Astronotes: August 22 - September 4, 2004

September 3

CubeSats: Opening up Orbital Space

Over a dozen tiny satellites built by various universities from several countries are being readied for launch on a booster initially built to toss nuclear warheads across intercontinental distances.

The miniature spacecraft are known as CubeSats. As the name implies, these satellites are small. Measuring 4-inches (10 centimeters) on a side, the high-tech space cubes each weigh all of a couple pounds (1 kilogram).

A Russian Dnepr rocket will eject the small satellites into Earth orbit. The launch is now being eyed for year's end. The Dnepr is a booster-for-hire offered by ISC Kosmotras and is a converted SS-18 ICBM that will depart from a silo at the Baikonur Cosmodrome in Kazakhstan.

Robert Twiggs of Stanford University spearheaded the CubeSat concept. The idea is catching on as classrooms around the globe rendezvous with real world problems in space engineering and packing high-tech gear into a small volume.

Students at California Polytechnic State University (CalPoly) in San Luis Obispo have designed a CubeSat deployment system known as P-POD. That stands for Poly Pico-satellite Orbital Deployer.

Several of the P-POD devices -- each stuffed with multiple CubeSats -- will be flown atop the Dnepr rocket and eject the small spacecraft into Earth orbit.

-- Leonard David

September 1

Hot News! Genesis to Double as Artificial Meteor

When NASA's Genesis sample return capsule dives in over Utah from interplanetary space next week, a group of scientists will view the fiery fall in a different light: As an artificial meteor.

Researchers from NASA's Ames Research Center and the SETI Institute, located in California's Silicon Valley, expect to obtain the most detailed look at a hypervelocity reentry.

The September 8 comeback of Genesis is to be witnessed by scientists flying aboard the U.S. Air Force's Flying Infrared Signatures Technologies Aircraft (FISTA).

From their front row seat flying at 39,000 feet altitude, specialists will use an array of instruments to record the Genesis reentry, taking measurements in ultraviolet, infrared and visible-light.

During its plunge through the atmosphere, the Genesis sample return capsule will turn briefly into a bright meteor over Oregon and Nevada. The capsule will experience peak heating conditions as it decelerates near the Oregon/Nevada border en route to Utah.

According to Paul Wercinski, the Genesis observation campaign project manager at NASA Ames: "This is a unique opportunity to study the physics of re-entry up close and assess the effectiveness of thermal protection systems for re-entry vehicles. What we learn from Genesis will be useful for those future missions."

There's another ballistic bonus to the Genesis reentry. The sample return capsule is an analog to meter-sized asteroids that deposit organic material in Earth's atmosphere. The return of the Genesis capsule is like a meteor on queue, giving scientists a unique opportunity to study what happens during the re-entry process.

"We are interested in the physical and chemical conditions in the shockwave that can change the organic material in asteroids into pre-biotic molecules for life's origins," added Peter Jenniskens of the SETI Institute.

-- Leonard David

August 31

Tiny Timepiece

Time marches on...and with a new atomic clock they're tiny steps that lead to big payoffs.

The heart of a minuscule atomic clock has been fabricated, believed to be 100 times smaller than any other atomic clock.

Here's the sweep hand of progress: First of all, the clock's inner workings are about the size of a grain of rice (1.5 millimeters on a side and 4 millimeters high). They consume less than 75 thousandths of a watt, enabling the clock to be operated on batteries. Lastly, the inner workings are stable to one part in 10 billion - equivalent to gaining or losing just one second every 300 years.

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The development opens the door to atomically precise timekeeping in portable, battery-powered devices for secure wireless communications, more precise navigation and other applications. For instance, in Global Positioning System (GPS) satellite receivers, small clocks could improve the precision of satellite-based navigation systems such as those used in commercial and military vehicles and emergency response networks.

In addition, this "physics package" could be fabricated and assembled on semiconductor wafers using existing techniques for making micro-electro-mechanical systems (MEMS), offering the potential for low-cost mass production of an atomic clock about the size of a computer chip and permitting easy integration with other electronics. Eventually, the physics package will be integrated with an external oscillator and control circuitry into a finished clock about 1 cubic centimeter in size.

Scientists at the Commerce Department's National Institute of Standards and Technology (NIST) made the announcement, describing the work in the August 30 issue of Applied Physics Letters. The work was supported by NIST and the Defense Advanced Research Projects Agency (DARPA).

-- Leonard David

August 30

Space Elevator: Climbers Wanted!

Step right up. See if you can make the grade - straight up.

