An international CSIRO-led team of astronomers has developed a new way to weigh the planets in our Solar System — using radio signals from the small spinning stars called pulsars.”This is first time anyone has weighed entire planetary systems — …
After more than 30 years, it appears the venerable Pioneer 10 spacecraft has sent its last signal to Earth. Pioneer’s last, very weak signal was received on Jan. 22, 2003. NASA engineers report Pioneer 10’s radioisotope power source has decayed, and it may not have enough power to send additional transmissions to Earth. NASA’s Deep Space Network (DSN) did not detect a signal during the last contact attempt Feb. 7, 2003. The previous three contacts, including the Jan. 22 signal, were very faint with no telemetry received. The last time a Pioneer 10 contact returned telemetry data was April 27, 2002. NASA has no additional contact attempts planned for Pioneer 10.
The horse, a classic model of grace and speed on land, is now an unlikely source of inspiration for more efficient flight. So says a group of University of Florida engineers who have recreated part of a unique bone in the horse’s leg with an eye toward lighter, stronger materials for planes and spacecraft.
The third metacarpus bone in the horse’s leg supports much of the force conveyed as the animal moves. One side of the cucumber-sized bone has a pea-sized hole where blood vessels enter the bone. Holes naturally weaken structures, causing them to break more easily than solid structures when pressure is applied. Yet while the third metacarpus does fracture, particularly in racehorses, it doesn’t break near the hole – not even when the bone is subjected to laboratory stress tests. UF engineering researchers think they’ve figured out why – and they’ve built and are testing a plate that mimics the bone’s uncanny strength in a form potentially useful for airplanes and spacecraft.