Plus: The World’s Biggest Rocket, the Majestic Plastic Bag and a U.S. Mood-Swing Map.

NASA Tests World’s Biggest Solid Rocket
Late last month, NASA and aerospace manufacturer ATK Aerospace Systems successfully tested the most powerful solid-fuel rocket engine ever produced, a massive five-segment motor intended to replace the current booster used to launch the space shuttle off its pad.

Known as the DM-2, this rocket is “the most heavily instrumented solid rocket motor in NASA history” and is designed to generate up to 3.6 million lbs. of thrust, according to a release from NASA. Although it resembles earlier rocket booster systems, the DM-2 features numerous motor upgrades, a larger nozzle throat and upgraded insulation and liner.

“For every few degrees the temperature rises, solid propellant burns slightly faster and only through robust ground testing can we understand how material and motor performance is impacted by different operating conditions,” Alex Priskos, first-stage manager for Ares Projects at NASA’s Marshall Space Flight Center, said. “Ground-testing at temperature extremes pushes this system to its limits, which advances our understanding of five-segment solid rocket motor performance.”

Although the rocket performed well under testing, its future remains uncertain, since the 29-year-old space shuttle is scheduled to be retired in 2011. However, “this vehicle — like the Constellation rockets — should lean on shuttle heritage, legislators have said. ATK’s test therefore still has high relevance,” BBC News reports.

Here’s a look at the impressive new rocket engine firing at full power:

Mapping the Country’s Mood
Everyone has their good days and bad days, but does anyone stop to ask how the country itself is feeling? A new study has found a way to track shifting mood patterns across the United States, measuring the disposition of millions of people through social networking tools.

Researchers from Northeastern University studied more than 300 million Twitter messages between September 2006 and August 2009, evaluating each tweet based on the number of positive or negative words it contained, New Scientist explains. The team then calculated average mood scores of all the users living in a state hour by hour, creating a timed series of mood maps.

Here’s a time-lapse video of shifting moods in the U.S., with the size of each county adjusted to reflect the number of Twitter users living there:

No Danger of Extinction for this Species
This summer, California was poised to become the first state to ban single-use plastic bags. Under a bill approved by California’s state Assembly in June, the distribution of single-use plastic shopping bags was to be barred at grocery stores, convenience stores and pharmacies statewide beginning in 2012, and in liquor stores and convenience stores in 2013.

Following a contentious debate over whether the state was going too far in trying to regulate personal choice, however, the California Senate rejected the bill earlier this month.

In this video, from environmental group Heal the Bay, the lifecycle of the majestic plastic bag is shown in its natural habitat.

Top 3 Fictional Inventors
As highlighted by IMT last month, August was National Inventors Month. Eureka was the name of Gizmodo’s celebration of a number of inventors, “from Tesla to Popeil.” But the tech blog also included a roundup of some of the most memorable inventors who themselves were invented. A few of our favorites from Gizmodo’s 10 Greatest Fictional Inventors of All Time:

• Q — “Major Boothroyd, MI6 Quartermaster, Q was responsible for keeping James Bond one laser watch ahead of the bad guys.”
• Doc Brown — The eccentric physicist in the Back to the Future movies invented, among other things, “the flux capacitor, the core component of a machine that allowed Brown to travel through time,” first implemented in a DeLorean.
• Tom Swift — A “precocious teenage tinkerer with little formal education,” this fictional character’s greatest invention was, according to Gizmodo, The Giant Telescope, “a pioneering stargazing device made possible by a rare mineral discovered in a meteorite.”

For the rest of the top 10 list, and for a collection of features celebrating inventors and their creations, check out Gizmodo’s Eureka.

Business Cards for Fictional Companies
Speaking of fiction, Fro Design Co.’s Fernando Reza recently created a fun series of business cards for fictional companies, “a nod to the hard-working men and women who keep our beloved fictional companies going.”

Click image for larger view. Source: Fro Design Co.

Laughing Squid notes that the limited-edition print is “printed on card stock and each card is the standard 3.5 by 2 inch business card, so if you take a pair of scissors to it you could fill a Rolodex.”

Can you name the pop-culture origin of each fictional company?