A year of scientific discovery at JPL

At Jet Propulsion Laboratory, studying the sun, the moon and the stars are only part of the universe they reached out to during 2007.

Each year Cassini continues to explore Saturn and its famous rings. During the past 12 months, exploring the moons of Saturn supplied more data, which answered as many questions of the past while posing new ones for the future.

JPL scientists and engineers also made progress on looking for Earth-like planets. The problem of looking for an exoplanet, a planet orbiting a star other than the sun, had been difficult because its dim glow is overpowered by the intense glare of a much brighter parent star.

Wesley Traub and John Trauger overcame that glaring problem with a telescope designed to see objects very close to the sun. A mission has yet to be approved for this telescope, but when it is needed it is ready to serve.

The sun was the object of much attention with a new 3-D glimpse into the weather of our nearest star.

The twin spacecraft called Solar Terrestrial Relations Observatory [STEREO] takes images from opposite sides of the sun. This allows scientists to analyze solar flares and predict their strength. Solar flares can affect communications on Earth.

Many JPL scientists participated in the IPCC [Intergovernmental Panel on Climate Control] report on Global Warming. The organization along with former Vice President Al Gore shared the Nobel Peace awarded this year. Earth science continued to be a focus throughout the year at JPL.

It is common with space exploration to have on and off days because, from conception to final destination, a million things can go wrong or right on a minute by minute basis. But from the end of 2006 to the end of 2007 Mars has been on one long roller coaster ride that saw the loss of one spacecraft and the unexpected longevity of two rovers.

At the end of 2006 JPL had lost communications with the Mars Global Surveyor, a spacecraft that reached Martian orbit in September 1997. Surveyor had operated longer at Mars than any other spacecraft in history, more than four times its original prime missions. But just days before its tenth anniversary it sent its last communication.

Mission specialists tried to find the spacecraft. Finally, in the spring of 2007, it was pronounced officially lost. The Mars Reconnaissance Orbiter and Odyssey continued to send back information as well do the rovers Spirit and Opportunity, which continue to impress and amaze.

“This year the rovers will be celebrating their fourth Earth year birthday on Mars’ surface,” said Richard Morris, mission manager.

Spirit and Opportunity were originally planned for a 90-day mission on the red planet. They have survived well past that as they roll over the Martian surface, surviving everything the planet throws at them. A series of Martian sandstorms put both rovers in jeopardy for a while, but they survived the storm and continue to explore.

At present Opportunity is traveling back into Martian history, studying layers of geology in Victoria Crater. Spirit had a little more difficulty finding a safe place to sit out the severe Mars’ winter.

The rover was losing power; its only hope was to get to the north side of an area scientists have named Home Plate, with its solar panels aimed toward the sun.

“Despite dropping power levels we have been driving it every day,” Morris said. “The team has been working weekends and even went on Mars time for three weeks but we made it.”

The next step in Mars exploration will be the Phoenix, which is on its way and is scheduled to arrive at Mars in the spring of 2008.

The spacecraft will land by using retrorockets that decelerate and then conduct a soft landing. This type of landing has not been done since the Viking landing a decade ago.

The Phoenix will continue the Mars program goal of finding water and looking for life.

But before the Phoenix lands some fireworks may be seen on the planet’s surface if an asteroid that appears to be heading for Mars hits on Jan. 30, 2008. Information released on Dec. 28 now has the asteroid 2007 WD5 impact probability with Mars at 3.9%. The same asteroid first passed close to Earth in November, then made on to Mars.

Although the impact percentage is small, scientists are still excited about the possibility, according to JPL.

The potential impact zone is close to 800 km wide, Opportunity is close to the southern edge of the impact but is far enough away to remain at a safe distance.

Scientists have calculated that if the impact will occur on Jan. 30 at around 2:55 a.m. Pacific Standard Time, give or take a few minutes.