Blades Bring Mars Down to Earth
The Web site provides a public version of Maestro, the program used by NASA scientists to operate the Spirit and Opportunity rovers surface activities. Since the site was launched last month, it has seen an astronomical number of hits, according to John Graham, Maestro Web site developer. The crush of visitors continued even after Spirit lost contact with NASA at the end of last month, Graham said.
The Maestro Web site is hosted at the San Diego Supercomputer Center at the University of California at San Diego, in cooperation with San Diego State University.
To enable all these novice astronomers to have access to the latest Mars data, the Jet Propulsion Laboratory at the California Institute of Technologywhich developed the Maestro applicationneeded a way to ensure its Web sites uptime and scalability. After a month of investigating their options, Graham and his colleague in the geological sciences department at SDSU, Professor Eric Frost, turned to a blade server cluster from Sun Microsystems Inc.
The combination of blade servers and a collection of open-source software enabled the Maestro Web site to scale, easily handling downloads of the Maestro application, Graham said. Although he couldnt provide the actual number of hits per day, Graham said the blades have averaged about 300,000 hits each whenever significant Mars mission announcements were made.
"We were looking for hardware that would be able to perform under pressure, and the Sun blade servers, in conjunction with open-source software, proved to be more than capable," Graham said.
With the Sun system, people can take an interactive look at Mars instead of passively admiring the planet. Although most interest has been from hobbyists, the site has also attracted many newcomers drawn by the drama of the mission and the sites easy access to it.
To meet the publics desire for more educational resources on the Mars mission, JPL decided to host a public version of Maestro, a collaborative command-and-control software tool developed by JPL and the primary software that NASA mission scientists use to operate the rovers.
Visitors to the Maestro Web site (mars.telascience.org) can download and install a scaled-down version of the Maestro application. With the Maestro version distributed by JPL, users see a three-dimensional model of the Martian terrain as well as 3-D models of the rovers, and they can "drive" the rover on the simulated terrain using real Mars data transmitted by the rovers.
The Maestro applicationa 38MB downloadalso allows users to view Mars data from rover activities throughout their missions, to look at the scenes and topography of Mars, and to create 3-D reconstructions of terrain.
The supercomputer center has a history of using Sun hardware, which is the main reason Graham decided to power his Maestro Web site using the Sun Fire B1600 Blade Server cluster.
Sun designed the Sun Fire blade server with self-containment in mind. This enabled Graham to deploy multiple types of servers in one box. For example, the Maestro blade server cluster includes six Sun Fire B100x single-processor x86 server blades running Red Hat Inc.s Red Hat Enterprise Linux Server 9, six Sun Fire B100 single-processor SPARC server blades running Suns Solaris 9 operating system, two Sun Fire B10n load balancing blades and two Sun Fire B10p SSL (Secure Sockets Layer) proxy blades. (The hardware was donated by Sun.) The load balancing and SSL proxy blades are running Wind River Systems Inc.s VXWorks real-time operating system.
The use of low-cost open-source software meant that JPL was able to provide a host of information and tools to the public for very little money. Graham used Zope, an open-source application server layer, after asking its creators if they would help with an educational Mars Web site. Graham runs Plone, an open-source content management system, on top of Zope to serve content to the Web site. (See eWEEK Labs review of Plone.)
The software monitoring the site is also open-source: Graham said he monitors everything using RRDtool (Round Robin Database tool), a graphical statistical analysis package. He uses the open-source Cricket Graph reporting tool to determine how many times an object in his MySQL AB database has been called.
"This Web site started out as a wish list by the JPL and just amplified over the Internet when volunteers all over the world from the open-source community came together to make this happen," Graham said.
The day the Web site went live, a Slashdot Web site reader posted the URL, and subsequent traffic brought the Web site to a crawl before it was taken down. To ensure this doesnt happen again, Graham said, the site is now fully redundant, with five load balanced grid servers and six Zope clusters.
Given the popularity of the Maestro Web site, new applications are now in the works, Graham said. This will include the use of Globus Alliance grid tools, which will enable users to annotate Mars data and render data sets as they become available.
Graham said he will also work with 3-D visualization company GeoFusion Inc. to provide real-time visualization tools that will allow Web site visitors to manipulate and view Mars data in 3-D. Users will need to download a 300MB GeoFusion playeractivity that will be supported by the Web sites blade serversto use the tool.
"This particular project is one of the most amazing collaborations of people I have experienced, and the fact that we have the infrastructure to keep it running is important," Graham said. "People are excited because having real access to data opens windows to the truth."
Senior Writer Anne Chen can be reached at firstname.lastname@example.org.