* Astronomy

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RE: Mars Exploration Probes

Blobrana · L

NASA is extending, for a fifth time, the activities of the Mars Exploration Rovers Spirit and Opportunity. The decision keeps the trailblazing mobile robotic pioneers active on opposite sides of Mars, possibly through 2009. This extended mission and the associated science are dependent upon the continued productivity and operability of the rovers.

"We are extremely happy to be able to further the exploration of Mars. The rovers are amazing machines, and they continue to produce amazing scientific results operating far beyond their design life" - Alan Stern, associate administrator for NASA's Science Mission Directorate, Washington.

The twin rovers landed on Mars in January 2004, 45 months ago, on missions originally planned to last 90 days. In September, Opportunity began descending into Victoria Crater in Mars' Meridiani Planum region. At approximately a half mile wide and 230 feet deep, it is the largest crater the rover has visited. Spirit climbed onto a volcanic plateau in a range of hills that were on the distant horizon from the landing site.

"After more than three-and-a-half years, Spirit and Opportunity are showing some signs of aging, but they are in good health and capable of conducting great science" - John Callas, rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, California, US.

The rovers each carry a suite of sophisticated instruments to examine the geology of Mars for information about past environmental conditions. Opportunity has returned dramatic evidence that its area of Mars stayed wet for an extended period of time long ago, with conditions that could have been suitable for sustaining microbial life. Spirit has found evidence in the region it is exploring that water in some form has altered the mineral composition of some soils and rocks.
To date, Spirit has driven 4.51 miles and has returned more than 102,000 images. Opportunity has driven 7.19 miles and has returned more than 94,000 images.

Among the rovers' many other accomplishments:

- Opportunity has analysed a series of exposed rock layers recording how environmental conditions changed during the times when the layers were deposited and later modified. Wind-blown dunes came and went. The water table fluctuated.
- Spirit has recorded dust devils forming and moving. The images were made into movie clips, providing new insight into the interaction of Mars' atmosphere and surface.
- Both rovers have found metallic meteorites on Mars. Opportunity discovered one rock with a composition similar to a meteorite that reached Earth from Mars.

JPL manages the rovers for NASA's Science Mission Directorate.

Source NASA

Blobrana · L

Here you can find descriptions of the various attempts; past, present and occasionally future, of exploring the planet Mars.

