The six-wheeled Opportunity was set to enter Victoria Crater in late June but was forced to delay its journey due to dust storms in the area. Dust in the air prevents much of the sunlight from contacting its solar arrays, which lowers the amount of energy it gets to power all of its systems. Opportunity and Spirit are on opposite sides of Mars. And, Opportunity is getting the brunt of the storm from its location on the Martian surface.

Back up batteries store excess energy, which are used when the probes use more energy than they receive on any given day. However, the batteries only have so much storage capacity, and once used up the probes have no way to power their heaters, which safeguards its delicate electronics from the coldness of the Martian nights.

Given that both rovers were only expected to rover around the planet for about three months—and its now been about 3.5 years since they have been operational—NASA mission planners are anxious to descend Victoria Crater before the twin Mars Exploration Rovers (MER), Opportunity (MER-B) and Spirit (MER-A), fail to respond to commands from the Earth.

Victoria Crater, about seven kilometers from Opportunity’s original landing site, is an immense impact crater when compared to others on the Martian surface. It is about 800 meters (about 0.5 mile) wide. Scientists think that if Opportunity can descend into it, analyses of the rock formations along its walls can be made about the geologic history of Mars. Opportunity is waiting patiently about 40 meters (130 feet) from its intended point of entrance into the crater.

Dust storms have helped and hindered the two twin rovers. For instance, in November 2005, a small dust storm helped to remove dust off of the solar arrays so that additional power was received from sunlight off of the arrays. However, the larger dust storms, like they are experiencing now, are depleting their power reserves, and are jeopardizing the mission.

The dust storms started around June 22, 2007 and have become major problems for the rovers now in the middle of July.

Additional information on what was happening earlier, when the dust storm first hit, is found at the iTWire article: “Martian storm blocks Sun, delays Opportunity’s descent into Victoria Crater” .

The storms are blocking about 99% of the sunlight from the solar arrays. NASA MER mission planners are hoping that the storms will subside within a few more weeks. Of course, they were hoping for that several weeks ago. Currently, mission managers are reducing the power levels of both rovers, trying to conserve as much power as possible while they wait out the storm.

Additional information on the MER mission is located from  the iTWire article: “Smarter is better for Mars Rovers Spirit and Opportunity” .

{moscomment}