December 2003 - January 2004
Let the cutting begin
HIAPER work reaches pivotal stage
Work has reached a critical junction on the much-anticipated new research aircraft known as the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER). After more than a year of studies into how to modify the Gulfstream V airplane to accommodate scientific instruments, Lockheed Martin workers at a Greenville, South Carolina, plant will begin cutting into its fuselage in January.
“It’s the moment we’ve been preparing for,” says Krista Laursen, director of the HIAPER Project Office. “We’re very confident that the engineering work performed by Gulfstream, Lockheed, and NCAR personnel will pass this test—but it is a bit of a stressful time.”
Krista Laursen.
If all goes as planned, the jet will arrive at the Research Aviation Facility at Jefferson County Airport next fall for a final round of modifications. It’s scheduled to begin limited research flights in the summer of 2005, then take off for full-scale missions at the end of the year. Although NSF will own the title to the aircraft, NCAR will be responsible for operating and maintaining it.
HIAPER is designed to meet research needs in the atmospheric sciences over the next several decades. It will be able to reach an altitude of 51,000 feet (15,500 meters), enabling scientists to collect data at the tops of storms and the lower edge of the stratosphere. With a range of about 7,000 miles (11,265 kilometers), the plane will have the ability to track atmospheric particles across the oceans or reach the South Pole from bases in South America or New Zealand. Although some research planes can fly higher, HIAPER’s combination of altitude and range is unmatched in atmospheric research.
First, however, the plane has to be modified from a standard Gulfstream V—a jet typically used for whisking around corporate travelers—to a state-of-the-art research platform.
“Lengthy engineering process”
Constructed in 2002, the plane has a paint coat of drab green (which is actually a primer to prevent against corrosion) and doesn’t look like much more than the shell of an aircraft with engines and wings. But it’s been the subject of intense work by Gulfstream, Lockheed, and NCAR staffers.
The HIAPER aircraft is undergoing modifications. (Photo by Brent Kidd and Jim Nolan, ATD.)
In one of the first steps in the modification process, Gulfstream engineers, consulting with scientists from NCAR and several universities, conducted studies to characterize the airflow around the aircraft. They determined the best locations for instruments to gather data on airborne chemicals and other atmospheric characteristics.
Next, the team had to determine how the instruments could be mounted without weakening the aircraft structure or disrupting flight systems. To give an idea of the complexity of that task, consider the belly of the fuselage, which will support two optical view ports (for remote sensing and other instruments), two aperture plates (for small instruments that gather air samples), and four hard points (for instrument packages that can be mounted in small pods or fairings).
In deciding on final locations for each of those eight modifications, Gulfstream, Lockheed, and NCAR personnel had to work around a number of cables and aircraft systems mounted in the belly of the aircraft. Lockheed personnel also ran computer simulations for all planned aircraft modifications to determine whether the work to the fuselage would jeopardize the stability of the frame or the aerodynamic qualities of the aircraft.
“It’s a very lengthy engineering process,” explains Krista, who regularly flies down to Greenville with other NCAR and UCAR staffers to consult with Lockheed engineers. “Before you start cutting into this aircraft, you want to be very sure you’ve done your homework.”
In addition to installing mounts for instruments, Lockheed will add a chemical exhaust system to the Gulfstream V, which will discharge gases used by sensors flown on the aircraft. The workers also will install a research power system and a liquid cooling system to ensure that delicate scientific instruments are maintained at the correct temperatures in flight.
Lockheed workers have already started removing rivets from the upper fuselage in preparation for the start of modifications to the top of the Gulfstream. If all goes as planned, Lockheed will finish its share of the modifications in the middle of 2004 and will then run tests on the modified airplane. The plane will then be flown to a plant in Savannah, Georgia, where another contractor, Garrett Aviation Consulting Group, will oversee painting of the aircraft and installation of the interior.
NCAR is scheduled to receive the plane in October 2004. ATD staffers will then make additional modifications, including installing a data acquisition system and data display and access software. They will also equip the aircraft with a satellite communication system that will allow for voice and fax communications and enable scientists on the ground to receive a near real-time data stream from the aircraft during flights.
After further testing will come the stage that the scientific community has been waiting for: preliminary research flights out of Jeffco during the second half of 2005. These flights, known as progressive science missions, will allow pilots, engineers, and scientists to become more familiar with the performance capabilities of the aircraft and to carry out initial scientific measurements before the launch of full-scale research missions in late 2005.
What about the research?
Scientists now are submitting formal research proposals for the progressive science missions. In April, the Observing Facilities Advisory Panel (which consists of scientists from NSF, NCAR, federal labs, and universities) will announce which projects will be flown on HIAPER. Starting in 2005, scientists will begin submitting proposals for full-scale HIAPERresearch missions.
Because of its maximum altitude and range, HIAPER will greatly advance our understanding of Earth and the atmosphere. Here are a few broad research areas where the plane may produce indispensable research:
Severe weather. HIAPER will be able to fly near the tops of thunderstorms, following the movement of water droplets and ice particles, analyzing electrical charges, and measuring air flows. It can also fly far over the ocean to areas where tropical disturbances are just beginning. Scientists may be able to determine the location in a hurricane where water vapor is converted to ice—a key process that releases energy and provides hurricanes with added strength.
With its exceptional range and altitude, the HIAPER aircraft will enable researchers to gather data about interactions between the oceans and the atmosphere, as well as about other science issues.
Atmospheric chemistry. The tropopause, which is the boundary between the atmosphere’s two lowest layers, plays a critical role in Earth’s climate system. It ranges from 5 to 10 miles (8 to 16 kilometers) above Earth’s surface. HIAPER will be able to fly in or near this important area for thousands of miles, collecting data on chemicals, such as ozone and water vapor, that affect the amount of solar radiation in the atmosphere and influence temperatures around the globe.
Clouds. Learning more about what causes certain types of clouds to form and the resultant impacts on regional and even global climate is a high research priority. Using HIAPER, scientists will fly through high-forming cirrus clouds, collecting data on solar radiation, droplets, and wind, and characterizing the clouds from the inside. They will also create vertical profiles of clouds to solve such fundamental mysteries as the movement of water droplets and the creation of rain, and they can reach less-polluted areas in the Southern Hemisphere, allowing them to compare rain formation and other cloud processes in pristine and industrialized regions.
Remote sensing. When it comes to mapping large areas of the planet with optical instruments and other remote sensors, HIAPER fills an invaluable niche. Flying higher than most aircraft, but much lower than satellites, it can cruise above turbulence in Earth’s lower atmosphere while staying close enough to the surface to capture high spatial resolution. As a result, scientists hope to use HIAPER to help society with a wide variety of remote sensing projects, which may include studying surface waters to find dangerous areas of water contamination, surveying forest growth to anticipate wildfire risk, and mapping agricultural regions to predict crop yields. •David Hosansky
The people behind HIAPER
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