is NASA’s first planetary mission with instruments fully dedicated to education and public outreach.While the twin GRAIL satellites orbited the Moon to learn more about its gravity and interior composition, MoonKAM gave students a unique opportunity to snap their own images of the Moon’s surface using cameras on board the spacecraft.The GRAIL satellites captured thousands of images during their yearlong mission. 
 
 
 
 Browse the MoonKAM image gallery ||||| NASA is going back to the moon once again, sending a pair of spacecraft on a quest to learn the origins of our closest companion by studying its interior and its gravitational field. But beyond new lunar science, the Gravity Recovery and Interior Laboratory, GRAIL, will also help cement NASA's legacy of lunar exploration in the public imagination. 
 
 GRAIL A and its twin GRAIL B are set to launch Thursday morning aboard a Delta II rocket from Cape Canaveral Air Force Station. The launch window opens at 8:37 a.m. EDT, although weather looks pretty iffy for the next couple days, according to NASA. Once they arrive at the moon, the two washing machine-sized probes will fly in formation, with instruments sensitive enough to detect a hair's breadth separation. Along with those gravity-mapping instruments, GRAIL will carry something called MoonKAM — "Moon Knowledge Acquired by Middle school students." 
 
 Logging in from schools around the country, students will be able to virtually coast a few miles above the surface of the moon, scanning the pallid dirt for craters or perhaps an open plain that might someday make a nice lunar homestead. Students can select target areas by studying topographic maps on the MoonKAM website, and send them to NASA's MoonKAM operations center. The images will be fairly high-resolution, but they won't approach the abilities of the Lunar Reconnaissance Orbiter, which took the snapshots we saw this week of Apollo landing sites. But that's not the point, said Maria Zuber, a professor of geophysics at MIT and the mission's lead investigator. 
 
 "If a student takes an image of the surface, it's really a transformative experience. You can bet that a smart kid will take the time to sit down and figure out how to use this software," she said in an interview. 
 
 Each spacecraft will carry a digital camera setup with four camera heads, one pointed ahead, two pointed below and one pointed behind the spacecraft's trajectory. They can capture video and still images up to 30 fps, and downlink them to the project's control center at the University of California-San Diego. The program is a partnership with Sally Ride Science, a company founded by Ride, the first American woman in space. 
 
 Zuber and the other mission scientists, many of whom have kids and grandkids, hope the moon images will inspire a new generation of lunar scientists — who will understand, as they have, that the history of the moon is crucial for understanding the history of Earth. 
 
 With its perennially unchanging mountains and craters, the moon is a good proxy for the early Earth, Zuber said. Understanding how it formed could shed some light on the geologic processes behind Earth's formation, and that of the other terrestrial planets. Just last month, researchers from the University of California-Santa Cruz said the moon may have once had a smaller sibling that it absorbed after a collision. Grail will shed some light on this question, as well as explain whether the moon has a molten core, which will provide some more information about how it coalesced. 
 
 Zuber said Grail will solve a few pieces of the larger lunar puzzle. 
 
 "If you think about your family and friends and the people you know best, if you just see what they're like on the outside, you don't really know them," she said. "If you really want to know them, you want to understand what's inside of them, and that tells you what they're all about." ||||| This still from a NASA broadcast shows the Delta 2 rocket carrying NASA's twin Grail moon gravity probes on Sept. 10, just one hour away from a morning launch attempt - the second liftoff try for the mission. 
 
 After two days of delay caused by bad weather and a technical glitch, NASA is once again ready to launch two probes toward the moon to unlock the secrets of lunar gravity. 
 
 The twin Grail spacecraft are expected to launch from Florida's Cape Canaveral Air Force Station today (Sept. 10) at 8:29 a.m. EDT (1229 GMT), with a second opportunity available at 9:08 a.m. EDT (1308 GMT), if needed, NASA officials said. 
 
 The $496 million moon probes were initially slated to launch atop their unmanned Delta 2 rocket on Thursday (Sept. 8), but unacceptable high-altitude winds forced NASA to delay the liftoff. 
 
 Another chance on Friday was called off to give engineers time to assess the rocket's propulsion system after a potential glitch was detected.After a series of reviews, the team concluded that there are no issues with the rocket or its propulsion system, NASA officials said. [Photos of NASA's Grail Moon Gravity Mission] 
 
 Today's weather forecast is more optimistic, and current predictions show a 60 percent chance of acceptable conditions at the time of launch, agency officials said. 
 
 NASA has specific limits for acceptable launch weather conditions, with high winds, rain, thunder and lightning all present potential safety risks. For example, high upper level winds can affect the way rockets fly through Earth's upper atmosphere as they blast into orbit. 
 
 The agency will closely monitor weather conditions overnight in preparation for tomorrow's attempt. The Grail mission (whose name is short for Gravity Recovery and Interior Laboratory) has a 42-day launch window that extends through Oct. 19, officials have said. [Video: Grail's Mission to Map Moon Gravity] 
 
 Infographic shows how GRAIL mission maps the moon's gravity field Credit: Karl Tate, SPACE.com 
 
 The twin Grail spacecraft, called Grail-A and Grail-B, will closely examine the composition of the lunar interior, and will make detailed and precise maps of the moon's gravitational field. The three-month mission is expected to help scientists solve mysteries of the moon's origin and its evolution since the natural satellite was formed 4.6 billion years ago. 
 
 Researchers are also hoping to use Grail's observations to better understand how other large, rocky bodies in the inner solar system were formed. 
 
 You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcomand on Facebook.
– NASA's not done with the moon yet. It launched two unmanned spacecraft today (Grail A and Grail B) to study the lunar gravitational field and interior, reports Space.com. The $496 million mission has an interesting twist, notes the PopSci blog: a MoonKAM that will allow students to log in, scan the moon's surface, and request particular images for study. The two probes, which lifted off aboard a Delta 2 rocket shortly after 9am EDT, aren't expected to be in place until the end of the year. (If you like your moon missions with astronauts, click here for newly released images of the Apollo era.)