gravity recovery and climate experiment (grace) satellite gravimetry mission launched in march 2002 based on its twin gravimetric satellites makes application of both high-low (hl) and law-low (ll) gravimetric techniques possible. the ll is based on satellite-to-satellite tracking (sst) via the one way two frequencies k-band-ranging between the two grace satellites. as a result of combination o...

Low Earth Orbits (LEO) satellites are used for public communication and for scientific purposes. These satellites provide opportunities for investigations for which alternative techniques are either difficult or impossible to apply. Ground stations have to be established in order to communicate with such satellites. Usually these satellites communicate with ground stations at S-band. The commun...

The number of sensors for Earth environmental observation is growing. Several new sensors have been announced for the near future and several proposals for smart sensors have been proposed. In particular, distributed sensors, sensor network and sensor integration are being taken into account, and smart sensors, intelligent sensors, sensor’s autonomy, etc. is beginning to be used in future earth...

Centromeres are required for faithful segregation of chromosomes in cell division. It is not clear what kind of sequences act as functional centromeres and how centromere sequences are organized in Oryza punctata, a BB genome species. In this study, we found that the CentO centromeric satellites in O. punctata share high homology with the CentO satellites in O. sativa. The O. punctata centromer...

Directorate, we are developing architectures for commanding and controlling a cluster of cooperating satellites through autonomous software development for the TechSat 21 program (see the “TechSat 21” sidebar starting on page XX). Many space missions require large, monolithic satellites. This often results in costly, complex, failure-prone vehicles whose physical size constraints limit their pe...

Space Resource America Corporation is engaged in developing new concepts for communications satellite systems that will avoid interference with any of the Geostationary satellites and can provide a significant increase in global capacity compared with that of the GEO ring. Additionally, since all satellites in such a system are flying in formation, they will not interfere with each other. The c...

Introduction: With the approach of Cassini to the Saturn system, attention naturally focuses on the planet, its rings and Titan, but the Saturn system is also populated by a number of smaller satellites. The seven middle-sized icy satellites, along with those of Uranus, (between 400 and 1500 km wide) are distinctly different geophysically and geologically from their much larger Galilean-class b...

The CSA has initiated a feasibility study for a constellation of low-cost small SAR satellites to ensure C-band data continuity beyond RADARSAT-2. The concept involves three satellites with an option of flying up to six satellites. This is to provide operationally SAR imagery for key maritime surveillance applications such as ship detection, oil spill monitoring, and sea ice mapping. Other appl...

The properties of multiple image gravitational lenses require a fractional surface mass density in satellites of fsat = 0.02 (0.006 < ∼ fsat < ∼ 0.07 at 90% confidence) that is consistent with the expectations for CDM. The characteristic satellite mass scale, 10 6-10 9 M⊙, is also consistent with the expectations for CDM. The agreement between the observed and expected density of CDM substructu...

SMALL satellites are enablingmultisatellite missions that were not otherwise possible because of their small size and modular nature [1].Multiple small satellites can be flown instead of amuch bigger and costlier conventional satellite for distributed sensing applications such as atmospheric sampling, distributed antennas [2], and synthetic apertures [3,4]. Missions with multiple small satellit...