• → European Space Agency

    • About Science & Technology

    • For Public

    • For Educators

    • ESA

    • Science & Technology

    • Planck

    • Missions
    • Show All Missions
    • Mission Home
    • Summary
    • Fact Sheet
    • Objectives
    • Participants
    • Mission Team
    • Industrial Team
    • Spacecraft
    • Spacecraft
    • 3D Model
    • Instruments
    • Cooling system
    • Mission Operations
    • Launch Information
    • Orbit/Navigation
    • Launch Vehicle
    • Launch Campaign
    • Science Operations
    • Science Ground Segment
    • Planck Legacy Archive
    • Outreach Resources
    • Outreach Resources
    • Resources
    • News Archive
    • Multimedia Gallery
    • Publication Archive
    • Calendar of Events
    • Services
    • Contact Us
    • Subscribe
    • Terms and Conditions
    • Bookmark and Share

    Planck cooling system

    Passive cooling

    The key elements of the Planck spacecraft's passive cooling system are the three V-groove thermal shields and the telescope baffle.

    V-grooves

    The Planck spacecraft with its characteristic V-grooves and telescope baffle (26 Feb 2009)

    The V-grooves are a set of three specular, conical thermal shields with an opening angle of 5° between adjacent shields. They are located between the service module, which operates at ambient temperatures and houses all spacecraft's warm elements, and the telescope that is at about 50 K or -220 °C.
     
    Each V-groove is composed of six 60° sections. The layout of the V-grooves with their reflective surfaces and the opening angle make them efficient insulators (any radiated heat is reflected out into space). The V-grooves are at progressively colder temperatures, dropping in three steps from the 300 K of the service module to about 45 K at the topmost V-groove, closest to the payload.

    Baffle

    The telescope baffle surrounds the telescope and the focal plane. It is a high-efficiency radiator made of aluminium honeycomb and painted black on the outside. The baffle is fully reflective inside and also acts as a straylight shield, preventing unwanted radiation from entering the telescope and the instrument detectors located in the focal plane underneath the telescope's primary mirror.

    Together, the baffle and V-grooves provide a thermal environment at about 45 K for the telescope and the focal plane units (FPU) of the LFI and HFI instruments. This passive cooling is an important pre-cooling stage for the active cooling system.

    An important factor for the effectiveness of the spacecraft's passive cooling is that Planck is operated at the second Lagrange point L2 of the Sun-Earth system, where the lower side of the spacecraft is continuously oriented towards the Sun, keeping the V-grooves and the telescope always in the shadow with direct view to cold space.

    Summary
    Active cooling system

    Last Update: 17 Sep 2009

    • Shortcut URL
    • http://sci.esa.int/jump.cfm?oid=45498
    • Related Articles
    • Summary
    • Passive cooling
    • Active cooling system
    • Images and Videos
    • 3D Model
    • Planck Build-up
    • 20 K Cooler
    • 4 K Cooler
    • 0.1 K Cooler
    • Temperature stages within the HFI FPU

    Connect with us

    • RSS
    • Youtube
    • Twitter
    • Flickr
    • Google Buzz
    • Livestream
    • Subscribe
    • App Store
    • ESA Science Twitter

    Follow ESA science

    • Copyright 2000 - 2013 © European Space Agency. All rights reserved.

    • Terms and Conditions