  We introduce a million-second observation of the supernova remnant Cassiopeia
A with the Chandra X-ray Observatory. The bipolar structure of the Si-rich
ejecta (NE jet and SW counterpart) is clearly evident in the new images, and
their chemical similarity is confirmed by their spectra. These are most likely
due to jets of ejecta as opposed to cavities in the circumstellar medium, since
we can reject simple models for the latter. The properties of these jets and
the Fe-rich ejecta will provide clues to the explosion of Cas A.
