What's Happening in Space Exploration

New Images From Phoenix Lander May Show Martian Ice
By Tariq Malik - Senior Editor, Space.com

NASA's Phoenix Mars Lander may have already caught its first glimpse of Martian ice less than a week after arriving at its new red planet home.

New images released Saturday reveal what could be a patch of exposed ice beneath the Phoenix lander, mission managers said in an announcement today. Phoenix beamed the images back to Earth late Friday from its Vastitas Borealis landing site in the northern polar region of Mars after using a robotic arm-mounted camera to peer beneath its undercarriage.

The new views revealed patches of smooth, level surfaces beneath Phoenix's thrusters, boosting the confidence of researchers who had hoped the spacecraft's pulse rocket engines could kick up the Martian topsoil to expose a buried layer of water ice.

"This suggests we have an ice table under a thin layer of loose soil," said Horst Uwe Keller, the lead scientist for Phoenix's robotic arm camera at the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany.

This image, released on May 31, 2008, shows the ground underneath NASA's Phoenix Mars Lander,

adding to evidence that descent thrusters dispersed overlying soil and exposed a harder

substrate that may be ice. Credit: NASA/JPL-Caltech/UA.

Phoenix, a stationary lander, set down in the Martian arctic on May 25 to begin a planned three-month mission to probe its surroundings for buried water ice using a scoop-mounted robotic arm, as well as onboard ovens and wet chemistry lab. The probe's $422 million mission is aimed at determining whether the icy Martian north could have once been habitable for primitive life.

"We were expecting to find ice within two to six inches of the surface," said Phoenix principal investigator Peter Smith of the University of Arizona in a statement. "The thrusters have excavated two to six inches and, sure enough, we see something that looks like ice. It's not impossible that it's something else, but our leading interpretation is ice."

Phoenix pulsed its rocket engines to make a three-point landing on a broad, flat valley in a region similar in latitude northwestern Canada on Earth. The area is in a region where spacecraft orbiting Mars have spotted indications of subsurface water ice in the past, making it a prime digging site for Phoenix's robotic arm.

NASA's Phoenix spacecraft is one of three now currently operating on the surface of Mars. The lander joined two twin robots, the Spirit and Opportunity rovers, which landed in 2004 and continue to explore different areas of the planet's equatorial regions.

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Shuttle Discovery Launches Space Station's Largest Lab
By Clara Moskowitz - Staff Writer, Space.com

CAPE CANAVERAL, Fla. - NASA's shuttle Discovery rocketed into space Saturday with a massive Japanese laboratory bound for the International Space Station.

Discovery shot up into the sky from its seaside Launch Pad 39A at NASA's Kennedy Space Center carrying what will soon be the largest single room aboard the space station - the tour bus-sized main cabin of the Japan's Kibo ("hope" in Japanese) laboratory.

"While we've all prepared for this event today, the discoveries from Kibo will definitely offer hope for tomorrow," said Discovery's commander Mark Kelly just before launch. "Now stand by for the greatest show on Earth."

During their planned 14-day mission, Discovery's seven crewmembers will perform three spacewalks to install the $1 billion Kibo laboratory, relocate its smaller storage cabin from its current perch to the main room, and activate the laboratory's robotic arm. The shuttle is slated to dock at the International Space Station (ISS) on Monday afternoon.

Watching the launch here was Kelly's identical twin brother, Scott Kelly, who is also a veteran astronaut. Their father Richard celebrated his 68th birthday while his son Mark launched into space.

"I'm excited for him - it's an amazing experience," Scott Kelly, a veteran spaceflyer, said. "I think it's a unique privilege to not only fly in space but then have your brother that you can talk about it with and he understands exactly what you're talking about 'cause he's shared those experiences and memories."

An artist's depiction of Japan's Kibo lab, shown two-thirds complete, after the STS-124 shuttle flight to the ISS.

The mission will deliver the tour bus-sized central module (horizontal) to the station. Credit: NASA.

