One chance only
noted that even if something goes wrong, the IceCube telescope “is
unrecoverable, and can’t be repaired.” It’s “unlike the Hubble space
telescope” which was serviced several times by shuttle astronauts, he
added. “Essentially, we only have one chance to get this right.”
the electronics, once deployed in the ice, are inaccessible, extremely
high reliability is the prerequisite for every component used inside
the digital optical modules (DOMs).
electronics include: a photomultiplier tube made by Hamamatsu;
analog-to-digital converters, digital-to-analog converters and
amplifiers from Analog Devices Inc.; a main board controlled by
Altera’s FPGA with an embedded CPU based on an ARM 32-bit processor.
the DOM, a very high voltage generator sits next to delicate CMOS
circuitry, representing “another challenge for reliability,” explained
IceCube project also uses racks full of computing cards located at the
IceCube Laboratory. Since the lab is built on a surface of snow,
electronics can be replaced and upgraded. Still, the reliability of
such components is important because scientists may not be able to
repair them in time. The warmest-weather working season is limited,
from mid-November to mid-February.
describing how extreme technology is required in the telescope design,
Karle noted that the IceCube project wouldn’t have been possible
without “collaboration with the electrical engineering community.”