Space Surveillance Network Capabilities Evaluation Mission

The last years saw the diffusion of nano, pico and femto satellite missions launched by multiple entities thanks to the launch cost reduction and the electronics miniaturization. Such missions usually present limited capabilities in terms of precise orbit determination and extremely small radar and optical cross-sections. Often these missions carry one or more laser retro-reflectors for precise orbit determination but precise orbital measurements cannot be found in the literature. Miniaturized GNSS receivers are also often carried out but due to the experimental nature of such missions, the reliability and time span of such measurements is limited, leaving radar tracking as the only reliable tracking method. Due to the size of such satellites, the signal-to-noise ratio of such radar measurements is typically low and satellite identification (when launched on ride-share launches with a hundred or more other satellites) proves difficult and time-consuming.Being these very small satellites at the edge of the radar detection capabilities and not providing independent orbit determination means, their position uncertainty could be quite significant, leading to an increased orbit collision perceived risk.With this paper, we present a dedicated small satellite formation, made by multiple nano and pico satellites to evaluate the space surveillance network tracking capabilities and limits. The formation is made by a 3U CubeSat to be deployed as part of a rideshare launch. The satellite would be equipped with multiple means to track it, including a GNSS receiver, a set of multiple laser retro-reflectors, and LEDs for optical, laser, and radar tracking, allowing to characterize also different detection means in terms of capabilities. Such a satellite is made of two independent smaller satellites that can be un-docked in orbit upon command, reducing the satellite size and cross-section. This would push the detection limit for the space surveillance networks starting from an already acquired object and with limited clutter around it. Independent laser and GNSS tracking would allow ground measurement validation and validate position estimations. Further pico-satellites would be deployed by each sub-satellite to further push the detection limits and validate up to which size objects are trackable (still optically, radar and GNSS), thanks to miniaturized GNSS receivers already flown by several other missions.Sub-satellite separation is implemented upon command to ensure the process can be followed and executed at lower altitudes to limit the orbital lifetime of eventually hard-to-track small objects that could worsen the space debris problem. Ground characterization (in terms of optical and radar properties) will be performed, also including polarimetric measurements used to identify the separate satellites. All these technologies together would contribute to creating a unique tool to estimate the tracking capabilities of multiple instruments, specifically tailored for very small objects, the hardest to track, as compared to other characterization activities performed on much bigger objects

Observations of the Perseids 2015 using the SPOSH cameras

We will organize a meteor campaign in Greece focusing on the observation of the meteor activity during this year’s maximum of the Perseids meteor shower. Double-station observations will be carried out from 10th until 14th of August using SPOSH cameras. During this period, we anticipate rates up to 100 Perseids per hour. The participation of graduate students during the observations and the data reduction will strengthen the educational aspect of the campaign

Fibers and fiber-optic components for high-power fiber lasers

The major challenge in the development of monolithic kW class CW fiber lasers is the efficient conversion of pump photons into a high brightness laser beam under the constraints of heat management, long term stability and nonlinearities. This article reviews the interaction of some fiber related aspects as e.g. fiber core composition, photodarkening and modality, as well as their influence on system complexity and power scalability. Recent work on active fibers, pump couplers, mode field adaptors and other fiber-optic components will be presented

The Smart Panoramic Optical Sensor Head (SPOSH) - A camera for observations of transient luminous events on planetary night sides

We have developed a camera dedicated to imaging faint transient noctilucent phenomena, such as aurorae, electric discharges, meteors or impact flashes, on dark planetary hemispheres. The SPOSH (Smart Panoramic Optical Sensor Head) is equipped with a back-illuminated 1024 x 1024 CCD chip E2V 47-20 with up to 90 % quantum efficiency and has a custom-made optical system of high light-gathering power with a wide field of view of 120 x 120º. Images can be obtained over extended periods at high rate to make monitoring for transient events possible. To reduce the data transmission rate, only those images (or relevant portions thereof) that contain events are returned to the user. The camera has a sophisticated processing unit prepared to interface with a spacecraft system, for image processing and event detection at rates of up to 3 images per second at full resolution. While software optimized for detection of any noctilucent phenomenon can be implemented, the software is currently optimized for the detection of meteors. Over the past years, we have routinely carried out outdoor tests with 4 camera breadboard units that demonstrate that the camera has excellent radiometric performance and geometric resolution at low light levels over its large field of view. The camera has been demonstrated to capture meteors of magnitudes as faint as +6 m moving at angular speeds of 5°/s. The camera opens up new science opportunities for planetary missions