Japan's 'hopes' reach space

Discovery's STS-124 mission is the second of three planned shuttle flights to bring all of Kibo's elements into space. It follows the shuttle Endeavour's March 2008 flight, which delivered the small storage room, and precedes a planned spring 2009 mission to deliver Kibo's porch-like external platform.

The launch of Kibo's main element represents the fruition of more than 20 years of work and planning by Japan to add its own segment to the space station. The new module is about 37 feet (11 meters) long and about 14.4 feet (4.4 meters) wide. It weighs about 32,000 pounds (14,514 kg).

"It shows ISS is coming into the stage of the truly international," said Yoshiyuki Hasegawa, Japanese Experiment Module program manager. "This Kibo is known for the Japanese people, even child and old man and government senator. Even my mother knows that Kibo is the international station and made in Japan."

Japan's stake in Discovery's mission is embodied by crewmember Akihiko Hoshide, a Japan Aerospace Exploration Agency astronaut who will serve as the resident Kibo expert when he and his crewmates work to install the lab on the ISS.

"This is a big step for the Japanese community, the science community especially, because that means that they can start their own science," Hoshide said before launch. "It's a big milestone for Japan."

Crew's dreams

Other STS-124 astronauts include pilot Ken Ham, mission specialist Karen Nyberg - who became the 50th woman to fly in space with today's launch - and fellow NASA spaceflyers Rob Garan, Mike Fossum and Greg Chamitoff. Chamitoff will stay aboard the orbital outpost after Discovery departs, replacing U.S. astronaut Garrett Reisman as a member of the ISS's three-man Expedition 17 crew. Reisman is slated to return with Discovery during its planned June 14 landing.

"The idea of just living in space for a long period of time and knowing what it's like to live there, I think, is one thing I'm looking forward to," Chamitoff, a first-time spaceflyer, said before flight. "That's going to be an amazing experience up there just to have one part of one step of getting humanity up to the stars."

Besides dropping off the Kibo lab and Chamitoff, Discovery is hauling a few other important pieces of cargo.

The shuttle is carrying a replacement pump to fix the space station's faulty toilet. The orbital loo, the only one on the ISS except for the facilities on the docked Soyuz spacecraft, is working partially, though it is inconvenient and time-consuming. Space station residents are hoping the new pump will fix the problem, though previous spare pumps have so far failed to do so.

Discovery is also carrying an action figure of the Buzz Lightyear character from the 1995 Disney-Pixar movie "Toy Story." By flying into space, the toy will perform educational demonstrations for kids and also fulfill Buzz's goal of reaching "infinity and beyond."

Landmark trip

Today's launch marks the third of up to five shuttle flights planned for the busy 2008 year. Discovery's voyage is the 123rd space shuttle mission to fly and the 26th trip to the ISS. NASA aims to retire the shuttle program in 2010, with just 11 more shuttle flights planned to complete space station construction and overhaul the Hubble Space Telescope. Discovery's STS-124 mission marks the shuttle's 35th trip to space.

In an unusual move, Discovery launched without its sensor-tipped robotic arm inspection boom aboard, in order to make room for its giant Japanese payload, the largest ever launched to the ISS.

Since Columbia's tragedy in 2003, astronauts usually spend the day following launch using the boom to inspect their orbiter's heat shield tiling for damage such as that which caused the earlier disaster. Luckily, the previous shuttle flight, Endeavour's STS-123 mission, left Discover's boom waiting for it on the space station.

"After we launch, before we rendezvous, we're going to use the shuttle arm and the camera that's on the end of the shuttle arm to do as much of the rudimentary inspection as we can of the wings of the orbiter," Ham said in a preflight interview. "After we undock, we will do the traditional detailed survey of the thermal protection system of the orbiter so that we can guarantee that we are safe to enter."

Upon the shuttle's arrival in space, mission control congratulated Kelly and his team.  "It's good to be back, and it's good for everybody to be here," Kelly replied

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NASA's Next Big Space Telescope Passes Brain Test

By Dave Mosher - Space.com

Engineers have successfully tested the mirror-controlling "brain" of the James Webb Space Telescope (JWST), which is expected to rival imagery taken by the Hubble Space Telescope.

