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A low-mass, low-cost photon-counting scientific payload has been developed and launched on a commercial microsatellite in order to study the near-UV night-sky background emission with a telescope nicknamed “Notte” and the Aurora emission with “Alba”. AURORA, this is the name of the experiment, will determine, with the “Notte” channel, the overall night-side photon background in the 300–400 nm spectral range, together with a particular 2 + N 2 line ( λ c =337 nm). The “Alba” channel, on the other hand, will study the Aurora emissions in four different spectral bands (FWHM=8.4–9.6 nm) centered on: 367 nm (continuum evaluation), 391 nm (1 − N + 2 ), 535 nm (continuum evaluation), 560 nm (OI). The instrument has been launched on the 26 September, 2000 from the Baikonur cosmodrome on a modified SS18 Dnepr-1 “Satan” rocket. The satellite orbit is nearly circular ( h apogee =648 km, e =0.0022), and the inclination of the orbital plane is 64.56°. An overview of the techniques adopted is given in this paper.

The CARSO laboratory has recently built a calibration bench for electro-optical qualification of CCD sensors. For the CCD characterization the following measurements are operative: linearity, quantum efficiency, charge transfer efficiency, photon-transfer curve, dark charge and pixel-to-pixel sensitivity nonuniformity. The optical system is essentially made of two different optical paths: the first produces a spot of a few microns diameter, the second gives a uniform beam. For a 98% uniformity illumination, an integrating sphere is also available. There is a choice of two lamps, tungsten and xenon, to illuminate the optical path. The CCD sensor is positioned on a three axis assembly which can be displaced with a resolution of 1 μm on three degrees of freedom. It is set into a thermo-cryostatic vacuum chamber that can maintain the temperature between −140 and +80°C with a stability better than 0.1°C. The bench permits a quasi-automatic control of the various components and interfaces different types of CCDs of different sizes (up to 2048×2048 pixels). Some results of characterization measurements of a Thomson TH7863 CCD are presented.

Four different thermal-vacuum tests were performed on AMICA Star Tracker (AST) in the period March-July 2006 in the space simulator of the SERMS laboratory in TerniItaly. Each of these tests was designed to verify different AST camera design features. The Thermal Balance test was conceived to validate the thermo-elastic model of the instrument and the active and passive thermal control subsystems. The Thermal Vacuum Cycling test was conceived to validate the AST electronics operative and survival temperature limits under vacuum conditions. The worst hot and cold operative and survival limits of the lens and filters in the AST optical system were assessed by means of the “Sun in the lens” and Lens Cold tests.

The Alpha Magnetic Spectrograph (AMS) is a composite particle detector to be accommodated on the International Space Station (ISS) in 2008. AMS is mainly devoted to galactic, charged Cosmic Rays studies, Antimatter and Dark Matter searches. Besides the main, classical physics goals, capabilities in the field of GeV and multi-GeV gamma astrophysics have been established and are under investigation by a number of groups. Due to the unsteadiness of the ISS platform, a star-mapper device is required in order to fully exploit the intrinsic arc-min angular resolution provided by the Silicon Tracker. A star-mapper is conceptually an imaging, optical instrument able to autonomously recognize a stellar field and to calculate its own orientation with respect to an inertial reference frame. AMICA (Astro Mapper for Instruments Check of Attitude) on AMS is responsible for providing real-time information that is going to be used off-line for compensating the large uncertainties in the ISS flight attitude and the structural degrees of freedom. In this paper, we describe in detail the AMICA sub-system and the accommodation/integration issues and the in-flight alignment procedure adopting identified galactic (pulsars) and extragalactic (AGNs) sources., Comment: 7 pages, 6 figures, submitted to Astroparticle Physics

A light photon-counting scientific payload, named AURORA, has been developed and launched on a commercial microsatellite in order to study the near-UV night-sky background emission (channel Notte) and the Aurora (Alba). AURORA is mapping, with the Notte channel, the night-side photon background in the 300-400 nm spectral range, together with a particular 2+ nitrogen line ((lambda) = 337nm). These measurements are required in the framework of the Extreme Universe Space Observatory (EUSO) experiment, approved by the European Space Agency (ESA) for the phase A and to be flown on the International Space Station (ISS) in 2009. The Alba channel studies the Aurora emissions in four different spectral bands centered on: 367nm, 391nm, 535nm, 560nm (OI). The instrument has been integrated on the MEGSAT-1 satellite and launched, on the September, 26th 2000, from the Baikonur cosmodrome. The nearly circular Low Earth Orbit (LEO), with inclination of 64.56 degrees, fully includes the ISS ground track envelope. The satellite overall mass is about 60 kg. An overview of the techniques adopted, including detectors, front-end electronics, Central Processor Unit (CPU), is given in this paper, together with a brief report on the mission status and plans.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

SD2000 is a new photon counting MCP based detector. It consists of a single MCP, coated with a suitable photocathode, closely coupled to a Silicon Drift Detector (SDD). The electron clouds generated by the MCP channels are accelerated by a strong electric field applied and proximity focussed on the SDD, that works as a position sensitive read-out detector. The SDD, developed by the INFN laboratories in Trieste, is a butterfly Silicon Drift Detector with no metal deposition on its cathodes. The absence of metallization in the sensitive zone of the chamber allows the electron clouds to penetrate uniformly into the active region of the detector and to be revealed. A suitable front-end amplifier, that works as a charge preamplifier and a bipolar shaper, has been developed starting from SPICE simulations and tested. A proto-type of the detector has been realized and tested and the first results have been achieved and compared with the expected best performances of the detector.

