Wednesday, April 25, 2012

Dawn Reveals




Four and a half years ago a Delta II rocket arced high over Florida, carrying what has proven to be one of the most fantastic unmanned explorers ever launched from our planet: Dawn.



September 27, 2007: As the sun rises, Dawn is carried aloft by a Delta II rocket at pad 17-B, Cape Canaveral Air Force Station.


Dawn’s mission is to explore the asteroid belt, with particular focus on two objects: the asteroid Vesta, and the so-called “minor planet” Ceres. Vesta’s dimensions are roughly 359 by 348 by 285 miles, while Ceres is much larger: nearly as big across as the state of Texas, and an object that may bear a weak atmosphere. Both objects are believed to have formed early in the inception of our solar system. Despite that similarity, the objects are vastly different entities – the very reason they were selected for exploration.


In this artist concept, Dawn is shown traveling among the asteroids. Each of the solar panels providing power measures 8 feet by 27 feet.


While Ceres will fall under Dawn’s gaze in 2015, the explorer arrived at Vesta in the middle of 2011, and has been hard at work ever since. On April 25, some of Dawn’s intriguing findings were presented by NASA’s Jet Propulsion Laboratory in Pasadena, CA.



NASA's Dawn spacecraft approaches orbit around the giant asteroid Vesta on July 24, 2011. This photo was taken from a distance of about 3,200 miles.



The surface of Vesta contains a wide variety of composition and patterns – including material that was at one time molten and beneath the asteroid’s surface. There are rocks apparently fused by collisions encountered in the asteroid’s travels, as well as smooth surface areas described by JPL scientists as “pond-like.”
Vesta is a frigid asteroid, with Dawn measuring temperatures ranging from minus 10 to minus 150 Fahrenheit – demonstrating how much of a role illumination from the sun can alter temperatures without atmospheric considerations.

 
A relatively new crater spreads approximately nine miles across the surface of Vesta. Boulders and other debris around the crater are believed to have originated deep beneath the asteroid’s surface, cast outward upon impact with the object that created this large surface scar.



So what’s next for Dawn? The explorer will continue work at Vesta, swooping to within 130 miles of the asteroid’s surface, until August 26. Then it’s off to Ceres, with arrival planned for February, 2015.
For more on Dawn and the incredible scientific discoveries being revealed by this vehicle, please visit NASA’s mission page at:  http://www.nasa.gov/dawn








Sunday, April 22, 2012

It Figures: Enterprise in Holding Pattern



UPDATE 4/24/2012:


NASA has announced the flight of Enterprise on board the NASA 905 Shuttle Carrier Aircraft is now scheduled for Friday morning, with the orbiter arriving in the New York area at approximately 10AM. Please refer to the link below for continuing updates.




UPDATE 4/23/2012:

NASA has announced the flight of Enterprise on board the NASA 905 Shuttle Carrier Aircraft is now scheduled for Wednesday morning, with the orbiter arriving in the New York area at approximately 10AM. Please visit the Intrepid Sea, Air and Space Museum web site for confirmation and scheduling announcements:




ORIGINAL POST CONTENT:


Going to see a space shuttle in action at Kennedy Space Center could be easier said than done during the program’s decades-long service life. Equipment failures during the countdown could lead to lengthy delays. Bad weather at the KSC Shuttle Landing Facility could lead to a last-minute diversion to a California landing.

Back in the days before everything was available for instant updating via the Internet, the main method of keeping up to date on shuttle launch preparations was to call a special number which allowed one to listen to a recording of George Diller reporting on the latest developments. I called this number so many times it’s permanently ingrained in my memory: 407-867-2525.

But in the years before cell phones were common you couldn’t just call the info line while cruising down I-95 toward Florida. I recall one depressing launch journey pit stop at South of the Border in South Carolina, where I happened to hear a news broadcast reporting the launch had been scrubbed due to a major component replacement that could take weeks. Reverse course.


Welcome to the moment of truth.


But perhaps nothing was worse was than the pit-in-the-stomach feeling as the countdown clock ticked down to 31 seconds - perhaps the most significant moment of each countdown, when the Ground Launch Sequencer would hand over control of the countdown to the shuttle’s onboard computers. Several times I stood in the Florida sun and watched that clock come to a halt just a half minute from launch. Sometimes the resulting delay was brief; other times, the launch was pushed back by a week or more. After all, changing out an Auxiliary Power Unit deep within the innards of an orbiter was no small task.

Even the charmed final flight of the shuttle program had its moment. As Atlantis waited on the pad, poised to begin the STS-135 mission, the clock crept toward the dreaded 31 second mark. Then it hit 30. Then it climbed back up to 31! Mercifully, the resulting delay was one of moments rather than days, and soon Atlantis was thundering uphill for one final time.

These thoughts all came to mind this week as Discovery made her way to a new home in the Washington D.C. area, and the original flight test orbiter Enterprise was prepared for a journey to New York.


Enterprise: ready to depart, just not yet.


I had planned on attending Discovery’s arrival, but family medical issues disrupted that plan. Instead, I made plans to cover the arrival of Enterprise in New York on April 23. I would be witnessing a significant reunion: the Shuttle Carrier Aircraft that will lift Enterprise into the skies one last time is the same plane that carried this first orbiter into the air for the very first atmospheric flight tests back in 1977.

And then, on April 20, came the Media Advisory from NASA:

WASHINGTON -- NASA's planned flight to New York City of space shuttle Enterprise atop the 747 Shuttle Carrier Aircraft (SCA) has been postponed until further notice due to an unfavorable weather forecast for Monday, April 23.


File this under "unfavorable conditions."


Somehow, it seems appropriate. This will likely be the last time I will ever see a space shuttle in flight, even if it is attached to a modified Boeing 747. A shuttle-related delay? I’d expect nothing less. But I also know that - as always - the wait will be worth it.