July 2006 Newsletter

Stockton Astronomical Society

Valley Skies

Valley Skies - July 2006 Issue

Editor's Corner...

Energy and enthusiasm to spare...

This month we're in for another update on the wide-ranging activities at NASA and its affiliates. Robert "Chuck" Marble, our roving Solar System Ambassador from Patterson will be at our July 13 meeting to bring us up to date on all the current goings on in space exploration.

Chuck is one of 470 Solar System Ambassadors throughout the 50 states and Puerto Rico, one of over 70 in California alone. When you read the scope of Chuck's interests and activities, you have to wonder how he finds the time and energy to do it all, but he carries it all off with seemingly boundless enthusiasm.

The program notes on page 1 of the newsletter cover the 'probable' topics for the SAS meeting. However, Chuck usually has something unexpected and up-to-the-minute up his sleeve.

Be ready on the 13th for another of Chuck's signature rapid-fire, high-energy presentations. Welcome back, Chuck!

* * *

The evening of Saturday, July 29 is set for this year's SAS Midsummer Family Potluck Picnic and Star Party. It will be at the same location as last year, the 4,000 ft. heliport off Highway 88. We had a nice size crowd there last year, including many friends and families who don't normally make it to the regular star parties. That's what it's all about...a chance to share the wonders of the night sky with those who wonder where you disappear to on dark Saturday nights!

All the necessary information is on page 3 of the newsletter. Enjoy!

Unfortunately, I'll have to miss this one, since I will be roughing it at Webelos scout camp with my grandson Skyler that weekend, filling in for his Dad who has to work weekends. But I'll be thinking about you. Have a great time.

I'd very much appreciate receiving photos and a brief report about the picnic to put in the September issue.

* * *

Finally, while we're not in the real estate business, members Bernie and Nancy Knoll of Coulterville have opened up a special opportunity that I can't resist passing on to all SAS members...a country home with a 30" telescope included! Bernie and Nancy are looking to move to the Modesto area to be closer to their grandkids.

Sure would be nice to keep that 30" in the club. Check out the details on page 8 of the newsletter.

...Trevor Atkinson

SAS Midsummer Family Potluck Picnic and Star Party - Saturday, July 29th

It's time for our annual summertime high-altitude star party and potluck dinner. We'll meet at around 7 p.m. at the 4000' heliport on Highway 88.

Bring a main dish and salad or dessert to share, as well as beverages for yourself. A two-burner camp cooking stove will be available if anything needs reheating. There will be a table or two for setting out food, but you'll need to bring your own chairs, picnic blankets, etc., for your dining comfort. Please bring serving utensils with your potluck offerings. Plates, napkins and eating utensils will be provided. (And yes, the sani-hut will be there.)

If you feel like bringing camping gear and staying the night, feel free!

But of course bring your telescopes and observing gear, however late you plan to stay. The annual picnic is a time to bring families together, but also a time for you diehard observers to let your families in on the joys of night sky observing.

Questions? Call Becky Greider [see newsletter for phone numbers].

(If the weather is questionable, call Becky or Miguel or check the Web site for last-minute information.)

The Science Directorate at NASA's Marshall Space Flight Center sponsors the Science@NASA web sites. The mission of Science@NASA is to help the public understand how exciting NASA research is and to help NASA scientists fulfill their outreach responsibilities.

Droids on the ISS

June 1, 2006: Six years ago, MIT engineering Professor David Miller showed the movie Star Wars to his students on their first day of class. There's a scene Miller is particularly fond of, the one where Luke Skywalker spars with a floating battle droid. Miller stood up and pointed: "I want you to build me some of those."

So they did. With support from the Department of Defense and NASA, Miller's undergraduates built five working droids. And now, one of them is onboard the International Space Station (ISS).

MIT undergrads flight-test a prototype droid onboard NASA's KC-135 reduced gravity aircraft.
"It only looks like a battle droid," laughs Miller. It's actually a tiny satellite-the first of three NASA plans to send to the ISS. Together, they'll navigate the corridors of the space station, learning how to fly in formation.

Tiny satellites are a hot new idea in space exploration: Instead of launching one big, heavy satellite to do a job, why not launch lots of little ones? They can orbit Earth in tandem, each doing their own small part of the overall mission. If a solar flare zaps one satellite-no problem. The rest can close ranks and carry on. Launch costs are reduced, too, because tiny satellites can hitch a ride inside larger payloads, getting to space almost free of charge.

But there's a problem: Flying in formation is trickier than it sounds. Ask a crowd of people to line up single file, and they'll be able to figure it out and do it rather easily. Getting a group of orbiting satellites to do the same thing, it turns out, is extremely hard.

"Suppose you've got a cluster of satellites in orbit," says Miller, "and one or two of them lose their place." Maybe a solar flare temporarily scrambles their nav-computers, or a thruster firing didn't work as expected. The whole cluster finds itself out of whack. Correcting the problem requires a complex set of 3-dimensional adjustments, coordinated among all the satellites-perhaps dozens or hundreds of them. "We've got to break this down into step-by-step, concrete instructions that a computer can understand," Miller says.

And that takes us back to the ISS:

A CAD-model of a SPHERES satellite.

