High temperature, wireless seismometer sensor for Venus
Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462°C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426°C. This result indicates that the concept may be used on Venus.
A Concept of Operations for an Integrated Vehicle Health Assurance System
This document describes a Concept of Operations (ConOps) for an Integrated Vehicle Health Assurance System (IVHAS). This ConOps is associated with the Maintain Vehicle Safety (MVS) between Major Inspections Technical Challenge in the Vehicle Systems Safety Technologies (VSST) Project within National Aeronautics and Space Administration's (NASA's) Aviation Safety Program. In particular, this document seeks to describe an integrated system concept for vehicle health assurance that integrates ground-based inspection and repair information with in-flight measurement data for airframe, propulsion, and avionics subsystems. The MVS Technical Challenge intends to maintain vehicle safety between major inspections by developing and demonstrating new integrated health management and failure prevention technologies to assure the integrity of vehicle systems between major inspection intervals and maintain vehicle state awareness during flight. The approach provided by this ConOps is intended to help optimize technology selection and development, as well as allow the initial integration and demonstration of these subsystem technologies over the 5 year span of the VSST program, and serve as a guideline for developing IVHAS technologies under the Aviation Safety Program within the next 5 to 15 years. A long-term vision of IVHAS is provided to describe a basic roadmap for more intelligent and autonomous vehicle systems.
Stability of Sulfur Compounds on Venus
Abstract The abundances of the major sulfur compounds in the lower atmosphere of Venus have been calculated assuming equilibrium between the atmospheric gases and the mineral phases CaSO 4 , CaSiO 3 , SiO 2 , Fe 3 O 4 , FeS, and FeS 2 . Various combinations of these phases form stable assemblages under different conditions of oxidation while certain other assemblages are excluded. By analogy with Earth, it is expected that iron will be more abundant than sulfur in the Venus crust, and this should result in iron compounds controlling the degree of oxidation as well as the abundances of the sulfur compounds. Maximum surface fugacitied in atmospheres for the major sulfur species at the mean temperature of 700°K and all oxidation conditions are as follows: P S 2 ≈10 −3 , P SO 2 ≈10 1.6 , P SO 3 ≈10 −6 , and P H 2 S ≈ 10 −2.5 with P h 2 S the leat certain of these values.