ATK Supports Successful Launch of Pegasus Rocket Carrying NASA's AIM Satellite

MINNEAPOLIS, April 25 /PRNewswire-FirstCall/ -- Alliant Techsystems (NYSE: ATK - News) solid propulsion and composite technologies supported the successful launch yesterday of an Orbital Sciences Corporation (NYSE: ORB - News) air-launched Pegasus XL® rocket from Vandenberg Air Force Base, Calif. The Pegasus XL carried NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite into space.

ATK's Orion solid propulsion motors provided power for all three stages of the air-launch vehicle. The motors, which have flown on all Pegasus rockets since its first mission in 1990, are manufactured in Salt Lake City, Utah. The composite payload fairing, filament-wound solid rocket motor cases, the interstage that form the Pegasus vehicle's main structure and the first stage igniter case were produced by ATK in Clearfield, Utah.

The AIM satellite mission will explore Polar Mesospheric Clouds (PMCs), also called noctilucent clouds. PMCs, form about 50 miles above the Earth's surface and are commonly seen over the polar regions. More recently these clouds have been sighted in Colorado and Utah where they have never before been observed.

The satellite will generate electricity from a six panel, two stage deployable solar array system custom built by ATK's Goleta, California site.

ATK is the world's leading supplier of solid-propellant rocket motors. Products include propulsion systems for the Delta, Pegasus®, Taurus®, Atlas, H-IIA, and Titan IV expendable space launch vehicles, NASA's Space Shuttle, the Trident II Fleet Ballistic Missile, the Minuteman III Intercontinental Ballistic Missile, and ground-based missile defense interceptors.

The AIM satellite mission will explore Polar Mesospheric Clouds (PMCs), also called noctilucent clouds. PMCs, form about 50 miles above the Earth's surface and are commonly seen over the polar regions. More recently these clouds have been sighted in Colorado and Utah where they have never before been observed.

Interesting, considering where we are in the present inter-glacial part of the earth's glacial cycle.

Spectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity
Richard A. Muller^* and Gordon J. MacDonald

Figure 2. Spectral fingerprints in the vicinity of the 100 kyr peak: (a) for data from Site 607; (b) for data of the SPECMAP stack; (c) for a model with linear response to eccentricity, calculated from the results of Quinn et al. (ref 6); (d) for the nonlinear ice-sheet model of Imbrie and Imbrie (ref 22); and (e) for a model with linear response to the inclination of the Earth's orbit (measured with respect to the invariable plane). All calculations are for the period 0-600 ka. The 100 kyr peak in the data in (a) and (b) do not fit the fingerprints from the theories (c) and (d), but are a good match to the prediction from inclination in (e). return to beginning

Far more important to our present analysis, however, is the fact that the predicted 100 kyr "eccentricity line" is actually split into 95 and 125 kyr components, in serious conflict with the single narrow line seen in the climate data. The splitting of this peak into a doublet is well known theoretically (see, e.g., ref 5), but in comparisons with data the two peaks in the eccentricity were merged into a single broad peak by the poor resolution of the Blackman-Tukey algorithm (as was done, for example, in ref 8). The single narrow peak in the climate data was likewise broadened, and it appeared to match the broad eccentricity feature.
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Figure 3. Variations of the inclination vector of the Earth's orbit. The inclination i is the angle between this vector and the vector of the reference frame; Omega is the azimuthal angle = the angle of the ascending node (in astronomical jargon).. In (A), (B), and (C) the measurements are made with respect to the zodiacal (or ecliptic) frame, i.e. the frame of the current orbit of the Earth. In (D), (E), and (F) the motion has been trasformed to the invariable frame, i.e. the frame of the total angular momentum of the solar system. Note that the primary period of oscillation in the zodiacal frame (A) is 70 kyr, but in the invariable plane (D) it is 100 kyr.