The Spaceward Foundation of Mountain View, California is organizing through their Elevator: 2010 project the first annual climber competition.

A climber is a key piece of hardware needed to build an Earth-to-space elevator. This automated machinery is primarily designed to haul up ribbon material to complete the super-structure.

Competing teams would provide climber designs that have to use power beamed to them in order to scale a ribbon while carrying some amount of payload. Climbers will be rated according to their speed and the amount of payload they carried.

The competition provides the racetrack, in the form of a crane-suspended vertical ribbon, and a strong light source to power the climbers.

"The event will be held in May-June 2005, in a yet to be determined San Francisco Bay Area location," according to Meekk Shelef, Manager of the Spaceward Foundation. Sponsors for the event are welcome, with NASA already expressing interest and support for the effort.

Building a climber is not an easy task. The designers have to juggle lightweight structure, efficient light-soaking and power-generating arrays, economical motors and electronics, low-loss traction mechanisms, as well as thermal management and control systems.

"Not a walk in the park, but we'll make it worth your while. We will be offering $50,000, $20,000 and $10,000 to the 3 best teams," explains promotional material on the competition.

For more information:

http://www.elevator2010.org/site/index.html

-- Leonard David

August 25

Hands-on Satellite Teaching Tool

There is nothing like hands-on practice before the satellite you're running is out of reach, orbiting high above Earth.

And that is where the EyasSAT ™ Educational Satellite System comes in -- a working satellite model perfect for a classroom setting.

Originally developed for use in the Astronautics Department at the U.S. Air Force Academy in Colorado Springs, Colorado, EyasSAT is a set of circuit boards that plug together to form a complete satellite. Each board or module functions as a satellite sub-system. Add among other items a case with separation switch, a couple of solar panels, antenna port, position sensors, reaction wheel, light sensors and a thermal control surface - now you've got yourself a complete satellite ideal for in-the-lab learning.

Nearly 35 EyasSATs are out in classrooms explained Jim White, head of Colorado Satellite Services in Parker, Colorado. He worked with the Air Force Academy under a cooperative agreement to hammer out the EyasSAT idea and supportive educational materials.

Paper design studies of building a spacecraft are one thing...actually working with hardware is another, White said. "Students using EyasSat come away with a broad understanding of all of the systems on satellites, and how those systems work together to perform a mission," he told SPACE.com .

White said better and more prepared space engineers are needed in the workforce, individuals that can get up to speed quicker and become productive faster -- a key ambition behind the effort. EyasSAT technical details and costs are available at: www.eyassat.com

-- Leonard David

August 23

Home Depot on Mars

It appears that tossing rocks around and living in glass houses on Mars may be a perfect mix. University of Missouri-Rolla (UMR) scientists are studying ways to house future astronauts on Mars by utilizing Martian minerals as building materials. And while research work is underway here on Earth, that dynamic duo of Mars rovers -- Spirit and Opportunity -- are not only relaying key science data, they are also helping to catalog the raw materials available for construction workers on the red planet. For long stays, not only on Mars but the Moon too, using local resources is important, explains Delbert Day, Curators' Professor emeritus of ceramic engineering at UMR. "Astronauts can stay in the landing vehicle for a short time, but eventually we'll need to construct some type of structure for people to stay in." Day and Chandra Ray, research professor of ceramic engineering at the Graduate Center for Materials Research at UMR, are examining the properties of glass formed by melting simulated Martian soil. "You can think of it as making concrete without cement," Day explains. "You would gather up Martian soil and rocks and then glue them together with glass, rather than cement. A solar furnace could be the source of heat to melt the material." What remains unknown is how the lower gravity field would affect the process of forming glass. Day and Ray have conducted glass-melting research for more than 20 years, including space shuttle experiments. Testing their ideas on the International Space Station is also being planned. The surprising result from early experiments was that when melts in space were cooled, they tended to form glass easier than what they did on Earth. Ray is currently studying the properties of simulated Martian soils using an electrostatic levitator at NASA's Marshall Space Flight Center in Alabama . An electrostatic levitator uses an electrical field between two electrodes to hold the levitated sample in place. Lasers then zap the material, heating it and turning that material into a floating molten sphere that can later cool without ever touching a container. "We take advantage of gravity in a lot of the processing that we do with glass on Earth, such as removing gas bubbles. But the gravity on Mars is 60 percent less than it is on Earth, so we need to know how differences in gravity might affect the way glass can be processed on other planets," Day concludes. Using local resources "is one of the important challenges to be met in establishing a permanent presence on any planet," he adds. -- Leonard David

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