Development and Testing of a High-Precision Position and Attitude Measuring System for a Space Mechanism

This paper describes a high-precision optical metrology system - a unique ground test equipment which was designed and implemented for simultaneous precise contactless measurements of 6 degrees-of-freedom (3 translational + 3 rotational) of a space mechanism end-effector [1] in a thermally controlled ISO 5 clean environment. The developed contactless method reconstructs both position and attitude of the specimen from three cross-sections measured by 2D distance sensors [2]. The cleanliness is preserved by the hermetic test chamber filled with high purity nitrogen. The specimen's temperature is controlled by the thermostat [7]. The developed method excludes errors caused by the thermal deformations and manufacturing inaccuracies of the test jig. Tests and simulations show that the measurement accuracy of an object absolute position is of 20 micron in in-plane measurement (XY) and about 50 micron out of plane (Z). The typical absolute attitude is determined with an accuracy better than 3 arcmin in rotation around X and Y and better than 10 arcmin in Z. The metrology system is able to determine relative position and movement with an accuracy one order of magnitude lower than the absolute accuracy. Typical relative displacement measurement accuracies are better than 1 micron in X and Y and about 2 micron in Z. Finally, the relative rotation can be measured with accuracy better than 20 arcsec in any direction

The STEAMR Instrument: Optical Design, Development & Testing

The STEAMR instrument is a Swedish national contribution to the ESA PREMIER mission, which is a candidate for the upcoming Earth Core Explorer mission. The STEAMR instrument is envisaged as a multi-beam limb sounding satellite, which will utilise 14 simultaneously observing beams in two 12 GHz wide bands from 323 to 357 GHz. To maximize spatial sampling in the elevation direction the observing beams have an elliptical geometry, which defines the incoming beams as being astigmatic. In this paper we present an antenna optics scheme which corrects for this inherent astigmatism, thereby ensuring optimum imaging of the incoming to the circularly symmetric receiver feed horns. Furthermore, the design, synthesis and electromagnetic verification of a prototype focal plane array for the STEAMR instrument is also reported

Development and preliminary testing of a high precision long stroke slit change mechanism for the SPICE instrument

In the frame of ESA’s Solar Orbiter scientific mission, Almatech has been selected to design, develop and test the Slit Change Mechanism of the SPICE (SPectral Imaging of the Coronal Environment) instrument. In order to guaranty optical cleanliness level while fulfilling stringent positioning accuracies and repeatability requirements for slit positioning in the optical path of the instrument, a linear guiding system based on a double flexible blade arrangement has been selected. The four different slits to be used for the SPICE instrument resulted in a total stroke of 16.5 mm in this linear slit changer arrangement. The combination of long stroke and high precision positioning requirements has been identified as the main design challenge to be validated through breadboard models testing. This paper presents the development of SPICE’s Slit Change Mechanism (SCM) and the two-step validation tests successfully performed on breadboard models of its flexible blade support system

Development and testing of a bi-stable actuator based on a high transition temperature shape memory alloy

Pyrovalves, i.e., valves actuated by a pyrotechnical device, are very often used in space propulsion systems for their fast response, high reliability, low mass and low cost. However, they are hazardous and single use items. Their operation induces shocks and can generate contaminants. If a slower actuation is required or possible, shape memory-based actuators avoid the generation of shocks and contaminants while being fully resettable and non-hazardous devices. The goal of this project was to develop a bi-stable Shape Memory Alloy (SMA) actuator for a specific Slow Acting Latch Valve with long life capability. The benefits of this actuator makes it interesting not only for valve actuation but also for any device that has to be actuated in a smooth and reliable way. This paper presents the development of a bi-stable actuator based on high temperature shape memory alloys

Development and testing of a high-precision position and attitude measuring system for a space mechanism

Pyrovalves, i.e., valves actuated by a pyrotechnical device, are very often used in space propulsion systems for their fast response, high reliability, low mass and low cost. However, they are hazardous and single use items. Their operation induces shocks and can generate contaminants. If a slower actuation is required or possible, shape memory-based actuators avoid the generation of shocks and contaminants while being fully resettable and non-hazardous devices. The goal of this project was to develop a bi-stable Shape Memory Alloy (SMA) actuator for a specific Slow Acting Latch Valve with long life capability. The benefits of this actuator makes it interesting not only for valve actuation but also for any device that has to be actuated in a smooth and reliable way. This paper presents the development of a bi-stable actuator based on high temperature shape memory alloys

The STEAMR Instrument: Optical Design, Development & Testing

The STEAMR instrument is a Swedish national contribution to the ESA PREMIER mission, which is a candidate for the upcoming Earth Core Explorer mission. The STEAMR instrument is envisaged as a multi-beam limb sounding satellite, which will utilise 14 simultaneously observing beams in two 12 GHz wide bands from 323 to 357 GHz. To maximize spatial sampling in the elevation direction the observing beams have an elliptical geometry, which defines the incoming beams as being astigmatic. In this paper we present an antenna optics scheme which corrects for this inherent astigmatism, thereby ensuring optimum imaging of the incoming to the circularly symmetric receiver feed horns. Furthermore, the design, synthesis and electromagnetic verification of a prototype focal plane array for the STEAMR instrument is also reported

The STEAMR instrument ::optical design, development & testing

The STEAMR instrument is a Swedish national contribution to the ESA PREMIER mission, which is a candidate for the upcoming Earth Core Explorer mission. The STEAMR instrument is envisaged as a multi-beam limb sounding satellite, which will utilise 14 simultaneously observing beams in two 12 GHz wide bands from 323 to 357 GHz. To maximize spatial sampling in the elevation direction the observing beams have an elliptical geometry, which defines the incoming beams as being astigmatic. In this paper we present an antenna optics scheme which corrects for this inherent astigmatism, thereby ensuring optimum imaging of the incoming to the circularly symmetric receiver feed horns. Furthermore, the design, synthesis and electromagnetic verification of a prototype focal plane array for the STEAMR instrument is also reported