NASA Internal memo: Hail and Farewell from Deputy Administrator Gregory
Point of Contact: Dean Acosta, Public Affairs, 202/358-1898 Hail and Farewell from Deputy Administrator Gregory After 31 wonderful years working for the world's greatest research and exploration agency, and with some of the finest friends one could hope for, I have decided to call it a career. It is with tremendous appreciation for the opportunity my country has given me to be associated with NASA, first as a research test pilot, then as an astronaut, and most recently as deputy administrator, that I have informed the President of my resignation effective Oct. 3. During my time at NASA, I have been ever humbled by the support that our nation has provided for our journeys, the positive influence NASA has had on our next generation of explorers, and the great respect and admiration demonstrated by our international friends.
As the deputy administrator, I have been privileged to have a front row seat for some of our agency's greatest successes, including the unstoppable Mars Exploration Rovers, the Cassini-Huygens Saturn Mission, Deep Impact and the flight of the X-43A scramjet-powered research vehicles. I will always be amazed by the images we've received from the Hubble and Spitzer space telescopes. And I know that our Earth will profit from the knowledge gained and insight provided by the Aura and IceSat spacecrafts. Another measure of progress that gives me great pride is the five years of continuous human occupancy we've achieved on the International Space Station. Many said that it would be unachievable. What we will learn from this experience, however, will yield unimagined knowledge necessary for our next human endeavors in space exploration. Sadly, I also recall being at headquarters the day we lost my friends on board the Columbia and nearly 20 years ago serving as capcom when my friends on board the Challenger launched into the heavens. I will never forget these amazing individuals and their contributions to the exploration of the vast universe around us. In taking leave now, I am most gratified to observe the many positive changes taking place throughout the agency with regard to how we work collectively to ensure mission safety, and I'm confident that the NASA team will be able to sustain this vital focus. In my letter of resignation, I personally thanked the President for his confidence in NASA, which will allow this agency to lead the exploration vision, the great adventure that will take the pioneers of the future well beyond low Earth orbit in search of the unknown. This is an adventure that will have a profound impact, not only on our understanding of what's out there, but also, how that understanding will help prepare us for the challenges of the future, no matter what they are. I wish Mike Griffin and his team the best of success as they take on the challenge of implementing the exploration vision. I know they will succeed and do so with tremendous skill and dedication. To all of you who welcomed a young helicopter pilot turned test pilot into the fold back in 1974, supported me and my crewmates on three incredible shuttle missions, and extended to my wife Barbara and me your warm friendship and hospitality throughout the years, you have my deepest gratitude. From the bottom of my heart thank you and Godspeed to the good people of NASA. Fred GregoryNASA Deputy Administrator
Intense Solar Flaring Continues
Active sunspot complex 10808 (also known as Region 808) continues to impress. It is now more fully in-view and is presenting itself as a very large sunspot complex that will (if its present size persists) be visible to the unaided (protected) eye over the next week to 10 days. Aside from the very large class X17 flare reported in the last Astroalert, it has managed to produce two additional major flares: a class X5 and a smaller class X1 within six hours of each other (the X5 occurred at 21:06 UTC [5:06 pm EDT] on 8 September, and the X1 occurred at 03:00 UTC on 9 September [11 pm EDT on 8 September]).
Region 10808 appears to be a magnetically complex monster, with at least one very probable strong delta magnetic configuration visible (opposite polarity umbrae located within a single penumbra). Such configurations are inherently less stable and are often associated with energetic solar flares. There is obvious strong magnetic shear visible in solar images of this region at various wavelengths that are undoubtably contributing to the energetic events. No significant change has been observed in the sunspot complex during the last 24 hours. Granted, it would be difficult to discern significant changes given its close proximity to the solar limb, but there is sufficient data available now to suggest that additional very strong solar flare activity will likely persist in the form of moderate to strong X-class events.
