Opportunity is Working Well

Image credit: NASA/JPL

Opportunity, NASA’s second Mars Exploration rover, has been in space for a few days now and everything seems to be going according to plan. The spacecraft has reduced its spin rate from 12 rotations a minute to just 2; enabling it to switch to celestial navigation using its star scanner. In fact, one of the first reference points Opportunity used was Mars – already one of the brightest objects in view. It’s already over 7 million kilometres away from the Earth and on track to arrive at Mars on January 25.

NASA’s Opportunity spacecraft, the second of twin Mars Exploration Rovers, has successfully reduced its spin rate as planned and switched to celestial navigation using a star scanner.

Prior to today?s maneuver, Opportunity was spinning 12.13 rotations per minute. Onboard thrusters were used to reduce the spin rate to approximately 2 rotations per minute, the designed rate for the cruise to Mars. After the spinning slowed, Opportunity’s star scanner found stars that are being used as reference points for spacecraft attitude. One of the bright points in the star scanner’s first field of view was Mars.

All systems on the spacecraft are in good health. As of 6 a.m. Pacific Daylight Time July 10, Opportunity will have traveled 6.6 million kilometers (4.1 million miles) since its July 7 launch. The Mars Exploration Rover flight team at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is preparing to command Opportunity’s first trajectory-correction maneuver, scheduled for July 18.

Opportunity will arrive at Mars on Jan. 25, 2004, Universal Time (evening of Jan. 24, 2004, Eastern and Pacific times). The rover will examine its landing area in Mars’ Meridiani Planum area for geological evidence about the history of water on Mars.

Opportunity’s twin, Spirit, also continues in good health on its cruise to Mars. As of 6 a.m. Pacific Daylight Time July 10, it will have traveled 82.6 million kilometers (51.3 million miles) since its June 10 launch.

JPL, a division of the California Institute of Technology, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Additional information about the project is available from JPL at http://mars.jpl.nasa.gov/mer or and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Beagle 2 Tests Complete

Image credit: ESA

The European Space Agency has been testing all aspects of the Mars Express spacecraft to ensure that it’s ready for its encounter with Mars. This week they put the UK-built Beagle 2 lander through its paces. The tests included uploading software and turning various instruments on and off, and everything seems to be working properly. A final series of tests will be done in mid-July. Mars Express is expected to reach the Red Planet on December 19 – Beagle 2 will land on the surface on December 25.

On Friday 4 July, and Saturday 5 July 2003, engineers successfully carried out overnight tests on the Mars Express lander, Beagle 2.

Ground controllers at the European Space Agency’s Operations Centre in Darmstadt, Germany, contacted Mars Express at the weekend to carry out the tests on the lander, which were rescheduled from two weeks ago. These functional tests included uploading software and switching units on and off.

With these tests, the near-Earth phase of the Mars Express payload check-outs is almost complete. All instruments, including the lander, have performed as expected. Star calibration of some instruments is scheduled for mid-July, which marks the first attempt to make scientific measurements. This will also be done in the same way when nearer to Mars.

Rudi Schmidt, ESA Mars Express Project Manager, said: “This check-out was a marvellous example of complete cooperation between ESA?s Mars Express and the Beagle lander teams Another major milestone has been achieved successfully. What a fantastic feeling!”

Original Source: ESA News Release

Opportunity Blasts Off for Mars

NASA’s second Mars Exploration Rover, Opportunity, successfully lifted off from Florida early Tuesday morning after several delays. The launch was halted only seven seconds away from liftoff during the first window because of a problem with a valve on the rocket, but during the second window at 0318 GMT (11:18 pm EDT Monday) the Delta II successfully blasted off. Opportunity will reach Mars on January 25.

Another Delay for Opportunity

Image credit: NASA

NASA has pushed back the launch of its second Mars Exploration rover, “Opportunity”, again; this time because of a battery failure on the Boeing Delta II booster. The launch has now been set for Tuesday, July 8 at 0235 GMT (10:35 pm EDT Monday). Even this launch date is at risk, though, as there’s a 30% chance of weather problems. It looks like the previous problem with the booster’s cork insulation has been resolved; although, engineers will be performing further tests to ensure that everything’s fine. The spacecraft must launch before July 15 in order to reach Mars.

The launch of the MER-B Mars Exploration Rover ?Opportunity? aboard a Boeing Delta II rocket has been postponed an additional 24 hours. The delay is due to the failure of a battery cell associated with a component of the launch vehicle?s flight termination system. The battery must be removed and replaced.

Launch is now targeted for no earlier than Monday, July 7. The two launch times available are 10:35:23 and 11:18:15 p.m. EDT. The forecast calls for a 30% chance of not meeting the launch weather criteria on Monday evening.

At Pad 17-B, a tanking test of the Delta rocket was conducted this morning. The first stage was loaded with cryogenic liquid oxygen to evaluate the bonding of the lower band of cork thermal insulation. This afternoon, NASA and Boeing managers met to discuss the outcome of the tanking test and other associated testing and engineering evaluations that have been conducted over the last several days.

