Winter Solstice Just Three Weeks Away For Spirit

Spirit remains silent at her location called "Troy" on the west side of Home Plate. No communication has been received from the rover since Sol 2210 (March 22, 2010).

It is likely that Spirit has experienced a low-power fault and has powered off all sub-systems, except her master clock. The rover will use the available solar array energy to recharge her batteries.

When the batteries recover to a sufficient state of charge, Spirit will wake up and begin to communicate. When that does happen, Spirit will also trip an up-loss timer fault.

This fault response will allow the rover to communicate over Ultra-High Frequency (UHF) as well as X-band.

It is not know when the rover will wake up, so the project has been listening for any X-band signal from Spirit through the Deep Space Network every day.

The relay orbiters are also listening over any scheduled UHF relay passes. The winter solstice is just three weeks away (Sol 2261, or May 13, 2010).

Total odometry is unchanged at 7,730.50 meters (4.80 miles).

Soviet Moon 'Mirror' Finally Identified

The location of the Lunokhod 2 rover on the surface of the Moon. Its twin, Lunokhod 1, was recently found as well

Using data collected by a NASA spacecraft, experts were finally able to rediscover a long-lost, Soviet-built reflecting device on the surface of the Moon. The exact location of the scientific payload has remained a mystery since September 14, 1971. At that date, the Soviet Union lost contact with its Lunokhod 1 rover, which was carrying the mirrors. Nearly 40 years later, American physicists were able to identify the instrument using lasers beamed to the Moon all the way from Earth, Space reports.

The reflecting device itself was built by France for the Soviet Union, and it landed on the natural satellite on November 17, 1970, aboard the lander segment of the Lunokhod 1 mission. The rover was then deployed, and began its trek across the lunar surface. Eventually, in September the following year, contact with the small exploration robot was lost, and its location became a mystery. “No one had seen the reflector since 1971,” explains University of California in San Diego (UCSD) associate professor of physics Tom Murphy, who led the group that identified the Russian instrument.

This particular science team has been conducting laser experiments between Earth and the Moon for several decades. NASA has its own mirrors placed on the natural satellite, and laser beams shone on them help physicists test for gaps in Einstein's Theory of General Relativity. Light emitted from special facilities here travels to the mirrors, and then gets reflected back. The experts then look at the modifications the laser beam suffered, and calculate if the time needed for it to return is in tune with theoretical predictions based on Albert Einstein's calculations.

“We routinely use the three hardy reflectors placed on the moon by the Apollo 11, 14 and 15 missions, and occasionally the Soviet-landed Lunokhod 2 reflector – though it does not work well enough to use when illuminated by sunlight. But we yearned to find Lunokhod 1,” Murphy adds. Over the past two years, the group occasionally took some time from their work to look for the rover, but the breakthrough came only last month, when new images from the NASA Lunar Reconnaissance Orbiter (LRO) were made available.

Snapped using the Lunar Reconnaissance Orbiter Camera (LROC) instrument, the photographs were sufficiently detailed to allow for the team to identify the rover as a speck of dust in the desolate lunar landscape. The machine was located miles from where initial estimates had placed it, and from where Murphy and his team had been looking for it. Using the 3.5-meter telescope at the Apache Point Observatory, in New Mexico, the researchers sent a beam of laser light in the direction of the reflecting device, and even managed to get a hit back.

“We quickly verified the signal to be real and found it to be surprisingly bright: at least five times brighter than the other Soviet reflector, on the Lunokhod 2 rover, to which we routinely send laser pulses. The best signal we've seen from Lunokhod 2 in several years of effort is 750 return photons, but we got about 2,000 photons from Lunokhod 1 on our first try. It's got a lot to say after almost 40 years of silence,” Murphy reveals.

“Not only now do we know that Lunokhod 1 is there, we also know that it is parked perfectly so that its reflector faces Earth. In fact, the signal is so surprisingly strong that the rover could not be in anything but a level parking spot with its commanded roll on the lunar surface deliberately oriented toward the Earth,” the expert concludes.

