Near-optimal Science Data Return Using Hybridized Physical And Protocol Layer Strategy—in-flight Experiments Performed On MESSENGER
- Paper number
IAC-07-B2.2.01
- Author
Mr. Karl Fielhauer, Johns Hopkins University Applied Physics Laboratory, United States
- Coauthor
Mr. Dipak Srinivasan, Johns Hopkins University Applied Physics Laboratory, United States
- Coauthor
Mr. Christopher Krupiarz, United States
- Year
2007
- Abstract
Overview
The MErcury: Surface, Space ENviroment, Geochemistry and Ranging (MESSENGER) spacecraft is its way to Mercury after a successful 3 August 2004 launch and is now in interplanetary cruise. MESSENGER will explore and return science that will dramatically enhance mankind’s knowledge of Mercury and our knowledge of the solar system. The Johns Hopkins University Applied Physics Laboratory performed several in-flight tests of science data return improvement techniques that will enhance the science volume for the mission. This paper will discuss those techniques and test results.
During cruise and orbital operations, MESSENGER will downlink science data files, via its deep space network compatible X-Band communications system (the physical layer), stored on the spacecraft’s solid-state recorder via a protocol defined by the Consultative Committee for Space Data Systems (CCSDS) called the CCSDS File Delivery Protocol (CFDP). CFDP (the protocol layer) enables the automatic retransmission of lost data thus allowing the X-Bank link to operate at lower link margins, target the performance of individual DSN antennas and enable a variable downlink symbol rate to map the changing G/T of the antennas. These techniques together will dramatically increase the science return rate over pre-launch estimates. This can be accomplished without penalty to the mission or science operations team, relieving the team of finding and requesting retransmission of missing science data.
An additional application of this technique will also be for future mission including an eccentric Earth-orbiting Radiation Belt Storm Probe (RBSP) mission.
- Abstract document