Phoenix (spacecraft)
Phoenix was an uncrewed space probe that landed on the surface of Mars on May 25, 2008, and operated until November 2, 2008. Phoenix was operational on Mars for sols. Its instruments were used to assess the local habitability and to research the history of water on Mars. The mission was part of the Mars Scout Program; its total cost was $420 million, including the cost of launch.
The multi-agency program was led by the Lunar and Planetary Laboratory at the University of Arizona, with project management by NASA's Jet Propulsion Laboratory. Academic and industrial partners included universities in the United States, Canada, Switzerland, Denmark, Germany, the United Kingdom, NASA, the Canadian Space Agency, the Finnish Meteorological Institute, Lockheed Martin Space Systems, MacDonald Dettwiler & Associates in partnership with Optech Incorporated and other aerospace companies. It was the first NASA mission to Mars led by a public university.
Phoenix was NASA's sixth successful landing on Mars, from seven attempts, and the first in Mars's polar region. The lander completed its mission in August 2008, and made a last brief communication with Earth on November 2 as available solar power dropped with the Martian winter. The mission was declared concluded on November 10, 2008, after engineers were unable to re-contact the craft. After unsuccessful attempts to contact the lander by the Mars Odyssey orbiter up to and past the Martian summer solstice on May 12, 2010, JPL declared the lander to be dead. The program was considered a great success because it completed all planned science experiments and observations.
Mission overview
The mission had two goals. One was to study the geological history of water, the key to unlocking the story of past climate change. The second was to evaluate past or potential planetary habitability in the ice-soil boundary. Phoenix's instruments were suitable for uncovering information on the geological and possibly biological history of the Martian Arctic. Phoenix was the first mission to return data from either of the poles, and contributed to NASA's main strategy for Mars exploration, "Follow the water."The primary mission was anticipated to last 90 sols —just over 92 Earth days. However, the craft exceeded its expected operational lifetime by a little over two months before succumbing to the increasing cold and dark of an advancing Martian winter. Researchers had hoped that the lander would survive into the Martian winter so that it could witness polar ice developing around it – perhaps up to of solid carbon dioxide ice could have appeared. Even had it survived some of the winter, the intense cold would have prevented it from lasting all the way through. The mission was chosen to be a fixed lander rather than a rover because:
- costs were reduced through reuse of earlier equipment ;
- the area of Mars where Phoenix landed is thought to be relatively uniform, thus traveling on the surface is of less value; and
- the weight budget needed for mobility could instead be used for more and better scientific instruments.
History
While the proposal for Phoenix was being written, the Mars Odyssey orbiter used its gamma-ray spectrometer and found the distinctive signature of hydrogen on some areas of the Martian surface, and the only plausible source of hydrogen on Mars would be water in the form of ice, frozen below the surface. The mission was therefore funded on the expectation that Phoenix would find water ice on the arctic plains of Mars. In August 2003 NASA selected the University of Arizona "Phoenix" mission for launch in 2007. It was hoped this would be the first in a new line of smaller, low-cost, Scout missions in the agency's exploration of Mars program. The selection was the result of an intense two-year competition with proposals from other institutions. The $325 million NASA award is more than six times larger than any other single research grant in University of Arizona history.Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory, as Principal Investigator, along with 24 Co-Investigators, were selected to lead the mission. The mission was named after the Phoenix, a mythological bird that is repeatedly reborn from its own ashes. The Phoenix spacecraft contains several previously built components. The lander used was the modified Mars Surveyor 2001 Lander, along with several of the instruments from both that and the previous unsuccessful Mars Polar Lander mission. Lockheed Martin, who built the lander, had kept the nearly complete lander in an environmentally controlled clean room from 2001 until the mission was funded by the NASA Scout Program.
File:Sojourner, MER, Phoenix lander, and Curiosity comparisons, in Metric units.jpg|thumb|left|A comparison of sizes for the Sojourner rover, the Mars Exploration Rovers, the Phoenix lander and the Mars Science Laboratory.
Phoenix was a partnership of universities, NASA centers, and the aerospace industry. The science instruments and operations were a University of Arizona responsibility. NASA's Jet Propulsion Laboratory in Pasadena, California, managed the project and provided mission design and control. Lockheed Martin Space Systems built and tested the spacecraft. The Canadian Space Agency provided a meteorological station, including an innovative laser-based atmospheric sensor. The co-investigator institutions included Malin Space Science Systems, Max Planck Institute for Solar System Research, NASA Ames Research Center, NASA Johnson Space Center, MacDonald, Dettwiler and Associates, Optech Incorporated, SETI Institute, Texas A&M University, Tufts University, University of Colorado, University of Copenhagen, University of Michigan, University of Neuchâtel, University of Texas at Dallas, University of Washington, Washington University in St. Louis, and York University. Scientists from Imperial College London and the University of Bristol provided hardware for the mission and were part of the team operating the microscope station.
On June 2, 2005, following a critical review of the project's planning progress and preliminary design, NASA approved the mission to proceed as planned. The purpose of the review was to confirm NASA's confidence in the mission.
Specifications
;Launched mass;Lander Mass
;Lander Dimensions
;Communications
;Power
Lander systems include a RAD6000 based computer system for commanding the spacecraft and handling data. Other parts of the lander are an electrical system containing solar arrays and batteries, a guidance system to land the spacecraft, eight and monopropellant hydrazine engines built by Aerojet-Redmond Operations for the cruise phase, twelve Aerojet monopropellant hydrazine thrusters to land the Phoenix, mechanical and structural elements, and a heater system to ensure the spacecraft does not get too cold.
Scientific payload
Phoenix carried improved versions of University of Arizona panoramic cameras and volatiles-analysis instrument from the ill-fated Mars Polar Lander, as well as experiments that had been built for the canceled Mars Surveyor 2001 Lander, including a JPL trench-digging robotic arm, a set of wet chemistry laboratories, and optical and atomic force microscopes. The science payload also included a descent imager and a suite of meteorological instruments.During EDL, the Atmospheric Structure Experiment was conducted. This used accelerometer and gyroscope data recorded during the lander's descent through the atmosphere to create a vertical profile of the temperature, pressure, and density of the atmosphere above the landing site, at that point in time.
Robotic arm and camera
The robotic arm was designed to extend from its base on the lander, and had the ability to dig down to below a sandy surface. It took samples of dirt and ice that were analyzed by other instruments on the lander. The arm was designed and built for the Jet Propulsion Laboratory by Alliance Spacesystems, LLC in Pasadena, California. A rotating rasp-tool located in the heel of the scoop was used to cut into the strong permafrost. Cuttings from the rasp were ejected into the heel of the scoop and transferred to the front for delivery to the instruments. The rasp tool was conceived of at the Jet Propulsion Laboratory. The flight version of the rasp was designed and built by HoneyBee Robotics. Commands were sent for the arm to be deployed on May 28, 2008, beginning with the pushing aside of a protective covering intended to serve as a redundant precaution against potential contamination of Martian soil by Earthly life-forms.The Robotic Arm Camera attached to the robotic arm just above the scoop was able to take full-color pictures of the area, as well as verify the samples that the scoop returned, and examined the grains of the area where the robotic arm had just dug. The camera was made by the University of Arizona and Max Planck Institute for Solar System Research, Germany.