NuSTAR observatory science operations: on-orbit acclimation

Abstract

The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing high energy (3-79 keV) X-ray observatory. The NuSTAR project is led by Caltech, which hosts the Science Operations Center (SOC), with mission operations managed by UCB Space Sciences Laboratory. We present an overview of NuSTAR science operations and describe the on-orbit performance of the observatory. The SOC is enhancing science operations to serve the community with a guest observing program beginning in 2015. We present some of the challenges and approaches taken by the SOC to operating a full service space observatory that maximizes the scientific return from the mission.

GettingNuSTARon target: predicting mast motion

“…The mast structure was designed to minimize thermal flexing, reducing the motion of the telescope optical axis on the detectors during each observation to < 3 mm (~ 1¢). The flexing is primarily due to the mast thermal response as the spacecraft enters and exits the Earths shadow each orbit, and closely matches the pre-launch predictions 2 . However, it was apparent during observatory commissioning that some unexpected additional effects were resulting in incorrect placement of celestial sources on the detectors.…”

“…It can clearly be seen that the parameters of both the mast and misalignment are correlated and tracking the same motions, though in different reference frames. Residual features are apparent, such as the spike in Qmis [2,3] , Qmast [2] , and Tmast[x] at ~110°, because the majority of observations are not part of these outliers.…”

“…The NuSTAR mission is a collaboration between NASA, and the Agenzia Spaziale Italiana (ASI), and the Danish National Space Institute (DTU Space) and is managed by the Jet Propulsion Laboratory on behalf of the California Institute of Technology (Caltech). The operation of the NuSTAR observatory is a partnership between the Science Operations Center (SOC) 2 , located in the Cahill center for astronomy and astrophysics at Caltech, and the Mission Operations Center 3 managed by the UC Berkeley Space Sciences Laboratory, Berkeley, CA. The NuSTAR primary mission was successfully completed in April 2015 and multiple opportunities are now available each year for the astronomical community to propose to use the observatory as guest investigators.…”

Focusing diffraction optics for orbital telescopes

“…Different methods of fabrication of optical systems, substrate materials [1], and compositions of gradient MISs may be used. For example, the focusing optics of HEFT [145][146][147][148][149][150][151] and NuSTAR [151][152][153][154][155][156][157][158][159] telescopes is based on multilayer gradient coatings deposited onto thermally shaped thin glass mirror segments [160][161][162].…”