6,741 to 6,750 of 6,809 Results
Nov 6, 2001
Shishko, Robert, 2001, "Risk analysis simulation of rover operations for Mars surface exploration", https://hdl.handle.net/2014/39010, Joint ESA-NASA Spaceflight Safety Conference, November 06-2001, JPL Open Repository
Risk management advocates have long sought to directly influence the early stages of the systems engineering process through a more effective role in system design trade studies. The principal obstacle to this has been the lack of credible ways to represent and quantify mission r... |
Oct 29, 2001
Berner, Jeff B.; Kinma, Peter W.; Layland, James M., 2001, "Regenerative pseudo-noise ranging for deep space applications", https://hdl.handle.net/2014/39302, ESA 3rd Workshop on Tracking, Telemetry and Command Systems for Space Applications, Noordwijk, the Netherlands, October 29, 2001., JPL Open Repository
Currently, ranging for deep space missions is performed by turning around the uplink ranging modulation and remodulating it onto the downlink carrier. This method results in about 1.5 MHz of noise also being modulated onto the downlink, severely degrading the received ranging SNR... |
Oct 29, 2001
Sherwood, Rob; Mishkin, Andrew; Estlin, Tara; Chien, Steve; Backes, Paul; Cooper, Brian; Maxwell, Scott; Rabideau, Gregg, 2001, "Autonomously generating operations sequences for a Mars Rover using AI-based planning", https://hdl.handle.net/2014/39436, IEEE/RSJ International Conference on Intelligent Robots and Systems, Maui, HI, 29 October - 03 November, 2001, JPL Open Repository
This paper discusses a proof-of-concept prototype for ground-based automatic generation of validated rover command sequences from highlevel science and engineering activities. This prototype is based on ASPEN, the Automated Scheduling and Planning Environment. This Artificial Int... |
Oct 29, 2001
Berner, Jeff B.; Odea, J. Andrew; Bryant, Scott H.; Guerreo, Ana Maria P.; Louie, John J., 2001, "Telemetry, tracking, and command consolidation in the Deep Space Network.", https://hdl.handle.net/2014/39281, ESA 3rd Workshop on Tracking, Telemetry and Command Systems for Space Applications, Noordwijk, the Netherlands, October 29, 2001., JPL Open Repository
Currently, in NASA’s Deep Space Network (DSN), telemetry, tracking, and command (TT&C) functions are distributed between multiple subsystem computers. Control design of these subsystems did not consider the interaction necessary between the functions, which create opportunities f... |
Oct 29, 2001
Berner, Jeff B.; Bryant, Scott H., 2001, "New tracking implementation in the Deep Space Network.", https://hdl.handle.net/2014/39284, ESA 3rd Workshop on Tracking, Telemetry and Command Systems for Space Applications, Noordwijk, the Netherlands, October 29, 2001., JPL Open Repository
As part of the Network Simplification Project, the tracking system of the Deep Space Network is being upgraded. This upgrade replaces the discrete logic sequential ranging system with a system that is based on commercial Digital Signal Processor boards. The new implementation all... |
Oct 29, 2001
Berner, Jeff B.; Andrews, Kenneth S.; Bryant, Scott H., 2001, "Deep Space Network turbo decoder implementation", https://hdl.handle.net/2014/39266, ESA 3rd Workshop on Tracking, Telemetry and Command Systems for Space Applications, Noordwijk, the Netherlands, October 29, 2001., JPL Open Repository
A new decoder is being developed by the Jet Propulsion Laboratory for NASA's Deep Space Network. This unit will decode the new turbo codes, which have recently been approved by the Consultative Committee for Space Data Systems (CCSDS). Turbo codes provide up to 0.8 dB improvement... |
Oct 21, 2001
Brenner, Michael; Imbriale, William A.; Britcliffe, Michael K., 2001, "Gravity deformation measurements of 70m reflector surfaces.", https://hdl.handle.net/2014/39146, 23rd Annual Meeting & Symposium of the Antenna Measruement Techniques Associations, Denver, Colorado, October 21-26, 2001., JPL Open Repository
Two of NASA’s Deep Space Network (DSN) 70-meter reflectors are measured using a Leica TDM-5000 theodolite. The main reflector surface was measured at five elevation angles so that a gravity deformation model could be derived that described the main reflector distortions over the... |
Oct 20, 2001
Toomarian, Nikzad; Kohen, Hamid S.; Bearman, Gregory H.; Seligson, David B., 2001, "Cancer detection using neural computing methodology", https://hdl.handle.net/2014/40401, 13th European Simulation Symposium (ESS), Marseilles, France, October 18-20, 2001, JPL Open Repository
This paper describes a novel learning methodology used to analyze bio-materials. The premise of this research is to help pathologists quickly identify anomalous cells in a cost efficient method. Skilled pathologists must methodically, efficiently and carefully analyze manually hi... |
Oct 15, 2001
Polk, James E.; Sekerak, Mike; Ziemer, John K.; Schein, Jochen; Qi, Niansheng; Binder, Robert; Anders, André, 2001, "A theoretical analysis of vacuum arc thruster performance", https://hdl.handle.net/2014/39349, 27th International Electric Propulsion Conference, Pasadena, California, October 15-19, 2001., JPL Open Repository
In vacuum arc discharges the current is conducted through vapor evaporated from the cathode surface. In these devices very dense, highly ionized plasmas can be created from any metallic or conducting solid used as the cathode. This paper describes theoretical models of performanc... |
Oct 15, 2001
Johnson, Lee K.; Conroy, David G.; Spanjers, Greg G.; Bromaghim, Daron R., 2001, "Propulsion instruments for small Hall thruster integration", https://hdl.handle.net/2014/40398, 27th International Electric Propulsion Conference(IEPC), Pasadena, California, October 15-19, 2001, JPL Open Repository
Planning and development are underway for the propulsion instrumentation necessary for the next AFRL electric propulsion flight project, which includes both a small Hall thruster and a micro-PPT. These instruments characterize the environment induced by the thruster and the assoc... |
