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Igenbergs, E.

Publications and source records attributed to Igenbergs, E..

Cometary Matter Analyser (COMA/CRAF)

This project was part of an international program under which the chemical composition of cometary dust particles was to be measured 'in situ' during a rendezvous and flyby mission of a Mariner Mark 2 space probe and a comet (depending on the time of launch). Two necessary tasks, preliminary hardware development and interface definition, have been completed within the projects submitted for approval. As a result a model close to the flight configuration has been created, which was to be made available to the flight hardware contractor and his purposes. The Comet Rendezvous and Asteroid Flyby (CRAF) mission was abandoned after joint resolution adopted by NASA and the Federal Ministry for Research and Technology in 1992. Since an instrument like CoMA is an important contribution both to future cometary rendezvous missions, such as ROSETTA, as well as for accompanying laboratory activities, this project was terminated in a 'qualified conclusion'. In the process, components suitable for the laboratory developed from the preliminary units were produced and put into operation.

COMETARY MATTER

Acoustic penetration and impact detector for micrometeoroid and space debris application

The Two-Stage Acoustic Penetration and Impact Detector is a simple device for measuring the impact event time, the projectile velocity, the flight path direction and the momentum. The results of laboratory tests have shown that this detector can be used in a wide range of projectile size and velocity. According to measurement purposes the size of the detection area, the distance between the front foil and the target plate and the number of microphones as well as the evaluation procedure can easily be adjusted. The target plate area can also be replaced by another foil detector, if two penetration stages are preferred. This active detector is suitable for a variety of applications in meteoroid and space debris exploration. It can also be supplied with capture cell properties for chemical analysis of inside-deposits. Therefore, this measurement principal has been taken into consideration as a possible flight experiment for instance for a later Longer Duration Exposure Facility (LDEF) flight or future space station activities.

Kuzcera, H.

On the search for trajectories for a cometary nucleus sample return mission

The steps in the procedure for the generation of single trajectories for a comet nucleus sample return mission described by Stuhlinger et al. (1985) are discussed. The following assumptions are made for such a mission: (1) the spacecraft is equipped with an ion propulsion system supplied by solar cells, and (2) the comet has a low inclination and a period of about six years. The calculation of a specific trajectory incorporates the following main parameters: (1) the spacecraft mass at the beginning of the mission and the hyperbolic excess velocity, (2) the mass as a function of the injection energy, and (3) the available thrust level. The limitation of a supply of solar electric power to the region within 3 AU of the sun and the placement of permanent in-situ experiments at the comet are discussed. It is concluded that single trajectories for a nucleus sample return mission can be generated. A further step would be an integration of single solutions into classes of trajectories.

Schobert, D.

Measurements of the elemental and isotopic composition of interplanetary dust collected on LDEF

A passive interplanetary dust collection experiment, currently in orbit aboard the Long Duration Exposure Facility, is described. The collectors, germanium target plates covered by metallized Mylar foils, are designed for secondary ion mass spectrometry measurements of the elemental and isotopic compositions of residues resulting from micrometeoroid (greater than 10 to the -10th grams) impacts. Impact simulation experiments have demonstrated the validity of the collection concept. Quantitative elemental analyses are complicated by the nonuniform distribution of projectile-derived elements.

Fechtig, H.