MER-B

From Wikinfo

MER-B (Opportunity) is one of the two rovers of NASA's Mars Exploration Rover Mission. Its twin, Spirit, successfully landed on Mars on January 3, 2004.

Timeline

2003

July 5 - MER-B (Opportunity) was launched aboard a Delta II rocket.

2004

January 16 NASA's Opportunity spacecraft adjusted its trajectory, or flight path, today for the first time in four months. Engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., commanded Opportunity at 6 p.m. PST to fire thrusters in a sequence carefully calculated by the mission's navigators. The spacecraft is spinning at two rotations per minute. The maneuver began with a 20-second burn in the direction of the axis of rotation, then included two 5-second pulses perpendicular to that axis.
January 24 at 9:05 pm PST, MER-B began bouncing on the surface of Mars in Meridiani Planum. Unlike the Spirit landing three weeks earlier where signal was lost immediately after touchdown, Opportunity continued broadcasting strong signals to Earth even after touching down. Opportunity continued bouncing and rolling on the surface of Mars for up to ten minutes after touchdown. California Governor Arnold Schwarzenegger and former Vice President Al Gore were both present at Mission Control and congratulated mission scientists after touchdown.
January 25 Opportunity returns the first photographs of its surroundings and the terrain is unlike any seen before on Mars. The area around the lander appears to be a small crater with a rock outcropping on the rim.

Initial panoramic image of landing site,

NASA (larger version)

Opportunity also returns its first color photograph of its landing site. Various "bounce marks" from Opportunity' landing are visible in the soil nearby. The color photos of the outcropping appear to be the first photographs of Martian bedrock.

Initial color image of landing site,

NASA (larger version)

January 26 (Sol 2) -
- During the second day on Mars for Opportunity, key science instruments passed health tests and the rover made important steps in communicating directly with Earth. Opportunity has tested the three scientific sensing instruments on its robotic arm that will be used for up-close examination of rocks and soil: the microscopic imager, the alpha particle X-ray spectrometer for determining what elements are present, and a Mossbauer spectrometer for identifying iron-containing minerals. "I'm pleased to report that all are in perfect health," said Dr. Steve Squyres of Cornell University principal investigator for the science instruments on the rovers.

January 27 (Sol 3) -
- Opportunity deployed, pointed, and started using the high-gain antenna.

January 27 (images from January 27)
- At the 12:00 EST press briefing, Squyres goes into further detail concerning the outcroppings: "The thinnest layers are a centimeter, something like that. The total height at highest point of outcrop is a foot and a half, maybe. That's good news. Less threatening to the rover because you can drive right up on to it."
- Dr. Andrew Knoll, Mission Scientist from Harvard University, describes the possibility of water in these areas of Mars: "If [the cause of the outcropping formations] is volcanic then all bets are off for liquid water. Simply wouldn't need it. If it's sedimentary I think you need water, I doubt these are windblown. Doesn't tell you about the duration of the water though. There has to be a role for liquid water in sculpting the surface of Mars. The question we're trying to answer is was it a short burst or persistent water. Both Gusev and Meridiani are interesting because they could be consistent with persistent water. What we see in front of us today makes no strong claims for longstanding persistence of water."
- Squyers says that he believes the hematite "is most likely to be present in finer grained soil. In floors of craters the soil is strikingly dark. Surrounding plains somewhat lighter (though still dark relative to rest of Mars) We think that soil has hematite. What we don't understand is the relationship between the soil and this rock layer. Not a surprise to find no hematite in this layered rock unit. We'll find out soon enough." Knoll adds that "Intriguing in the hematite and this rock layer, if you back up and look at the distribution they're co-existent. The light rock unit and the hematite are found together. While there's a range of processes going on, if we can understand this bed in front of us it will be helpful in understanding this co-existent pair."
- Opportunity experienced unexpected power losses. Engineers theorized that a heating element designed to keep the rover arm warm was being turned on anytime the temperature reached a certain temperature rather than only when the arm is operating at that temperature.

January 28 (Sol 4) -
- Opportunity 's "stand up" procedure was initiated. The rover successfully deployed its front wheels during this Sol. A lift mechanism in the lander base jacked up the rover, allowing the front two wheels to be released from their launch stowage locations and extend into position.

January 29 (Sol 5) -
- Further steps in Opportunity 's "stand up" were completed during this Sol: First, the lift mechanism was lowered, so that the rover now supports its own weight. After that the rear wheel base was bushed back to its full length.
- In preparation for driving the rover off the lander (called "egress") the backwards pointing petal was moved downward. This pushed the forward pointing ramp closer to the ground and made driving down onto Martian soil easier. "The tips of the egress aid (a reinforced fabric ramp) are now in the soil. That makes egress look perfect. It's going to be an easy ride." said mission manager Matt Wallace.
- Opportunity was also commanded to take the first large set of pictures with the Mini-Thermal Emission Spectrometer (MiniTES) instrument.
- NASA announced plans to name the landing site of the Mars Opportunity rover in honor of the Space Shuttle Challenger's final crew. The area in the vast flatland called Meridiani Planum, where Opportunity landed this weekend, will be called the Challenger Memorial Station.

January 30 (Sol 6) -
- All mechanical steps to make Opportunity ready to roll off the lander were completed on this Sol. A single umbilical cord is left to be cut before the egress can begin. The rover lowered its middle wheel pair to the ground, and released its instrument arm from launch position to be moved in place for roving. Rover systems engineer Daniel Limonadi said: "We've had a good couple of days on Opportunity. As a result, we are a little bit ahead of schedule."

January 31 (Sol 7) -
- After some preparation during the first part of Sol 7, Opportunity was sent to the command to drive off the lander. It did so successfully, and was on Martian soil with all six wheels, for the first time. Pictures from the front and rear hazard cameras were taken and sent to mission control.
January 31
- At a 3:45AM PST press conference, flight director Chris Lewicki reported that Opportunity 's drive began at 1:50:07 AM PST (09:50:07 GMT). It took 83 seconds to move about 10 feet, coming to rest at 1:51:30 AM PST (09:51:30 GMT).
- It was also announced that, using the Mini-TES panorama pictures, Opportunity has discovered hematite in the layer just above the white bedrock and in the undisturbed soil around the lander. Hematite was not detected inside the airbag bounce marks. Dr. Phil Christensen from Arizona State University, lead scientist for both rovers' Mini-TES, said "As we get out of the bowl we're in, I think we'll get onto a surface that is rich in hematite."
- Christensen also reported that the data from the outcrop rocks indicate that they are not quartz or any material containing carbon. A better identification of the rocks is expected when the instrument arm can be used to investigate them closely.