* Astronomy

OPPORTUNITY UPDATE: Investigating a Dark Streak - sol 1139-1144, April 17, 2007:

Opportunity is healthy and spent the last week investigating the dark material trailing north from "Victoria Crater." The plan this week included two brief robotic arm campaigns at different areas roughly 33 metres  apart. Opportunity will collect a series of microscopic images and alpha particle X-ray spectrometer integrations on the soil along with other remote science observations.

Sol-by-sol summary:
Each sol starts with a panoramic camera tau and miniature thermal emission spectrometer mini sky and ground stare right after handing over from the previous sol's master sequence. At the end of each sol's plan, right before transitioning to the following sol, there is a navigation camera bitty cloud observation and a miniature thermal emission spectrometer mini sky and ground stare.

Sol 1139 (April 8, 2007): Opportunity conducted remote sensing on the dark streak. The rover then took stereo microscopic images of "Palencia" and "Pontevedra." Opportunity then moved its robotic arm out of the way to prepare for argon integration position. The panoramic camera was then used to image the rover tracks. The rover began alpha particle X-ray spectromter argon integration. Opportunity then had a mini deep sleep. After waking, the rover looked for clouds with its navigation camera. The panoramic camera was used to image the sky.

Sol 1140: On this sol, Opportunity continued to conduct remote sensing on the dark streak. The rover then placed the alpha particle X-ray spectrometer on the soil. The panoramic camera conducted some photometry, then took a 13-filter image of track target "Zamora." The miniature thermal emission spectrometer examined Zamora and then the undisturbed soil behind it. The alpha particle X-ray spectrometer was then placed on the soil. The rover then went into deep sleep.

Sol 1141: Opportunity continued remote sensing on the dark streak. The panoramic camera took a panoramic image to test for albedo (light reflectivity). The miniature thermal emission spectrometer did a 7-point sky & ground stare. Before the Mars Odyssey pass, the panoramic camera was used for photometry experiments. The miniature thermal emission spectrometer conducted an elevation sky & ground stare and then it stared at the calibration target. After a deep sleep, the navigation camera looked for clouds in the sky.

Sol 1142: On the morning of this sol, the miniature thermal emission spectrometer conducted a mini sky & ground stare. The rover then drove 31.23 metres  to a second location in the dark streak. The navigation camera imaged a future robotic arm target and the panoramic camera imaged a future drive direction and then took a tau measurement.

Sol 1143: Opportunity bumped 2.21 metres. The panoramic camera took a tau measurement and the miniature thermal emission spectrometer did a sky and ground stare. Before it moved again, Opportunity took a 13-filter panoramic camera image of target "Alicante." The rover then stowed its arm and drove about 3 metres  to Alicante. Opportunity then unstowed its arm and autoplace software put it on Alicante. A microscopic image mosaic of Alicante was taken. The Mössbauer spectrometer did a quick touch of Alicante before the alpha particle X-ray spectrometer was placed on the target. Before the Odyssey pass, the panoramic camera took a tau measurement. During the orbiter's pass, Opportunity's miniature thermal emission spectrometer did a sky and ground stare. After the Odyssey pass, the alpha particle X-ray spectrometer was integrated on target Alicante.

Sol 1144: This sol saw more remote sensing on the dark streak. The panoramic camera took a tau measurement, the miniature thermal emission spectrometer did a sky and ground stare. The panoramic camera took a 13-filter image of "Avila," and then the miniature thermal emission spectrometer stared at the same target. Before the Odyssey pass, the panoramic camera took another tau measurement. During the pass, the miniature thermal emission spectrometer conducted an elevation sky and ground stare. The rover then went into deep sleep.

Current Odometry:
As of sol 1143, Opportunity's total odometry is 10,443.41 metres.

OPPORTUNITY UPDATE: Characterizing Wind Streaks - sol 1131-1138, April 10, 2007:

Opportunity is healthy and is attempting to characterize the dark wind streak material which emanates from Victoria Crater as seen from orbital images.
On Sol 1132 the team planned a four-hour alpha particle X-ray spectrometer integration to measure atmospheric Argon. The purpose of this measurement is to determine the atmospheric mixing processes and track their changes with time.
Sol 1137 included a test of a fix for a steering bias bug in the mobility flight software. This is the fix for the problem the team saw on sol 1114, when the software selected an arc that was 13 degrees off course from the goal.