launch	Launch Date/Time (UTC)	Name	country	Information
1	1960 Oct 10 14:27:49	Marsnik 1	USSR	The first attempt. After launch, the third stage pumps were unable to develop enough thrust to commence ignition, so Earth parking orbit was not achieved. The spacecraft reached an altitude of 120 km before reentry.
2	1960 Oct 14 13:51:03	Marsnik 2	USSR	Another Failure, unable to reach orbit.
3	1962 Oct 24 17:55:04	Sputnik 22	USSR	The spacecraft and attached upper stage either broke up as they were going into Earth orbit or had the upper stage explode in orbit during the burn to put the spacecraft into Mars trajectory. The pieces, some of which apparently remained in Earth orbit for a few days, was detected by the U.S. Ballistic Missile Early Warning System radar in Alaska and was momentarily feared to be the start of a Soviet nuclear ICBM attack.
4	1962 Nov 01 16:14:16	Mars 1	USSR	Early telemetry indicated that there was a leak in one of the gas valves in the orientation system so the spacecraft was transferred to gyroscopic stabilization. On its way to Mars, communications ceased, probably due to failure of the spacecraft orientation system.
5	1962 Nov 04 15:35:15	Sputnik 24	USSR	The booster and spacecraft broke up during the burn to transfer to Mars trajectory. Five large pieces were tracked by the U.S. Ballistic Missile Early Warning System.
6	1964 Nov 05 19:22:05	Mariner 3	USA	The first american attempt, Unfortunately a protective shield failed to eject after the spacecraft had passed through the Earth's atmosphere. None of the instrument sensors were uncovered, and the added weight prevented the spacecraft from attaining its prescribed Mars trajectory.
6	1964 Nov 28 14:22:01	Mariner 4	USA	Mariner 4 successfully flies by Mars on 1965 July 14 and returns the first pictures of the Martian Surface.
7	1964 Nov 30 13:12:00	Zond 2	USSR	One of the two solar panels failed so only half the anticipated power was available to the spacecraft. After a mid-course maneuver, communications with the spacecraft were lost in early May, 1965. The dormant spacecraft flew by Mars on 6 August 1965.
8	1967 Mar 27	Unnamed	USSR	"Launch Failure"
8	1969 Feb 24 01:29:02	Mariner 6	USA	Another successful flyby mission on 1969 July 31.
9	1969 Mar 27 10:40:45	Mars 1969A	USSR	This Soviet Mars mission was never officially announced but has since been identified as a planned orbiter. After successful operation of the first two stages, the third stage launcher experienced a malfunction in a rotor bearing which caused the turbo pump to catch fire. The engine shut down and exploded; the remains of the craft landing in the Altai mountains.
9	1969 Mar 27 22:22:01	Mariner 7	USA	Mariner 7 flies by Mars on 1969 August 05.
10	1969 Apr 02 10:33:00	Mars 1969B	USSR	OUCH! This Soviet Mars mission was never officially announced but has since been identified as a planned orbiter. The first stage of the launcher failed almost immediately. At 0.02 seconds after liftoff, one of the six first-stage rockets exploded. The control system initially compensated for the lost engine and the launch proceeded on 5 engines---until 25 seconds after liftoff, at approximately 1 km altitude, the rocket began to tip over to a horizontal position. The five engines shut down and the rocket impacted and exploded 41 seconds after liftoff approximately 3 km from the launch pad.
11	1971 May 08 01:11:00	Mariner 8	USA	The main Centaur engine was ignited 265 seconds after launch, but the upper stage began to oscillate in pitch and tumbled out of control. The Centaur stage shut down 365 seconds after launch due to starvation caused by the tumbling. The Centaur and spacecraft payload separated and re-entered the Earth's atmosphere approximately 1500 km downrange and fell into the Atlantic Ocean about 560 km north of Puerto Rico.
12	1971 May 10 16:58:42	Cosmos 419	USSR	The booster successfully put the spacecraft into low Earth parking orbit, but the stage 4 failed to function due to a bad ignition timer setting (the timer, which was supposed to start ignition 1.5 hours after orbit, was erroneously set for 1.5 years.) The orbit decayed and the spacecraft re-entered Earth's atmosphere 2 days later on 12 May 1971.
12	1971 May 19 16:22:44	Mars 2	USSR	The USSR finally orbits Mars on 1971 Nov 27. The descent module, however, entered the Martian atmosphere at a steeper angle than planned. The descent system malfunctioned and the lander crashed at 45 deg S, 302 deg W.
12	1971 May 28 15:26:30	Mars 3	USSR	The USSR sends another orbiter/lander to Mars. Twenty seconds after landing, the lander stopped working... Unfortunately the orbiter had suffered from a partial loss of fuel and did not have enough to put itself into a planned 25 hour orbit? But it managed to send back stunning pictures!
12	1971 May 30 22:23:00	Mariner 9	USA	Mariner 9 arrived at Mars and began orbiting on 1971 Nov 14. The orbit decay will plunge the spacecraft into the Martian atmosphere in late 2022.
