BIRD - A Microsatellite for Hot Spot Detection

The BIRD mission of the German Aerospace Centre shall demonstrate the scientific and technological value and the technical and programmatic feasibility of a remote sensing small satellite mission under low budget constraints. The payload -a new generation of cooled infrared detectors- is adapted to the mission objective - the investigation of hot spots caused by forest fires or volcanic activities completed by the diagnosis of vegetation conditions and changes. BIRD -the Bispectral Infra-Red Detector- is a three-axis stabilised spacecraft within a volume of 0.21 m3 and a mass of 88 kg. In flight configuration with one fixed and two deployed solar panels, providing 40 W average and 200 W peak power, the spacecraft dimensions are 620x 1600x 620 mm3 • Although compatible to several launchers due to the highly compact design, the launch is scheduled for mid 2000 as a piggy-back payload. To fit in this time scale a modular design was chosen for parallel development, manufacturing and integration of all functional segments. The article gives an overview of the mission objectives and some of the main design aspects as well as shows the status of work of the space segment

Electrified branes

A geometrical form of the supersymmetry conditions for D-branes on arbitrary type II supersymmetric backgrounds is derived, as well as the associated BPS bounds. The treatment is general and allows to consider, for instance, non-static configurations or D-branes supporting a non-vanishing electric flux, hence completing previous partial results. In particular, our discussion clarifies how the notion of calibration can be extended in order to be applicable to the most general supersymmetric configurations. As an exemplifying preliminary step, the procedure followed is first applied to fundamental strings.Comment: 36 page

Borcherds Algebras and N=4 Topological Amplitudes

The perturbative spectrum of BPS-states in the E_8 x E_8 heterotic string theory compactified on T^2 is analysed. We show that the space of BPS-states forms a representation of a certain Borcherds algebra G which we construct explicitly using an auxiliary conformal field theory. The denominator formula of an extension G_{ext} \supset G of this algebra is then found to appear in a certain heterotic one-loop N=4 topological string amplitude. Our construction thus gives an N=4 realisation of the idea envisioned by Harvey and Moore, namely that the `algebra of BPS-states' controls the threshold corrections in the heterotic string.Comment: 39 page

Fault Tolerance and COTS: Next generation of high performance satellite computers

The increasing complexity of future satellite missions requires adequately powerful on- board computer systems. The obvious performance gap between state-of-the-art micro- processor technology ("commercial-off-the-shelf", COTS) and available radiation hard components already impedes the realization of innovative satellite applications requiring high performance on-board data processing. In the paper we emphasize the advantages of the COTS approach for future OBCS and we show why we are convinced that this approach is feasible. We present the architecture of the fault tolerant control computer of the BIRD satellite and finally we show some results of the BIRD mission after 20 months in orbit, especially the experience with its COTS based control computer

The BIRD Mission

For hot spot events as forest and vegetation fires, volcanic activity or burning oil wells and coal seams a dedicated space instrumentation does not exist. Sensors being used now for the observation of these events have some drawbacks because they are not designed for the hot spot investigation. For the near future there are missions planned with a new generation of cooled infrared array sensors. The German BIRD (Bi-spectral Infrared Detection) mission will answer a lot of technological and scientific questions related to the operation of a compact bi-spectral infrared push-broom sensor on board of a micro satellite and related to the detection and investigation of fires from space. The DLR small satellite mission BIRD is dedicated to the remote sensing of hot spot events like vegetation fires, coal seam fires or active volcanoes from space and to the in-orbit verification and demonstration of new micro-satellite technologies. The total mass of the complete spacecraft is 92 k

Die Deutschen Kameras auf der Russischen Mission MARS '96

Berlin 311096

The BIRD Payload Platform

For hot spot events as forest and vegetation fires, volcanic activity or burning oil spills and coal seams a dedicated space instrumentation does not exist. Respectively missions with a new generation of cooled infrared array sensors are planned for the near future. According to their objectives the BIRD (Bispectral Infra-Red Detection) mission will answer several technological questions related to the operation of this infrared sensors in space. As space segment serves a three-axis stabilised micro-satellite with a mass of 92 kg including a contingent of over 30 % for the payload. The article focuses on the scientific instruments and special aspects of their adaptation to the satellite platform and shows the spacecraft design status

The BIRD payload platform

For hot spot events as forest fires, volcanic activity or burning oil spills and coal seams a dedicate dspace instrumentation does not exist. With its successful launch end of October 2001 with the Indian Polar Satellite Launch Vehicle the German Aerospace Center starts closing this gap with the micro-satellite mission BIRD. As space segment serves a three-axis stabilized satellite of 92 kg including a contingent of over 30% for the scientific instruments. The main payload of the BIRD micro-satellite is the newly developed Hot Spot Recognition System. It's a dual-channel instrument for middle and thermal IR imagery based on cooled MCT line detectors. The miniaturization by integrated detector/cooler assemblies provides a highly efficient design. A complement for the hot spot detection is the wide-angle stereo-scanner WAOSS-B. It is a hardware re-use dedicated to vegetation and cloud assessment in the visible spectral range. Besides the main objective of hot spot detection the mission has to answer several technological questions of the operation of cooled detectors in space, special aspects of their adaptation to the satellite platform as well as their calibration

Die Sensorplattform des Kleinsatelliten BIRD

Mit dem erfolgreichen Start des DLR Kleinsatelliten BIRD im Oktober 2001 ist die wissenschaftliche Erkennung und Bewertung von heißen Umweltereignissen möglich. Der 3-Achsen-stabilisierte Satellit hat eine Masse von 92 kg mit einem Anteil wissenschaftlicher Instrumente von über 30 %. Die Sensorplattform, ein Multi-Sandwich aus Karbonfaserhalbzeugen ist thermooptisch stabil, Basis für den Einsatz gekühlter Detektoren, Grundplatte wissenschaftlicher Instrumente und Schnittstelle zum Satellitenbus. Hauptbestandteil der Sensorplattform ist der zweikanalige Infrarotzeilensensor kombiniert mit der im visuellen Bereich arbeitenden Stereo-Zeilenkamera WAOSS und einem panchromatischen Kanal. Alle Systeme arbeiten ohne Probleme und zeigen beachtliche Ergebnisse

Resumes of the Bird Mission

The DLR micro satellite BIRD (Bi-Spectral Infra Red Detection)was the Indian Polar Satellite Launch Vehicle PSLV-C3 into a 570 km ciracular sun-synchronous orbit on 22 October 2001. The BIRD mission, fully funded by the DLR, answers topical technologal and scientific questions related to the operation of a compact infra-red push-broom sensor system on board of a micro satellite and demonstrates a new spacecraft bus technologies. BIRD mission control is conducted by DLR/GSOC in Oberpfaffenhofen commanding, data reception and data processing is performed via ground stations in Weilheim and Neustrelitz (Germany). The BIRD mission is a demonstrator for small satellite projects dedicated to the hazard detection and monitoring. In the year 2003 BIRD has been used in the ESA project FUEGOSAT to demonstrate the utilisation of innovative space technologies for fire risk management