Category: Other Worlds and Tech

Following my last Curiosity update, which noted that other than for one potential drilling / sampling target, work was wrapping-up for the Mars Science Laboratory in the “Pahrump Hills” location on the lower slopes of “Mount Sharp”, the decision was taken to indeed gather one more sample.

The selected target had been dubbed “Telegraph Peak”, and sits towards the top end of “Pahrump Hills”. It was selected because Alpha Particle X-ray Spectrometer (APXS) measurements carried out by the rover during its 5-month “walkabout” in “Pahrump Hills” revealed the rocks in the area to be relatively enriched in silicon when compared to the corresponding amounts of aluminium and magnesium, which is somewhat different to rocks sample prior to the rover arrival at the basal slops of “Mount Sharp”. This enrichment has also shown to increase the further up the slopes of “Pahrump Hills” the rover climbed, which is of interest to the science team.

“When you graph the ratios of silica to magnesium and silica to aluminium, ‘Telegraph Peak’ is toward the end of the range we’ve seen,” Curiosity co-investigator Doug Ming explains. “It’s what you would expect if there has been some acidic leaching. We want to see what minerals are present where we found this chemistry.”

Sampling took place on February 24th, 2015 (PDT) or Sol 908 for the rover on Mars. For the first time in Curiosity’s time on Mars, it was carried out with no preliminary “mini-drill” operation. Instead, the science team judged that analysis of the rock by APXS indicted it was of a very similar nature to the previous two sample drilling sites in “Pahrump Hills”, and the new lower percussion drilling capabilities the rover now has were judged as sufficiently safe enough to go ahead with a direct sample gathering operation.

As I’ve covered previously in these pages, obtaining a sample for analysis is a multi-part operation. First the rock is drilled, and a core sample forced up through the drill bit into a one of two sample collection chambers at the top of the drill mechanism. From here, the sample is “shaken” through a feed to another device in the rover’s robot arm turret called CHIMRA – the Collection and Handling for In-Situ Martian Rock Analysis system, used to separate the tailings through a series of sieves, ready for different sizes of sample grains to be passed through the the rover’s on-board laboratory systems.

Both of these operations require the use of the drill’s percussive system to vibrate the turret, forcing material both from the drill’s sample collection chamber and through CHIMRA. However, on February 27th, during the initial operation to move the sample tailings from the drill chamber to CHIMRA, Curiosity’s on-board fault protect system identified a transient short circuit within the robot arm’s electronics. The immediately resulted in all arm-related activities being shut down, and the arm and turret locked into position ready for diagnostic operations to commence.

A transient short can occur for a number of reasons, and can pass without significant problems. However, it may also indicate a potential issue which might require some measure of action, such as a change in operating procedures or a restriction on how a mechanism is used, in order to avoid the issue becoming a serious problem in the future. To this end, following the fault report, mission engineers started diagnosing the problem, with almost all rover operations halted while they did so.

On Thursday, March 5th, as a part of the investigative process, the rover was commanded to carry out a series of vibration tests of the kind performed while forcing the transfer of samples from the drill to CHIMRA. The vibrations were carried out with the robot arm and turret in the same orientation and position which caused the initial triggering of the fault protection system, and in the third of 180 repeat motions, a similar transient short occurred, lasting less than one one-hundredth of a second, enough to trigger the rover’s fault protection systems, and confirming there does appear to be some kind of electrical issue.

Tests are now under-way to determine whether or not the short will occur with the turret in different orientations, and may be followed by additional tests to see if it occurs with the arm in different positions. If no shorting occurs with either a change in the orientation or position of the turret / arm, then the most obvious step in preventing any recurrence of the issue is to avoid placing the turret / arm in the same orientation for sample transfer operations during future drilling activities.

It is hoped that the tests can be completed in the course of the next week. If they show that operations can be resumed safely, it is anticipated that the sample transfer operations will be completed, and Curiosity will then be ready to resume its climb up “Mount Sharp”, leaving “Pahrump Hills” via a narrow valley the science team have dubbed “Artist’s Drive”.

Continue reading “Short circuits on Mars and mapping asteroids” →

Curiosity, NASA’s Mars Science Laboratory (MSL), has been wrapping things up in the “Pahrump Hills” region at the base of “Mount Sharp”, the mountain-sized mound of deposited material occupying the centre of Gale Crater.

