grunt

grunt

[gruhnt]
grunt, common name for members of the family Pomadasyidae, carnivorous fish of warm seas, most species of which are small and brightly colored. They are sound-producers, creating their noises by grinding their pharyngeal teeth together. Croakers, which belong to another family, are also sound-producing fish. Grunts are bottom-feeders with large mouths vividly colored in red or orange on the inside. The common, or white, grunt is a favorite food fish found on shallow sandy bottoms from the West Indies to the Carolinas; it averages 1 ft (30 cm) in length and 1 lb (.5 kg) in weight. The many species abundant off the Florida coasts include the margate, blue-striped, and gray grunts and the bizarre porkfish, with a blue-striped yellow body and black head-bands. The California sargo is common along the Pacific coast and the commercially important pigfish is found from Long Island Sound to Texas. Grunts are classified in the phylum Chordata, subphylum Vertebrata, class Osteichthyes, order Perciformes, family Pomadasyidae.
Phobos-Grunt (Russian: Фобос-Грунт) is a planned Russian sample return mission to Phobos, one of the moons of Mars. It will be the first Russian interplanetary mission since the failed Mars 96 mission. Its name means "Phobos Soil".

Overview

Phobos-Grunt is an unmanned lander that will study Phobos and then return a soil sample to Earth. It will also study Mars from orbit, including its atmosphere and dust storms, plasma and radiation. The mission may be propelled by controllable electric jet propulsion due to its capability for smooth changing of the propulsion output parameters along the flight trajectory. Phobos-Grunt is currently scheduled to be launched in October 2009 on a Zenit rocket launcher with a Fregat upper stage. The return vehicle will be back on Earth in 2012. An alternative launch window would be in 2011.

Partners

The Chinese Mars probe Yinghuo-1 will be sent together with Phobos-Grunt. On August-September 2010, after a 10 – 11.5 months cruise, Yinghuo-1 separates and enters a 800 x 80,000 km three day equatorial orbit (5° inclination). The spacecraft is expected to remain on Martian orbit for one year. Yinghuo-1 will focus mainly on the study of the external environment of Mars. Space center researchers will use photographs and data to study the magnetic field of Mars and the interaction between ionospheres, escape particles and solar wind.

Another passenger on the Phobos-Grunt is an experiment from the U.S.-based Planetary Society called Living Interplanetary Flight Experiment, or LIFE, which will send 10 types of microorganisms and a natural soil colony of microbes on the three-year round trip. The results may fuel the debate about whether meteorite-riding organisms can spread life throughout the solar system.

Furthermore, two MetNet Mars landers, developed by the Finnish Meteorological Institute, are planned to be included as a payload to the Phobos-Grunt mission.

Mission description

Immediately after the touchdown on Phobos, Phobos-Grunt will load a soil sample into a return rocket. In case of a breakdown of communications with mission control, it can enter an emergency mode to collect samples and still send them home in the return rocket. Normal collection could last from two days to a week. The robotic arm can collect rocks up to about half an inch in diameter. It ends in a pipe-shaped tool that splits to form a claw. This encloses a piston that will push the soil sample into an artillery-shell-shaped container. A light-sensitive photo-diode in the claw will help scientists confirm that the device did scoop material. They hope also to see images of trenches the claw leaves on the surface. The manipulator should perform 15 to 20 scoops yielding a total of three to five and a half ounces of soil.

The return rocket will sit atop the spacecraft, and will need to rise at 22 mph to escape Phobos’ gravity. To protect experiments remaining on the lander, springs will vault the rocket to a safe height, at which its engines will fire and begin maneuvers for the eventual trip to Earth.

The lander’s experiments will continue in-situ on Phobos’ surface for a year. To conserve power, mission control will turn these on and off in a precise sequence. The robotic arm will place more samples in a chamber that will heat it and analyze its spectrum. This analysis might determine the presence of easily vaporized substances, such as water.

The landing site that has been chosen is a region from 5°S to 5°N, 230° to 235°W.

Mission objectives and studies

  • Collect soil samples from Phobos and return them to Earth for scientifc research on Phobos, Mars, and Martian space.
  • In situ and remote studies of Phobos (to include analysis of soil samples)
  • Monitoring the atmospheric behavior of Mars, including the dynamics of dust storms
  • Studies of the vicinity of Mars, to include its radiation environment and plasma and dust
  • Study of the origin of the Martian satellites and their relation to Mars
  • Study of the role played by asteroid impacts in the formation of terrestial planets
  • Search for possible life or paleolife

Development

The space mission component development is led by the company NPO Lavochkin. Phobos soil sampling and downloading have been assigned to the GEOHI RAN Institute of the Russian Academy of Science (Vernadski Institute of Geochemistry and Analytical chemistry) and the integrated scientific studies of Phobos and Mars by remote and contact methods are being developed by the Russian Space Research Institute.

Development started in 2001 and the preliminary design was completed in 2004. As of May 2008, the following components of the spacecraft had been manufactured:

  • The main antenna
  • Elements of the propulsion system for the cruise stage
  • Components of the antenna feeder system
  • A prototype of the frame for the equipment compartment on the cruise stage for vibration tests
  • Landing gear
  • Elements of the separation system
  • A prototype of the return vehicle propulsion system for thermal-vacuum tests

Some project participants and outside experts have expressed sceptisism about the planned 2009 launch date, citing problems with the development of the spacecraft's onboard flight control system and its operating software and the complex avionics of the spacecraft. Francis Rocard, the head of France's space agency CNES described the mission as "very ambitious" and expressed uncertainty about the project.

Russian space officials have, however, insisted that the probe will fly in 2009. In January 2008, Director General of NPO Lavochkin Georgy Poleshyuk one more time confirmed that the spacecraft is set for launch in 2009. "We haven't have any discussions (about delaying the mission.) Work proceeds strictly on schedule", he said. Poleshyuk has identified the integration of the Chinese micro-satellite, the development of the ground control tracking complex and the development of scientific payloads as the most critical aspects of work for achieving a launch on time.

According to Poleshyuk, the flight version of the spacecraft bus should be ready by January 2009, so that in February 2009 the installation of scientific instruments and the final assembly of the vehicle could begin. The Russian Space Research Institute, IKI, had committed to the delivery of instruments by the end of 2008 - beginning of 2009.

See also

References

  • M. Ya. Marov, V. S. Avduevsky, E. L. Akim, T. M. Eneev, R. S. Kremnevich, S. D. Kulikovich, K. M. Pichkhadzec, G. A. Popov, G. N. Rogovshyc (2004). "Phobos-Grunt: Russian sample return mission". Advances in Space Research 33 (12): 2276–2280.

External links

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