An article in the July 16 issue incorrectly identified the sponsor of the first U.S. space-station utilization conference (p. 50). The conference was sponsored by the American Astronautical Society.

Sir Martin Sweeting Age: 61 Education: : Ph.D. in electronic engineering and communications from the University of Surrey.

On July 23, NASA and the U.S. Geological Survey (USGS) celebrated the 40th birthday of Landsat, the Earth-observing satellite series most closely identified with building a continuing data stream about how population growth, climate change, natural events and man's activities are influencing the planet.

Aerojet and Rocketdyne trace their roots to the dawn of the space age, with both companies building the engines that powered multiple generations of ICBMs and manned space vehicles. But the long-term outlook for both suppliers became clouded in recent years with the sharp decline in the demand for government launch services and the advent of new, lower-cost rivals, such as Space Exploration Technologies (SpaceX).

For Sally Ride, who died July 23, 2012, of pancreatic cancer, being the first U.S. woman in space was only the beginning of a long and productive career.

WASHINGTON - Small satellites, once the realm of one-off low-budget science missions and undergraduate engineering classes, have come full circle with the growing realization among hard-pressed, high-end users that the little birds can do the big jobs, too. (Cubesat image: Raytheon)