PILOT (Polarized Instrument for Long wavelength Observations of the Tenuous interstellar medium) is a balloonborne astronomy experiment designed to study the polarization of dust emission in the diffuse interstellar medium in our Galaxy. The PILOT instrument allows observations at wavelengths 240 μm and 550 μm with an angular resolution of about two arcminutes. The observations performed during the two first flights performed from Timmins, Ontario Canada, and from Alice-springs, Australia, respectively in September 2015 and in April 2017 have demonstrated the good performances of the instrument. Pilot optics is composed of an off axis Gregorian type telescope combined with a refractive re-imager system. All optical elements, except the primary mirror, which is at ambient temperature, are inside a cryostat and cooled down to 3K. The whole optical system is aligned on ground at room temperature using dedicated means and procedures in order to keep the tight requirements on the focus position and ensure the instrument optical performances during the various phases of a flight. We’ll present the optical performances and the firsts results obtained during the two first flight campaigns. The talk describes the system analysis, the alignment methods, and finally the inflight performances.
Here we discuss advances in UV technology over the last decade, with an emphasis on photon counting, low noise, high eﬃciency detectors in sub-orbital programs. We focus on the use of innovative UV detectors in a NASA astrophysics balloon telescope, FIREBall-2, which successfully ﬂew in the Fall of 2018. The FIREBall-2 telescope is designed to make observations of distant galaxies to understand more about how they evolve by looking for diﬀuse hydrogen in the galactic halo. The payload utilizes a 1.0-meter class telescope with an ultraviolet multi-object spectrograph and is a joint collaboration between Caltech, JPL, LAM, CNES, Columbia, the University of Arizona, and NASA. The improved detector technology that was tested on FIREBall-2 can be applied to any UV mission. We discuss the results of the ﬂight and detector performance. We will also discuss the utility of sub-orbital platforms (both balloon payloads and rockets) for testing new technologies and proof-of-concept scientiﬁc ideas.
In the frame of the CNES Pleiades satellite, a reduction of the star tracker low frequency error, which is the most penalizing error for the satellite attitude control, was performed. For that purpose, the SED36 star tracker was developed, with a design based on the flight qualified SED16/26. In this paper, the SED36 main features will be first presented. Then, the reduction process of the low frequency error will be developed, particularly the optimization of the optical distortion calibration. The result is an attitude low frequency error of 1.1" at 3 sigma along transverse axes. The implementation of these improvements to HYDRA, the new multi-head APS star tracker developed by SODERN, will finally be presented.
PILOT (Polarized Instrument for Long wavelength Observations of the Tenuous interstellar medium) is a balloonborne astronomy experiment designed to study the polarization of dust emission in the diffuse interstellar medium in our Galaxy. The PILOT instrument allows observations at wavelengths 240 μm (1.2THz) with an angular resolution about two arc-minutes. The observations performed during the first flight in September 2015 at Timmins, Ontario Canada, have demonstrated the optical performances of the instrument.
PILOT is a balloon-borne astronomy experiment designed to study the polarization of dust emission in the diffuse
interstellar medium in our Galaxy at wavelengths 240 μm with an angular resolution about two arcminutes. Pilot optics
is composed an off-axis Gregorian type telescope and a refractive re-imager system. All optical elements, except the
primary mirror, are in a cryostat cooled to 3K. We combined the optical, 3D dimensional measurement methods and
thermo-elastic modeling to perform the optical alignment. The talk describes the system analysis, the alignment
procedure, and finally the performances obtained during the first flight in September 2015.
PILOT is a stratospheric experiment designed to measure the polarization of dust FIR emission, towards the diffuse interstellar medium. The first PILOT flight was carried out from Timmins in Ontario-Canada on September 20th 2015. The flight has been part of a launch campaign operated by the CNES, which has allowed to launch 4 experiments, including PILOT. The purpose of this paper is to describe the performance of the instrument in flight and to perform a first comparison with those achieved during ground tests. The analysis of the flight data is on-going, in particular the identification of instrumental systematic effects, the minimization of their impact and the quantification of their remaining effect on the polarization data. At the end of this paper, we shortly illustrate the quality of the scientific observations obtained during this first flight, at the current stage of systematic effect removal.
FIREBALL (the Faint Intergalactic Redshifted Emission Balloon, funded by CNES-NASA, PI C.Martin, Caltech) is a balloon-borne 1m telescope coupled to an ultraviolet Multi Object Spectrometer (MOS), designed to study the faint and diffuse emission of the circumgalactic medium. The third flight of the experiment is planned in summer 2017. The goal of this paper is to describe the accurate pointing system of the 5-metres high / 1500kg gondola - that has been designed to fulfill stringent pointing requirements: less than 1 arcsec in elevation and cross elevation, and about 1 arcmin in field rotation (around the line of sight axis), over long integration time (a few hours). The pointing system is based on a multi stage closed loop scheme (4 Degrees Of Freedom), relying on a 1DOF gondola azimuth controller, a 2DOF gimbal frame supporting a 1.2-meter plano siderostat, and a 1DOF field rotation control system. The attitude determination is based on the hybridization of two accurate sensors: a Fiber Optic Gyrometer measurement unit and a star sensor integrated inside the instrument. The manuscript presents the design of the ACS. We also focus on flight train stability issues - due to the pendulum and torsion modes -, on the geometric equations specific to a siderostat pointing system, and on the description of the tests facilities.