As NASA engineers ponder how the shuttle Endeavor's gaseous hydrogen venting system started leaking and delayed the spacecraft's launch, the agency said it will try to put the shuttle in orbit on Wednesday at 5:40 a.m. ET. The shuttle's problems likewise push the launch of the moon-probing Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) back at least one day, to Thursday, June 18.

NASA believes a seal on the external fuel tank that was misaligned when it was coupled to one of the shuttle's engines caused the leak, NASA Shuttle Test Director Stephen Payne, said today during a press conference. "Our teams have been working very hard over the last couple of days to get this piece of equipment fixed," he said, adding, however, that the space agency was unsure of what's causing the misalignment.

Nearly a decade ago, Leik Myrabo shared with Scientific American readers his vision for the future of space travel: a "LightCraft" pushed out to the stars by a pulsed infrared laser beam from the ground or pulled into space by a laser beamed down from a solar-powered station orbiting Earth. (Read the article here.) Myrabo, an associate professor of engineering physics at Rensselaer Polytechnic Institute in Troy, N.Y., described in his April 1999 article a grand plan for constructing these orbital stations and a beamed-energy craft that could transport passengers out to space.

Ten years—and reportedly 140 test flights using small prototypes—later, he foresees laser flight carrying people around the globe and into space by 2020, Wired.com reported from "Expanding the Vision of Sustainable Mobility," a conference hosted last week by the Art Center College of Design in Pasadena, Calif. For this scenario, ground-based lasers called LightPorts would provide the energy needed to propel the crafts, although Myrabo acknowledges that this won't become viable until more powerful lasers are developed and jet fuel becomes expensive enough to force the aviation industry to search for an alternative.

Think garbage is a problem on the ground? Out-of-this-world solutions may be needed to get rid of the growing swarm of space trash, including debris from last week's smashup between a Russian and a U.S. satellite.

That's the word from this week's meeting of the United Nations Committee on the Peaceful Uses of Outer Space, the Associated Press reports. Among the possible remedies floating around the Vienna confab: giving orbital debris parachute-like balloons that would increase their atmospheric drag and pull them back to Earth faster or attaching a 10-mile (16-kilometer) electrodynamic tether to a piece of circling junk that would allow technicians to control its descent.

Just how special is your intelligence? If you're a unique kind of smarty-pants, you can go to Singularity University, a program launched this week with the lofty intention of tackling "humanity's grand challenges."

Peter Diamandis, a promoter of personal space flight, got the idea while reading Raymond Kurzweil's 2005 book The Singularity Is Near, which discusses the merging and rapidly advancing areas of bio, nano and information technology. Singularity's students — world leaders and CEOs, its founders hope (perhaps appropriately, given the $25,000 tuition for nine weeks of study) — will contemplate those heavy subjects and how they can be used to improve, not harm, humanity.

Iran says it launched a satellite last night as part of what officials there described as the country’s bid to develop a space program.

The satellite, named Omid, or “hope,” was “successfully sent into orbit” with a Safir 2 (or "ambassador") rocket, according to IRNA, Iran’s official news agency. The “data-processing” satellite project began nearly four years ago “as the first practical step toward acquiring national space technology,” says another IRNA report, noting that “its main objective is to prepare the grounds for promoting [a] national space industry in Iran.”

Take a deep breath: there's now a satellite monitoring how much greenhouse gas we're expelling into Earth's atmosphere.

"Ibuki"—"breath" in Japanese—was launched into the cosmos today from Tanegashima, a remote island in the southern part of the country. As it circles the planet every 100 minutes for the next five years, Ibuki will collect information about carbon dioxide (CO₂) and methane (the crucial culprits in rising temperatures on Earth) that will provide insight into global warming.

"Global warming is one of the most pressing issues facing the international community, and Japan is fully committed to reducing CO₂," Yasushi Tadami, who's working on the project for Japan's Environment Ministry, told the Associated Press. "The advantage of Ibuki is that it can monitor the density of CO₂ and methane gas anywhere in the world."

The Indian space probe Chandrayaan 1 adjusted its orbit around the moon in one of its final maneuvers before releasing a lunar impactor.

Chandrayaan 1 entered into an elliptical orbit around the moon on Saturday, 17 days after blasting off from Satish Dhawan Space Center in Sriharikota. Yesterday, it fired up its engine to lower its orbit, which now ranges from a high point of about 4,660 miles (7,500 kilometers) to a low point above the lunar surface of 120 miles (200 kilometers). It is now orbiting the moon about every 10 and a half hours.

The Indian Space Research Organization (ISRO), which leads the unmanned mission, says they plan to circularize Chandrayaan 1's polar orbit to about 60-mile (100-kilometer) altitude before dropping its Moon Impact Probe and booting up its scientific instruments.

In 2011 NASA’s MESSENGER spacecraft will insert itself into Mercury’s orbit, ending a nearly seven-year journey spanning billions of miles. The real work begins, though, once MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) settles in as Mercury’s lone satellite and provides the first prolonged look at the dense little planet. Until that time, planetary scientists have to settle for tantalizing but fleeting glimpses of Mercury from MESSENGER’s three flybys, the second of which took place on October 6.

Some of the results of that up-close peek were announced at a NASA news conference today, providing a taste of what revelations will come once MESSENGER takes up residence in Mercury’s orbit. (The flybys are gravity-assist procedures to bring MESSENGER’s trajectory into line for the future orbit insertion; any scientific data collected during them are icing on the cake.) Relatively little is known about the planet, because its proximity to the sun largely precludes ground-based study; before MESSENGER’s first pass, less than half the planet had even been imaged.

China's Shenzhou 7 spacecraft is in Earth orbit, carrying a three–astronaut crew, one of whom is expected to make that country's first spacewalk this weekend.

The rocket took off from Jiuquan Satellite Launch Center in Ganzhou Province in Western China at 9:10 P.M. today (9:10 A.M. Eastern time), the country's third manned trip in the last five years. Its first manned mission was in 2003, and the second, two years later.

Although citizens of at least three-dozen nations have traveled into the cosmos on international missions, just three countries—the U.S., Russia and, in the last five years, China—have sent humans into space using their own spacecraft.

Of course he already thought he was, but millennia from now, when whatever life form looks back on humanity, Stephen Colbert will be the Homo sapiens prototype.

Colbert, 44 , Comedy Central's mock-conservative newsman, is sending his DNA to the International Space Station next month in an attempt to stave off human extinction.  No joke.

"I am thrilled to have my DNA shot into space, as this brings me one step closer to my life-long dream of being the baby at the end of [the 1968 classic sci-fi film] 2001," Colbert quipped in a news release.