For the last several months, the rover has been engaged on what geologists on Earth call a “walkabout”, zigzagging back and forth across the area, looking for targets of interest for follow-up investigations, and allow the science team to better understand the geology and form of the region.

This method of activity is a change from how Curiosity has largely operated to date, which has seen the rover primarily move from point-to-point along its route, only re-visiting sites as a part of its onward movement towards the goal of reaching and climbing “Mount Sharp” (such as when travelling into, and then back out of the “Glenelg” and “Yellowknife Bay” regions Curiosity first explored in 2012 / 2013).

In this respect, and as Aileen Yingst, the Deputy Principal Investigator with the Mars Hand Lens Imager (MAHLI) on the rover, describes, Curiosity has been demonstrating just how much of an avatar it is for the science team, allowing them to careful investigate, examine and catalogue “Pahrump Hills” in a rich, practical way using the very human technique of the “walkabout”, which will serve the mission well as the ascent up “Mount Sharp” continues.

Most recently, and since collecting samples from “Mojave 2″, the area of rock displaying interesting crystalline elements within it, Curiosity has been looking at an area geologists dubbed “pink cliffs”, which shows further signs of the crystalline structures, and might be a candidate for further investigation. If so, it will be the last stopping point in “Pahrump Hills” before Curiosity continues its climb up “Mount Sharp”.

Oppy Reaches 11

January 25th, 2015 saw NASA’s Mars Exploration Rover, Opportunity, reach it’s eleventh anniversary on Mars. The rover, one of two MER vehicles, arrived on Mars at January 25th, 2004 (Universal Time), ready to start a mission initially planned to last just 90 days.

Since then, and up to its anniversary, “Oppy” has travelled a distance of some 41.7 kilometres (25.9 miles). While this doesn’t sound that much (and in truth, a human science team could have travelled that far in just a few days, including time for any science carried out along the way), remember that “Oppy’s” forward speed is measured in centimetres per hour.

As one of two solar-powered MER rovers (the second, Spirit having finally succumbed to the hostile environment on Mars around March 215th, 2011), Opportunity has carried out an incredible amount of work, and greatly contributed to our understanding of the planet, returning compelling evidence about wet environments on ancient Mars.

The rover marked its anniversary by reaching the summit of “Cape Tribulation”, an uprising close to the rim of 20 kilometre (13.7 mile) wide Endeavour Crater, which the rover has been gradually circumnavigating. This involved a change in elevation for “Oppy” of about 135 metres (440 feet), and afforded it a panoramic view of the crater and the land around it, presenting a unique opportunity for geological observations of the crater and its rim.

 A New Mars Mystery

That night, too, there was another jetting out of gas from the distant planet. I saw it … That night another invisible missile started on its way to the earth from Mars, just a second or so under twenty-four hours after the first one.

– The narrator, H.G. Wells’ The War of the Worlds

Okay, so it’s unlikely to be the sign of an impending invasion of Martians possibly ticked-of at the way we’re cluttering-up their planet with our probes and landers and rovers, but recent events high in the atmosphere of Mars have given rise to some excitement.

The images, originally capture in 2012, show huge plumes rising some 250 kilometres (156 miles) into the most tenuous reaches of Mars’ thin atmosphere.

The plumes occurred on two separate occasions in March and April 2012, and were spotted by amateur astronomers. Each time, they developed with relative rapidity, rising upwards and outwards to cover areas of some 1000 x 500 kilometres (625 x 312.5 miles) in a period of around 10 hours before remaining visible for up to 10 days at a time, their structure and form changing on a daily basis.

Unfortunately, neither event was seen from orbit about Mars, occurring so high on the planet’s limb as to be effectively out-of-sight for the NASA and ESA orbital vehicles, and by the time word had spread sufficiently about the observations, the events were largely over.

However, investigations into images of the planet taken by the Hubble Space Telescope in orbit around the Earth have revealed similar plumes being imaged in the past. However, with the exception of an image captured in 1997, none have been anywhere near as high or dramatic as the 2012 events.

So what might have caused this plumes to occur? The answer to that question is uncertain.

Continue reading “Avatars on Mars, Falcons in Florida and oceans in space” →