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Tibor Kremic

Publications and source records attributed to Tibor Kremic.

31 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

GEER (Glenn Extreme Environments Rig): An Introduction

Our solar system contains many examples of what may be called extreme environments. These can be examples of high temperature and pressure environments in places like the deep atmospheres of the gas giants or on the surface of Venus. The permanently shadowed regions of the moon are examples of extreme cold conditions, a more common phenomena in space. Other extreme environments may be driven by high radiation conditions, or perhaps reactive atmospheric chemistry, which happens to be another feature of Venus. The extreme environments in the solar system pose interesting challenges to missions and technologists as they plan approaches to exploring and understanding our solar system.

GEER↗
NASA NTRSDate not supplied

Capabilities for Long-Duration Landers in Extreme Environments

Missions to the surface of planets that experience high temperatures, like Venus or Mercury, have had limited consideration and development in recent decades partially because of the extreme temperatures and environments the planets experience. In the case of Mercury this is up to 430C for nearly 30 days and for Venus almost 60 days at 460C. Several landers have been sent to Venus many decades ago but 127 minutes was the longest any operated on the surface. Venus, and Mercury, hold many mysteries and successful surface missions will result in compelling new science that will have significant bearing on us here on Earth. To enable this compelling new science, NASA has been developing capabilities for a small lander that is designed to operate for months in the extreme temperatures found on Venus and Mercury. The capabilities promise to enable new missions not yet considered. This work summarizes technical advances that are preparing us for long-duration (months) operations in extreme environments on other planets.

Extreme Environment Lander↗
NASA NTRSDate not supplied

Glenn Extreme Environments Rig (GEER)

World class facility and a Planetary Science Community's asset. GEER is capable of simulating a variety of temperature, pressure and atmospheric gas mixes to simulate extreme environments in the Solar System.

GEER↗
NASA NTRSDate not supplied

Venus Atmosphere Experimental Simulation Performance of the Glenn Extreme Environment Rig

The rejuvenated exploration of Venus remains a high priority within NASA, as evidenced by the selection of two Discovery class missions (DAVINCI and VERITAS) to be launched within the decade, and the support of the European Space Agency’s EnVision mission. All three missions represent a transformative advancement in the understanding of Earth’s enigmatic neighbor. In order to maximize the science return from these missions, and to facilitate the infusion of new technologies into potential future missions, NASA’s Glenn Research Center operates a unique facility, the Glenn Extreme Environment Rig (GEER), to simulate ambient conditions at Venus’ surface for long durations.

GEER↗
NASA NTRSDate not supplied

Glenn Extreme Environments Rig (GEER)

World class facility and a Planetary Science Community's asset. GEER is capable of simulating a variety of temperature, pressure and atmospheric gas mixes to simulate extreme environments in the Solar System.

GEER↗
NASA NTRSDate not supplied

High-Temperature MEMS Based Venus Seismometer

Seismology is the method of choice for studying a planet’s interior and assessing current tectonic activity. With a single strategically placed seismometer, or preferably a network of seismometers, a variety of key aspects of a planet can be evaluated. The level and nature of seismicity observed provides a gauge of current geologic, especially tectonic, activity. Where tectonic activity is and is not occurring illuminates what regions and geologic features on the planet are currently active, thus, constraining global geodynamics. Larger distal earthquakes can be used to determine major compositional and structural boundaries within a planet’s interior, providing major constraints on planet formation and interior evolution. Seismometers have been deployed successfully on the Moon and Mars. Only small subsets of the scientific knowledge that can be gained from seismology can be obtained from alternative scientific approaches, such as global gravity solutions or repeat-pass interferometry. By virtue of its similar size to Earth, Venus is likely to be highly seismically active (Fig. 1). Even at Earth-like levels of seismology, returning meaningful data would require observation over a period that is at least 2–3 orders of magnitude longer than the 1–2 h lifetime of previous Soviet landers. Clever insulation could extend the lifetime of standard electronics in a modern lander to perhaps 24 h. While active cooling of electronics for a Venusian lander is plausible, this approach would require considerable technological advancement and will likely come at a high monetary and mass cost. The high density of the Venusian atmosphere at the surface should mean that there is good coupling of seismic energy into the atmosphere, such that seismology using infrasound from a balloon platform is currently being explored, and observations of the upper levels of the atmosphere from orbit has also been proposed [3]. Besides losing all shear wave information with these two methods, calibrating and interpreting seismic information that has been distorted by, and convolved with, atmospheric phenomena will be challenging without existing seismology data collected through surface seismometers (optimally, simultaneous surface seismological observations would be made).

silicon carbide↗