Sat end of full-on operational readiness testControl teams who will guide the Mars Polar Lander through every minute of its scheculed 4-month mission near Mars' southern pole have completed a full-scale simulation of landing and the first four days of the operations that will follow a successful touchdown Dec. 3.
Scientists and engineers at the Jet Propulsion Laboratory, Lockheed Martin and the science operations center at the University of California at Los Angeles conducted a fully-staffed test designed to mimic every detail of the actual mission. The test was completed Saturday.
"We landed on Mars successfully on Wednesday. It was very exciting actually," said Laurie Leshin, a cosmic geochemist at Arizona State University and a member of the Mars Polar Lander science team.
After landing, the mission teams started receiving dummy data sets, then received simulated image data from the spacecraft, Leshin said. Officials even put together a press conference and rehearsed revealing to the world the first closeup images of the martian polar region.
The rehearsal incorporated all the engineering, science and command teams that will be working on the polar lander mission. Engineers at Lockheed Martin in Denver, Colo. are responsible for sending the commands that actually control the spacecraft. Scientists and engineers at JPL manage the mission, while the science team will be based at UCLA.
"The things that you really need to practice are the communications, the handoff between JPL and UCLA and Lockheed Martin, and how that actually works. And the only way to really make that smooth is to practice it, and that's what we've been doing," Leshin said. "It's gone extremely well."
For much of the 4-day practice session teams operated and received data from a working copy of the Mars Polar Lander set in a 15- by 15-foot sandbox called the mars test bed. The lander mock-up uses an engineering copy of the Surface Stereoscopic Imager, the camera that will send back 3-dimensional panoramic shots of the martian landscape.
A model of the Mars Polar lander sits in the test bed at the Mars Science Operations Center at UCLA. The lander has a working copy of the Surface Stereoscopic Camera and the robotic arm that will dig as deep as 20 inches into the surface.
A photographic mural of Antarctica covers the wall behind the bed, and scientists and engineers have arranged several "geologic" features in the sand to give them something to focus the camera on. The lander has a robotic arm that will be used to dig into the martian soil and take samples which will then be analyzed by another instrument aboard the spacecraft. Mission controllers practiced digging a trench with the arm, and controlling the small camera that is mounted on it to examine soil.
Looking out from the test bed, the camera views the control room at UCLA where engineers monitor and analyze the data coming back from the lander.
Peter Smith is the principal investigator for the stereo camera and the robotic arm camera aboard the spacecraft. Smith, who also built the stereo camera for the Mars Pathfinder said the simulations went very well.
"We had a great time because we make these 3-D, virtual reality scenes out of our data. We can fly down between the rows of chairs, and zoom in across the room on a fire extinguisher or an exit sign. It's really neat."
The 3-D effects aren't created by actually zooming in with the camera, but by specialized image processing program that makes three-dimensional terrain maps out of the stereo camera data.
For every point imaged by the camera, the software determines X, Y, and Z coordinates that define its location in three-dimentional space. Those points yield a three-dimensional terrain map for the area around the spacecraft.
"Within the arm reach and maybe 2 to 3 times that distance, you can really make some remarkable discoveries, just kind of flying through the scene," Smith said. "You can get down -- kind of a snake's-eye view above the ground -- and you can look at the smallest rises and falls and as you dig the trench, you can make it look like the grand canyon. It's incredible."
This 90-degree panoramic image of a portion of the Mars experimental test bed shows several "geologic" features that members of the mission team installed for the camera's practice run. At the left edge is a trench that was dug by the lander's robotic arm.
The practice run helped the teams find several logistical problems that could have otherwise slowed operations on Mars. Most these troubles were minor, though, Smith said, things that would have been little goof-ups but certainly not fatal to the mission.
For example, at one point during the practice session, operators were trying to use the robotic arm to observe a magnet on another of the lander's science instruments, but the view was blocked by a small thermal probe that takes temperatures above the surface.
"By running these tests you can see ahead of time where you need to put more thought into the (command) sequences," Smith said. "Obviously you don't want to put that thermal probe in front of the object you want to photograph. So that will be modified, and it won't happen during the mission."
With less than two weeks left to go before landing Smith said he isn't exactly excited about the landing day.
"I don't know if excited is the right word," Smith said. "It's a sense of dread here. It's like my whole life focuses on December 3, and I don't know what happens on the 4th. I have no idea. I figure we're heroes or zeros."
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