The software, known as Wavefront Sensing and Control (WFSC), will allow the Webb telescope to adjust its 18 hexagonal mirrors.

"It's critical that all 18 mirror segments be aligned in position so that they act as one smooth surface," said Bill Hayden, a systems engineer at NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Md. "This will allow scientists to clearly focus on very dim objects that we can't see now."

JWST is slated for launch in 2013.

Hubble rival

With a combined mirror surface of 269 square feet (25 square meters), the Webb telescope will have nearly six times the light-gathering ability of Hubble Telescope, which has one giant 46-square-foot (4.3-square-meter) mirror. Astronomers expect such sensitivity to allow them to see the first stars and galaxies of the universe as well as young planetary systems.

A comparison of the light-gathering abilities of the Hubble Space Telescope versus the yet-to-be-launched James Webb Space Telescope. The Webb will have nearly six times the light-gathering ability of the Hubble. Credit: NASA

The Webb telescope will launch in a folded-up configuration, later unfurling its lightweight beryllium mirrors in orbit one million miles (1.6 million kilometers) from Earth. Unadjusted, however, the Webb telescope's mirrors would produce blurry images like Hubble did when it first peered into the cosmos.

David L. Taylor, president and chief executive officer of Ball Aerospace & Technologies Corp., said WFSC software that will prevent the problem is based on the same code used to fix the Hubble telescope's imperfections.

"This major technological accomplishment, which built on the legacy of software algorithms used to fix the Hubble Space Telescope and align the Keck telescope," said John Mather, the Webb telescope's senior project scientist at GSFC.

Mini-Webb

To test the WFSC software, engineers created a one-sixth scale model of the Webb telescope model in the laboratory. Once in space, the real 6.2-ton (13,700-pound) telescope will snap a picture of the cosmos, run the software correlating the 18 different light sources (its mirrors) and then correct them using tiny motors.

In the quarterly newsletter issued by the Webb telescope's scientists, Hayden said the testing isn't fully complete, but should go forward without a hitch. "The tests started in mid-October and will finish by early December," Hayden said, adding that recent results suggest final testing "will be very successful."

Webb telescope scientists presented their mirror-adjusting work on Aug. 26 at the Society for Photo-Optical Instrumentation Engineers meeting in San Diego, Calif.

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Mounting Mysteries at Saturn Keep Scientists Guessing
By Charles Q. Choi - Special to SPACE.com

Humanity has known of Saturn since prehistory, but enigmas about this ringed world still abound-from new mysteries concerning a baffling hexagon of clouds on the planet to perennial puzzles concerning its famous rings.

The latest mystery is the giant hexagon circling Saturn's north pole. Scientists caught glimpses of it decades ago from the Voyager mission, but confirmed its existence with the Cassini spacecraft.

Nothing like the hexagon has ever been seen at any other planet, with each of its sides nearly 7,500 miles (12,500 kilometers) across-big enough to fit nearly four Earths inside. Thermal images show it reaches roughly 60 miles (100 kilometers) down into the planet's atmosphere. "It's a very bizarre object," said Kevin Baines, atmospheric expert and member of Cassini's visual and infrared mapping spectrometer team at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Although water swirling inside a bucket can generate whirlpools possessing geometric holes, "there's no bucket here," Baines said. "You're not flinging fluid against some wall."

Scientists have bandied about several other ideas concerning the hexagon's origin. Perhaps a giant spinning cylinder of gas stretching thousands of kilometers into Saturn lies at the hexagon's center, and the hexagon's cloudy walls emerged from interactions with slower-spinning gas at the cylinder's edges that did not spin as fast, Baines said. Or perhaps the hexagon arises from a complex interaction between waves undulating through the atmosphere and gas churning up it.