12	1973 July 21 19:30:59	Mars 4	USSR	The spacecraft reached Mars on 10 February 1974. But due to the degradation of the computer chip during the voyage to Mars, the retro-rockets never fired to slow the craft into Mars orbit, and Mars 4 flew by the planet at a range of 2200 km. It returned one swath of pictures and some radio occultation data which constituted the first detection of the nightside ionosphere on Mars.
12	1973 July 25 18:55:48	Mars 5	USSR	Another successful orbiter reached Mars on 1974 Feb 12.
13	1973 August 05 17:45:48	Mars 6	USSR	Contact with the descent module was lost at 09:11:05 UT in "direct proximity to the surface", probably either when the retrorockets fired or when it hit the surface at an estimated 61 m/s. The descent module transmitted 224 seconds of data before transmissions ceased. Unfortunately, much of the data were unreadable due to degradation of the onboard computer chip.
14	1973 August 09 17:00:17	Mars 7	USSR	Due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) the landing probe separated prematurely (4 hours before encounter) and missed the planet by 1300 km.
14	1975 August 20 21:22:00	Viking 1	USA	On 1976 June 19 the orbiter began to orbit and the lander landed on July 20.
14	1975 Sep 09 18:39:00	Viking 2	USA	Orbit on 1976 August 07 and a soft landing on September 03.
15	1988 July 07 17:38:04	Phobos 1	USSR	Phobos 1 operated nominally until an expected communications session on September 02 failed to occur. The failure of controllers to regain contact with the spacecraft was traced to an error in the software uploaded on 29/30 August which had deactivated the attitude thrusters. This resulted in a loss of the lock on the Sun, causing the spacecraft to orient the solar arrays away from the Sun and depleting the batteries.
15	1988 July 12 17:01:43	Phobos 2	USSR	Phobos 2 collected some useful data upon approach to one of the red planet's moons. Shortly before the final phase of the mission, during which the spacecraft was to approach within 50 m of Phobos' surface and release two landers, one a mobile `hopper', the other a stationary platform, contact with Phobos 2 was lost.
16	1992 Sep 25 17:05:01	Mars Observer	USA	Mars Observer makes it all the way to Mars orbit insertion. After which it exploded.
16	1996 Nov 07 17:00:50	Mars Global Surveyor	USA	The probe began orbiting Mars on 1997 Sep 12.
17	1996 Nov 16 20:48:53	Mars 96	USSR	The spacecraft was launched into Earth orbit, but failed to achieve insertion into Mars cruise trajectory and re-entered the Earth's atmosphere at about 00:45 to 01:30 UT on 17 November and crashed within a presumed 320 km by 80 km area which includes parts of the Pacific Ocean, Chile, and Bolivia. The cause of the crash is not known.
17	1996 Dec 04 06:58:00	Mars Pathfinder	USA	Mars Pathfinder lands on the Martian surface on 1997 July 04.
18	1998 July 03 18:12:00	Nozomi	Japan	On 20 December, the spacecraft attempted to use gravitational assist from an Earth flyby to put it on a course for Mars. Unfortunately, a malfunctioning valve caused excessive loss of fuel causing the spacecraft to miss its trajectory. Two further course corrections expended further fuel. To save the play, it was decided to allow the spacecraft to orbit the sun for four years when a lower velocity trajectory would be available. However, on 2002 April 21, powerful solar flares damaged the spacecraft's onboard communications and power systems. An electrical short then shut down the heaters causing the hydrazine fuel to freeze. The spacecraft made it back for another Earth swing-by and the fuel was thawed out on 2003 June 19. Another attempt was made to put it back on course, but the main thruster orbital insertion burn failed on 9 December.
19	1998 Dec 10 18:45:51	Mars Climate Orbiter	USA	Doh! nasa didn`t use the same units for measurement, miles instead of kilometres. Causing the probe to crash.
20	1999 Jan 03 20:21:10	Mars Polar Lander	USA	The last telemetry from Mars Polar Lander was sent just prior to atmospheric entry on 3 December 1999. No further signals have been received from the lander, the cause of this loss of communication is not known.
20	2001 Apr 07 15:02:22	Mars Odyssey	USA	Successfully made it to orbit on 2001 Oct 24
20	2003 June 02 17:45:00	Mars Express	ESA	Mars Express fired its main thrusters on 25 December and has successfully gone into orbit around Mars. The Beagle 2 lander, however, has not been heard from and presumed lost.
20	2003 June 10 17:58:47	Spirit	USA	The spirit rover landed on Mars on 2004 Jan 04.
20	2003 July 08 03:18:15	Opportunity	USA	The spacecraft landed on Mars on January 25. 2004
20	2005 Aug 10 11:54	Reconnaissance Orbiter		The 2-ton reconnaissance orbiter is NASA's last Mars orbiter this decade.
20	2011 Nov 08 20:16	Phobos-Grunt spacecraft	Russia	Radio contact lost soon after launch.
??	2011 Nov 26 15:46	Mars Science Laboratory mission	USA

