Home / Science / Astronomy / Mars Rover Mission Progresses Toward Resumed Drilling

Mars Rover Mission Progresses Toward Resumed Drilling

Mars Rover Step Toward Possible Resumption of Drilling

NASA’s Curiosity Mars rover conducted a test on Oct. 17, 2017, as part of the rover team’s development of a new way to use the rover’s drill. This image from Curiosity’s front Hazard Avoidance Camera (Hazcam) shows the drill’s bit touching the ground during an assessment of measurements by a sensor on the rover’s robotic arm.

Curiosity used its drill to acquire sample material from Martian rocks 15 times from 2013 to 2016. In December 2016, the drill’s feed mechanism stopped working reliably. During the test shown in this image, the rover touched the drill bit to the ground for the first time in 10 months. The image has been adjusted to brighten shaded areas so that the bit is more evident. The date was the 1,848th Martian day, or sol, of Curiosity’s work on Mars

In drill use prior to December 2016, two contact posts — the stabilizers on either side of the bit — were placed on the target rock while the bit was in a withdrawn position. Then the motorized feed mechanism within the drill extended the bit forward, and the bit’s rotation and percussion actions penetrated the rock.

A promising alternative now under development and testing — called feed-extended drilling — uses motion of the robotic arm to directly advance the extended bit into a rock. In this image, the bit is touching the ground but the stabilizers are not. Compare that to the positioning of the stabilizers on the ground in a 2013 image of the technique used before December 2016.

In the Sol 1848 activity, Curiosity pressed the drill bit downward, and then applied smaller sideways forces while taking measurements with a force/torque sensor on the arm. The objective was to gain understanding about how readings from the sensor can be used during drilling to adjust for any sideways pressure that might risk the bit becoming stuck in a rock.

While rover-team engineers are working on an alternative drilling method, the mission continues to examine sites on Mount Sharp, Mars, with other tools.

Credit: NASA/JPL-Caltech

 

Mars Rover Mission Progresses Toward Resumed Drilling

NASA’s Mars rover Curiosity team is working to restore Curiosity’s sample-drilling capability using new techniques. The latest development is a preparatory test on Mars.

The five-year-old mission is still several months from the soonest possible resumption of drilling into Martian rocks. Managers are enthusiastic about successful Earth-based tests of techniques to work around a mechanical problem that appeared late last year and suspended use of the rover’s drill.

“We’re steadily proceeding with due caution to develop and test ways of using the rover differently from ever before, and Curiosity is continuing productive investigations that don’t require drilling,” said Deputy Project Manager Steve Lee, of NASA’s Jet Propulsion Laboratory, Pasadena, California.

Curiosity touched its drill to the ground Oct. 17 for the first time in 10 months. It pressed the drill bit downward, and then applied smaller sideways forces while taking measurements with a force sensor.

“This is the first time we’ve ever placed the drill bit directly on a Martian rock without stabilizers,” said JPL’s Douglas Klein, chief engineer for the mission’s return-to-drilling development. “The test is to gain better understanding of how the force/torque sensor on the arm provides information about side forces.”

This sensor gives the arm a sense of touch about how hard it is pressing down or sideways. Avoiding too much side force in drilling into a rock and extracting the bit from the rock is crucial to avoid having the bit get stuck in the rock.

Curiosity has used its drill to acquire sample material from Martian rocks 15 times so far, from 2013 to 2016. It collected powdered rock samples that were delivered to laboratory instruments inside the rover. On each of those occasions, two contact posts — the stabilizers on either side of the bit — were placed on the target rock while the bit was in a withdrawn position. Then a motorized feed mechanism within the drill extended the bit forward, and the bit’s rotation and percussion actions penetrated the rock.

Testing New Techniques for Mars Rover Rock-Drilling

In the summer and fall of 2017, the team operating NASA’s Curiosity Mars rover conducted tests in the “Mars Yard” at NASA’s Jet Propulsion Laboratory, Pasadena, California, to develop techniques that Curiosity might be able to use to resume drilling into rocks on Mars.

