page_title: Spirit (rover)
section_title: Design and construction
hierarchical_section_title: Spirit (rover) / Design and construction
caption_attribution_description: English: The piece of metal with the American flag on it in this image of a NASA rover on Mars is made of aluminum recovered from the site of the World Trade Center towers in the weeks after their destruction. The piece serves as a cable guard for the rock abrasion tool on NASA's Mars Exploration Rover Spirit as well as a memorial to the victims of the Sept. 11, 2001, attacks. An identical piece is on the twin rover, Opportunity.
context_page_description: Spirit, also known as MER-A or MER-2, is a robotic rover on Mars, active from 2004 to 2010. It was one of two rovers of NASA's Mars Exploration Rover Mission. It landed successfully within the impact crater Gusev on Mars at 04:35 Ground UTC on January 4, 2004, three weeks before its twin, Opportunity, which landed on the other side of the planet. Its name was chosen through a NASA-sponsored student essay competition. The rover became stuck in a "sand trap" in late 2009 at an angle that hampered recharging of its batteries; its last communication with Earth was sent on March 22, 2010.
  The rover completed its planned 90-sol mission. Aided by cleaning events that resulted in more energy from its solar panels, Spirit went on to function effectively over twenty times longer than NASA planners expected. Spirit also logged 7.73 km of driving instead of the planned 600 m, allowing more extensive geological analysis of Martian rocks and planetary surface features. Initial scientific results from the first phase of the mission were published in a special issue of the journal Science.
  On May 1, 2009, Spirit became stuck in soft sand.
context_section_description: Spirit (and its twin, Opportunity) are six-wheeled, solar-powered robots standing 1.5 meters (4.9 ft) high, 2.3 meters (7.5 ft) wide and 1.6 meters (5.2 ft) long and weighing 180 kilograms (400 lb). Six wheels on a rocker-bogie system enable mobility over rough terrain. Each wheel has its own motor. The vehicle is steered at front and rear and is designed to operate safely at tilts of up to 30 degrees. Maximum speed is 5 centimeters per second (2.0 in/s); 0.18 kilometers per hour (0.11 mph), although average speed is about 1 centimeter per second (0.39 in/s). Both Spirit and Opportunity have pieces of the fallen World Trade Center's metal on them that were "turned into shields to protect cables on the drilling mechanisms".
  Solar arrays generate about 140 watts for up to four hours per Martian day (sol) while rechargeable lithium ion batteries store energy for use at night. Spirit's onboard computer uses a 20 MHz RAD6000 CPU with 128 MB of DRAM, 3 MB of EEPROM, and 256 MB of flash memory. The rover's operating temperature ranges from −40 to +40 °C (−40 to 104 °F) and radioisotope heater units provide a base level of heating, assisted by electrical heaters when necessary. A gold film and a layer of silica aerogel provide insulation.
  Communications depends on an omnidirectional low-gain antenna communicating at a low data rate and a steerable high-gain antenna, both in direct contact with Earth. A low gain antenna is also used to relay data to spacecraft orbiting Mars.
caption: The piece of metal with the American flag on Spirit's rock abrasion tool is made of aluminum recovered from the site of the World Trade Center towers.
exif: {}