UVSTAR: An imaging spectrograph with telescope for the Shuttle Hitchhiker-M platform

UVSTAR is an EUV spectral imager intended as a facility instrument devoted to solar system and astronomy studies. It covers the wavelength range of 500 to 1250 A, with sufficient spectral resolution to separate emission lines and to form spectrally resolved images of extended plasma sources. Targets include the Io plasma torus at Jupiter, hot stars, planetary nebulae and bright galaxies. UVSTAR consists of a pair of telescopes and concave grating spectrographs that cover the overlapping spectral ranges of 500-900 and 850-1250 A. The telescopes use two 30 cm diameter off-axis paraboloids having focal length of 1.5 m. An image of the target is formed at the entrance slits of the two concave grating spectrographs. The gratings provide dispersion and re-image the slits at the detectors, intensified CCD's. The readout format of the detectors can be chosen by computer, and three slit widths are selectable to adapt the instrument to specific tasks. UVSTAR has internal gimbals which allow rotation of plus or minus 3 deg about each of two axes. Dedicated finding and tracking telescopes will acquire and track the target after rough pointing is achieved by orienting the Orbiter. Responsibilities for implementation and utilization of UVSTAR are shared by groups in Italy and the U.S. UVSTAR is scheduled for flight in early 1995, timed for an opportunity to observe the Jovian system

The star identification, pointing and tracking system of UVSTAR, an attached payload instrument system for the Shuttle Hitchhiker-M platform

We describe an algorithm for star identification and pointing/tracking of a spaceborne electro-optical system and simulation analyses to test the algorithm. The algorithm will be implemented in the guiding system of UVSTAR, a spectrographic telescope for observations of astronomical and planetary sources operating in the 500-1250 A waveband at approximately 1 A resolution. The experiment is an attached payload and will fly as a Hitchhiker-M payload on the Shuttle. UVSTAR includes capabilities for independent target acquisition and tracking. The spectrograph package has internal gimbals that allow angular movement of plus or minus 3 deg from the central position. Rotation about the azimuth axis (parallel to the Shuttle z axis) and elevation axis (parallel to the Shuttle x axis) will actively position the field of view to center the target of interest in the fields of the spectrographs. The algorithm is based on an on-board catalog of stars. To identify star fields, the algorithm compares the positions of stars recorded by the guiding imager to positions computed from the on-board catalog. When the field has been identified, its position within the guiding imager field of view can be used to compute the pointing corrections necessary to point to a target of interest. In tracking mode, the software uses the past history to predict the quasi-periodic attitude control motions of the shuttle and sends pointing commands to cancel the motion and stabilize UVSTAR on the target. The guiding imager (guider) will have an 80-mm focal length and f/1.4 optics giving a field of view of 6 deg x 4.5 deg using a 385 x 288 pixel intensified CCD. It will be capable of providing high accuracy (better than 2 arc-sec) attitude determination from coarse (6 deg x 4.5 deg) initial knowledge of the pointing direction; and of pointing toward the target. It will also be capable of tracking at the same high accuracy with a processing time of less than a few hundredths of a second

Information management e ricerca scientifica : coordinate per documentare l'aerospazio. Contenuti informativi : stato dell'arte delle tecnologie spaziali in Italia [Information management nel settore aerospaziale. Atti del seminario svoltosi al CIRA - Centro Italiano Ricerche Aerospaziali. Capua, 22 marzo 2002]

This speech describes ASI (Agenzia Spaziale Italiana) activities being carried on in order to realize an updated chart of basic technologies in the Space sector. This kind of information is critical in the new ASI policy, in the placing of Italy in the space sector, in the definition of the mid-term developments

Far-Ultraviolet Stellar Emission Measurements from UVSTAR

We present UVSTAR and some of the relevant science results from the three UVSTAR missions performed so far: on STS69, STS85 and STS95. In particular we discuss hot sub-dwarf stars, Beta Lyr and Epsilon CMa (500 - 1250 Angstrom) observations

Comet Hale-Bopp (C/1995 O1): UVSTAR-FUV Spectroscopy from the Space Shuttle

New methods for the separation of of airglow emissions are discussed

AtmoCube: Observation of the Earth Atmosphere from the Space to Study \u201cSpace Weather\u201d Effects

\u2014 AtmoCube represents an innovative measurement system for the study of the Earth atmosphere starting from altitude of the order of 600 km. It appears as a cubic nano-satellite that has dimensions of 10 710 710 cm3 with a total weight of 1 kg (aluminium structure). The main scientific instrument is a spectral dosimeter-radiometer allowing continuous monitoring of the radiation environment. The payload includes also a magnetometer belonging to the passive stabilization system. A GPS (Global Positioning System) provides a continuous measurement of the satellite position and allows to build a map of the measured atmospheric parameters. \u2014 AtmoCube represents an innovative measurement system for the study of the Earth atmosphere starting from altitude of the order of 600 km. It appears as a cubic nano-satellite that has dimensions of 10 710 710 cm3 with a total weight of 1 kg (aluminium structure). The main scientific instrument is a spectral dosimeter-radiometer allowing continuous monitoring of the radiation environment. The payload includes also a magnetometer belonging to the passive stabilization system. A GPS (Global Positioning System) provides a continuous measurement of the satellite position and allows to build a map of the measured atmospheric parameters

Comet Hale-Bopp (C/1995 O1): UVSTAR-FUV Spectroscopy from the Shuttle

Es wird die Entdeckung von N2 in den UV-Spektren des Kometen Hale-Bopp beschrieben und die Wasserproduktionsrate hergeleitet. Ein Nachweis von Argon ist schwierig, das Signal-/Rauschverhältnis nicht genügend groß ist

AIRWATCH: the fast detector

The discovery of the extreme energy cosmic rays (EERC) with energy greater than 10(superscript 20) 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 km(superscript 2) per EECR of E approximately equals 10(superscript 20) 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