IDL Helps Scientists Understand the Solar System’s Formation

Customer Challenge

NASA planned an historic mission to impact a comet in outer space. Lead mission engineers needed sophisticated space vehicles, onboard imaging instruments, and a solution for calibrating the instruments and visualizing and analyzing huge amounts of data.

Solution Achieved

Ball Aerospace built a space system for NASA that consisted of a flyby spacecraft and an impactor spacecraft, both of which carried imaging and remote sensing instruments as well as instruments to monitor the flight systems. The flight system was designed as a single unit to be launched on a Boeing Corporation Delta II Rocket. The impactor would eventually break free from the flyby, keeping its speed and course toward the comet, while the flyby would slow down, image the impact and receive data from the impactor. Throughout the process, an antenna would transmit near-real-time imagery to the Deep Space Network on Earth.

The flyby spacecraft carried two, sophisticated imaging instruments, also designed and built by Ball Aerospace and tested and calibrated with IDL^®: the High Resolution Instrument (HRI) and the Medium Resolution Instrument (MRI). The HRI combined a telescope with a 30 cm aperture, an infrared spectrometer and a multi-spectral CCD camera - the narrow fieled of view and very high resolution ideal for detailed imaging of the comet’s nucleus. The MRI had a pixel scale five times larger and served as a better navigation instrument, as its lower resolution and wider lens allowed a broader view from the spacecraft. The impactor carried the Impactor Targeting Sensor (ITS), a near-carbon copy of the MRI.

During testing, calibration and integration, IDL’s built-in data processing capabilities were instrumental in determining quality, noise and performance defects. In addition, Hampton used IDL in lab testing to determine each instrument’s response to radiation by subjecting them to different frequencies of radiation. IDL routines helped him to create transforms of each image and plot those images against the frequencies to determine the susceptibility of the instruments based on frequency changes.

Another program used by Ball Aerospace engineers and the entire science team was a GUI-based, custom IDL application called Deep Impact Viewer (DIVE), which was used to measure instrument performance by viewing and stretching images to see details at low and high signal levels. Engineers used IDL to plug in specific image statistics and measure signals to put together absolute calibrations. “This was a way to read each mode very quickly,” says Hampton, “With IDL, I could put a cursor anywhere on the picture or click a box within an image and get statistics quickly.”

• IDL allowed mission engineers and scientists to analyze and visualize instrument data.

• Using IDL, the team could work seamliessly with the rest of the Deep Impact team around the country, many of whom also used IDL in different facets of the mission.

• IDL allowed mission members to disseminate useful information to mission commanders and the media.