Engineering topics
Abraham, D. S.
Publications and source records attributed to Abraham, D. S..
Deep-Space Optical Communications: Visions, Trends, and Prospects
Current key initiatives in deep-space optical communications are treated in terms of historical context, contemporary trends, and prospects for the future. An architectural perspective focusing on high-level drivers, systems, and related operations concepts is provided. Detailed subsystem and component topics are not addressed. A brief overview of past ideas and architectural concepts sets the stage for current developments. Current requirements that might drive a transition from radio frequencies to optical communications are examined. These drivers include mission demand for data rates and/or data volumes; spectrum to accommodate such data rates; and desired power, mass, and cost benefits. As is typical, benefits come with associated challenges. For optical communications, these include atmospheric effects, link availability, pointing, and background light. The paper describes how NASA's Space Communication and Navigation Office will respond to the drivers, achieve the benefits, and mitigate the challenges, as documented in its Optical Communications Roadmap. Some nontraditional architectures and operations concepts are advanced in an effort to realize benefits and mitigate challenges as quickly as possible. Radio frequency communications is considered as both a competitor to and a partner with optical communications. The paper concludes with some suggestions for two affordable first steps that can yet evolve into capable architectures that will fulfill the vision inherent in optical communications.
Long-range planning for the Deep Space Network
Explore the source record for details and available documents.
Long-range planning for the Deep Space Network
Conduct of space exploration is undergoing a significant transformation. Initial reconnaissance missions are giving way to long duration observations with data-intensive instruments, in situ investigations and complex operations. To keep pace, a transformation in the Deep Space Network is in order.
Long-range planning for the Deep Space Network
Explore the source record for details and available documents.
An introduction to the DSMS strategic mission model V5.0
Explore the source record for details and available documents.
Deep Space C3: high power uplinks
The uplink transmitters of the Deep Space Network (DSN) perform three support functions in support of space missions: navigation, command, uplink, and emergency recovery.
Identifying future mission drivers on the Deep Space Network
Explore the source record for details and available documents.
Identifying future mission drivers on the Deep Space Network
This paper discusses the methodology used to identify mission drivers on the future architecture for the Deep Space Network.
Identifying future mission drivers on the Deep Space Network
Explore the source record for details and available documents.
Pluto Fast Flyby: An Overview of the Mission and Spacecraft Design, Advanced Technology Insertion Efforts, and Student Involvement Opportunities
In an effort to complete the initial reconnanissance of our solar system, the Jet Propulsion Laboratory (JPL) is designing a mission to send two very small spacecraft to explore Pluto and its moon, Charon.