These recent events (the three X-class flares observed thus far) have elevated the population of energetic protons in the near-Earth space environment to levels that are now roughly 100 times more dense than normal background levels. Energetic protons are being redirected by the Earth's magnetic field toward the polar ionospheres, where they are bombarding and ionizing the polar ionosphere to levels sufficient to produce a phenomenon known as Polar Cap Absorption (or PCA). PCA is not harmful to human health, but can be dissasterous to high-frequency radio communications through the polar regions. Such radio signals are normally bounced off the lower side of the ionosphere and are returned back to the Earth, permitting long-distance radio communications to take place. But the energetic protons have ionized the lower ionospheric layers to levels capable of absorbing most radio signals that attempt to pass through that region. As a result, for large regions of the Earth where radio paths traverse the high and polar latitudes, a radio blackout is currently in effect.
Additional strong solar flare activity could significantly elevate proton populations over and above what is currently being observed, during the next two weeks. This could prove to be hazardous to the health of spacecraft in orbit around the Earth. Indeed, it is possible for vulnerable spacecraft to become crippled or even irrevocably lost. It is also possible that spacecraft reliant upon solar arrays for power may observe permanent degradations in performance. In other words, another effect of strong space radiation is to permanently reduce the efficiency of solar panels, causing a reduction in electrical output and therefore reduced lifetimes.
Space weather storms caused by the high velocity mass that is often ejected from such powerful solar events can also significantly reduce the lifetime of spacecraft through another method as well. During strong storms, the outer reaches of the Earth's atmosphere heats up and bloats outward into space. This bloating effect increases the atmospheric drag on spacecraft in near-Earth orbits and can cause their orbital parameters to change rapidly. Their lifetimes can therefore be reduced simply because the drag reduces their altitude, which can result in early re-entry of the spacecraft back to the Earth.
The intense radio bursts associated with these solar flares can produce interference with antennas that happen to be directed toward the Sun during the bursts. For example, if a strong solar flare occurs when the Sun is just rising and a cellular phone or other radio communications network (wireless internet, etc.) happens to be aligned in the direction of the rising Sun, the intense radio emissions from the Sun may interfere with the communications occurring in the network. This can result in poorer communications performance.
Thus, there are many ways in which Region 10808 may influence our activities here on the Earth during the next two weeks. Of course, this is all dependent upon whether it is capable of retaining its volatile nature. At the present time, this appears to be likely in the short-term. But such strong activity also often results in some stabilization in the sunspot complex, which could help curb future energetic activity.
Solar Terrestrial Dispatch: http://www.spacew.com
NASA Announces Detection Of Most Distant Explosion
NASA is hosting a media teleconference at 2 p.m. EDT, Monday, September 12 to announce the detection of the most distant explosion yet, a gamma-ray burst from the edge of the visible universe.
Scientists detected the burst using NASA's Swift satellite. Several ground-based telescopes, including the international Southern Observatory for Astrophysical Research (SOAR) in Chile, measured the astounding distance as the embers faded. Panelists:
- Kim Weaver, Program Scientist, NASA Headquarters, Washington
- Richard Reichart, assistant professor, Department of Physics and Astronomy, University of North Carolina, Chapel Hill
- Neil Gehrels, Swift principal investigator, NASA's Goddard Space Flight Center, Greenbelt, Md.
- Donald Lamb, professor, Department of Astronomy and Astrophysics, University of Chicago, Chicago Media can participate by calling Dolores Beasley or Erica Hupp at 202/358-1753/1237. The teleconference will be available live on the Web at:
Teleconference LiveFor more information about the Swift mission on the Web, visit: http://swift.nasa.gov
Major Solar Flare
Today, Earth-orbiting satellites detected a major X-class solar flare coming from the sun's eastern limb. The source of the explosion is probably returning sunspot 798, which sparked strong geomagnetic storms in August. Although today's flare was not Earth-directed, explosions later this week could be as the active region turns more and more toward our planet. September, like August, could turn into a good month for auroras.Visit http://Spaceweather.com for images and updates.