Miller's challenge to his undergraduate engineering class back in 1999 was to design a small, roughly spherical robot that could float aboard the ISS and maneuver using compressed CO₂ thrusters. The project, called SPHERES (Synchronized Position Hold Engage Re-orient Experimental Satellite), would serve as a testbed for trying out experimental software to control clusters of satellites. The robotic spheres provide a generic platform consisting of sensors, thrusters, communications and a microprocessor; scientists working on new software ideas can load their software into that platform to see how well those ideas work. It's a quick and relatively cheap way to test new theories on software design.

Possible applications include NASA's return to the Moon. One way to build a moonship is to assemble it piece by piece in Earth orbit. "Software designed to control small satellites could just as well be used to maneuver the pieces of a spaceship together," says Miller.

The first SPHERE arrived on the ISS in April tucked inside a Progress supply rocket. (Remember, tiny satellites make good hitchhikers.) Eventually two more SPHERES will join it, one later this year when the space shuttle Discovery (STS-121) returns to the station, and another carried to orbit by a future shuttle mission.

How will astronauts tell the three SPHERES apart? "They're color coded," explains Miller. The one onboard now is red; the second will be blue and the third yellow.

"Red" is already busy. "We've commanded it to do a variety of maneuvers-loops and turns, for instance. And we've tested the robot's ability to solve problems." Astronauts tried to trick Red by causing one of its thrusters to stick "on." The robot diagnosed the fault, turned the thruster off, and returned to station-keeping.

"Not bad for one little droid," says Miller. "I can't wait to see what three of them can do."

Authors: Dr. Tony Phillips and Patrick L. Barry | Production Editor: Dr. Tony Phillips | Credit: Science@NASA

From Thunderstorms to Solar Storms...

by Patrick L. Barry

When severe weather occurs, there's a world of difference for people on the ground between a storm that's overhead and one that's several kilometers away. Yet current geostationary weather satellites can be as much as 3 km off in pinpointing the true locations of storms.

A new generation of weather satellites will boost this accuracy by 2 to 4 times. The first in this new installment of NOAA's Geostationary Operational Environmental Satellites series, called GOES-N, was launched May 24 by NASA and Boeing for NOAA (National Oceanic and Atmospheric Administration). (A new polar-orbiting weather satellite, NOAA-18, was launched May 2005.)

New GOES-N satellite launches, carrying an imaging radiometer, an atmospheric sounder, and a collection of other space environment monitoring instruments.

Along with better accuracy at pinpointing storms, GOES-N sports a raft of improvements that will enhance our ability to monitor the weather-both normal, atmospheric weather and "space weather."

"Satellites eventually wear out or get low on fuel, so we've got to launch new weather satellites every few years if we want to keep up the continuous eye on weather that NOAA has maintained for more than 30 years now," says Thomas Wrublewski, liaison officer for NOAA at NASA's Goddard Space Flight Center.

Currently, GOES-N is in a "parking" orbit at 90° west longitude over the equator. For the next 6 months it will remain there while NASA thoroughly tests all its systems. If all goes well, it will someday replace one of the two active GOES satellites-either the eastern satellite (75°W) or the western one (135°W), depending on the condition of those satellites at the time.

Unlike all previous GOES satellites, GOES-N carries star trackers aboard to precisely determine its orientation in space. Also for the first time, the storm-tracking instruments have been mounted to an "optical bench," which is a very stable platform that resists thermal warping. These two improvements will let scientists say with 2 to 4 times greater accuracy exactly where storms are located.

Also, X-ray images of the Sun taken by GOES-N will be about twice as sharp as before. The new Solar X-ray Imager (SXI) will also automatically identify solar flares as they happen, instead of waiting for a scientist on the ground to analyze the images. Flares affect space weather, triggering geomagnetic storms that can damage communications satellites and even knock out city power grids. The improved imaging and detection of solar flares by GOES-N will allow for earlier warnings.

So for thunderstorms and solar storms alike, GOES-N will be an even sharper eye in the sky.

Find out more about GOES-N at goespoes.gsfc.nasa.gov/goes. Also, for young people, the SciJinks Weather Laboratory at scijinks.nasa.gov now includes a printable booklet titled "How Do You Make a Weather Satellite?" Just click on Technology.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Jupiter's Great Red Spot has Competition

Here's the Hubble image of Jupiter's two red spots.

According to the August issue of Sky & Telescope, the new spot was white until it suddenly changed to red in February. Since the two storms are in cloud bands moving in opposite directions, they are expected to pass close by each other sometime in July.

Rich Combs at the June 8 Meeting

Photo by Paul Neidhamer

Jim and Emelia Seiferling (foreground), were among those treated to an informative and entertaining program by Rich Combs. An optical engineer at Lawrence Livermore National Lab. for the last 25 years, Rich has used his knowledge of optics to help many amateur astronomers to build and understand telescopes.

His presentation provided a quick overview of the history of telescope making, fundamentals of design, and a brief hands-on demonstration of the mirror-grinding technique. He presented the 6" mirror blank and tool to a lucky young boy who, with his mother, was a first-time visitor to an SAS meeting. A generous gesture that may just spark another addition to the ranks of amateur astronomy-or, who knows...maybe another astronaut.

Thanks Rich.