A September 8 press release from the laboratory revealed that a rock abrasion tool for the Mars rover Spirit, launched in 2004, was made from aluminum recovered from the World Trade Center. Intended as an interplanetary memorial, the tool is emblazoned with an American Flag. Last Sunday, the Mars rover Opportunity snapped a photo of Spirit still intact on the surface of the Red Planet. No matter what happens here on Earth, that rover will remain on Mars.