LDCM’s requirements.

That omission upset water resource planners and other users that have come to depend on Landsats 5 and 7’s thermal bands, with governors from the relatively arid western United States leading the charge for adding the capability to LDCM.