SENER's pointing mechanism for the rover Curiosity demonstrates its efficiency on Mars21/08/2012 (Spain)
The SENER engineering and technology group is participating in the Mars Science Laboratory mission as part of a technology collaboration agreement between NASA's Jet Propulsion Laboratory (JPL) and the Spanish Center for the Development of Industrial Technology (CDTI). More specifically, the company has supplied the pointing mechanism for the high-gain antenna that enables bi-directional communication between the rover Curiosity and the mission's tracking stations on Earth. The antenna's main job is to receive Curiosity's daily work orders promptly, and this has been done with excellent results during the initial weeks of the mission to Mars, thanks to the precision of the mechanism supplied by SENER.
After an eight-month journey and a successful landing on the Martian surface on August 6th, the various on-board devices and instruments have been activated and fine-tuned via commands relayed from the JPL in Pasadena (California). One of these fine-tuning activities involved determining the vehicle's exact location, which is crucial for correctly orienting the high-gain antenna toward Earth. This task was successfully completed on August 8th and at this point broadband communication with Earth is functioning normally.
Over the last weeks, the anntena has daily communicated the rover with the control center on Earth. In the next days, Curiosity will start using the on board scientific instruments for the exploration of a Martian area called Glenelg, where it will take the first geological samplers.
A fully autonomous antenna
SENER's mechanism is the first ever to allow a rover to position itself independently with its own antenna, without the entire vehicle having to turn to point toward Earth, thus providing significant energy savings. The antenna communicates directly with NASA's deep space stations in Pasadena (USA), Canberra (Australia) and Robledo de Chavela, in Madrid (Spain), with a lag of just 13.8 minutes, so that all of the information arriving from Mars is closer than ever to real-time.
The pointing mechanism has two degrees of freedom and elevation over azimuth, and is integrated on the rover platform, from where it can point the antenna precisely toward Earth. An actuator moves each axis independently to achieve the required velocity and accuracy. SENER has also designed the antenna's connection and deployment systems, which worked seamlessly after Curiosity's landing.
The main challenges SENER's team had to face stemmed from the unique conditions of the Martian atmosphere. First, the broad temperature range the rover (and therefore all of its equipment and instruments) is subjected to will range from -130 °C to 50 °C. Secondly, there is the phenomenon of suspended fine dust, which worsens during the infamous Martian storms. This made it critical to take special care when designing the mechanism's seals and in its lubrication. Lastly were the reliability requirements needed throughout the mission, since the rover is designed to function for at least two years, but experience has shown that these missions tend to extend beyond their scheduled dates.
The high-gain antenna's pointing mechanism is SENER's first device operating on a heavenly body other than Earth, making it a new milestone in the company's work in the space industry.
SENER is a global leader in the space industry, with over 208 devices launched in 48 satellites or space vehicles to date: for the space agencies of the US (NASA), Europe (ESA), Japan (JAXA) and Russia (Roscosmos), all without a single recorded failure.