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PROBA-3 is an ESA mission aimed at the demonstration of formation flying performance of two satellites that will form a giant coronagraph in space. The first spacecraft will host a telescope imaging the solar corona in visible light, while the second, the external occulter, will produce an artificial eclipse. This instrument is named ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun). To accomplish the payload's scientific tasks, PROBA-3 will ensure sub-millimeter reciprocal positioning of its two satellites using closed-loop on-board metrology. Several metrology systems will be used and the Shadow Position Sensors (SPS) subsystem senses the penumbra around the instrument aperture and returns the 3-D displacement of the coronagraph satellite, with respect to its nominal position, by running a dedicated algorithm. In this paper, we describe how the SPS works and the choices made to accomplish the mission objectives.

PROBA-3 is a two-spacecraft ESA mission carrying the space-based diluted coronagraph ASPIICS. The imaging instrument is hosted on the first spacecraft with the second acting as external occulter. In order to accomplish the payload’s scientific tasks, PROBA-3 will ensure sub-millimeter reciprocal positioning of its two satellites by means of closedloop on-board metrology. The Shadow Position Sensors (SPS) sense the penumbra around the instrument aperture and return the 3-D displacement of the coronagraph satellite with respect to its nominal position by running a dedicated algorithm. In this paper we describe how the SPS works and the choices made in order to accomplish the mission objectives.

The Air Force Research Laboratory/Space Vehicles Directorate (AFRL/RV) is developing a satellite structural architecture in support of the Department of Defense's Operationally Responsive Space (ORS) initiative. Such a structural architecture must enable rapid Assembly, Integration, and Test (AI&T) of the satellite, accommodate multiple configurations (to include structural configurations, components, and payloads), and incorporate structurally integrated thermal management and electronics, while providing sufficient strength, stiffness, and alignment accuracy. The chosen approach will allow a wide range of satellite structures to be assembled from a relatively small set of structural components. This paper details the efforts of AFRL, and its contractors, to develop the technology necessary to realize these goals.

The United States is striving to develop an Operationally Responsive Space capability. The goal is to be able to deliver tailored spacecraft capabilities to the warfighter as needs arise. This places a premium on the timespan between generating that requirement and having a functioning satellite performing its mission on orbit. Although there is lively debate regarding how to achieve this responsive space capability, one thing remains undeniable; the satellite flight qualification and launch vehicle integration process needs to be dramatically truncated. This paper describes the Air Force Research Laboratory's attempts to validate the use of Structural Health Monitoring (SHM) in lieu of traditional structural flight qualification testing schemes (static and shock loads, random vibration, coupled loads analysis, thermal vacuum testing, etc.) for potential Responsive Space (RS) satellites.

Small satellites require a variety of release devices to accomplish mission-related functions such as separation from the launch vehicle, separation from each other, and deployment of instruments. This paper summarizes low-shock non-pyrotechnic separation efforts that are being managed by the Air Force Research Laboratory Space Vehicles Directorate (AFRL/VS). The AFRL/VS has been actively developing low-shock, non-pyrotechnic spacecraft release devices to mitigate problems associated with traditional pyrotechnic release devices. Specifically, pyrotechnic devices produce high shock, create unnecessary contamination, and have costly handling requirements due to their hazardous nature. Small satellites are particularly susceptible to shock related failure because of the close proximity of sensors and instruments to the shock source. Reducing shock-induced loads on the spacecraft dramatically lowers the overall cost of a spacecraft's design, testing, and operation. Lower loads allow spacecraft components, such as solar arrays and other flexible structures, to be made lighter and use less expensive materials. This results in both smaller mass and reduced production costs. The AFRL/VS is sponsoring the development of several innovative technologies that can provide solutions to these problems. The devices are being designed to replace existing separation and deployment systems.