CRaTER Science


LET Spectra

Galactic Cosmic Rays

Solar Proton Events

Biological Effects of


Estimate Your Annual
Radiation Exposure

Radiation dose chart
  (interactive & print versions)

Reading Room

Cancer risk from GCR
  (pdf, 2006)
Cell damage detection
  (pdf, 2005)
One-Two Particle Punch
  (website, 2006)
Cosmic Radiation and Bones
  (text, 2005)
Are We Trapped on Earth?
  (website, 2006)
2006 Space Weather Week
  Presentation by H.Spence
  (pdf, 2006)
  describing instrument
  (pdf, 2006)
Radioactive Moon
  (website, 2005)
Proton Inelastic Processes
  (pdf, 2004)
Monte Carlo Simulation
  to Assess True Risk
  (pdf, 2002)
Response of Silicon-based
  LET Spectrometers
  (pdf, 2005)

nasa logo

Science Overview

A top priority of the NASA Lunar Reconnaissance Orbiter (LRO) mission is the “characterization of the global lunar radiation environment and its biological impacts and potential mitigation, as well as investigation of shielding capabilities and validation of other deep-space radiation mitigation strategies involving materials”.

The CRaTER investigation addresses the effects of ionizing energy loss in materials due to solar energetic particle events and galactic cosmic rays, specifically in silicon and in an analogue to human tissue.

Our investigation focuses on understanding the linear energy transfer (LET) spectrum inside materials through direct measurement in the space radiation environment, particularly ions with energies above 10 MeV/nucleon, combined with models of radiation transport through materials.

The CRaTER results will have direct application to the biological effects of the lunar radiation environment as well as the environmental effects on electronic systems. The details of the LET spectra will have direct use in evaluating Single Event Effect vulnerabilities.