Planetary scientists looking for water ice on Mars have employed a number of tactics to great success in their search. The Phoenix lander dug it up; orbiting radar measurements have seen it under insulating blankets of debris. (Frozen water sublimates to vapor in Mars's climate and so is not stable when exposed at the surface.)

Now a team of researchers has let meteorite impacts do the digging for them—a paper in this week's Science presents observations of fresh impacts and what they turn up from below the surface.

Using instruments on NASA's Mars Reconnaissance Orbiter (MRO), a group led by Shane Byrne, a planetary scientist at the University of Arizona's Lunar and Planetary Laboratory, found five recent impact craters in the Martian mid-latitudes, near the boundary where subsurface ice is thought to be no longer tenable. All were relatively small, ranging in size from about four to 12 meters across.

The Lunar Reconnaissance Orbiter (LRO), launched in June to survey the moon with an eye toward a human return there, is already hard at work. At a news conference from the Goddard Space Flight Center in Greenbelt, Md., NASA presented preliminary results from the spacecraft's instruments, which have just finished a transition from the commissioning to operational phases.

In its one-year primary mission, LRO will seek to map the moon in great detail, measure the radiation that human tissue would be subjected to during a lengthy lunar stay, and search for traces of water ice on the lunar surface. Water would be an invaluable resource for future lunar explorers—astronauts could save enormous amounts of launch weight if they did not have to carry their own water supply.

One of NASA's moon probes, the Lunar Crater Observation and Sensing Satellite (LCROSS), will complete a relatively simple mission next month: releasing a spent rocket stage toward a shadowy crater, then following it to see what the impact stirs up before crashing the mother ship itself into the crater. All the while, Earth-based and orbiting telescopes will be watching, looking for any evidence of water ice that might be hidden in the crater's depths.

Today, NASA unveiled its target of choice for LCROSS's double impact on October 9: a south-polar crater known as Cabeus A. The 48-kilometer-wide crater is named for 17th-century Italian astronomer Niccolo Cabeo. According to NASA, Cabeus A was chosen both for its potential for harboring water ice and for its location, which will allow Earth observers to track the plumes thrown up by the LCROSS impacts. For a fuller description of the LCROSS mission, see our coverage from June, just before the spacecraft launched.

It hasn't been the best of times for NASA in recent days. Not only is a presidential panel warning that the space agency will have to dramatically scale back its long-term ambitions if it wishes to stay on budget, but August has been plagued by malfunctions and delays across multiple projects and missions in progress.

A probe known as LCROSS, set to release a spent rocket booster to the moon's surface this fall in a hunt for water ice there, has suffered perhaps the most serious setback. This week, NASA announced that the spacecraft had unexpectedly squandered its fuel in an attempt to maintain its orientation after switching to an alternate attitude sensor.

"Our estimates now are if we pretty much baseline the mission, meaning just accomplish the things that we have to (do) to get the job done with full mission success, we're still in the black on propellant, but not by a lot," LCROSS project manager Daniel Andrews told Spaceflight Now.

A team from NASA, the military and academia has developed and tested a simple solid rocket fuel of fine-grained aluminum and water ice that the researchers say could provide a cleaner alternative to propellants now in use.

The propellant, known as ALICE (for aluminum and ice), showed its stuff by shooting a nine-foot test rocket a quarter of a mile into the sky this month, according to NASA.

Mitat Birkan, program manager for space power and propulsion at the U.S. Air Force Office of Scientific Research, one of the agencies working on the fuel, says that ALICE is more environmentally friendly, before and after burning, than conventional fuel. The only by-products of ALICE combustion, Birkan says, are gaseous hydrogen and relatively innocuous aluminum oxide.

The launch of space shuttle Discovery, planned for early this morning, was called off deep into the countdown due to inclement weather at Kennedy Space Center in Florida. NASA will try again in the wee hours of Wednesday, weather permitting. The launch time is set for 1:10 a.m. (Eastern Daylight Time)—which would provide sky-watchers another chance to see the orbiter climbing in the night sky—and the space agency forecasts a 70 percent chance of favorable conditions.

This is hardly the first time, of course, that a launch has been postponed in Florida's mercurial climate. Last month's STS-127 mission of space shuttle Endeavour to the International Space Station was pushed back three times due to weather, before the skies finally cleared. At that time, we checked in with space historian Roger Launius of the Smithsonian National Air and Space Museum to find out why NASA shoots all their rockets for manned missions from such a stormy place—you can read our Q&A with Launius here.

To quote Elton John, it's lonely out in space.  

Luckily, the residents of the International Space Station (ISS) have an entertainment library to keep them company during their stays, which can be several months long. But some have taken issue with the cultural diet on board the ISS, complaining that our astronauts deserve a better reminder that there's intelligent life back on Earth.

The story began two years ago, when the Web site governmentattic.org made a seemingly benign request of the feds—asking for a list of the books, movies, TV shows and music kept onboard the station. The site, a repository of U.S. government files obtained through the Freedom of Information Act, received the list (pdf) from NASA in April 2008 and posted it on the Web.  

Less than a month after the U.S. celebrated the 40th anniversary of its first moon landing, the country's space agency faces the dour possibility that it lacks the funds needed to be able to return there by 2020, a goal established by the Bush Administration in 2004.

The conclusion of the 10-member Augustine panel—formed in June and headed by Norman Augustine, a former chief executive of Lockheed Martin, to evaluate the direction of NASA's human spaceflight program—is that the space agency has some tough budgetary decisions to make if it wants to meet the 2020 deadline. This includes whether it should continue to provide funding for the International Space Station (ISS) or divert more money to its moon-bound Constellation program.

The indefatigable Opportunity rover, still motoring across the Red Planet five years into its mission, recently came across what may be a large meteorite sitting on the Martian surface.

The 0.6-meter rock, dubbed Block Island [detail below], would not be the first meteorite discovered on Mars by the rover, but would be notable for its size. Block Island is nearly twice as long as the meteorite known colloquially as Heat Shield Rock and formally designated Meridiani Planum, which Opportunity spotted in 2005. That meteorite was the first to be found on another planet and remains the only one formally accepted by the Meteoritical Society. (Meridiani Planum was found on a plain of the same name; the Meteoritical Society's convention is to name meteorites for a nearby geographic feature.)

The shuttle mission that didn't get off the ground until its sixth scheduled launch attempt earlier this month made it home much more smoothly, landing this morning during its first opportunity to do so. Endeavour returned to Earth at 10:48 a.m. (Eastern Daylight Time), touching down at Kennedy Space Center in Florida under blue skies.

In a 16-day mission to the International Space Station (ISS), the seven-member crew of Endeavour delivered and installed the final pieces of the station's Japanese Kibo science lab. NASA now rates the ISS as 83 percent complete—only recently did it reach its design capacity of six resident crew members. With the shuttle slated to be retired next year, NASA has a packed full manifest of launches so that the ISS can be finished before the U.S. loses its capacity to send humans into orbit.