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Highlights 2005 — Space

Q&A with David J. Stevenson: Exploring the Universe Print exclusive
Rovers still trucking
New “planetary” neighbors
Back to space
For a complete list of space headlines from 2005, see the December 2005 print issue.

Rovers still trucking

The Mars Exploration rovers Spirit and Opportunity have spent 664 and 644 sols (Mars days) respectively on the red planet, as of Nov. 15, well beyond their expected one-year lifetimes. Their travels have provided a wealth of data on water, soils and other geologic characteristics, in particular the presence of goethite, nodular “blueberries” (first discovered last year by Opportunity) and other evidence for settings that may have held shallow lakes or were saturated with water in the past. The rovers have also overcome a variety of obstacles — from big boulders and a damaged wheel on Spirit, to diminished power from their solar panels, coated by Mars’ dust. See the Geotimes online archive for this year’s rover news.

The Mars Exploration Rover Spirit took this panorama of Mars’ very own “Mount Everest,” a 106-meter-high hilltop, on its 608th martian day (Sept. 18). Image courtesy of NASA/JPL-Caltech/Cornell.


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New “planetary” neighbors

Announcements this year of two planet-like bodies discovered orbiting the sun — one with a moon — have many astronomers rethinking the definition of “planet.” These newest celestial neighbors are fueling the debate about which planetary bodies qualify for the term.

Mike Brown of Caltech in Pasadena, Calif., announced the discovery of a body larger and farther out than Pluto, in a debris reservoir called the Kuiper Belt. Brown and colleagues first imaged 2003 UB313 (nicknamed Xena by astronomers, after the TV show’s warrior princess) in October 2003, but its motion remained undetected until January. “We are 100 percent confident that this is the first object bigger than Pluto ever found in the outer solar system,” Brown said in a Sept. 29 NASA press release. Depending on planetary definitions, the body may be considered the 10th planet in our solar system.

A new moon discovered orbiting 2003 UB313 (nicknamed Gabrielle, after Xena’s sidekick) further complicated its planetary status. Initial estimates indicate that the moon is about one-tenth the size of its host and that it completes an orbit once every few weeks. “Having a moon is just inherently cool — and it is something that most self-respecting planets have, so it is good to see that this one does too,” Brown said in a Sept. 30 Caltech press release.

Also fighting for planetary status is Ceres: Once considered the solar system’s largest asteroid, scientists have recently discovered that it is remarkably round, implying that distinct layers may compose its interior — a planetary characteristic not found in asteroids. The Hubble Space Telescope captured the images of Ceres, and researchers published an analysis in the Sept. 8 Nature, saying that gravitational tugs on the “embryonic” planet, located in the asteroid belt between Mars and Jupiter, prevented it from developing into a full-fledged planet. The Texas-sized object is 14 times less massive than Pluto.

Comparing new discoveries to Pluto, however, will not likely be sufficient to determine planetary status for the new objects, as not all astronomers consider Pluto a planet. The International Astronomical Union (IAU) charged an expert panel, led by Iwan Williams of University of London, to consider the terminology, which included the option of dropping the term all together, according to a Sept. 22 Nature news story. Other options included using categories such as “Trans-Neptunian planets,” “terrestrial planets” and “gas giants.” As of November, Williams says that the panel sent three possible definitions to the IAU executive committee for a decision.

At the end of October, scientists announced the discovery of two more moons for Pluto — drawing more attention to Pluto’s planetary status.

Kathryn Hansen

Links:

"Two more moons for Pluto," Geotimes online, Web Extra, Nov. 3, 2005.

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Back to space

Almost two years have passed since President Bush announced his new vision for space exploration, which called for sending humans to the “moon, Mars and beyond.” Now, to stay on schedule, NASA has four years to complete the International Space Station and retire the space shuttle, eight years to develop and fly its new exploration vehicle, and 14 years to return to the moon.

NASA recently unveiled its plans to return to the moon, presenting illustrations of a new lunar lander, which will accommodate four crew members. The new system will not require an astronaut to remain in orbit while the others explore the surface, as was the case with the Apollo missions. Image courtesy of NASA.


