NASA Gears Up ComPair Balloon Mission to Detect Gamma Rays

NASA is preparing to launch the ComPair balloon-borne science instrument from Fort Sumner, New Mexico, to test innovative technologies for detecting gamma rays, the most energetic form of light.

Slated for launch within NASA's upcoming 2023 fall scientific balloon campaign, commencing on August 10, the ComPair mission is designed to capture gamma rays spanning energy levels between 200,000 and 20 million electron volts, significantly surpassing the energy of visible light.

NASA: 'Lots of Interesting Science'

Nicholas Kirschner, a graduate student at George Washington University and NASA's Goddard Space Flight Center, highlighted the significance of ComPair's mission: "Lots of interesting science happens in the energy range that ComPair is designed to study."

"These gamma rays are hard to capture with existing methods, so we need to create and test new ones. ComPair's flight gets us one step closer to putting a similar detector in space," Kirschner added.

The range of energy that ComPair focuses on is where phenomena like supernovae, gamma-ray bursts, and emissions from distant active galaxies powered by supermassive black holes are most prominent.

This energy range remains inadequately covered by current missions, making ComPair's contribution valuable in enhancing astronomers' understanding.

ComPair will ascend to approximately 133,000 feet (40,000 meters) using a scientific balloon to overcome the challenge of Earth's atmosphere filtering out most high-energy radiation from space.

This elevation places the instrument above 99.5% of the atmosphere. Following the construction and testing of ComPair at Goddard, the mission team moved the instrument to Fort Sumner, where they undertook its reassembly and recalibration.

ComPair's launch will synchronize with the GRAPE (Gamma-Ray Polarimeter Experiment) mission, overseen by the University of New Hampshire. Upon the successful attachment of both ComPair and GRAPE to the gondola that will link to the scientific balloon, the teams will be poised for launch.

ComPair's Major Components

ComPair derives its name from the two methods it employs to study gamma rays: Compton scattering and pair production.

The instrument's innovative design enables interaction with gamma rays using layers of different elements and compounds. The instrument is composed of four major components:

1. The tracker, equipped with 10 layers of silicon detectors, determines the positions of incoming gamma rays.

2. The high-resolution calorimeter, made of cadmium, zinc, and telluride, measures lower-energy Compton-scattered gamma rays and converts some into electron-positron pairs.

3. The high-energy calorimeter, constructed with cesium iodide, primarily measures electron-positron pairs and captures certain Compton-scattered gamma rays.

4. An anticoincidence detector detects the entry of high-energy cosmic rays.

ComPair is a collaborative effort involving NASA's Goddard Space Flight Center, the US Naval Research Laboratory (NRL), Brookhaven National Laboratory, and Los Alamos National Laboratory.

NASA's scientific balloons provide a budget-friendly avenue for carrying out scientific investigations and advancing technology in areas like astrophysics and atmospheric research.