Reaching Orbit – NASA’s NuSTAR
The next satellite that NASA intends to launch into space is the Nuclear Spectroscopic Telescope Array (NuSTAR) mission. However, its launch has been postponed in order to test the flight software.
NuSTAR is comprised of a telescope that will image space in the X-ray region of the electromagnetic spectrum. This is no ordinary telescope however, it is a focusing telescope. In order to accurately measure X-rays, the telescope must have a long focal length, which means that the two optical units have to be separated from the detectors by several meters. NuStar will consist of two Wolter-I optic units. Each optic unit is made of two reflective mirrors used to focus and image X-ray waves. The X-ray detectors will extend from the body of the satellite by a deployable mast after launch; while the optics will remain at the body of the satellite at the focus of the two detectors. The optics will be focused on the same area of the sky and will be merged once down linked from the satellite.
This new fangled design for a focal telescope along with the specialized optics and detectors will allow for measurements in the high energy portion of the X-ray spectrum. Up until now, telescopes have only been able to detect low energy X-ray waves and this has limited astronomers’ ability to observe a wide array of intergalactic phenomenon.
Above is an artist's concept of NuSTAR in orbit with the deployable mast extended. (Image Source: Caltech University)
The goal of the NuSTAR mission is to survey the black holes of the universe. When a star goes supernova and explodes, the core's gravity increases tremendously as the size of the star diminishes resulting in a black hole. While a black hole's gravity is so strong that even light is absorbed, radiation is emitted from just outside of the black hole as matter is absorbed into it, creating friction that becomes so hot that it emits X-rays. NuSTAR will look for black holes in our own galaxy and throughout the universe. It will also look at black holes that have been discovered by telescopes that detect lower energy x-rays. It will pay special attention to the center of our own Milky Way Galaxy where we find the black hole, Sagittarius A.
Above is an image of the Tycho supernova taken by Chandra, a low X-ray observing telescope. The Tycho supernova was created by the explosion of a white dwarf star. (Image Source: NASA)
NuSTAR will also monitor supernovae and supernovae remnants to better understand the lifecycle of stars. NuSTAR will study the emissions from radioactive nuclei that are a result of star explosions. Supernova remnants create the next generation of stars by moving through space and sweeping up matter that contains immense energy. NuSTAR's new capability will allow for new research into this cyclical process of star formation and destruction.
NASA is coordinating with the launch site to set a new date and time for the blast-off of NuSTAR. The NuSTAR mission will help astronomers unravel the complexity of matter and processes in space as it will collect information about the universe that has never been seen and analyzed before.