Search results for "Orbital mechanics"

The on-board calibration system of the X-ray Imaging Polarimetry Explorer (XIPE)

2016

The calibration system for XIPE is aimed at providing a way to check and correct possible variations of performance of the Gas Pixel Detector during the three years of operation in orbit (plus two years of possible extended operation), while facilitating the observation of the celestial sources. This will be performed by using a filter wheel with a large heritage having a set of positions for the calibration and the observation systems. In particular, it will allow for correcting possible gain variation, for measuring the modulation factor using a polarized source, for removing non interesting bright sources in the field of view and for observing very bright celestial sources. The on-board …

Collision orbits in the oblate planet problem

1984

Some of the properties of the oblate planet problem are derived. We use the technique of blowing up the singularity to study the collision orbits. We define some families of them in terms of their asymptotic behavior.

JEM-X: three years in space

2006

We report on the technical and scientific performance of JEM-X, the X-ray monitor on ESA's INTEGRAL mission. INTEGRAL has now been in orbit for more than three years, and the mission is foreseen to be extended until the end of 2010. Overall, JEM-X performs very well, and can be expected to continue to do so for the duration of the mission. We discuss in some detail the operational experiences and the problems encountered with the microstrip detectors caused by the space environment and give one example of the interesting scientific results obtained. The analysis software is still being improved on, and we discuss briefly the significance of these improvements.

A flux retrieval error behavior with CERES/TRMM data

2003

With the aid of CERES/TRMM (Clouds and the Earth's Radiant Energy System/Tropical Rainfall Measuring Mission) data, sampling problems that may impact the construction of anisotropic models have been investigated. We show the influence of the sun-orbit geometry, which causes a lack of measurements in forward and backward scattering directions at large viewing zenith angles, and how cloud properties retrieval algorithms as obtained from the Visible Infrared Scanner (VIRS) also affect sampling. We have also focused our attention on the dependency of the cloud cover retrieval algorithm with respect to the viewing zenith angle (VZA), showing that the shape of the cloud cover probability density …

DEPFET based Instrumentation for the MIXS focal plane on BepiColombo

2009

BepiColombo, ESA's fifth cornerstone mission, is a planetary exploration mission to Mercury. On board of BepiColombo's Mercury Planetary Orbiter (MPO), the MIXS instrument will perform a complete X-ray fluorescence analysis of Mercury's crust with unprecedented spectral and spatial resolution. This is achieved by using a lightweight X-ray mirror system and by using of DEPFET based Macropixel devices as X-ray detectors. DEPFET based Macropixel detectors combine the advantages of the DEPFETs, like flexible readout modes, Fano-limited energy resolution and low power consumption, with the properties of the drift detectors, like arbitrary scalable pixel size and geometry. In addition, the excell…

The Cryogenic AntiCoincidence detector for ATHENA: the progress towards the final pixel design

2014

“The Hot and Energetic Universe” is the scientific theme approved by the ESA SPC for a Large mission to be flown in the next ESA slot (2028th) timeframe. ATHENA is a space mission proposal tailored on this scientific theme. It will be the first X-ray mission able to perform the so-called “Integral field spectroscopy”, by coupling a high-resolution spectrometer, the X-ray Integral Field Unit (X-IFU), to a high performance optics so providing detailed images of its field of view (5’ in diameter) with an angular resolution of 5” and fine energy-spectra (2.5eV@E<7keV). The X-IFU is a kilo-pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy …

2015

Advanced Astronomy for Heliophysics Plus (ADAHELI+) is a project concept for a small solar and space weather mission with a budget compatible with an European Space Agency (ESA) S-class mission, including launch, and a fast development cycle. ADAHELI+ was submitted to the European Space Agency by a European-wide consortium of solar physics research institutes in response to the "Call for a small mission opportunity for a launch in 2017," of March 9, 2012. The ADAHELI+ project builds on the heritage of the former ADAHELI mission, which had successfully completed its phase-A study under the Italian Space Agency 2007 Small Mission Programme, thus proving the soundness and feasibility of its in…

The cryogenic anticoincidence detector for ATHENA-XMS: preliminary results from the new prototype

2012

ATHENA has been the re-scoped IXO mission, and one of the foreseen focal plane instrument was the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV, which was a kilo-pixel array based on TES (Transition Edge Sensor) detectors. The need of an anticoincidence (AC) detector is legitimated by the results performed with GEANT4 simulations about the impact of the non x-ray background onto XMS at L2 orbit (REQ. < 0.02 cts/cm2/s/keV). Our consortium has both developed and tested several samples, with increasing area, in order to match the large area of the XMS (64 mm2). Here we show the preliminary results from the last prototype. The results achieved in this work off…

A next generation Ultra-Fast Flash Observatory (UFFO-100) for IR/optical observations of the rise phase of gamma-ray bursts

2012

The Swift Gamma-ray Burst (GRB) observatory responds to GRB triggers with optical observations in ~ 100 s, but cannot respond faster than ~ 60 s. While some ground-based telescopes respond quickly, the number of sub-60 s detections remains small. In mid- to late-2013, the Ultra-Fast Flash Observatory-Pathfinder is to be launched on the Lomonosov spacecraft to investigate early optical GRB emission. This pathfinder mission is necessarily limited in sensitivity and event rate; here we discuss a next generation rapid-response space observatory. We list science topics motivating our instruments, those that require rapid optical-IR GRB response, including: A survey of GRB rise shapes/times, meas…