The Cosmic Ray Energetics and Mass (CREAM) experiment was designed and constructed to measure cosmic ray elemental spectra using a series of long duration balloon flights around the south pole in Antarctica. It is a cooperative effort of the University of Maryland, Pennsylvania State University, Northern Kentucky University and NASA Goddard Space Flight Center from USA, Ewha Woman's University from Korea, LPSC Grenoble and CESR Toulouse of France and finally UNAM from Mexico.
The goal of the experiment is to extend direct measurement of cosmic-ray composition to the energies capable of generating gigantic air showers which have been mainly observed on the ground, thereby providing calibration for indirect measurements. The instrument has redundant and complementary charge identification and energy measurement systems capable of precise measurements of elemental spectra for Z = 1 - 26 nuclei over the energy range ~1011 to 1015 eV. Precise measurements of the energy dependance of elemetal spectra at the highest of these energies, where the rigidity-dependant supernova acceleration limit could be reflected in a composition change, provide a key to understanding cosmic ray acceleration and propogation. The instrument includes a Timing Charge Detector (TCD), a Cherenkov Detector (CD), a Transition Radiation Detector (TRD), a Cherenkov Camera (CherCam), a Silicon Charge Detector (SCD), scintillating fiber hodoscopes, and a tungsten-scintillating fiber calorimeter.
The CREAM mission has had six successful flights with different detector configurations between 2004 and 2010. A total cumulative exposure of ~162 days has been achieved.
Launch base | Date | Flight Duration | Experiment | Payload landing place or cause of the failure |
---|---|---|---|---|
McMurdo | 12/16/2004 | 41 d 22 h | CREAM I (Cosmic Ray Energetics And Mass) | 410 miles SSE of McMurdo Station, Antarctica |
McMurdo | 12/15/2005 | 28 d 9 h 52 m | CREAM II (Cosmic Ray Energetics And Mass) | 249 nautic miles Northwest from McMurdo Antarctic base. |
McMurdo | 12/19/2007 | 28 d 21 h 53 m | CREAM III (Cosmic Ray Energetics And Mass) | 177 nautic miles SW from McMurdo Antarctic base |
McMurdo | 12/19/2008 | 19 d 13 h | CREAM IV (Cosmic Ray Energetics And Mass) | 560 nautic miles N-NW of McMurdo Station, Antarctica |
McMurdo | 12/1/2009 | 37 d | CREAM V (Cosmic Ray Energetics And Mass) | 185 nautic miles SSE of McMurdo, Antarctica |
McMurdo | 12/21/2010 | 5 d 16 h 28 m | CREAM VI (Cosmic Ray Energetics And Mass) | Over Queen Maud Land, Antarctica |
McMurdo | 11/28/2016 | 30 d 2 h 1 m | BACCUS (Boron And Carbon Cosmic rays in the Upper Stratosphere) | 50 miles E of McMurdo Station |