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The San Diego Supercomputer Center (SDSC) is helping to ensure that everyone who wants to get an online look at the latest mission to Mars can access up-to-the-minute information on America's return to the red planet. On January 3 a robot rover named Spirit made a flawless landing on the planet Mars after a journey of 300 million miles, and at press time has resumed its exploration of the martian surface after a memory problem took it out of action for a week. Three weeks after Spirit landed, its sister rover Opportunity successfully touched down inside a small crater on the opposite side of the planet and now is exploring its own locale. Millions of people are watching their progress on the World Wide Web, creating the potential for a massive Internet traffic jam. To ensure the free flow of information to the public, SDSC is hosting two different mirror sites for the Mars Exploration Rover mission. One site distributes the latest data from NASA's Jet Propulsion Laboratory (JPL) -- and the software to display and interpret the data -- to researchers, educators, and personal computer users across the country and around the world. The other is an educational site supported by NASA and the National Science Foundation (NSF).

Maestro: Directing the Mars Exploration Rovers

NASA has released Maestro, a public version of the primary software tool used by scientists to operate the Mars Exploration Rovers from JPL. Members of the rover operations team use Maestro to view pictures from Mars in 2-D and 3-D and to create simplified activity plans for the rovers. As the Spirit and Opportunity rovers explore the martian terrain, updates will be released for Maestro containing the latest images from Mars. Now scientists, educators, and the general public can download Maestro for free from http://mars.telascience.org/ and use it to follow the rovers' progress during the mission -- and to view the latest images just as JPL's mission planners and space scientists see them.

Unfortunately, the public is very interested in doing this -- so much that the original Maestro website was completely swamped with requests shortly after the URL was posted on the popular Slashdot website ("News for nerds"). Before it was "slashdotted," the Maestro site had been listed on more than 340 other websites, and had served up 344,000 hits in two days.

NASA's solution in situations like this is to use mirror sites, servers at other institutions and on other data links that could handle some of the access requests. For example, between 12:00 noon Pacific Standard Time on Saturday, January 3 and 6:30 a.m. PST Tuesday, January 6, NASA's Web portal http://www.nasa.gov/ received 916 million hits, and visitors downloaded nearly 15 terabytes of information. (It would take more than 20,000 CDs to hold 15 terabytes of data; a stack of CDs without cases would be more than 80 feet high.) NASA has a network of more than a thousand mirror sites around the world, all serving requests from users; without it, NASA would have been overwhelmed by the traffic. But the Maestro website isn't mapped into the main NASA portal system, and can't take advantage of the system's overflow capacity.

A couple of weeks before the end of 2003, SDSC was contacted by Eric Frost, an Associate Professor of Geological Sciences at San Diego State University (SDSU), Co-director of SDSU's Visualization Laboratory, and frequent collaborator with researchers at SDSC. Frost sought assistance for his colleague John Graham, who was working with the Mars Exploration Rovers team at JPL to distribute the Maestro software package and data sets. With support from a NASA grant and the generous donation of a brand new Sun Fire B1600 server by Sun Microsystems, Graham was nearly ready to go. But SDSU didn't have the facilities and the manpower to support this machine 24/7 on a high-speed link to the Internet. Could SDSC help?

"We are delighted to assist the space science community in conveying the excitement of planetary exploration to the public," said Joshua Polterock, Group Leader for SDSC's Server Systems. "In 1997 we aided NASA on the Mars Pathfinder mission, when the Sojourner rover landed on Mars. Our server helped take over the load when the main JPL website was swamped. We handled more than four million hits back then. This time we expect to be able to serve several times as many users with much more information -- including animations -- and much less effort. SDSC's servers are on gigabit data links, only one hop away from the main Internet border routers, so we expect to be able to provide smooth, fast data transfers."

"The new Sun Blade server has 16 processor boards -- called "blades" in the computer industry -- working together to deliver pretty awesome performance," Frost said. "This was a major donation from Sun; the machine is worth more than $80,000, and we're very glad to have a machine this powerful to support the site. We also have one of Sun's new Zulu graphics machines here at San Diego State University serving the development site."

In a few short days, a team of experts tackled the technical and administrative problems in setting up the server at SDSC. Frost and Graham delivered the Sun Fire hardware to SDSC just before the Spirit rover's successful landing. Joshua Polterock and SDSC network engineer Nathaniel Mendoza set up several gigabit-speed connections to the Internet (three to eight links, depending on demand). They and Sun engineers Larry MacIntosh and Frank Leers configured the machine with server software and Maestro files. Meanwhile, Mike Bailey, SDSC's Director of Visualization, got enthusiastic approval of the effort from SDSC's Director Fran Berman.

The Maestro website went on line just as the first information from the Spiritrover was being released by NASA. Maestro can be accessed either via http://mars.telascience.org/ or http://wits.sdsu.edu/. These are the "public" URLs; requests for information from these websites are automatically routed to one of the connections to CPU blades in the server at SDSC. (Since each request can go to any one of several addresses at SDSC, these addresses are not made public -- in fact, giving out a direct URL for the server would defeat the load-balancing of the system.)

"The website is all open-source, using bunch of new and powerful tools, so it is able to download software and interact with the public," Graham explained, "including scientists, educators, and anyone with a modern personal computer. Visitors from more than 100 countries across the world have already downloaded the software."

