Journal of Earth System Science

, Volume 114, Issue 6, pp 749-760

First online:

Low energy neutral atom imaging on the Moon with the SARA instrument aboard Chandrayaan-1 mission

  • Anil BhardwajAffiliated withSpace Physics Laboratory, Vikram Sarabhai Space Centre
  • , Stas BarabashAffiliated withSwedish Institute of Space Physics
  • , Yoshifumi FutaanaAffiliated withSwedish Institute of Space Physics
  • , Yoichi KazamaAffiliated withSwedish Institute of Space Physics
  • , Kazushi AsamuraAffiliated withJapan Aerospace Exploration Agency
  • , David McCannAffiliated withSwedish Institute of Space Physics
  • , R. SridharanAffiliated withSpace Physics Laboratory, Vikram Sarabhai Space Centre
  • , Mats HolmstromAffiliated withSwedish Institute of Space PhysicsCurrently at NASA Goddard Space Flight Center
  • , Peter WurzAffiliated withPhysikalisches Institut, University of Bern
    • , Rickard LundinAffiliated withSwedish Institute of Space Physics

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This paper reports on the Sub-keV Atom Reflecting Analyzer (SARA) experiment that will be flown on the first Indian lunar mission Chandrayaan-1. The SARA is a low energy neutral atom (LENA) imaging mass spectrometer, which will perform remote sensing of the lunar surface via detection of neutral atoms in the energy range from 10 eV to 3 keV from a 100km polar orbit. In this report we present the basic design of the SARA experiment and discuss various scientific issues that will be addressed. The SARA instrument consists of three major subsystems: a LENA sensor (CENA), a solar wind monitor (SWIM), and a digital processing unit (DPU). SARA will be used to image the solar wind-surface interaction to study primarily the surface composition and surface magnetic anomalies and associated mini-magnetospheres. Studies of lunar exosphere sources and space weathering on the Moon will also be attempted. SARA is the first LENA imaging mass spectrometer of its kind to be flown on a space mission. A replica of SARA is planned to fly to Mercury onboard the BepiColombo mission.


Moon, Moon-solar wind interaction lunar elemental composition lunar magnetic anomalies Energetic Neutral Atom (ENA) lunar mission