STEREO Ground Segment, Science Operations, and Data Archive

Vitally important to the success of any mission is the ground support system used for commanding the spacecraft, receiving the telemetry, and processing the results. We describe the ground system used for the STEREO mission, consisting of the Mission Operations Center, the individual Payload Operations Centers for each instrument, and the STEREO Science Center, together with mission support from the Flight Dynamics Facility, Deep Space Mission System, and the Space Environment Center. The mission planning process is described, as is the data flow from spacecraft telemetry to processed science data to long-term archive. We describe the online resources that researchers will be able to use to access STEREO planning resources, science data, and analysis software. The STEREO Joint Observations Program system is described, with instructions on how observers can participate. Finally, we describe the near-real-time processing of the “space weather beacon” telemetry, which is a low telemetry rate quicklook product available close to 24 hours a day, with the intended use of space weather forecasting.     

Development of an Italian low cost GNSS/INS system universally suitable for mobile mapping

The first studies for the mobile mapping and creation of a vehicle for this kind of research was carried out by Canadian Researchers in the 1980s. Since then, these vehicles have been widely employed in several applications (road cadastre maps, terrestrial photogrammihetry, road sign recognition, etc.) for both commercial and research purposes throughout the world. Many GNSSIINS vehicles which can be equipped in different ways with one or more GPS, inertial sensors, and one or several cameras, have been realized. A characteristic shared by most of these devices concerns the high costs of the sensors, of the realization and of the maintenance. For this reason, a GNSSIINS system, that is suitable for any vehicle, made up of low cost devices (two GPS receivers, an INS, and a camera rigidly placed on a metallic bar), has been designed and built by our research group. Two tests run at different velocities have been carried out to evaluate the reliability of the system. After a presentation of the system, the differences that were witnessed during the application of these calibration methods are explained herein.     

The Juno Waves Investigation

Jupiter is the source of the strongest planetary radio emissions in the solar system. Variations in these emissions are symptomatic of the dynamics of Jupiter’s magnetosphere and some have been directly associated with Jupiter’s auroras. The strongest radio emissions are associated with Io’s interaction with Jupiter’s magnetic field. In addition, plasma waves are thought to play important roles in the acceleration of energetic particles in the magnetosphere, some of which impact Jupiter’s upper atmosphere generating the auroras. Since the exploration of Jupiter’s polar magnetosphere is a major objective of the Juno mission, it is appropriate that a radio and plasma wave investigation is included in Juno’s payload. This paper describes the Waves instrument and the science it is to pursue as part of the Juno mission.     

Range Contamination and Its Effect on Measurements

Increased sensitivity and dynamic range of the instrumental techniques used in conjunction with experiments on ballistic ranges have brought to the fore many problems arising from contamination in the ranges themselves. This is seldom discussed when experimental results are presented but is frequently the controlling limitation on the accuracy of the measurements. The authors discuss contamination due to dirt and debris resultant from gun operation, gaseous impurities, and projectile-borne impurities as they have occurred at the Re-entry Simulating Range of Lincoln Laboratory. The effects of these contaminants on measurements are discussed and illustrated, and measures for controlling them are outlined. Finally, a particular range operation is described from the standpoint of impurity control.     

Time-Optimal Control of a Bounded Phase-Coordinate Process II: High-Order Systems with Multiple Control Inputs

This paper considers the problem arising from the design of an autopilot for a large booster. The motion-controlling actuators of the booster have both position and rate limits. The problem is formulated as a bounded phase-coordinate problem and analyzed by the ``backing out of the target' procedure. A method of constructing the optimal control is presented. An example of an oscillatory system with two control inputs is given, and the optimal control is expressed as an explicit time function.     

Thick galactic cosmic radiation shielding using atmospheric data

NASA is concerned with protecting astronauts from the effects of galactic cosmic radiation and has expended substantial effort in the development of computer models to predict the shielding obtained from various materials. However, these models were only developed for shields up to about 120 g/cm² in mass thickness and have predicted that shields of this mass thickness are insufficient to provide adequate protection for extended deep space flights. Consequently, effort is underway to extend the range of these models to thicker shields and experimental data is required to help confirm the resulting code. In this paper empirically obtained effective dose measurements from aircraft flights in the atmosphere are used to obtain the radiation shielding function of the Earth's atmosphere, a very thick, i.e. high mass, shield. Obtaining this result required solving an inverse problem and the method for solving it is presented. The results are shown to be in agreement with current code in the ranges where they overlap. These results are then checked and used to predict the radiation dosage under thick shields such as planetary regolith and the atmosphere of Venus.     

Skylab experiment results: hematology studies

These studies were designed and coordinated to evaluate specific aspects of man's immunologic and hematologic systems which might be altered by or respond to the space flight environment. The biochemical functions investigated included cytogenetic damage to blood cells, immune resistance to disease, regulation of plasma and red cell volumes, metabolic processes of the red blood cell, and physical chemical aspects of red blood cell functions. Only minor changes were observed in the functional capacity of erythrocytes as determined by measuring the concentrations of selected intracellular enzymes and metabolites. Tests of red cell osmotic regulation indicated some elevation in the activity of the metabolic dependent Na-K pump, with no significant alterations in the cellular Na and K concentrations or osmotic fragility. A transient shift in red cell specific-gravity profile was observed on recovery, possibly related to changes in cellular water content. Measurements of hemoconcentration (hematocrit, hemoglobin concentration, red cell count) indicated significant fluctuations postflight, reflecting observed changes in red cell mass and plasma volume. There was no apparent reticulocytosis during the 18 days following the first manned Skylab mission in spite of a significant loss in red cell mass. However, the reticulocyte count and index did increase significantly 5 to 7 days after completion of the second, longer duration, flight. There were no significant changes in either the while blood cell count or differential. However, the capacity of lymphocytes to respond to an in vitro mitogenic challenge was repressed postflight, and appeared to be related to mission duration. The cause of this repression is unknown at this time. Only minor differences were observed in plasma protein patterns. In the second mission there were changes in the proteins involved in the coagulation process which suggested a hypercoagulative condition.     

Activity Planning for the Space Station

This paper presents an overview of the identification and selection process of experiments and payloads for manned space flight missions, emphasizing the scope and magnitude of the problem of doing activity planning and the need for a methodology to assure timely flight and appropriate spacecraft design. Conclusions and results derived from the past several years are presented together with an analysis of the current procedure for defining activity for the space station.