Engineers have shifted NASA’s Voyager 2 spacecraft into a mode that transmits only spacecraft health and status data while they diagnose an unexpected change in the pattern of returning data. Preliminary engineering data received on May 1 show the spacecraft is basically healthy, and that the source of the issue is the flight data system, which is responsible for formatting the data to send back to Earth.
The change in the data return pattern has prevented mission managers from decoding science data.
The first changes in the return of data packets from Voyager 2, which is near the edge of our solar system, appeared on April 22. Mission team members have been working to troubleshoot and resume the regular flow of science data. Because of a planned roll maneuver and moratorium on sending commands, engineers got their first chance to send commands to the spacecraft on April 30.
It takes nearly 13 hours for signals to reach the spacecraft and nearly 13 hours for signals to come down to NASA’s Deep Space Network on Earth.
Voyager 2 launched on August 20, 1977, about two weeks before its twin spacecraft, Voyager 1. The two spacecraft are the most distant human-made objects, out at the edge of the heliosphere, the bubble the sun creates around the solar system. Mission managers expect Voyager 1 to leave our solar system and enter interstellar space in the next five years or so, with Voyager 2 on track to enter interstellar space shortly afterward. Voyager 1 is in good health and performing normally.
“Voyager 2’s initial mission was a four-year journey to Saturn, but it is still returning data 33 years later,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “It has already given us remarkable views of Uranus and Neptune, planets we had never seen close-up before. We will know soon what it will take for it to continue its epic journey of discovery.”
The original goals for the two Voyager spacecraft were to explore Jupiter and Saturn.
As part of a mission extension, Voyager 2 also flew by Uranus in 1986 and Neptune in 1989, taking advantage of a once-in-176-year alignment to take a grand tour of the outer planets. Among its many findings, Voyager 2 discovered Neptune’s Great Dark Spot and 450-meter-per-second (1,000-mph) winds. It also detected geysers erupting from the pinkish-hued nitrogen ice that forms the polar cap of Neptune’s moon Triton. Working in concert with Voyager 1, it also helped discover actively erupting volcanoes on Jupiter’s moon Io, and waves and kinks in Saturn’s icy rings from the tugs of nearby moons.
Voyager 2 is about 13.8 billion kilometers, or 8.6 billion miles, from Earth. Voyager 1 is about 16.9 billion kilometers (10.5 billion miles) away from Earth.
The first scientific results from the Herschel infrared space observatory are revealing previously hidden details of star formation. New images show thousands of distant galaxies furiously building stars and beautiful star-forming clouds draped across our Milky Way galaxy. One picture even catches an “impossible” star in the act of formation.
Presented during a major scientific symposium held at the European Space Agency in the Netherlands, the results challenge old ideas of star birth, and open new roads for future research. The mission is led by the European Space Agency with important participation from NASA.
“Herschel is a new eye on a part of the cosmos that has been dark and buried for a long time,” said the mission’s NASA project scientist, Paul Goldsmith, at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
Herschel’s observation of the star-forming cloud RCW 120 has revealed an embryonic star, which appears ready to turn into one of the biggest and brightest stars in our galaxy within the next few hundred thousand years. It already contains eight to 10 times the mass of the sun and is still surrounded by an additional 2,000 solar masses of gas and dust from which it can feed further.
“This star can only grow bigger,” says Annie Zavagno, Laboratoire d’Astrophysique de Marseille in France. Massive stars are rare and short-lived. To catch one during formation presents a golden opportunity to solve a long-standing paradox in astronomy. “According to our current understanding, you should not be able to form stars larger than eight solar masses,” says Zavagno.
