This NASA DC-8-has been highly modified to support the agency’s Airborne Science mission. The aircraft, built in 1969 is a series 72 model, construction number 46802 and was delivered new to Italian airline Alitalia on the 14th May 1969 as I-DIWK spending 10 years in Service the aircraft was then sold to Braniff Airways in the USA and was acquired by NASA in 1986 and registered N717NA. Within 6 months the aircraft was re-registered N817NA. In 1998 the aircraft once again was re-registered and took up the registration N436NA before taking up Its previous registration N817NA back in 2006 which it still carries today.
The aircraft is 157 feet long with a 148 feet wingspan. With A range of 5,400 nautical miles (6,200 statute miles), the aircraft can fly at altitudes from 1,000 to 42,000 feet for up to 12 hours, although most science missions average 6 to 10 hours. The DC-8 can carry 30,000 pounds of scientific instruments and equipment and can seat up to 45 experimenters and flight crew.
Once purchased by NASA the power plants were changed and the aircraft now uses 4 CFM International CFM-56-2C Turbofan engines. A new instrument system was fitted with GPS navigation. A glass cock pit is planned for the future but this is a 2 Month project and NASA find themselves with a back log of missions at present so this modification will have to wait for another day.
NASA operates this highly modified Douglas DC-8 as a flying science laboratory. The aircraft, which is based at the NASA Armstrong Flight Research Centre facility in Palmdale, California, is used to collect data for experiments in support of projects serving the world’s scientific community. Federal, state, academic and foreign investigators are among those who use NASA’s DC-8.
Data gathered with the aircraft at flight altitude and by remote sensing have been used for studies in archaeology, ecology, geography, hydrology, meteorology, oceanography, volcanology, atmospheric chemistry, cryospheric science, soil science and biology.
Four types of missions are flown with the DC-8 : sensor development, satellite sensor verification, space vehicle launch or re-entry telemetry data retrieval and optical tracking, and basic research studies of Earth’s surface and atmosphere.
Because it is flown in the Earth’s atmosphere, the DC-8 offers a comparatively inexpensive way to test and verify prototype satellite instruments. Scientists use the DC-8 to develop ideas in instrument technology as well as to test new instruments and modify them if necessary based on flight results. Potential problems can be corrected before new instruments are launched into space. As a result, flight proven hardware can lead to substantial savings in time and resources.
As an example, the DC-8 conducted the Active Sensing of CO2 Emissions over Nights, Days and Seasons 2 campaign during the summer of 2011 supporting tests of four laser instruments used in gathering remote measurements of atmospheric carbon dioxide. Flights were flown over different land features from desert to snow to test surface reflectance effects on instrument performance. Space-borne lasers would find the same type of surfaces when used to study components of Earth’s atmosphere. This research will contribute to further development of laser-based Earth-observing satellite instruments designed to measure atmospheric carbon dioxide.
In 1991, NASA launched a comprehensive program to study Earth as an environmental system. The extended range prolonged flight duration capability, large payload capacity and laboratory environment of the DC-8 make it one of the premier research aircraft available to NASA’s Science Mission Directorate. Combined with other aircraft, satellites or ground stations, the DC-8 complements and extends the range of an instrument package, allowing scientists to successfully address today’s planetary issues
In 2009 the DC-8 began participation in Operation Ice Bridge, NASA’s annual polar ice field campaign, with flights over Antarctica from a deployment base at Punta Arenas, Chile. The aircraft carries researchers and their instruments over Western Antarctica in the largest airborne survey of Earth’s polar ice. During March and April 2010, the DC-8 was based in Green-land for Ice Bridge’s Arctic ice study. Ice Bridge’s research continues the multi-year measurements started by NASA’s Ice Cloud and Land Elevation Satellite ICE Sat-1, which ceased operation in 2009, and will continue until ICE Sat-2 is launched next year.
The latest mission is NASA’s most ambitious research study to date is will take place in August 2016. The Atmospheric Tomography (ATOM) mission will take off aboard the agency’s DC-8 flying laboratory on a 26-day journey from the North Pole down the Pacific Ocean to New Zealand and then across to the tip of South America and back north up the Atlantic Ocean to the Arctic.
The airborne mission will complement NASA’s current satellite-based efforts to monitor and understand the major gases of Earth’s atmosphere, such as carbon dioxide and ozone. In addition to validating space observations, the Atmospheric Tomography mission will zoom in to make the finely detailed measurements of atmospheric chemistry that are difficult or impossible to make from orbit “The best way to study the atmosphere is to fly through and measure as much of it as we can,” said Dave Jordan, project manager at NASA’s Ames Flight Research Centre.
The mission will measure more than 200 gases as well as airborne particles in the atmosphere over the oceans. The science team is trying to understand how greenhouse gases such as methane and ozone, and poorly understood airborne particles such as black carbon, enter, transform and ultimately are removed from the atmosphere processes essential for understanding Earth’s climate today and in the future.
NASA’s DC-8 aircraft will be loaded with 20 scientific instruments to measure the atmosphere on its around-the-World journey. The aircraft will make a series of gentle descents and ascents in order to capture the relatively warm humid air 500 feet (152 meters) above the ocean surface as well as the colder, dry air at its peak altitude of 35,000 feet (10,670 meters), and everything in between.
Being an airframe with the third least hours of any DC-8 still flying NASA expect many more missions collecting valuable atmospheric data.
Many thanks to Matt Hartman for some of the photos used in this article