Picking Up Pace To Endeavour Crater

Endeavour crater will be the final destination for Opporitnity.

Opportunity has picked up the pace a little as she presses on toward Endeavour crater, recharging her batteries between drives.

First, the rover must clear a region of large ripples, so Opportunity is heading south before the turn to the East. Sols 2206 (April 8, 2010) and 2208 (April 10, 2010), each saw a roughly 50-meter (164-foot) drive straight south.

On Sol 2211 (April 13, 2010), Opportunity drove 30 meters (98 feet) east, deliberately crossing a series of ripples to collect terrain data that will be used to calibrate simulation software. That software will help design future drives.

The right-front and right-middle wheel are exhibiting modestly elevated motor current levels, which the project continues to watch. The plan ahead is more driving. As of Sol 2211 (April 13, 2010), the solar array energy production was 227 watt-hours with an atmospheric opacity (tau) of 0.347 and a dust factor of 0.474.

Total odometry is 20,385.31 meters (20.39 kilometers, or 12.67 miles).

San Diego Team Delivers Camera for Next Mars Rover

The Mastcam instrument for NASA's Mars Science Laboratory will use a side-by side pair of cameras for examining terrain around the mission's rover. Right is a sample image from Mastcam 34 of Mastcam Principal Investigator Michael Malin. Image credit: NASA/JPL/Malin Space Science Systems

Malin Space Science Systems, Inc. (MSSS), has delivered the last two of four science cameras it developed for the NASA/Jet Propulsion Laboratory 2011 Mars Science Laboratory (MSL) rover mission. These cameras, known collectively as the Mast Camera (or Mastcam--see Figure 1a and b) are designed to be the science imaging "workhorse" for the MSL rover. The cameras, capable of taking full color images analogous to those taken by consumer digital cameras, will be mounted on the rover's remote sensing mast, where they can be panned and tilted to proved image coverage around the rover, both near the rover and out to the horizon. One of the two Mastcams has a telephoto lens, providing the rover with a long-distance reconnoitering capability. Also delivered to JPL for MSL with the two Mastcams was the Digital Electronics Assembly (DEA), which compresses and buffers the images from the Mast Cameras, and the Mars Hand Lens Imager (MAHLI) and Mars Descent Imager (MARDI), cameras also developed by MSSS for the MSL mission.

Figure 1a. The Mast Camera 34 mm fixed focal length flight camera head with a Swiss Army Knife (88.9 mm; 3.5 inches long) for scale. The Mastcam 34 consists of a refractive optics with a focus mechanism and a filter wheel, and a CCD sensor and associated electronics. Figure credit: Malin Space Science Systems.

Figure 1b. The Mast Camera 100 mm fixed focal length flight camera head with a Swiss Army Knife (88.9 mm; 3.5 inches long) for scale. The Mastcam 100 is a duplicate of the 34 mm Mastcam except for the lens, which has three times the focal length. The only external indication of which camera is which is that the front baffle opening for the Mastcam 100 is smaller than the front baffle opening of the Mastcam 34. Figure credit: Malin Space Science Systems.

The Mastcams were transported from the MSSS facility in San Diego to JPL on 17 March 2010 for an extremely sensitive contamination measurement. Prior the contamination test, the each camera was shown to be operating normally and capable of taking in-focus images (Figure 2). The contamination test was completed satisfactorily on 18 March, and instrument functionality was verified in testing the following day. The cameras and the DEA now await integration with the MSL rover.

Figure 2. During post-transportation instrument checkout in the Building 306 Low Bay Cleanroom at JPL, the Mastcam 34 mm flight unit was used to take this picture of Dr. Michael Malin, the Mastcam's Principal Investigator. A test target derived from the "1951 U. S. Air Force Resolution Chart" can be used to determine the spatial resolution of the camera as a function of contrast, a standardized test to demonstrate that the camera is functioning properly and that the optics have not experienced any change during transport to JPL. In this image, the camera is demonstrating a resolution of about 4.5 line pairs per millimeter (9 pixels per mm, or about 111 micrometers per pixel) at a distance of 2 meters. Figure credit: Malin Space Science Systems.

