HST SOLAR CELL REPORTS:
The recent recovery of the Hubble Space Telescope (HST) solar generator system offers a unique opportunity to examine the effect of prolonged exposure to the space environment on solar panel components. In this work, we examine the effects of the smaller meteoroid and debris particle impacts on HST thermal blankets and solar cells. The data from HST surfaces is particularly interesting for the meteoroid and debris community, as the Telescope was in orbit at an altitude of approx. 614 km and there has been no data from such a high orbit before. This work is divided into two sections: first, the investigation of the HST thermal blankets and second, the investigation of some selected solar cells.
This final report represents the first in a series of three &documents produced under the Hubble Micrometeoroid and Debris Post Flight Analysis contract (the other two &documents are the
nical Report and the User Manual). The aim of this final report is to &document the activities performed, identify and describe the data products produced and summarise the major conclusions from the two Hubble scanning sessions carried out at ESTEC during the summer of 1994. The associated Technical Report should be consulted for a more detailed discussion of the overall statistical analyses performed, and the results of individual site analysis.
The Technical Report contains a full description of the stages of data acquisition and analysis, with comprehensive graphical and tabular data enabling the reader to assess better the space impact environment experienced in the EuReCa's exposure. The Final Report should be consulted for broader aspects of the project and general conclusions.
Abstract: Return of the two Solar Array assemblies of the Hubble Space Telescope provided opportunity to characterise the Near Earth impact environment, over an exposure period of 8 years. Recovery in 2002, provided opportunity at ESTEC and Contractor Institutes for flux measurements and chemical analysis of impact features from micron- to centimetrescale. All results are presented in an updated meteoroid and debris database at ESA.
Technical Note 1 describes measurements performed in Survey Phases 1 and 2 in,
respectively December 2002 and February 2003, at the European Space Agency
ESTEC Holland under the guidance of contract Officer G. Drolshagen. Results of
analyses are reported in other Technical Notes, specifically TN3 for residue
studies, TN4 for crater morphologies and fluxes and TN5 for the complete
This Technical Note 2 describes measurements performed at Institutes following Surveys 1 and 2 (reported in TN 1) at the European Space Agency ESTEC Holland under the guidance of contract Officer G. Drolshagen. Results of analyses are reported in other Technical Notes, specifically: TN3 for residue studies; TN4 for crater morphologies and fluxes and TN5 for the complete database. Conventions for crater measurement, identification and scanning approaches are defined in TN1.
Analysis of Impact Residues on SM-3B HST solar cells - The focus of this investigation is to provide detailed chemical analysis of residues located in measured impact features across the entire size range &documented on Hubble Space Telescope (HST) solar cells returned by the shuttle Orbiter Columbia at the end of HST Service Mission 3B (SM-3B) in March 2002. The aim is to produce as complete a classification, in terms of Space Debris or Micrometeoroid, as is possible for the features examined, including mineral or component chemistry, with crater size expressed as conchoidal diameter (Dco of Herbert and McDonnell, 1997).
This Technical Note reviews flux and chemical data to interpret the environmental exposure history accumulated in terms of the impacting flux of Meteoroids and Space Debris.
The present Technical Note TN5 present an outline of the New Database where it will be possible to find all of the information relevant to the work performed during this study including all Technical Notes.
This report gives a summary of the analysis of the impact data from the first HST solar array retrieved in 1993. It also addresses the impact data from LDEF and EURECA again and presents the damage equation for the thin HST solar arrays.
HST RESIDUE ANALYSIS REPORTS:
This directory contains calibration views for the Hirox and Leica binocular optical photos. Views are in BitMaP Windows format. Views description is included in CALIB.DOC &document (Word 2 &document).
The array was transported to a clean facility at ESTEC so that the effects of space exposure could be investigated, under the aegis of the HST Post-Flight Investigation Program. Subsequent to the initial investigation, several European laboratories were involved in a co-ordinated survey of impact features and meteoroid/debris residue analysis. This report details the results of the survey undertaken by the Open University/Natural History Museum as part of the project.
ESTEC provided us for detailed analysis with 17 different solar cell samples comprising 23 individual cells from the so-called "Solar Panel Assembly - SPA ", four samples from the upper "Outer Buffer Assembly" (OBA), and one sample from the stiffener.
The Technical University of Darmstadt received 20 solar cell samples of the retrieved Hubble Space Telescope solar wing. The objective was the chemical characterization of hypervelocity impact residues in the in all impacts. The solar cells were analyzed with EPMA-EDX and SIMS. Because of the complexity of the solar cells it was extremely difficult to unequivocally identify fragments of space debris or micrometeoroides by EPMA-EDX. However, analyses with SIMS clearly indicate the presence of thin films of re-condensed projectile material. These films around impact craters consist of Na, K and Ca and can only be detected by SIMS.
From the total of 48760 solar cells bonded onto 20 so-called 'Solar Panel Assemblies' (SPAs), which in fact are the power-generating components of the flexible solar-array blankets of Hubble Space Telescope, the Institute of Planetology, University of M¸nster, has been provided with 20 solar cells and 6 buffer samples by ESA/ESTEC in order to perform a comprehensive search for impact craters and impactor residues on each sample.
Twenty-one solar cell samples were examined with the optical microscope and more than 100 possible impact craters were detected. Scanning electron microscopy was used for verifying the objects and for impact &documentation. The impacts detected range in size from about 10 µm to about 6200 µm (size of maximum destruction = D``). One hundred and four investigated structures are related to 98 impacts.
HST MLI & OTHER SURFACES REPORTS:
In this work, we examine the effects of atomic oxygen, UV radiation, thermal cycling and, in particular, particle impacts on the HST thermal blankets. These impacts occur at velocities of 10 to 20 km/s and create craters or holes in the top Teflon layer of the blankets.
In this work, we examine the effects of the smaller meteoroid and debris particle impacts on HST thermal blankets and solar cells. The data from HST surfaces is particularly interesting for the meteoroid and debris community, as the Telescope was in orbit at an altitude of approx. 614 km and there has been no data from such a high orbit before. This work is divided into two sections: first, the investigation of the HST thermal blankets and second, the investigation of some selected solar cells.