1、Lessons Learned Entry: 1861Lesson Info:a71 Lesson Number: 1861a71 Submitting Organization: GRCa71 Submitted by: Dale Forcea71 POC Name: Dale Forcea71 POC Email: Dale.A.Forcenasa.gova71 POC Phone: 216-433-3520Subject: TWT using WR-34 waveguide for K-band operation Abstract: It was necessary to use a
2、WR34 waveguide for the Lunar Reconnaissance Orbiter (LRO) traveling wave tube amplifier (TWTA) because the operating frequency would be 25.65 GHz, and the existing WR28 waveguide could not be used at this frequency. Because the WR34 is a bigger waveguide, it could potentially be flown on future miss
3、ions such as a Tracking and Data Relay Satellite (TDRS) or other near-Earth mission.Description of Driving Event: Previous NASA missions required TWTAs that operated in either the X-band or Ka-band. However, the TWTA for the LRO mission needed to operate in the intermediate K-band. Although the WR28
4、 waveguide used for Ka-band TWTAs would have worked at 25.65 GHz, waveguide losses would have been increased. In addition to its better performance, the WR34 waveguide will also work at lower frequencies than the WR28, frequencies that NASA plans to use in future near-Earth missions. Using WR34 wave
5、guide connections also allows larger and thicker quartz windows to be used for the seals inside the amplifier, which reduces the danger of multipaction and corona.Lesson(s) Learned: The TWTA was redesigned to work in a different waveguide so that it would perform better in the LRO mission and also i
6、n future missions. When developing a design, the next level of scale should Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-be considered to determine whether future needs can be met simultaneously with present needs. Because the WR34 is a bigger wav
7、eguide, it could potentially fly on a TDRS or other near-Earth mission.Recommendation(s): NASA needs to increase its capability to mount future missions by expanding the scale of its requirements for U.S. manufacturers.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/A
8、Mission 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 Orbiter Traveling Wave Tube AmplifierApproval 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-,-,-