The Mastcam focus and filter wheels are driven by precision mechanisms developed by Alliance Spacesystems (www.alliancespacesystems.com). The focus mechanism uses a stepper motor to position an internal focus group by means of a cam. The filter wheel mechanisms use stepper motors to drive 8-filter wheels to position the desired color filters in front of each camera's CCD detector.
The versions of the Mastcams delivered to JPL have fixed focal lengths (34 mm and 100 mm), and relatively small fields of view (15 degrees and 5 degrees). They would be used to build up coverage of the martian landscape around the rover from a series of small individual images.

The two Mastcams were originally proposed to have the identical 15:1 zoom (variable focal length) lenses on each camera [each camera could image from 100 mm focal length (telephoto) down to 6.5 mm focal length (wide angle)]. NASA directed that the development of the zoom lens be abandoned in 2007 as a cost saving measure, and the Fixed Focal Length Mastcams just delivered were developed to replace the zoom versions. With the two completed and delivered fixed focal length cameras in hand, NASA recently decided to fund completion of the zoom cameras by the Mastcam team, with the possibility of swapping out the old cameras for the new ones provided they can be assembled and tested in the time remaining before the MSL rover begins final testing early next year. The effort to build the zoom lens cameras has just started at MSSS.

"Restoring the zoom is not a science issue," said Michael Malin, Mastcam Principal Investigator, "although there will be some science benefits." "The fixed focal length Mastcams we just delivered will do almost all of the science we originally proposed. But they cannot provide a wide field of view with comparable eye stereo. With the zoom Mastcams, we'll be able to take cinematic video sequences in 3D on the surface of Mars. This will give our public engagement Co-Investigator, James Cameron, tools similar to those he used on his recent 3D motion picture projects."

MSSS has also provided two other cameras for the MSL mission: the Mars Hand Lens Imager (MAHLI) and the Mars Descent Imager (MARDI). The MAHLI, delivered to JPL in October of 2008, will be mounted at the end of the rover's robotic arm, and will be used to acquire very high resolution color images of the grain structure of individual rocks. The MARDI, delivered to JPL in July of 2008, will obtain color images of the martian surface during the descent of the MSL spacecraft to the surface, and may be used during rover traverses to acquire millimeter scale 3D views of the surface beneath the rover.

The Mastcam, MAHLI, and MARDI investigations were selected in 2004 by NASA's Science Mission Directorate in an open competition. The instruments share a common electronics design and were developed by Malin Space Science Systems, Inc., of San Diego, CA, under a single $18.9 million contract with Caltech's NASA-funded Jet Propulsion Laboratory in Pasadena, CA. MSSS will also be responsible for operating the cameras during the mission to Mars.

MSSS is currently building a camera for the Juno mission to Jupiter, that will also launch in 2011. MSSS built, and is presently operating two cameras onboard NASA's Mars Reconnaissance Orbiter (MRO), the Mars Color Imager (MARCI) and the Context Camera (CTX). MARCI provides a daily global weather map of Mars in five colors and two ultraviolet bands. CTX has already mapped more than 53% of Mars at 6 m per pixel resolution. Pictures from these cameras and other activities of the company are described at www.msss.com.

Opportunity Reaches New Drive Record on Mars

Astronomers announce today that the NASA rover Opportunity managed to break new records on March 24. More than 74 months after arriving on the Red Planet, the machine finally exceeded the 20-kilometer (12.43-mile) mark, meaning that it traveled further away than any other robotic explorer on Mars. Only a Soviet-built lunar rover traveled more, but that was a lot closer to home, and there are several advantages to a shorter distance. Experts at the NASA Jet Propulsion Laboratory (JPL), who manage the mission, are understandably ecstatic about this achievement.

