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Cheung, Kar-ming

Publications and source records attributed to Cheung, Kar-ming.

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Evolution of the Mars Relay Network End-to-End Information System in the Mars Human Era (2030-2040)

In order to help the reader understand this evolution from the current to the future MRN state in the Mars human era, we will provide a description of the current communication infrastructure supporting Mars mission users, and how we envision it to change in order to meet the needs and challenges of supporting both human and robotic communication by 2030-2040. This includes the introduction of new data types like audio and video, and new in-situ relay services for communications and navigation services.

Kazz, Greg J.↗
NASA NTRS2016

Architecture and CONOPS of Next-Generation Ground Network for Communications and Tracking of Interplanetary SmallSats

As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or addressed by the numerous low Earth orbit (LEO) CubeSat and Smallsat missions staged to date. The LEO CubeSats typically use low-cost, proven CubeSat radios, antennas, and university ground stations with small apertures. As more ambitious yet cost-constrained space mission concepts to the Moon and beyond are being developed, CubeSats and smallsats have the potential to provide a more affordable platform for exploring deep space and performing the associated science. Some of the challenges that have, so far, slowed the proliferation of small interplanetary spacecraft are those of communications and navigation.

Cheung, Kar-ming↗
NASA NTRS2016

Traffic Modeling for Deep Space Network in the Human Mars Exploration Era

In this article we describe the analysis and simulation effort of the end-to-end traffic flow for the Deep Space Network (DSN) in the Human Exploration Era, when DSN will provide communication and navigation services for human missions to distant celestial objects like the Moon, asteroids, and Mars. Using the network traffic derived for the 30-day period within July/August 2039 from the Space Communications Mission Model (SCMM), we simulate the bandwidths of the ground links and the buffer profiles of the network nodes. We also use a 2-state Markov scheme that models the store-and-forward mechanism that regulates the ground network traffic. The network traffic modeling and simulation generates ground bandwidth and buffer statistics, which in turn are used to formulate the future DSN ground network bandwidth and storage requirements.

Cheung, Kar-ming↗