After the tanking, inspections revealed some selective debonding of the cork from the surface of the vehicle within a limited area. These locations are being repaired using a different adhesive with a stronger bonding characteristic as demonstrated by tests conducted at KSC late this week. This work was completed tonight and the problem has been resolved to the satisfaction of engineers.

Original Source: NASA News Release

Opportunity Launch Delayed Again

The launch of NASA’s second Mars Exploration rover, Opportunity, has been delayed again to Monday, July 7 as early as 0243 GMT (10:43 pm EDT Sunday). The delay will give technicians time to ensure that the booster’s cork insulation is properly adhered. If all goes well, Opportunity will blast off from the Kennedy Space Center in Florida on board a Delta 2 rocket and follow its partner spacecraft, Spirit, already en route to the Red Planet. Launch windows for the spacecraft are available until July 15.

Mars Express Power Problems

Image credit: ESA

Operators with the European Space Agency are currently testing various systems on the Mars Express spacecraft, and it looks like there’s a bit of a problem. It seems that there’s a connection problem between the spacecraft’s solar panels and its power conditioning system. If they can’t fix this problem, the spacecraft will only be able to operate at 70% power; however, it will still be able to perform nearly all of its objectives for the mission. Ground engineers will begin tests on the Beagle 2 lander on July 4.

ESA?s Mars Express spacecraft is progressing further every day on its journey to the Red Planet. Everything is set for arrival at Mars on the night of 25 December 2003, after a journey of about 400 million kilometres. In the weeks since its launch, engineers have started to thoroughly test the spacecraft and its equipment.

This testing phase is standard for all spacecraft on the way to their destination. Known as commissioning, it began 3 weeks after the launch. During this time, ground controllers sent signals to each of the orbiter’s seven instruments to switch them on and verify their health status.

As well as commissioning the instruments, the ground controllers also tested each of the spacecraft?s subsystems. There was a thrilling moment when one of the on-board computer memory units, known as the Solid State Mass Memory (SSMM), seemed to not respond properly during the instruments check-out. Good progress has been made on this issue in the last few days: a test involving all instruments was completed successfully by recording and recovering the data through the SSMM.

Unfortunately, during the commissioning of the power subsystem, ground engineers recorded an interconnection problem between the solar arrays and the power conditioning unit on board the spacecraft. This means approximately 70% of the power generated by the solar arrays is available for the satellite and its payload to use. This anomaly has no effect on the state of the spacecraft and has no impact on the mission during the whole trip to Mars, including the orbit insertion phase once at destination.

Despite this, the experts analysing the anomaly believe that even with this power shortage, the nominal Mars observation mission will be achievable. However, satellite payload operations may have to be reviewed for certain short periods of the mission.

Ground engineers are now preparing for the last of the payload?s tests: the Beagle-2 lander will undergo its check-out on 4-5 July 2003. The experts are looking confidently to it. “In fact,” says Rudolf Schmidt, Mars Express Project Manager, “overall, the spacecraft is in good shape. We are simply getting to know its personality.”

Original Source: ESA News Release

Opportunity Launch Rescheduled

Image credit: NASA/JPL

NASA has decided to push back the launch of its second rover, Opportunity, to no earlier than Sunday, July 6 at 0251 GMT (10:51 pm EDT Saturday). The delays give engineers time to repair insulation which is failing to adhere properly to the first stage of the Delta II rocket. The launch was delayed over the weekend because of poor weather. If all goes well, Opportunity will follow NASA’s previous rover, Spirit, already en route to Mars to search for evidence of life on the Red Planet.

The launch of the MER-B ?Opportunity? Mars Exploration Rover aboard the Boeing Delta II Heavy Iaunch vehicle has been postponed to no earlier than Saturday, July 5.

A decision was made today to take additional time to perform tests on the process used to bond the cork insulation to the surface of the Delta II launch vehicle. These tests should be complete late on Wednesday.

The launch times on Saturday evening are: 10:51:25 p.m. and 11:34:05 p.m. EDT.

Original Source: NASA News Release

Opportunity Set for Weekend Launch

NASA’s second Mars Explorer rover, Opportunity, is set for launch on the weekend atop a Delta II rocket from Cape Canaveral, Florida. If all goes well, the spacecraft will lift off at 0356 GMT Sunday (11:56 pm EDT Saturday) and join the previous rover, Spirit, en route to the Red Planet. Weather forecasts currently give the rover a 60% chance of acceptable conditions for flight. Opportunity is targeted to land at Meridiani Planum, which is a prime location for search for past life on Mars.

Odyssey Reveals More of Frosty Mars

Image credit: NASA/JPL

It turns out that Mars has been hiding its water underneath a layer of dry ice. By tracking the seasonal changes at Mars northern ice cap, NASA’s Mars Odyssey spacecraft has watched how a layer of carbon dioxide permafrost comes and goes. When the permafrost dissipates in the Spring, Mars reveals a soil layer mixed with large amounts of water ice. In some places, the water ice content is more than 90% by volume. During the winter, the dry ice permafrost can reach more than a metre in thickness.