Opportunity, just like its twin MER component Spirit, was originally planned to endure for only three months on the Martian surface. After exceeding that duration more than 24 times over, it's safe to say that those who were in charge of building it did a fantastic job. Drivers and mission planners are to be praised for this achievement as well. Also worthy of mention is the fact that the robot has not been driving non-stop since it landed. It has had numerous pit stops along the way, as every time it found an interesting rock it stopped to take a closer look.

It only recently concluded a six-week stay on the rim of Concepción Crater, where it investigated a peculiar layer of material covering the otherwise-uniform rocks that it has been driving over for the past 6 years. The drive that made it achieve the new record took place on the 2,191st Martian day, or sol, of its mission, as the rover was heading southwards, towards the Endeavor Crater, its long-term mission. During the last trek, Opportunity covered some 67 meter, or 220 feet, its managers say. But its target is still a spectacular distance away. The robot needs to go an additional 12 kilometers (7.5 miles) farther to reach Endeavor.

There is currently no reason to believe that the rover won't make it to that location. Its primary systems are looking fine, and its wheels and driving train are in good shape. Naturally, all components are showing signs of aging, given the amount of time it endured on Mars. But, unlike its twin Spirit, the robot doesn't need to stop and shut down its systems for winter, which means that it can be operated around the year. Either way, if Opportunity is to reach Endeavor before old age and technical issues get to it, managers need to hasten the drive maneuvers, while at the same time remaining vigilant to the dangers ahead.

Diagnostic wheel tests continue; Investigating 'Marquette' and 'Islington Bay'

This blink comparison aids evaluation of a drive by NASA's Mars Exploration Rover Spirit during the rover's 2,099th Martian day, or sol (Nov. 28, 2009). A stall by the right-rear wheel ended the drive after the first 1.4 meters (4.6 feet) of wheel movement in a two-step drive that had been planned to include a totla of 5 meters (16.4 feet) of wheel movement. As anticipated, nearly all of the wheel movement was slippage. Credit: NASA/JPL-Caltech

Spirit's extrication from her embedded location at Troy on the west side of Home Plate has been complicated by a recurring stall condition with the right rear wheel.

After diagnostic tests on Sol 2095 (Nov. 24, 2009), indicated a freely moving wheel, another two-step drive with 5 meters (16 feet) of wheel spin was commanded on Sol 2099 (Nov. 28, 2009). That drive resulted in another right rear wheel stall after only 1.4 meters (5 feet) of wheel motion.

Analysis of a right rear wheel stall back on Sol 1837 (March 25, 2009), well before embedding, suggests that the stall may not be terrain related, but could be internal to the wheel motor and gearbox. To investigate this, three sets of rotor resistance tests at cold, ambient and warm temperatures were commanded over Sols 2104 (Dec. 3, 2009), and 2105 (Dec. 4, 2009), to check the health of the motor windings and motor brushes. A small right rear wheel motion in the direction of the stall was also commanded on Sol 2104 to see if the stall persists.

The results of these diagnostic tests should be known later tonight (Thursday) and Friday with analyses performed on Friday and over the weekend. The next drive for Spirit would be no sooner than Monday (Dec. 7, 2009).

As of Sol 2099 (Nov. 28, 2009), the rover solar array energy production was 316 watt-hours with an atmospheric opacity (tau) of 0.572 and a dust factor of 0.567. Total odometry is 7,730.00 meters (4.80 miles).

Opportunity has been investigating the rock known as "Marquette Island."

On Sol 2076 (Nov. 25, 2009), the robotic arm (IDD) placed the Mössbauer (MB) spectrometer on a rock target called "Islington Bay" for a long, multi-sol integration.

With the temporary loss of relay operations for a few sols because of the Odyssey spacecraft safe-mode, Opportunity has limited the collection of other science data and continued with the low-data volume MB integrations. The miniature thermal emission spectrometer (Mini-TES) elevation mirror shroud is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2079 (Nov. 28, 2009), the solar array energy production was 360 watt-hours with an atmospheric opacity (tau) of 0.508 and a dust factor of 0.529. Total odometry was 18,906.82 meters (11.75 miles).