Blobrana · L

Extreme Planet Takes Its Toll

Like Sun Belt retirees who complain about cold weather, NASA's Mars rovers are becoming less tolerant of temperature changes with age.

Near the martian equator, where the rovers are exploring opposite sides of the red planet, highs and lows make Earth temperatures look downright tropical. Temperatures often differ by more than 100 degrees Celsius. That's a change of 180 degrees Fahrenheit -- the equivalent of having the temperature drop from a high of 70 degrees F. at midday to minus 110 degrees F. the same night. That would be like going from a beach in Hawaii to the South Pole in mid-winter ... every day!

	Air Temperatures -- Spirit Temperatures in the shade for Spirit ranged from highs of about 35 degrees C. (95 degrees F.) in summer to lows of -90 degrees C. (-130 degrees F.) in winter. In the background is a panoramic camera image of sunset on Mars. Image courtesy: NASA/JPL-Caltech/Cornell/NMMNH Larger Image

Extreme Planet

Though both rovers are exploring Mars well beyond their initial 90-day missions, electrical connections and moving parts are showing signs of temperature-related fatigue.

"Every day we have a huge thermal cycle. That causes the solder in electrical connections to expand and contract until it breaks" - Jake Matijevic, chief of the rover engineering team.

Air Temperatures -- Opportunity Temperatures in the shade for Opportunity ranged from about 30 degrees C. (86 degrees F.) in summer to minus 80 degrees C. (-112 degrees F.) in winter. The background panorama shows a false-color view of dunes at the bottom of Endurance Crater. Credit: NASA/JPL-Caltech/Cornell/NMMNH Larger Image

Seasonal Change

During their exploration of Mars, the rovers have recorded temperatures ranging from midday highs of about 35 degrees C. (95 degrees F.) in spring and summer to nighttime lows of about minus 110 degrees C. (minus 166 degrees F.) in winter. Spirit has experienced greater swings in temperature because its location is farther from the martian equator, which puts it seasonally closer to or farther from the Sun than Opportunity.

	Solar Panel Temperatures -- Spirit Summer temperatures on Spirit's solar arrays have reached summertime highs of more than 30 degrees C. and winter lows of about minus 110 degrees C. The image in the background shows the rover's view of "Husband Hill" after cliimbing down from the top. Image courtesy: NASA/JPL-Caltech/Cornell/NMMNH Larger Image

Three Years of Data

Rover engineer Dan Porter has been tracking temperatures recorded by 50 or so sensors on each of the rovers since shortly after they landed on Mars in January 2004. The results are not only of interest to scientists, they're a favorite of human audiences as well.

"People ask about this all the time. These plots of daily temperature are destined to become an important part of all my public outreach talks" - New Mexico geologist Larry Crumpler, a member of the Mars rover science team who created the charts showing monthly average temperatures superimposed on panoramic-camera images from each of the rovers.

Solar Panel Temperatures -- Opportunity

Nighttime temperatures on Opportunity's solar panels fell within a fairly stable range of about minus 90 degrees C. (-130 degrees F.) to minus 100 degrees C. (-148 degrees F.) most nights. Daytime temperatures reached a high of around 30 degrees C. (86 degrees F.) in the summer. In the background of the chart is an outcrop known as "Cape St. Mary" in Victoria Crater.

Credit: NASA/JPL-Caltech/Cornell/NMMNH

Larger Image

This chart shows degrees C. on the left-hand axis and degrees F. on the right-hand axis. The horizontal x-axis at the bottom shows the number of sols, or Martian days, on Mars.