FOXSI-3 press releases

The FOXSI-3 sounding rocket experiment flew successfully on September 7, 2018.  See below for some of the news and web releases written about the FOXSI-3 flight.

September 7, 2018


FOXSI-3 will launch from White Sands, New Mexico on September 7, 2018. For this third flight, our team will be testing new instrumentation to further increase sensitivity and our ability to observe the quiet Sun.


May 4, 2018 Detectors delivered to UCB
May 7–13, 2018 Detector testing and integration at UCB
May 18, 2018 Optics delivered to UCB
May 21–June 1, 2018 SAAS and optics testing and alignment at UCB
June 1–29, 2018 Experiment integration and testing at UCB
July 2–7, 2018 Ship payload to White Sands Missile Range (WSMR)
July 9–26, 2018 Experiment integration and testing at WSMR
July 27–Aug. 20, 2018 Rocket and experiment integration at WSMR
September 7, 2018 Launch!

Please note, all dates are subject to periodic fluctuation due to scheduling variability! 


+Instrumentation Characteristics

Optics: Thus far, FOXSI is the only instrument to develop hard X-ray focusing optics especially for the sun. For our third campaign, we will use the same optics modules that flew on FOXSI-2, but two of them are currently being updated from 7-shells to 10-shells at NASA Marshall. Thus, FOXSI-3 will fly with four 10-shell and three 7-shell modules. 

Some of these modules have recently been calibrated by our team at the Stray Light Facility in NASA Marshall. The calibration included both the 7-shell and 10-shell module types and assessed the well state of the optics. Our team also observed the modules' behavior for sources at slightly high off-axis angles, which induce “ghost rays” at the focal plane. We are currently analyzing this data to gain a better understanding of the optics' performance for ghost rays.

Prototype against sunCollimators: Our collimators are cylindrical structures that filter photons by directing them through thousands of minute channels. This technology will be secured to two of our optics modules to prevent photons traveling from unwanted angles (i.e., ghost rays) from hitting our detectors. 

Two 3D-printed modules have been fabricated by TORAY, working with our collaborators in Japan. These models have been fit checked with a FOXSI optical module, and our team has since performed x-ray measurements of their open area performance. The bundled optical fiber collimator is still in development. Several "mini-bundles" have been etched and tested, verifying the elimination of internally reflected x-rays.  Seven of these mini-bundles will be bonded together and tested again to verify co-alignment of the bundles. The flight collimator will consist of ~400 of these mini bundles. 

DetectorsDetectors: For FOXSI-3, we will be flying a combination of double-sided Cadmium Telluride (CdTe) and Silicon (Si) strip detectors, as well as one CMOS soft X-ray detector. Our colleagues in Japan, who are building the detectors, have created the finest-resolution, 60µm, CdTe strip detectors ever made, one of which we tested at the University of Minnesota in May, 2017. (The image, right, depicts our focal plane with older detectors, which will be replaced by the new detectors once they arrive for calibration.)

The new set of CdTe detectors will arrive from Japan at the University of Minnesota by the end of 2017. We will then calibrate the detectors by conducting gain calibration, spectral response, and efficiency measurements. In addition to the tests we will conduct at Minnesota, we may seek further testing at an external facility to more precisely measure the efficiency of the detectors. Depending on the performance evaluations of these new detectors, we will then decide how many CdTe versus Si detectors will fly with FOXSI-3.