"Hopefully we'll learn more about the hexagon when the seasons on Saturn change and the sun begins to shine on the hexagon about 18 months from now," Baines said. Cassini's eagle-eyed cameras should show details of the hexagon 80 times sharper than those currently available via the spacecraft's thermal imagers.

Lord of the rings

Strange features abound within the rings of Saturn. These include hundreds of "record grooves" or narrow fluctuations in the B ring, the most massive ring. These also include "plateaus" in the C ring, the innermost main ring-broad, dark, sharp-edged features thicker than elsewhere in the ring. "No one has a clue what causes them," Jeffrey Cuzzi, a planetary scientist at the NASA Ames Research Center in California, said of these grooves and plateaus.

Not only are the origins of these features mysterious, but so are those of the rings themselves. Some researchers argue the rings are debris left over from Saturn's formation, making them roughly as old as the solar system itself, or about 4.5 billion years old. Others say that if they were that old, they should be polluted with dirty ice from comets, which are thought to rain down often on gas giants, as the comet Shoemaker-Levy illustrated when it smacked into Jupiter in 1994.

The fact that the rings seem be made of relatively clean and not dirty ice suggests they might be only a few hundred million years old, or "no more recent than the age of fish on Earth," Cuzzi said. In this idea, they're made of rubble perhaps from a moon that got ripped apart.

Future observations from Cassini might help really understand what the rings are made of, which scientists could then compare with the compositions of comets or Saturn's moons to find the better match-up, Cuzzi said.

More knowledge about the origins of the rings and their features could help scientists understand more of the dynamics involved in other kinds of astrophysical disks, "such as the one that formed the planets in our solar system," said Matthew Hedman, a research associate at Cornell University.

Time of day

The very length of the day on Saturn-that is, the rate at which the bulk of the planet spins-also remains a mystery. The planet's dense, cloudy atmosphere makes it impossible to simply peer down hundreds of miles to see how fast Saturn is actually spinning.

When measuring Jupiter's rate of spin, astronomers were helped by the fact that, like Earth, Jupiter's magnetic poles are not lined up with the axis on which it spins. This means when Jupiter spins, its magnetic poles move with it, and thus astronomers can determine how fast Jupiter is spinning by looking at its magnetic field.

However, Saturn's magnetic poles are lined up nearly perfectly with the axis on which it spins. This has led to confusing results, such as Saturn's day improbably lengthening by about six minutes in the past 26 years. One possible explanation was that puffs of water from the Saturnian moon Enceladus's geysers may have literally clouded Saturn's magnetic field with ionized particles that changed how we saw Saturn's magnetic field, Baines said.

The water molecules become ionized by charged particles they encounter in Saturn's magnetic field, and then become trapped for a time in the field, weighing and dragging it down a bit so that the field actually spins more slowly. Scientists hope that by comparing Enceladus's geyser activity with Saturn's magnetic field spin over the next few years-perhaps finding a span of time when there's a lull in that moon's eruptions-they might be able to finally determine the true rotation rate of Saturn.

Energy crisis

Saturn and the solar system's other giant planets also face what researchers call an "energy crisis"-their upper atmospheres are far hotter than can be explained by absorbed sunlight. Scientists had suspected the mechanism that causes the aurora borealis or Northern Lights on Earth might explain this heat. On Earth, super-hot particles from the solar wind collide with the planet's magnetic field  exciting atoms in the atmosphere that shed light and thus create auroras.

However, atmospheric physicist Alan Aylward at University College London along with physicist Chris Smith and their colleagues found auroras could actually cool the upper atmospheres of gas giants, by forcing air closer to the equator down to lower, colder depths.

The extra heat astronomers see might get explained by energy from gravity waves, atmospheric oscillations up and down caused by the tug of war between the planet's gravity and the buoyancy of the atmosphere's gas. (These gravity waves differ from gravitational waves, or fluctuations in space-time itself.) Or Saturn's electric fields could be even more complex than before thought.

"We don't even understand the details of the electric fields on Earth, and those on Jupiter and Saturn are quite a bit farther away and of different compositions," Aylward said

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