Enlarge / The main body of NASA's Europa Clipper spacecraft is reflected in one of the mission's deployable solar array wings during testing at Kennedy Space Center in Florida. (credit: NASA/Frank Michaux)

For a while earlier this summer, it looked like NASA's flagship mission to study Jupiter's icy moon Europa might miss its launch window this year.

In May, engineers raised concerns that transistors installed throughout the spacecraft might be susceptible to damage from radiation, an omnipresent threat for any probe whipping its way around Jupiter. The transistors are embedded in the spacecraft's circuitry and are responsible for approximately 200 unique applications, many of which are critical to keeping the mission operating as it orbits Jupiter and repeatedly zooms by Europa, interrogating the frozen moon with nine science instruments.

The transistors on the Europa Clipper spacecraft are already installed, and removing them for inspections or replacement would delay the mission's launch until late next year. Europa Clipper has a 21-day launch window beginning October 10 to begin its journey into the outer solar system.

Enlarge / Artist's illustration of NASA's Wide-field Infrared Survey Explorer spacecraft. (credit: NASA/JPL-Caltech)

Last week, NASA decommissioned a nearly 15-year-old spacecraft that discovered 400 near-Earth asteroids and comets, closing an important chapter in the agency's planetary defense program.

From its position in low-Earth orbit, the spacecraft's infrared telescope scanned the entire sky 23 times and captured millions of images, initially searching for infrared emissions from galaxies, stars, and asteroids before focusing solely on objects within the Solar System.

Wising up to NEOs

The Wide-field Infrared Survey Explorer (WISE) spacecraft launched in December 2009 on a mission originally designed to last seven months. After WISE completed checkouts and ended its primary all-sky astronomical survey, NASA put the spacecraft into hibernation in 2011 after its supply of frozen hydrogen coolant ran out, reducing the sensitivity of its infrared detectors. But astronomers saw that the telescope could still detect objects closer to Earth, and NASA reactivated the mission in 2013 for another decade of observations.