1、Lessons Learned Entry: 1862Lesson Info:a71 Lesson Number: 1862a71 Submitting Organization: GRCa71 Submitted by: Dale Forcea71 POC Name: Dale Forcea71 POC Email: Dale.A.Forcenasa.gova71 POC Phone: 216-433-3520Subject: High Data Rate K-band Transmitter for Lunar and Near Earth Missions Abstract: To se
2、nd images from the moon to Earth, the Lunar Reconnaissance Orbiter (LRO) uses a K-band data link that transmits at 25.65 GHz with a transmission rate of 100 Mbit/s, a significant increase in data return from what was possible with older technology. Because this development was based on a previous de
3、sign effort for a mission-of-interest, it was scaled back quickly to meet the timeline and requirements of the LRO project.Description of Driving Event: The LRO transmitter needed a high-power amplifier with a 40 W output at 25.65 GHz. Fortunately, a 180 W traveling wave tube amplifier had just been
4、 developed and space-qualified for a mission-of-interest. Prior to that development, the state-of-the-art had been a 10 W traveling wave tube built for the Cassini spacecraft in the early 1990s, which is still flying successfully. A traveling wave tube amplifier (TWTA) meeting the LRO requirements w
5、as developed by L-3 Communications Electron Technologies, Inc. under oversight of the Glenn Research Center.Lesson(s) Learned: Technology must be developed in advance of its anticipated use so that it can be available to meet the demanding schedules for development of lunar and near-Earth missions.
6、It was possible to obtain the TWTA needed for the LRO in time for its mission because the Glenn Research Center had previously sponsored development of a 180 W TWTA, and the work done in this previous effort was Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro
7、m IHS-,-,-reused in the LRO in a scaled-back version. Without the benefit of the previous development work, the LRO mission would have been delayed.Recommendation(s): NASA needs a continuing hardware development program to meet the challenging timelines of lunar and near-Earth missions.Evidence of R
8、ecurrence Control Effectiveness: N?ADocuments Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Sciencea71 Exploration SystemsAdditional Key Phrase(s): a71 Engineering Design (Phase C/D).Spacecraft and Spacecraft InstrumentsAdditional Info: a71 Project: Lunar Reconnaissance OrbiterApproval Info: a71 Approval Date: 2010-01-29a71 Approval Name: mbella71 Approval Organization: HQProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