Sol-by-sol summary:
In addition to Opportunity's usual observations of panoramic camera tau, navigation camera cloud captures, miniature thermal emission sky and ground stares, and panoramic camera sky spots, the rover did the following:

Sol 1131 (March 30, 2007): On this sol, Opportunity's panoramic camera began to take the first half of a long baseline stereo image of "Valley Without Peril." The navigation camera was used to fill gaps in the previous sol's panorama. The panoramic camera was then used again to image target "Almeria." The miniature thermal emission spectrometer also observed Almeria.

Sol 1132: Opportunity bumped 5.6 metres  to the second eye location of the stereo panorama of Valley Without Peril. The miniature thermal emission spectrometer observed target "Barcelona." The alpha particle X-ray spectromter completed a four-hour atmospheric Argon measurement.

Sol 1133: On this sol, the rover continued the long baseline stereo second eye image of Valley Without Peril and also conducted remote sensing.

Sol 1134: Opportunity drove to a bright spot between wind streaks to set up for microscopic imaging and alpha particle X-ray spectrometer measurements on sol 1135. The rover took panoramic camera images at three different times during the sol as part of a photometry experiment.

Sol 1135: On this sol, Opportunity used the microscopic imager to examine the soil target "Salamanca," in the bright spot area between wind streaks.

Sol 1136: Opportunity used the microscopic imager and the alpha particle X-ray spectrometer on soil target "Sevilla." The miniature thermal emission spectrometer did a foreground survey and the panoramic camera was used to image the rover tracks.

Sol 1137: The rover drove about 35 metres  to middle of a wind streak and then took images with its panoramic camera as part of a photometry experiment.

Sol 1138: On this sol, the miniature thermal emission spectrometer completed a foreground survey. The panoramic camera conducted a 13-filter foreground survey and took more images for the photometry experiment.

Current Odometry:
As of sol 1134, Opportunity's total odometry is 10,373.19 metres.

This image was taken by the Opportunity rover on Sol 1128.
(Version2 recolour)


Expand (146kb, 560 x 560)
Credit: NASA/JPL/Space Science Institute

OPPORTUNITY UPDATE: Opportunity Begins Imaging of 'Cape of Good Hope' - sol 1118-1125, March 27, 2007:

Opportunity is healthy and making progress on the imaging campaign of "Cape St. Vincent."
On Sol 1116, Opportunity experienced a fault due to a known but rare race condition in the flight software. This race condition fault has now occurred three times in 1,122 sols for Opportunity and three times in 1,143 sols for Spirit. Essentially, while the rover was booting up in the morning, two sequences were competing to complete first. The lower priority task was stopped by the higher priority task and when the former attempted to complete, it was locked out of the rover's memory. The software did as it is supposed to and threw up a red flag to programmers and awaited its next commands.
On Sols 1117 and 1118 were spent recovering the rover from the fault. Opportunity spent sols 1119 and 1120 resting since these sols fell on an Earth weekend (the project no longer has the resources to bring in a weekend sequencing team).
On Sol 1121, Opportunity drove to a position on the "Cape of Good Hope" to image the first half of a long baseline stereo image of Cape St. Vincent. On Sol 1123, Opportunity will bump 2.5 metres to image the second half of the Cape St. Vincent stereo image.
The remainder of the sols were spent obtaining remote sensing science.

Sol-by-sol summary:

In addition to Opportunity's usual observations of panoramic camera tau measurements, navigation camera bitty cloud scans (looking to the sky for clouds), miniature thermal emission spectrometer sky and ground stares, and panoramic camera sky spots, the rover also did the following:

Sol 1118 (March 17, 2007): On this sol, Opportunity recovered from the race condition fault.

Sol 1119: Opportunity rested this sol (weekend in Pasadena).

Sol 1120: Opportunity rested this sol (weekend in Pasadena).

Sol 1121: On this sol, the rover drove to the first eye position of long baseline stereo image of Cape St. Vincent (9.97 metres) and began imaging.

Sol 1122: The rover conducted remote sensing of atmosphere and soil properties on this sol.

Sol 1123: Opportunity bumped to the second eye position of long baseline stereo image of Cape St. Vincent (about 2.5 metres) and began imaging.

Sol 1124: On this sol the rover conducted a panoramic camera systematic soil and ground survey. The navigation camera was used in support of the miniature thermal emission spectrometer. The panoramic camera had a look at the horizon and the miniature thermal emission spectrometer assessed the foreground.

Sol 1125: Opportunity used this sol to look at the sky and ground with its miniature thermal emission. That instrument was also used to monitor for dust.

Current Odometry:
As of sol 1121, Opportunity's total odometry is 10,295.50 metres.