SAN FRANCISCO — In 1960, U.S. military leaders were eager to use images captured by Corona, the world’s first photographic reconnaissance satellite, to gauge the scope of the Soviet Union’s missile program by identifying manufacturing plants and launch sites. They quickly realized, however, that without timely meteorological data, much of the film recovered was useless.
“When we finally got the first pictures back, about 85 percent were obscured by clouds,” said retired U.S. Air Force Col. Thomas Haig, the original manager for the first National Reconnaissance Organization (NRO) weather satellite initiative.
To remedy that problem, the National Reconnaissance Office established a highly classified effort in 1961 to develop a weather satellite that could provide data to help the military schedule aerial reconnaissance and satellite photography when clouds were unlikely to impede the view. That effort, which was known by several names before being called the Defense Meteorological Satellite Program (DMSP), was expected to last for only a year or two, just until NASA’s National Operational Meteorological Satellite System (NOMSS) was capable of meeting U.S. military and civilian agency requirements.
Haig agreed to take on the job of “designing the new satellite, marrying it to a booster and getting it into orbit in nine months,” as long as his military bosses agreed to his conditions. He insisted on purchasing spacecraft under a fixed-price contract, selecting his own program staff and building satellites without relying on a systems engineering and technical design contractor. “I couldn’t meet the schedule without those conditions,” Haig said.
Once those conditions were met, the project moved forward quickly. The first satellite was designed and launched in May 1962, but destroyed when the Scout launch vehicle failed. On Aug. 23, 1962, a Scout rocket succeeded in sending the first DMSP spacecraft into sun-synchronous polar orbit. The spin-stabilized satellite, which carried an RCA television camera, weighed about 45 kilograms and measured approximately 58 centimeters across. With no redundant systems, the satellite worked until only March 23, 1963, but its utility during those six months assisted military leaders in conducting successful aerial reconnaissance flights during the Cuban Missile Crisis and highlighted the value of gathering weather data from space, said R. Cargill Hall, retired NRO chief historian.
Fifty years later, DMSP satellites continue to provide the military with weather and climate data to support tactical and strategic missions, although the current crop of satellites has little in common with the early spacecraft. Instead of a television camera, the six DMSP satellites currently in orbit carry seven sensors, including the Operational Linescan System built by Northrop Grumman Electronic Systems of Baltimore, which provides extensive visual and infrared imagery. Northrop Grumman also builds DMSP’s Special Sensor Microwave Imager/Sounder, which is used to monitor rain, humidity, temperature and sea-surface winds. Additional DMSP sensors gather space weather data and monitor the space environment near the satellites. DMSP “started out as a way to show cloud cover and ended up as a fully capable weather satellite that has demonstrated billions of dollars of advanced technology that has been shared with civil satellite systems,” said Mark Valerio, military space vice president and general manager for Lockheed Martin Space Systems.
Modern DMSP satellites are much larger than their predecessors, weighing more than 1,200 kilograms. They also work much longer. The six Air Force DMSP satellites currently in orbit have an average lifespan of more than 10 years. The constellation includes: F17 and F18, the two primary DMSP spacecraft; secondary satellites F15 and F16; and F13 and F14, which are no longer capable of storing data but share observations through a direct downlink. During successive program upgrades, Lockheed Martin and Northrop Grumman have added capability to DMSP spacecraft, including more-powerful computers, three-axis stabilization, precision pointing systems, advanced sensors, redundant electronics, improved batteries, larger solar arrays and propulsion systems designed to help the satellites maintain their orbits.
Many sophisticated sensors were first tested onboard DMSP spacecraft. For example, “DMSP pioneered the use of a microwave imager and sounder to augment visible data used in weather forecasting,” said Gilbert Chan, Northrop Grumman DMSP program manager.
DMSP was slated for cancellation in 2015 when the National Polar-orbiting Operational Environmental Satellite System (NPOESS) was scheduled to begin providing weather and climate data to meet forecasting requirements of U.S. military and civilian agencies.
When the White House announced plans in 2010 to dismantle the NPOESS program, the Air Force established the Defense Weather Satellite System (DWSS) to meet its needs. The DWSS program also was stopped early this year because Congress refused in the 2012 budget to fund the effort and instead earmarked $125 million to enable Air Force officials to craft a new weather satellite initiative.
While that new program takes shape, the Air Force plans to augment its aging DMSP constellation by launching F19 in March 2014 and F20 in 2020. In preparation for those launches, Air Force officials are working with DMSP prime contractor Lockheed Martin Space Systems and sensor support contractor Northrop Grumman Electronic Systems to test and upgrade various components of the two remaining DMSP satellites, DMSP F19 and F20, which were built during the 1990s.
“DMSP F19 sensors are being retested,” Chan said. Similarly, Lockheed Martin is performing electrical testing on the F19 satellite in addition to responding to an Air Force request for proposals on the work needed to prepare the F20 satellite for launch in 2020.