Imagery Of NASA's Michoud Assembly Facility Available
The first imagery showing the damage to NASA's Michoud Assembly Facility in New Orleans, La., is available on the Internet and will air during today's NASA TV noon EDT videofile. The Michoud facility manufactures Space Shuttle external fuel tanks.The facility received some damage to its buildings during Hurricane Katrina. First reports suggest none of the External Tanks were significantly damaged by the storm. The images are on the Web, at:
www.nasa.gov/hurricaneFor continental North America, NASA TV is carried on an MPEG-2 digital signal accessed via satellite AMC-6, at 72 degrees west longitude, transponder 17C, 4040 MHz, vertical polarization. A Digital Video Broadcast compliant Integrated Receiver Decoder is required for reception. It's available in Alaska and Hawaii in analog on AMC-7, at 137 degrees west longitude, transponder 18C, at 4060 MHz, horizontal polarization. For information about NASA TV, including complete digital downlink information, visit:
http://www.nasa.gov/ntvFamily members seeking information about NASA employees and others sheltering at Stennis Space Center and Michoud may call: 256/544-4700For Stennis/Michoud updates on the Web, visit:
http://www.nasa.gov/hurricane
Nasa's Durable Spirit Sends Intriguing New Images From Mars
Working atop a range of Martian hills, NASA's Spirit rover is rewarding researchers with tempting scenes filled with evidence of past planet environments.
"When the images came down and we could see horizon all the way around, that was every bit as exhilarating as getting to the top of any mountain I've climbed on Earth," said Chris Leger, a rover planner at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif.
The summit sits 82 meters (269 feet) above the edge of the surrounding plains. It is 106 meters (348 feet) higher than the site where Spirit landed nearly 20 months ago. Spirit and twin rover, Opportunity, successfully completed their three-month prime missions in April 2004. They have inspected dozens of rocks and soil targets since then, continuing their pursuit of geological evidence about formerly wet conditions on Mars.
"Spirit has climbed to the hilltop and looked over the other side, but NASA did not do this just to say we can do it. The Mars rovers are addressing fundamental questions about Martian history and planetary environments," said NASA's Mars Exploration Program Director Doug McCuistion.
The crest of "Husband Hill" offers Spirit's views of possible routes into a basin to the south with apparently layered outcrops. Shortly after Spirit landed, it observed a cluster of seven hills about 3 kilometers (2 miles) east of its landing site. NASA proposed naming the range "Columbia Hills" in tribute to the last crew of Space Shuttle Columbia. The tallest of the hills commemorates Rick Husband, Columbia's commander.
Volcanic rocks covering the plain Spirit crossed on its way to the hills bore evidence of only slight alteration by water. When Spirit reached the base of the hills five months after landing, it immediately began finding rocks with wetter histories.
"This climb was motivated by science," said Steve Squyres of Cornell University, Ithaca, N.Y. Squyres is principal investigator for the rovers' science instruments. "Every time Spirit has gained altitude, we've found different rock types. Also, we're doing what any field geologist would do in an area like this: climbing to a good vantage point for plotting a route," he added. Researchers are viewing possible routes south to apparently layered ledges and to a feature dubbed "home plate," which might be a plateau of older rock or a filled-in crater.
The landing site and the Columbia Hills are within Gusev Crater, a bowl about 150 kilometers (95 miles) in diameter. It was selected for the Spirit mission because the shape of the terrain suggests the crater once held a lake. Volcanic deposits appear to have covered any sign of ancient lakebed geology out on the plain, but scientists say the hills expose older layers that have been lifted and tipped by a meteorite impact or other event.
"We're finding abundant evidence for alteration of rocks in a water environment," said Ray Arvidson of Washington University, St. Louis, Mo. Arvidson is deputy principal investigator for the rovers' science instruments. "What we want to do is figure out which layers were on top of which other layers. To do that it has been helpful to keep climbing for good views of how the layers are tilted to varying degrees. Understanding the sequence of layers is equivalent to having a deep drill core from drilling beneath the plains," he added.
Both Spirit and Opportunity have been extremely successful. Their solar panels are generating plenty of energy thanks to repeated dust-cleaning events. Spirit has driven 4,827 meters (3.00 miles), and Opportunity 5,737 meters (3.56 miles).
JPL manages the Mars Exploration Rover project for NASA's Science Mission Directorate. For images and information about the rovers and their discoveries on the Web, visit:
http://www.nasa.gov/vision/universe/solarsystem/mer_main.htmlFor information about NASA and agency programs on the Internet, visit:
http://www.nasa.gov/home
12-16" Scope and SolarMax Scopes now available
The Telescope Store has been updated and a range of 12" to 16" telescopes (from various manufacturers such as Meade, Vixen, Takahashi, etc.) are now available. The SolarMax line of H-alpha solar telescopes and accessories are also available.
