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  About CRaTER

The primary goal of CRaTER is to characterize the global lunar radiation environment and its biological impacts. This objective is critical if we are to "implement a sustained, safe, and affordable human and robotic program to search for evidence of life, understand the history of the solar system, and prepare for future human exploration", a vision established by the President's Space Exploration Policy Directive.

  Measurement Goals

  • Measure and characterize that aspect of the deep space radiation environment, LET spectra of galactic and solar cosmic rays (particularly above 10 MeV), most critically important to the engineering and modeling communities to assure safe, long-term, human presence in space.
  • Develop a novel instrument, steeped in flight heritage, that is simple, compact, and comparatively low-cost, but with a sufficiently large geometric factor needed to measure LET spectra and its time variation, globally, in the lunar orbit.
  • Investigate the effects of shielding by measuring LET spectra behind different amounts and types of areal density, including tissue-equivalent plastic.
  • Test models of radiation effects and shielding by verifying/validating model predictions of LET spectra with LRO measurements, using high-quality GCR and SEP spectra available contemporaneously on ongoing/planned NASA.
CRaTER construction

CRaTER illustration
CRaTER preliminary design

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  Principal Investigator

  • , Space Science Center, University of New Hampshire, Durham, NH


The investigation hardware consists of a single, integrated sensor and electronics box with simple electronic and mechanical interfaces to the spacecraft. The CRaTER sensor frontend design is based on standard stacked-detector, cosmic ray telescope systems that have been flown for decades, using detectors developed for other NASA flight programs. The analog electronics design is virtually identical to the robust and flight-proven design of the NASA/POLAR Imaging Proton Spectrometer that has been operating flawlessly on orbit since 1996. The digital processing unit is a simple and straightforward design also based on similar instruments with excellent spaceflight heritage. No new technology developments or supporting research are required for the final design, fabrication, and operation of this instrument.
CRaTER illustration CRaTER illustration

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