As part of the plan, this year, NASA undertook the first shuttle launch since the February 2003 Columbia tragedy, and completed blueprints for a “retro” spacecraft to return astronauts to the moon. But advances this year were not without a number of technical, political and weather-related obstacles.

NASA faced a reshuffling of personnel starting on April 14, when the U.S. Senate confirmed Michael Griffin as the agency’s new administrator. Griffin replaced Sean O’Keefe, who resigned from the position in February. Griffin said that he planned to focus immediately on the “Return to Flight” mission, which would put the shuttles back in service after two and a half years on the ground.

On July 16, Discovery “returned to flight” after a 13-day delay to fix a faulty fuel sensor. During its launch, however, cameras recorded a chunk of foam detaching from the shuttle’s external fuel tank — a similar event led to the Columbia disaster.

Inspection of the shuttle’s exterior revealed no damage from the foam, but images did reveal filler material protruding from between the protective tiles, which engineers thought might compromise safety during the shuttle’s reentry. Astronauts remedied the problem during a spacewalk — the first ever heat-shield repair to be done in space — and safely returned to Earth on Aug. 8.

Following the mission, NASA ordered that the shuttles remain grounded for further testing, and no additional launches are planned until March 4, 2006, at the earliest. “We are giving ourselves what we hope is plenty of time to evaluate where we are,” Griffin said in an Aug. 18 NASA press release. “We don’t see the tasks remaining before us being as difficult as the path behind us.”

More obstacles came from hurricanes that struck in the vicinity of three NASA facilities this fall, momentarily halting preparation of the three shuttles for future flights. The Aug. 29 landfall of Hurricane Katrina ravaged buildings of the Michoud facility located east of New Orleans. Most of the external fuel tanks, manufactured at Michoud, escaped relatively unscathed. Damage to NASA facilities, however, were estimated to reach more than $1 billion.

In preparation for the Sept. 24 landfall of Hurricane Rita, the Johnson Space Center in Houston, Texas, turned over control of the International Space Station to Russian mission control, so that employees could evacuate. The center fared well through the storm with little to no damage, and reopened on Sept. 27, but NASA officials said it was too soon to know how the storms will affect the March launch date of Discovery.

If the future launch of Discovery is successful, then a following mission aboard Atlantis will carry components needed to resume assembly of the space station. After completion of the station planned for 2010, the shuttles will be retired indefinitely.

Until the space shuttles can reliably make flights to the space station, NASA is counting on the Russian Soyuz spacecraft to transport American astronauts and materials — an arrangement that could come to an end, Griffin said on Sept. 30, according to an Associated Press story. Russia has requested payment for seats aboard Soyuz starting with the next mission in April 2006, but the Iran Nonproliferation Act prevents the exchange of money with countries that aid Iran with weapons and missile technology. (Russia is helping Iran build a nuclear power plant.) Congress, however, amended the act to allow the payments, which Griffin said in a Nov. 9 NASA press release will ensure the continued presence of U.S. astronauts aboard the space station.

In the meantime, NASA is working on a new craft to replace the shuttle. Blueprints for the Next Generation Spacecraft unveiled on Sept. 19 were reminiscent of the Apollo capsules of the 1960s. The capsule would be launched atop a “shuttle-derived” rocket — a design that Griffin said “will build upon the foundation of the proven designs and technologies used in the Apollo and space shuttle programs.”

Some critics have questioned whether the United States should fund the mission in the midst of a costly recovery from Hurricane Katrina; NASA estimates a price tag of $104 billion, to make the first manned lunar mission in the new spacecraft. Griffin responded by emphasizing that space exploration is a long-term investment. “When we have a hurricane, we don’t cancel the Air Force, we don’t cancel the Navy, and we’re not going to cancel NASA,” Griffin said.

Kathryn Hansen

Links:

"NASA on deck," Geotimes, May 2005.
"Discovery returns to flight," Geotimes online, Web Extra, July 26, 2005.
"Shuttle repair rundown," Geotimes online, Web Extra, Aug. 4, 2005.
"Space administration shakeup," Geotimes, August 2005.

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