JPL robotics engineer Vladimir Arutyunov, in this June 29, 2017, photo, checks the test rover’s drill bit at its contact point with a rock. Note that the stabilizer post visible to the right of the bit is not in contact with the rock, unlike the positioning used and photographed by Curiosity when drilling into rocks on Mars in 2013 to 2016.

In late 2016, after Curiosity’s drill had collected sample material from 15 Martian rocks, the drill’s feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to the stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock.

In the alternative technique seen here, called “feed-extended drilling,” the test rover’s stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill’s feed mechanism.

Credit: NASA/JPL-Caltech

 

The drill’s feed mechanism stopped working reliably in December 2016. After exploring possibilities of restoring the feed mechanism’s reliability or using it despite unreliability, the project set a priority to develop an alternative method of drilling without use of the feed mechanism. The promising alternative uses motion of the robotic arm to directly advance the extended bit into a rock.

“We’re replacing the one-axis motion of the feed mechanism with an arm that has five degrees of freedom of motion,” Klein said. “That’s not simple. It’s fortunate the arm has the force/torque sensor.”

The sensor’s main use until now has been to monitor for a force so excessive of expectations that it would automatically halt all arm motion for the day. The new “feed-extended” drilling uses it to compensate for side loads. This test will help engineers determine how data from the sensor can be used most effectively.

New Rock-Drilling Method in ‘Mars Yard’ Test

This photo taken in the “Mars Yard” at NASA’s Jet Propulsion Laboratory, Pasadena, California, on Aug. 1, 2017, shows a step in development of possible alternative techniques that NASA’s Curiosity Mars rover might be able to use to resume drilling into rocks on Mars.

In late 2016, after Curiosity’s drill had collected sample material from 15 Martian rocks in four years, the drill’s feed mechanism ceased working reliably. That motorized mechanism moved the bit forward or back with relation to stabilizer posts on either side of the bit. In normal drilling by Curiosity, the stabilizers were positioned on the target rock first, and then the feed mechanism extended the rotation-percussion bit into the rock.

In the alternative technique seen here, called “feed-extended drilling,” the test rover’s stabilizers are not used to touch the rock. The bit is advanced into the rock by motion of the robotic arm rather than the drill’s feed mechanism. Compare the stabilizers’ position in this image to a sequence of images taken by Curiosity while drilling a Martian rock in 2013.

Credit: NASA/JPL-Caltech

 

Using this method, a near-twin of Curiosity at JPL has collected drilled samples from Earth rocks. The team has also developed methods to deliver drilled samples to the laboratory-instrument inlets on the test rover’s deck without use of the drill’s feed mechanism. Development of this alternative sample-transfer technique is needed because the process used previously depended on having the bit in a withdrawn, rather than extended, position.

“The development work and testing here at JPL has been promising,” Lee said. “The next step is to assess the force/torque sensor on Mars. We’ve made tremendous progress in developing feed-extended drilling, using the rover’s versatile capabilities beyond the original design concepts. While there are still uncertainties that may complicate attempts to drill on Mars again, we are optimistic.”

The rover’s current location is on “Vera Rubin Ridge” on lower Mount Sharp. Curiosity is nearing the top of the 20-story-tall ridge. It has been studying the extent and distribution of the iron-oxide mineral hematite in the rocks that make up the erosion-resistant ridge.

During the first year after Curiosity’s landing near Mount Sharp, the mission accomplished a major goal by determining that, billions of years ago, a Martian lake offered conditions that would have been favorable for microbial life. Curiosity has since traversed through a diversity of environments where both water and wind have left their imprint. Vera Rubin Ridge and layers above it that contain clay and sulfate minerals provide tempting opportunities to learn even more about the history and habitability of ancient Mars.

source: NASA – Jet Propulsion Laboratory – California Institute of Technology

Telegram Channel

About Mohammad Daeizadeh

  • تمامی فایل ها قبل از قرار گیری در سایت تست شده اند.لطفا در صورت بروز هرگونه مشکل از طریق نظرات مارا مطلع سازید.
  • پسورد تمامی فایل های موجود در سایت www.parsseh.com می باشد.(تمامی حروف را می بایست کوچک وارد کنید)
  • Password = www.parsseh.com

Leave a Reply

Your email address will not be published. Required fields are marked *

*