The European Space Agency Tender

To Implement Additional Function In Deep Space Transponder, Providing Accurate Onboard Time Based On Telemetry, Tracking, And Command (ttc) Signals And Time Transfer.descriptioncurrent Deep Space Transponders Include, In Addition To Uplink Telecommand (tc) And Downlink Telemetry (tm) Data Communications, The Functionality Of Two-way Code-based Ranging And Turnaround Carrier Phase Coherency. The Two-way Ranging Functionality Is Based On Sequences That Can Be E.g. Pseudo-noise (pn) Ranging (phase Modulated Together With The Tc/tm Data, And Turned Around Either Transparently (bent Pipe) Or Regeneratively), Or Using Spread Quadrature Pseudo Noise. Space Missions Could Benefit In Increased Accuracy And Onboard Autonomy From A Timestamping Function. It Is Based On A One Pulse-per-second (1 Pps) Signal And Time Information Generated By The Transponder Based On The Pn Ranging Epoch Combined With Known Range Information And Other Information From Ground Segment, Thus Implementing One-way Time Transfer From Earth.the Implementation Involves The Ttc Receiver Locking To The Pn Uplink Sequence And Generating Regular Epoch. The Ground Station Is Performing 2-way Ranging Usingthe Pn-ranging Signals, Including Removal Of Ambiguity And Other Processing On The Orbit. This Information Including Ranging/range-rate From The Ground Station Is Then Uplinked To The Ttc Receiver Via Telecommand. The Receiver Then Performs A Timing Algorithm And Dynamic Model, To Generate Onboard Time Using The Received Epoch Timing And The Information Uplinked From The Ground Station. Thisonboard Time Can Then Be Used In A Timestamping Function That Is Useful In Several Missions. The Onboard Time Can Be Synchronised To Universal Time Coordinated (utc).the Activity Includes Breadboarding The Additional Time Transfer Functionality, As Upgrade To Existing Deep Space Transponder Functionality, Operating In X-band (7/8ghz) Or Ka-band (26/32ghz).the Activity Encompasses The Following Tasks:- Review Of The Time Transfer Techniques And Maturity Of Elements Needed To Generate Onboard Real Time Clock Synchronised To Utc- Confirmation Of Parameters Needed For The Implementation Including Ranging Code Rates And Sequences- Design Of Architectural Defining The Elements Needed- Detailed Design And Simulation, Including (timing) Algorithm, Pn Epoch Generation, 1pps Generation- Implementation And Verification Of Timing Functions Breadboard Including Software / Fpga / Hardware In Line With Detailed Design- Demonstration Of Timestamping Function- Plan For Upgrade Path Of Deep Space Transponder