Curiosity: Sol 0 to Sol 2

It’s been an amazing few days since Curiosity landed on Mars. The rover is off to a good start in what is called the “characterisation activity phase” of the mission, which is scheduled to last around a month.

The rover landed on Mars at 15:00 “Mars time”, equating to 06:14 BST on August 6th, or  22:14 PDT August 5th, at NASA’s Jet Propulsion Laboratory in Pasadena, with confirmation being received on Earth at 06:32 / 22:32 respectively .

This marked the start of the rover’s first day on Mars, officially designated Sol 0. Activities during Sol 0 comprised releasing various instruments and protective covers, such as those over the Hazcams at the front and rear of the rover, checking-out the UHF telecommunications system and the rover motor controller, confirming its orientation (facing a heading of 112.7 degrees (+/- 5 degrees) and with a slight tilt) and relaying some 5 Mb of data back to Earth via Mars Odyssey.

Sol 1

Sol 1 saw the rover gather data from the Radiation Assessment Detector and Rover Environmental Monitoring Station instruments and further tests on the high-gain antenna (HGA), located towards the back of the vehicle. This is important, as the HGA enables the rover to communicate directly with Earth when it is above the rover’s horizon, rather than signals having to be relaid via Mars Odyssey and Mars Reconnaissance Orbiter (MRO) – although both of these will continue to be used when direct rover-Earth lines of communications are unavailable.

Curiosity took its first colour image of Mars using the Mars Hand Lens Imager, or MAHLI, located on the robot arm. This image appeared oddly rotated due to the arm being in its stowed position, MAHLI pointing outwards on the front left side of the rover.

First MAHLI image, taken with the camera in its stowed position, looking over the side of the rover. In the distance is the rim of the crater

The image appears cloudy as it was taken before MAHLI’s protective cover was still in place, coated by a film of dust thrown-up by the descent stage motors during landing.  The image is facing north, and the visible ridge is the rim of Gale Crater, with the peak to the left being some 1,150m (3,775 ft) high and 24 km (15 miles) from the rover

Sol 1 also saw the rover complete an initial deployment of the forward remote sensing mast to enable calibration of the navigation cameras (Navcams) to commence. Calibration was expected to take around a Sol to complete, as test images of targets on the rear section of the vehicle had to be returned to Earth in order for any “manual” adjustments yo the camera systems to be calculated and then transmitted back to the rover.

MAHLI’s image (above) given context is a computer simulation of Gale Crater developed from hi-resolution images returned by MRO’s HiRISE and the High Resolution Stereo Camera on Europe’s Mars Express.

During Sol 1, MRO also captured a fabulous image of the landing zone from some 300 km above the surface of Mars, using it’s HiRISE camera system. The image clearly shows the shadow cast by Curiosity, together with parachute and aeroshell to the left and slightly below it (approx. 615m away) and the impact points for the heat shield (some 1.5 km (1 mile) from the rover) and descent stage. The latter, having flown clear of the rover’s landing-zone, impacted on the surface around 650 metres from the rover, leaving a classic oblique impact mark (common to asteroids striking a planet), which forms an arrow pointing back towards the rover. This image was later combined with images of Mars to create a short movie called Zooming in on the scene of Curiosity’s Landing.

Sol 2

Curiosity’s remote sensing mast, seen fully deployed prior to launch in 2011

On Sol 2, Curiosity completed calibration testing on the Navcams, and raised the remote sensing mast to its fully deployed position. An initial high-resolution image was then captured by the Navcam, looking out over the front of the rover (part of an exercise to help confirm the rover’s alignment relative to the sun).

The first image taken by the Navcams following full deployment of the remote sensing mast. The cameras are looking forward and down over the front of the rover, away from the sun (what JPL calls the “anti-sun” image)

Following this, the mast was rotated, allowing the Navcams to be used to capture images of the rover’s immediate surroundings, including a 360-degree panoramic collage of Gale Crater and Aeolis Mons (referred to as “Mount Sharp” by NASA, the unofficial name given to the mound prior to its naming by the IAU). The panoramic view was initially returned to Earth as a collage of thumbnail images.

The first 360-degree panoramic view of the landing site and Gale Crater returned as thumbnails by Curiosity

As it is currently only available at thumbnail resolution, the panoramic view was somewhat overshadowed by high-resolution images also returned by the Navcams, which stand as promise of things to come once the Mastcams start operations.

The Navcams were also used to image elements of the rover itself in order to gain a further indication of the vehicle’s overall condition, and these revealed no nasty surprises, and were later strung together to give and overhead “fish-eye” view of  Curiosity (see the image towards the end of this article).

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3 thoughts on “Curiosity: Sol 0 to Sol 2

  1. I guess I should have read this post first. I’ll bet young boys see stuff like this and wanna get in there and fiddle with it. So, I’ll answer my own question. I suppose teenage boys get the difference. As for girls, I’m not sure how I’d have felt about it. I mean, someone telling me we’ve landed a rover on Mars, I think I’d say, duh. hehe. I mean, if I was a teen again.


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