A-STEP’s AstroPix Detectors Get Ready for Flight

An AstroPix detector rests inside a protective tray in a lab at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The squares in the center are silicon pixel sensors designed to detect gamma rays, the highest-energy form of light. They function similarly to the image sensors in cell phones. There are two more under the rectangular copper bus bar, which carries data from the sensors to rest of the A-STEP system. Gamma rays are sufficiently high energy that they will pass through the bar and interact in the silicon below.

Credit: NASA/Sophia Roberts

Alt text: An AstroPix detector rests on a blue lab bench inside a tray.

Image description: What looks like a large computer chip — an AstroPix detector — rests inside an orange-and-white tray set on a blue lab bench. The detector is green and has two reflective squares in the middle with a long copper rectangle at left parallel to them. The copper rectangle covers two additional reflective squares. On its right side, black wires extend out of frame. A piece of electrical equipment with various knobs is visible at the top of the image, and a strip of black-and-yellow tape is visible at bottom left.

AstroPix detectors, like the one shown here, detect both gamma rays and high-speed particles called cosmic rays. During the A-STEP flight one of the team’s goals is to measure the cosmic ray rate.

Credit: NASA/Sophia Roberts

Alt text: A gloved hand tilts an AstroPix detector toward the camera.

Image description: A blue-gloved hand rests on a blue lab bench. It holds an orange-and-white tray and tilts it slightly toward the camera. Inside the tray is what looks like a large computer chip — an AstroPix detector. The object has two reflective squares in the middle, with a copper rectangle at left. The copper rectangle covers an additional two reflective squares. Black wires attached to the right side of the detector extend out of frame. In the background is a piece of gray electrical equipment covered in knobs and buttons.

The A-STEP team uses power supplies, like the ones shown here, to provide energy to the AstroPix detectors during testing.

Credit: NASA/Sophia Roberts

Alt text: A gloved hand tilts an AstroPix detector toward the camera.

Image description: A blue-gloved hand rests on a blue lab bench. It holds an orange-and-white tray and tilts it slightly toward the camera. Inside the tray is what looks like a large computer chip — an AstroPix detector. The object has two reflective squares in the middle, with a copper rectangle left of them. The copper rectangle covers an additional two reflective squres. Black wires attached to the right side of the detector extend out of frame. In the background is a stack of three pieces of gray electrical equipment covered in knobs and buttons.

Kavic Kumar, a graduate student at the University of Maryland, College Park and NASA Goddard, holds an AstroPix detector.

Credit: NASA/Sophia Roberts

Alt text: A man holds an AstroPix detecor.

Image description: A man in a brown shirt and blue gloves holds what looks like a large computer chip in front of him. He is slightly out of focus, with a blurry wall in the background. The camera instead focuses on the chip — an AstroPix detector. The object is green, with two reflective squares in the middle. Beneath the squares is a copper rectangle. The copper rectangle covers an additional two reflective squares. The man holds the detector with two hands, one at the top and one on the bottom.

A-STEP will test a configuration of three AstroPix detectors stacked on top of each other. Future missions may use thousands of tightly packed detectors to get a wide view of the gamma-ray sky.

Credit: NASA/Sophia Roberts

Alt text: A gloved hand tilts a stack of three AstroPix detectors toward the camera.

Image description: In this photograph a blue-gloved hand rests on a blue lab table. It tilts a stack of what looks like three large computer chips — AstroPix detectors — toward the camera. The detectors are green, and the top one shows two reflective squares in the center with a copper rectangle to their right. The copper rectangle covers an additional two reflective squares. There is a small gap between each detector.

The A-STEP mission will test a stack of three AstroPix detectors, like the one shown here, by flying it to the edge of space on a sounding rocket. The flight will only last 10 minutes — enough time for the team to ensure the detectors work ahead of their use in future projects.

Credit: NASA/Sophia Roberts

Alt text: A gloved hand tilts a stack of three AstroPix detectors toward the camera.

Image description: In this photograph, a blue-gloved hand rests on a blue lab table. It tilts a stack of what looks like three large computer chips — AstroPix detectors — toward the camera. The detectors are green, and the top one shows two reflective squares in the center with a copper rectangle to their right. The copper rectangle covers an additional two reflective squares. There is a small gap between each detector. In the background is a gray piece of electrical equipment covered in knobs and buttons, a power strip, and a black monitor and keyboard.

A-STEP will use a stack of three AstroPix detectors, like the one shown here. Each detector has two square sensors, which measure 2 centimeters on a side and contain 1,225 pixels — so A-STEP will contain 3,675 pixels in all.

Credit: NASA/Sophia Roberts

Alt text: A pair of blue-gloved hands holds a stack of three AstroPix detectors.

Image description: A pair of blue-gloved hands holds a stack of what looks like three computer chips — these are AstroPix detectors. The detectors are green, and the top one shows two reflective squares in the center with a copper rectangle below them. The copper rectangle covers an additional two reflective squares. There is a small gap between each detector.