The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We report progress on an adversarial reasoning system, RAPSODI (rapid adversarial planning with strategic opponent-driven intelligence). RAPSODI consists of two modules, GameMaster and a fast single agent planner. GameMaster refines and expands plans for two or more adversaries by making calls to a planning service provided by the fast single agent local search planner. RAPSODI employs an iterative...
Optical modeling challenges of the ground alignment plan and optical test and verification of the NASA James Webb space telescope are discussed. Issues such as back-out of the gravity sag of light-weighted mirrors, as well as the use of a sparse-aperture auto-collimating flat system are discussed. A walk-through of the interferometer based alignment procedure is summarized, and sensitivities from...
An important preprocessing step in many automatic speech segmentation and speaker clustering systems is the accurate detection of speaker change points, the times when one speaker stops talking and another begins. However, this becomes very difficult in conversational speech since utterance lengths can be extremely short, speaker changes occur frequently, speakers may talk over one another (co-channel...
New 20kW S-and X-band transmitters were developed by JPL for the six 34-m beam waveguide antennas of the deep space network (DSN) to support NASA Mars missions starting in 2003. These transmitters were based upon design concepts published previously in the Proceedings of the 2003 IEEE Aerospace Conference. They provide a 7dB improvement in uplink power at X-band, coverage of both deep space and near-earth...
This publication reports the first steps taken towards designing sliding mode control laws for controlling multiple small-sized autonomous helicopters in arbitrary formations. Two control schemes, which are required for defining a unique three-dimensional formation, are discussed. One of the schemes is developed in this work as a step towards full formation control. The presented formation control...
In recent years the public has become more aware of the potentially catastrophic consequences of an asteroid collision with Earth. Congress has taken note of this and instructed NASA to develop a program to determine the resources required to detect, track, characterize, and, if necessary, mitigate potentially hazardous objects. Characterization of an asteroid deemed sufficiently dangerous requires...
An integrated, miniaturized, low-power instrument capable of the detection and early characterization of microbial life in the soil of mars is proposed. Based on the detection and monitoring of ongoing metabolism as being the surest evidence for extant life, the experiments will probe for chirality in metabolism, for circadian rhythmicity, and for photosynthesis. However, the instrument package will...
This paper presents and discusses a number of general global trends with potentially serious implications for the development and operation of aerospace systems. In this context, aerospace systems are those systems which include atmospheric or exo-atmospheric vehicles as a key component. The identified trends consist of widely discussed and anticipated changes in the areas of geologic resources, resource...
The Cassini-Huygens Program is a joint effort between European Space Agency (ESA), which delivered the Huygens probe, and the National Aeronautics and Space Administration (NASA), which delivered the Cassini spacecraft. The Jet Propulsion Laboratory (JPL) manages the Cassini spacecraft for NASA. Cassini's primary mission is to survey the complex Saturnian system and release the ESA-Huygens probe at...
Operating the International Space Station (ISS) involves many complex crew tended, ground operated and combined systems. Over the life of the ISS program, it has become evident that by having automated and autonomous systems onboard, more can be accomplished and at the same time reducing the workload of the crew and ground operators. Engineers at the National Aeronautics and Space Administration's...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.