"Recently, we assembled a team of eight volunteer artists and web developers who worked with us to improve the appearance of our old public outreach website," he added. "We have also made two major improvements to the software that will make it more accessible to the public. First, we have added a walkthrough system to Maestro called the Conductor that acts as a tour guide to the program for the user. Second, through a cooperative effort with Apple Computer, Maestro can now be used on Macintosh computers."

"As a geologist, I have to point out that Maestro is a wonderful example of using sensor networks and visualization to acquire data, solve problems, and enable us to see and discover what we cannot do in person," Frost said. "This is an example of how these technologies touch our lives in many unexpected ways. I see that happening to in many SDSC efforts like the GEON and Long Term Ecological Research projects and many of its educational activities."

The Mission

NASA's twin robot explorers, christened Spirit and Opportunity, were launched toward Mars this past summer. Their main mission is to investigate the terrain, rocks, and soils that hold clues to the present and past geology of Mars, and in particular the possible role of water in the evolution of the planet. The two spacecraft have been targeted to sites that appear to have been affected by liquid water -- Spirit landed at Gusev Crater, a giant impact crater that may once have held a lake, and Opportunity is exploring Meridiani Planum ("the plain of the meridian"), where sensors on orbiting spacecraft have indicated the presence of gray hematite, a mineral that on Earth is almost always formed in a wet environment.

When the Spirit probe entered Mars' atmosphere, nestled inside its aeroshell entry capsule, it was slowed in only four minutes from 12,000 miles per hour to 960 mph by atmospheric friction ... which heated the aeroshell to 2,600 degrees Fahrenheit. Then the aeroshell broke open, and the lander descended on a parachute to 50 feet above the surface. Retro rockets fired, halting the descent, and a cluster of airbags inflated around the landing module. The airbag-cushioned lander dropped to the ground and bounced across the martian landscape for about ten minutes before it rolled to a stop, perhaps half a mile from the original drop point. The airbags deflated, the lander module opened, and within two hours of touchdown Spirit had returned its first photographs from the surface of Mars.

During more than a week of checkout and preparation, each of the rovers took panoramic images with their stereoscopic cameras, to give scientists the information they need to select promising geological targets. Now the rovers are driving to those locations to perform on-site scientific investigations, using cameras, microscopes, spectrometers, rock grinders, magnetic particle collectors, robot arms, and digging tools.

NASA scientists hope that each rover will travel up to 40 meters (more than 120 feet) per day over the course of three months of exploration -- hardly comparable to the journey of Lewis and Clark, but not bad at all for a machine in a rocky, cold, gritty environment with no repairmen within 150 million miles.

Additional information about the Mars Exploration Rover mission is available at http://www.marsquestonline.org/ and at http://marsrovers.jpl.nasa.gov/.

Explore Mars with Maestro

Here's how you can use Maestro to access raw data from the Mars Exploration Rovers Mission, view the latest images from Mars in 2-D and 3-D, and even create simplified rover activity plans and chat with the mission scientists and engineers at JPL:

1. To be able to use Maestro, your computer must meet the following minimum requirements:

·  256 MB of memory

·  100 MB of available disk space

·  A Pentium 3 or 4 or equivalent processor, or a G3, G4, or G5 Macintosh

·  One of the following operating systems:

    - Windows XP/2000/98/Me
    - Mac OS X version 10.3 (Panther), with Java3D installed
    - Linux (recent versions)
    - Solaris (recent versions)

·     A 3-D graphics accelerator is strongly recommended.

2. Go to http://mars.telascience.org/ or http://wits.sdsu.edu/ -- either URL should work.

Download the appropriate version of the Maestro software package for your computer system:

·  Maestro for Windows XP/2000/Me/98
·  Maestro for Mac (requires Java3D)
·  Maestro for Linux
·  Maestro for Solaris

Make sure you also download the User Guide for Maestro, so you can take full advantage of all of the program's features.

3. Download the data. "Maestro already comes with data from the JPL In-Situ Instrument Laboratory testbed," said Jeff Norris, a computer scientist in the Telerobotics Research and Applications Group at JPL who is the chief software architect and development team lead for the Mars Exploration Rover Science Activity Planner software package, the "in-house" JPL precursor to Maestro. "We are planning to release data from the Spirit rover for Maestro on Wednesday, January 7."

JPL did indeed release the first batch of data from Spirit on January 7. There now is a link to this data set and several others from both rovers on the Maestro website. Additional updates will soon follow as the rovers continue their mission.

Please note: You must download the Maestro application before installing an update.

MarsQuest Online

Another pair of servers at SDSC will help handle requests from the public and from educators for access to MarsQuest Online, http://www.marsquestonline.org/, a Macromedia Flash-based site with Mars Exploration Rover information and interactive learning pages. As the website receives requests, they will be handled in sequence by servers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, at SDSC, at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, and at other mirror sites, so no single site has to handle the entire load.

MarsQuest Online is funded by the National Science Foundation's Division of Informal Science Education (http://www.ehr.nsf.gov/esie/programs/ise/ise.asp), which promotes public interest, understanding, and engagement in science, technology, engineering, and mathematics. It is supported by the Jet Propulsion Laboratory (http://www.jpl.nasa.gov/), NASA's lead center for robotic exploration of the solar system, by the Space Science Institute (http://spacescience.org/), which integrates research in Earth science, space physics, planetary science, and astrophysics with education and public outreach, and by TERC (http://www.terc.edu/), a not-for-profit education research and development organization based in Cambridge, Massachusetts that seeks to improve mathematics, science, and technology teaching.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington. See http://jpl.nasa.gov/ for more information.

Image credits: NASA/JPL/Cornell University.