There is evidence from the Infrared Astronomical Satellite (ref 39) of a narrow dust band extending only two degrees from the invariable plane. The precise location of these bands is uncertain; they may be orbiting in resonant lock with the Earth (ref 40, 41). It is not clear that these bands contain sufficient material to cause the observed climate effects. We note, however, that even small levels of accretion can scavenge greenhouse gases from the stratosphere, and cool the Earth's climate through the mechanism proposed by Hoyle (ref 30). The dust could also affect climate by seeding the formation of much larger ice crystals. The accreting material could be meteoric, originating as particles too large to give detectable infrared radiation.

Data on noctilucent clouds (mesospheric clouds strongly associated with the effects of high meteors and high altitude dust) supports the hypothesis that accretion increase significantly when the Earth passes through the invariable plane. As shown in Figure 6, a strong peak in the number of observed noctilucent clouds occurs on about July 9 in the northern hemisphere (ref 41, 42) within about a day of the date when the Earth passes through the invariable plane (indicated with an arrow). In the southern hemisphere the peak is approximately on January 9, also consistent with the invariable plane passage, but the data are sparse. The coincidence of the peaks of the clouds with the passage through the invariable plane had not previously been noticed, and it supports the contention that there is a peak in accretion at these times. On about the same date there is a similarly narrow peak is observed in the number of polar mesospheric clouds (ref43) and there is a broad peak in total meteoric flux (ref 44). It is therefore possible that it is the trail of meteors in the upper atmosphere, rather than dust, that is responsible for the climate effects.

Fig 6. Frequency of noctilucent clouds vs. day of year, in (A) the northern hemisphere, and in (B) the sourthern hemisphere (ref 41, 42). The arrows indicate the dates when the earth passes through the invariable plane. The coincidence of these dates with the maxima in the noctilucent clouds suggests the presence of a thin ring around the sun. Peaks on the same dates are seen in Polar mesospheric clouds (ref 44) and in radar counts of meteors.

Previous article in regards the noctilucent cloud formations:

http://www.newscientistspace.com/article/dn9228-mysterious-glowing-clouds-targeted-by-nasa.html

Mysterious glowing clouds targeted by NASA
26 May, 2006
High-altitude noctilucent clouds have been mysteriously spreading around the world in recent years (Image: NASA/JSC/ES and IA)
And coincident dust aggregations:

http://newton.ex.ac.uk/aip/physnews.252.html#1

INTERPLANETARY DUST PARTICLES (IDPs) are deposited on the Earth at the rate of about 10,000 tons per year. Does this have any effect on climate? Scientists at Caltech have found that ancient samples of helium-3 (coming mostly from IDPs) in oceanic sediments exhibit a 100,000-year periodicity. The researchers assert that their data, taken along the Mid-Atlantic Ridge, support a recently enunciated idea that Earth's orbital inclination varies with a 100-kyr period; this notion in turn had been broached as an explanation for a similar periodicity in the succession of ice ages. (K.A. Farley and D.B. Patterson, Nature, 7 December 1995.)
Farley & Patterson 1998, http://www.elsevier.com/gej-ng/10/20/36/33/37/32/abstract.html
Farley http://www.gps.caltech.edu/~farley/
Farley http://www.elsevier.nl/gej-ng/10/18/23/54/21/49/abstract.html

http://www.publicaffairs.noaa.gov/pr96/dec96/noaa96-78.html

ABRUPT CLIMATE CHANGE DURING LAST GLACIAL PERIOD COULD BE TIED TO DUST-INDUCED REGIONAL WARMING

Preliminary new evidence suggests that periodic increases in atmospheric dust concentrations during the glacial periods of the last 100,000 years may have resulted in significant regional warming, and that this warming may have triggered the abrupt climatic changes observed in paleoclimate records, according to a scientist at the Commerce Department's National Oceanic and Atmospheric Administration. Current scientific thinking is that the dust concentrations contributed to global cooling.

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