- Aerojet Rocketdyne Company Replaces President
- Source of the Chelyabinsk Meteor Remains Elusive
- NASA Celebrates 25 Years of 'Pale Blue Dot' Images
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Posted: 14 Feb 2015 03:19 PM PST
The chief executive of the parent company of Aerojet Rocketdyne announced Friday that he is taking over as president of the space propulsion company as the firm faces financial challenges. In the memo to employees obtained, Scott Seymour, chief executive of parent company GenCorp, announced he was taking over as president of Aerojet Rocketdyne from Warren M. Boley, Jr., effective immediately. The memo gave no reason for Boley’s departure. Seymour said he was retaining his position as chief executive of GenCorp as he takes over as president of Aerojet Rocketdyne, but offered few details about the transition. “On behalf of the leadership team, I sincerely thank Warren for his many contributions during his time with the company,” he said. “We wish him all the best in his future endeavors.”
Sources familiar with the company said Boley and Seymour disagreed about the company's future.
"It was time for a change. There had been differences about the company's direction," said one source who was not authorized to speak publicly.
Boley declined comment on the reason for his departure, but said he was upbeat about the company's prospects. "Great company, great portfolio, great future," he told Reuters.
Boley was named president of Aerojet in 2012, carrying on as president of Aerojet Rocketdyne in June 2013 at the close of Aerojet's acquisition of Rocketdyne from United Technologies's Pratt & Whitney business unit. Previously, he was president of the military engines division for United Technologies's Pratt & Whitney division.
Seymour, a longtime executive with Northrop Grumman Corp, was named in 2010 to head GenCorp, and also headed the Aerojet unit from 2010 to 2012.
Boley's sudden departure from Aerojet Rocketdyne comes at an uncertain time in the rocket-launch business and growing concern about the use of Russian-built rocket engines to power the rockets that lift U.S. satellites into space.
In October, GenCorp said it took a $17.5 million loss due to issues with the AJ-26 rocket engine that it provides for the Antares launch vehicle built by Orbital Sciences Corp, which this week completed its merger with Alliant Techsystems Inc, forming a new company known as Orbital ATK.
Orbital last year said it would swap out Aerojet's AJ-26 engine, which is based on the aging Soviet-era NK-22 engine, a move that came even before an Antares rocket exploded seconds after liftoff destroying a cargo ship bound for the International Space Station.
Last May, an AJ-26 engine exploded during a ground test at NASA's Stennis Space Center in Mississippi.
Aerojet Rocketdyne is also vying for a role in replacing the RD-180, a newer Russia-built engine that powers the Atlas 5 rocket used to lift U.S. military and spy satellites into space.
Credit: reuters.com, spacenews
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Posted: 14 Feb 2015 12:14 PM PST
Two years after a 20-meter rock slammed into the Earth after a meteoroid dramatically fragmented in the atmosphere over the Chelyabinsk region in Russia and injured hundreds of people, its parent asteroid remains elusive, a new paper published in the journal Icarus shows. Astronomers had originally predicted that a 2-km near-Earth asteroid (NEA) designated (86039) 1999 NC43 could be the source body from which the Chelyabinsk meteoroid was ejected prior to its encounter with the Earth. “These two bodies shared similar orbits around the sun and initial studies suggested even similar compositions,” said Planetary Science Institute Research Scientist Vishnu Reddy, lead author of “Link between the Potentially Hazardous Asteroid (86039) 1999 NC43 and the Chelyabinsk meteoroid tenuous” that appears in Icarus.
However, reanalysis of the orbital parameters and spectral data by an international team of researchers led by Reddy has shown that the link between Chelyabinsk and 1999 NC43 is unlikely. “The composition of Chelyabinsk meteorite that was recovered after the event is similar to a common type of meteorite called LL chondrites. However, the near-Earth asteroid has a composition that is distinctly different from this,” Reddy said.
The study also showed that linking specific meteorites to an asteroid is extremely difficult due to the chaotic nature of the orbits of these bodies.
While the researchers acknowledge that more studies are needed, the lack of spectral match between Chelyabinsk meteor and 1999 NC43, and their different chemistries described in this paper suggest that the asteroid is probably not the source object for this meteorite.
Identifying the parent asteroid of meteorites in terrestrial collections (asteroid-meteorite linkage) is one of the ultimate goals of meteoritics. To reach that goal, dynamical models have been employed to link bolides to their source regions in the main belt or parent asteroids in the NEA population based on their orbits. Bolide orbits are primary calculated based on video all sky camera networks and also surveillance footage.
On February 15, 2013, a 17-20 meter diameter asteroid entered the atmosphere over Chelyabinsk, Russia, and disintegrated in an airburst with an estimated energy of about 500±100 kilotons of TNT.
This research work was supported by grants from NASA’s Planetary Mission Data Analysis Program, NEOO Program and Planetary Geology and Geophysics Program.
Credit: psi.edu
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Posted: 14 Feb 2015 11:38 AM PST
Valentine's Day is special for NASA's Voyager mission. It was on Feb. 14, 1990, that the Voyager 1 spacecraft looked back at our solar system and snapped the first-ever pictures of the planets from its perch at that time beyond Neptune. This "family portrait" captures Neptune, Uranus, Saturn, Jupiter, Earth and Venus from Voyager 1's unique vantage point. A few key members did not make it in: Mars had little sunlight, Mercury was too close to the sun, and dwarf planet Pluto turned out too dim. Taking these images was not part of the original plan, but the late Carl Sagan, a member of the Voyager imaging team at the time, had the idea of pointing the spacecraft back toward its home for a last look. The title of his 1994 book, "Pale Blue Dot," refers to the image of Earth in this series.
"Twenty-five years ago, Voyager 1 looked back toward Earth and saw a 'pale blue dot,'" an image that continues to inspire wonderment about the spot we call home," said Ed Stone, project scientist for the Voyager mission, based at the California Institute of Technology, Pasadena.
The image of Earth contains scattered light that resembles a beam of sunlight, which is an artifact of the camera itself that makes the tiny Earth appear even more dramatic. Voyager 1 was 40 astronomical units from the sun at this moment. One astronomical unit is 93 million miles, or 150 million kilometers.
These family portrait images are the last that Voyager 1, which launched in 1977, returned to Earth. Mission specialists subsequently turned the camera off so that the computer controlling it could be repurposed. The spacecraft is still operating, but no longer has the capability to take images.
"After taking these images in 1990, we began our interstellar mission. We had no idea how long the spacecraft would last," Stone said.
Today, Voyager 1, at a distance of 130 astronomical units, is the farthest human-made object from Earth, and it still regularly communicates with our planet. In August 2012, the spacecraft entered interstellar space – the space between the stars -- and has been delivering data about this uncharted territory ever since. Its twin, Voyager 2, also launched in 1977, is also journeying toward interstellar space.
Voyager 1 is more than three times farther from Earth than it was on Valentine's Day 25 years ago. Today, Earth would appear about 10 times dimmer from Voyager's vantage point.
Sagan wrote in his "Pale Blue Dot" book: "That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world."
NASA's Jet Propulsion Laboratory, Pasadena, California, built and operates the twin Voyager spacecraft. The Voyagers Interstellar Mission is a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA's Science Mission Directorate in Washington.
Credit: NASA
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