The characteristics of the fine pointing and tracking system of UVISS, UltraViolet Italian Space Surveyor, which is proposed to fly as an external payload attached to the ISS (International Space Station) Express Pallet is presented. The system is derived from the pointing system of the UVSTAR telescope that has flown three times on the Shuttle. The electro-optical architecture of the tracking telescope, including the ICCD detector and the computational unit based on a DSP board with direct high speed interface to the camera and the on-board stellar catalog is described. The simulations performed to determine the instrument expected tracking precision and performances considering the dynamics of the ISS are reported. Finally the utilization of a high frequency tracking error correction based on the detection of the spectrographs zero-th order signal is considered as an independent tracking error measurement which provides information and corrections of possible residual tracking errors and could be used for alignment check as well.

A Mission into Hot Phenomena in the Universe is proposed by means of a small telescope of 50 cm aperture accommodated on the International Space Station. Two operating modes are envisaged: 3 angstrom dispersion imaging spectroscopy in the 90 - 320 nm range (1st priority) or wide field (1 degree) medium bandwidth imaging in the same range but Ly-(alpha) (2nd priority). It will use a pointing platform attached to an Express Pallet Adapter available to the Italian Space Agency (ASI) more than 4 - 6 months per year. During a life time of 6 yr focal plane instruments may be changed when on-ground refurbishment occurs. With reasonable exposure times hot thermal sources as faint as V equals 19 - 2 can be observed in the spectroscopy mode at 110 nm and active chromospheres on cool stars as faint as V equals 15 at 250 nm can be monitored. Assessment of FUV imaging is underway, possibly providing observations of hot sources as faint as V equals 21 - 22. Nominal uplift to ISS is set in Autumn 2005.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We present the characteristics of a star mapper, AMICA, which could be used for determining the pointing direction of external payloads mounted on the International Space Station. AMICA, which is complementary to the GPS attitude determination system provided by the ISS, is a stand alone system able to provide both the pointing direction in the inertial reference frame with arc-sec precision at a 1 Hz rate and the angular orientation of the stellar field with slightly lower precision. The star mapper is derived from the pointing system of the UVSTAR telescope that has flown three times on the Shuttle. We present a description of the AMICA optical and electronics architecture and its functionality. We also give a summary of the key pointing/tracking results obtained during the Shuttle missions. Finally we report on simulations performed to determine the instrument expected precision and performances, including the percentage of recognized stellar fields. AMICA is presently considered for flying in support ...

The discovery of the extreme energy cosmic rays (EERC) with energy greater than 1020 eV has opened a new research branch of astrophysics on both observational and interpretative point of views. Together with the EECR one has also to consider the neutrino component which, independently on its primary or secondary origin, can reach comparable energies. These particles can be detected through the giant showers (EAS) produced in the Earth atmosphere and the induced fluorescent molecular nitrogen emission. Observing the EECR 'signals' is very difficult; we need forefront technology or new developments. The main reason is that their flux is very weak, typically of the order of a few events/year/1000 km2 per EECR of E approximately equals 1020 eV. The proposed Airwatch mission, base don a single orbiting telescope which can measure both intensity and direction of the EAS, impose new concepts for the detectors; single photon sensitivity, fast response of the order of few microseconds with sampling times of tenths of nanoseconds, low noise and good S/N ratio, large area, adaptability to a curved surface. Fortunately the spatial resolution requirements are somehow relaxed. The peculiar characteristics of this application are such that no available detectors satisfies completely the requirements. Therefore the final detector has to be the result of a R and D program dedicated to the specific problem. In this paper we survey a number of possible detectors and identify their characteristics versus the Airwatch mission requirements.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

UVSTAR, UV Spectrograph Telescope for Astronomical Research operates in the 500-1200 angstrom waveband; it has capability for long slit spectral imaging of extended cosmic sources. UVSTAR has recently flown as a Hitchhiker-M payload on the STS 85 mission of the SHuttle Discovery. UVSTAR is a joint collaboration between the University of Arizona and the University of Trieste. The instrument consists of a movable platform and an optical system The platform provides fine pointing within +/- 3 degrees from the nominal view direction, which is near the shuttle +Y axis, i.e. perpendicular to the long axis of the Shuttle and in the plane of the wings. The optical system has two channels, each formed of a telescope and Rowland concave-grating spectrograph with intensified CCD detector. The first channel, FUV, operates in the 850-1250 angstrom spectral range, the second, EUV, has covered the 500-900 angstrom region. UVSTAR includes capabilities for independent target acquisition and tracking. Here we report FUV observations, obtained in August 1997, of the sdO star BD +28 degrees 4211 which is a secondary flux standard and of the central star of the planetary nebula NGC 246, a hot degenerate star which shows strong OVI lines in the optical region. The UVSTAR spectrum of NGC 246 displays remarkable P Cygni profiles indicating a very fast stellar wind.

Software for star field identification and star pointing and tracking is described. The software will be implemented in the guiding system of UVSTAR, a spectrograph/telescope system for UV astronomy and planetary physics that will operate as a Hitchhiker payload on the Shuttle. The software work with the wide-field CCD camera and an on-board stellar catalog. It is capable of (1) providing high accuracy (better than 2 arcsec) attitude determination from coarse (± 3 deg) initial knowledge of the pointing direction and (2) pointing toward the target. It is capable of tracking at the same high accuracy with a processing time of less than a few hundredths of a second. Simulation of observations and various types of tests are also discussed.

We propose an instrument to look for Extensive Air Showers (EAS) produced by Extremely High Energy Cosmic Rays (EHECR, E>1020 eV) from space (Airwatch concept) by observing nitrogen fluorescence radiation.