The European Space Agency Tender

The Laser Interferometer Space Antenna (lisa) Is An Esa-led Mission In Partnership With Nasa. Lisa Is The First Space Mission Designed To Observe The Universe Via Gravitational Waves, Ripples In The Fabric Of Space Time Caused By The Acceleration Of Massive Objects In The Universe.the Lisa Observatory Consists Of 3 Spacecrafts (each With A Mass/power Of About 2700kg/>3kw) And Forming An Equilateral Triangular Constellation Of 2.5 Million Km Side-length, In Trailing Orbit With Respect To The Earth At About 50 Million Km. The Passage Of A Gravitational Wave Results In A Modulation Of The Distance Between The Satellites; By Monitoring The Length Ofone Arm With Respect To Another Using Laser Interferometry, The Effect Of The Passage Of The Gravitational Wave Can Be Measured. Each Spacecraft In Lisa Is Notionally Identical, With The Constellation Of Three Forming The Science Instrument. Each Spacecraft Houses Two Optical Terminals Capable Of Transmitting And Receiving Laser Light To/from The Other Satellites, As Well As Two Drag-free Gravitational Reference Sensors Which Constitute The Fiducial Points At The End Of The Arms. These Terminals Are Referred To As The Moving Optical Subsystem Assemblies (mosas). Each Mosa Consists Of A Transmit/receive Off-axis Telescope (tel), An Ultra-stableoptical Bench Assembly (oba) Hosting The Optical Elements Of The Michelson Interferometers, The Gravitational Reference (gr) Sensor Head, A Set Of Diagnostics Sensors And Actuators, Optical And Electrical Harnesses And Associated Mounting Hardware. All These Elements Are Customer Furnished Items (cfis) That Member States And Nasa Will Provide To The Agency That Will Eventually Be Integrated By The Prime Contractor As Part Of The Satellite Integration.lisa Is Planned To Be Launched On An Ariane 64 In 2035 Into A Direct Escape Trajectory. Each Spacecraft Is Endowed With Electric Propulsion For The Transfer To Its Operational Orbit, Attained After1.5 Years, Where, After The Acquisition Of The Interferometric Links Between The Three Spacecraft, The Gravitational Wave Observatory Will Operate For 4.5 Years (nominally).the Spacecraft Platform Provides All Necessary Infrastructure Enabling Space Operations,and A Set Of Electronic Units Provided By The Agency As Customer Furnished Items (cfis) Under Member States Funding, Among Which-notably For The Subject Of This Procurement - The Interferometric Detection Subsystem (ids), Composed Of The Phasemeter To Readoutthe Interferometer Signal (pms), The Mechanism Control Units (mcu), And The Optical Bench Assembly (oba). The Oba Embeds Several Optical Elements Mechanisms And The Constellation Acquisition System (cas).the Timely Availability Of The Cas Is Of Paramount Importance To Ensure The Fulfilment Of The Agency's Cfis Obligations Vis--vis The Spacecraft. This Subsystem Is Composed Of Two Major Units: The Cas Optical Head (coh), Directly Integrated On The Optical Bench (ob) And Coaligned With The Photo-receivers Of The Long-arm Interferometer. The Coh Encompasses An Optical System Enabling Imaging Of The Laser Spot Received From The Telescope On The Detector. The Detector Is Composed Of Pixels That Cover The Full Cas Field Of View With The Ability To Accurately Determine The Position Of Target Sources Within The Field. The Cas Electronic Unit (ceu) On The Spacecraft To Generate The Secondary Voltage And High Level (spacewire) Interface To The On-board Computer (obc).the Cas Main Functions Are To: Identify The Presence Of The Laserbeam Incoming From A Remote Spacecraft Into Its Field Of View (fov); Measure The Direction Of The Incoming Laser Beam In Its Reference Frame; Identify The Presence Of Stars In Its Field Of View; Measure The Direction Of All The Other Detected Stars In Its Reference Frame, This Being The Last Function Necessary To Support The In-flight Measurement Of The Mutual Alignment Between The Cas And The Star Trackers Used To Control The Spacecraft Attitude During The First Step Of The Constellation Acquisition. Disclaimer : Closing date mentioned is an assumption date, Please contact the tendering authority to get exact closing date.