A model of the planned Dream Chaser mini-shuttle designed by Sierra Nevada Corp. is displayed in March 2014 for a news conference at NASA's Michoud Assembly Facility in New Orleans.
An illustration of Rosetta just before Friday's expected landing on the comet known as 67P/Churyumov-Gerasimenko. The final approach aims to be only at "walking speed," mission specialists say, but that's enough to tip the antenna away from Earth.
A multi-million dollar effort to produce a test to guide treatment for a potentially lethal skin cancer recently fell apart after the scientific investigator discovered that the commercial antibodies he was using were unreliable.
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