McArthur launched on two spaceflights, logging 213 days in orbit across her nearly 25 years, and held leadership positions at NASA's Johnson Space Center in Houston.
Around 11,300 years ago, a massive star teetered on the precipice of annihilation. It pulsed with energy as it expelled its outer layers, shedding the material into space. Eventually it exploded as a supernova, and its remnant is one of the most studied supernova remnants (SNR). It's called Cassiopeia A (Cas A) and new observations with the Chandra X-ray telescope are revealing more details about its demise.