NASA’s Mars Odyssey spacecraft is revealing new details about the intriguing and dynamic character of the frozen layers now known to dominate the high northern latitudes of Mars. The implications have a bearing on science strategies for future missions in the search of habitats.

Odyssey’s neutron and gamma-ray sensors have tracked seasonal changes as layers of “dry ice” (carbon-dioxide frost or snow) accumulate during northern Mars’ winter and then dissipate in the spring, exposing a soil layer rich in water ice– the martian counterpart to permafrost.

Researchers used measurements of martian neutrons combined with height measurements from the laser altimeter on another NASA spacecraft, Mars Global Surveyor, to monitor the amount of dry ice during the northern winter and spring seasons.

“Once the carbon-dioxide layer disappears, we see even more water ice in northern latitudes than Odyssey found last year in southern latitudes,” said Odyssey’s Dr. Igor Mitrofanov of the Russian Space Research Institute (IKI), Moscow, lead author of a paper in the June 27 issue of the journal Science. “In some places, the water ice content is more than 90 percent by volume,” he said. Mitrofanov and co-authors used the changing nature of the relief of these regions, measured more than 2 years ago by the Global Surveyor’s laser altimeter science team, to explore the implications of the changes.

Mars Odyssey’s trio of instruments, called the gamma-ray spectrometer suite, can identify elements in the top meter (3 feet) or so of Mars’ surface. Mars Global Surveyor’s laser altimeter is precise enough to monitor meter-scale changes in the thickness of the seasonal frost, which can accumulate to depths greater than a meter. The new findings show a correlation in the springtime between Odyssey’s detection of dissipating carbon dioxide in latitudes poleward of 65 degrees north and Global Surveyor’s measurement of the thinning of the frost layer in prior years.

“Odyssey’s high-energy neutron detector allows us to measure the thickness of carbon dioxide at lower latitudes, where Global Surveyor’s altimeter does not have enough sensitivity,” Mitrofanov said. “On the other hand, the neutron detector loses sensitivity to measure carbon-dioxide thickness greater than one meter (3 feet), where the altimeter obtained reliable data. Working together, we can examine the whole range of dry-ice snow accumulations.”

“The synergy between the measurements from our two ‘eyes in the skies of Mars’ has enabled these new findings about the nature of near-surface frozen materials, and suggests compelling places to visit in future missions in order to understand habitats on Mars,” said Dr. Jim Garvin, NASA’s Lead Scientist for Mars Exploration.

Another report, to be published in the Journal of Geophysical Research-Planets, combines measurements from Odyssey and Global Surveyor to provide indications of how densely the winter layer of carbon-dioxide frost or snow is packed at northern latitudes greater than 85 degrees. The Odyssey data are used to estimate the mass of the deposit, which can then be compared with the thickness to obtain a density. The dry-ice layer appears to have a fluffy texture, like freshly fallen snow, according to the report by Dr. William Feldman of Los Alamos National Laboratory, N.M., and 11 co-authors. The study also found that once the dry ice disappears, the remaining surface near the pole is composed almost entirely of water ice.

“Mars is constantly changing,” said Dr. Jeffrey Plaut, Mars Odyssey project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. With Mars Odyssey, we plan to examine these dynamics through additional seasons, to watch how the winter accumulations of carbon dioxide on each pole interact with the atmosphere in the current climate regime.”

Mitrofanov’s co-authors include researchers at the Institute for Space Research of the Russian Academy of Science, Moscow; MIT, Cambridge, MA; NASA’s Goddard Space Flight Center, Greenbelt, Md.; TechSource, Santa Fe, N.M.; and NASA Headquarters, Washington. Feldman’s co-authors include researchers at New Mexico State University, Las Cruces; Cornell University, Ithaca, N.Y.; and Observatoire Midi-Pyrenees, Toulouse, France.

JPL manages the Mars Odyssey and Mars Global Surveyor missions for NASA’s Office of Space Science in Washington. Investigators at Arizona State University, the University of Arizona, and NASA’s Johnson Space Center, Houston, built and operate Odyssey science instruments. The Russian Aviation and Space Agency supplied the high-energy neutron detector and Los Alamos National Laboratory supplied the neutron spectrometer. NASA’s Goddard Space Flight Center supplied Global Surveyor’s laser altimeter. Information about NASA’s Mars exploration program is available online at: http://mars.jpl.nasa.gov

Original Source: NASA/JPL News Release

Summer Will Bring Mars’ Closest Approach

Image credit: Ron Wayman

Earth and Mars are rapidly converging, and are expected to reach their closest point on August 27, 2003. Already amateur astronomers with modest telescopes are reporting they can see features on the surface of Mars with greater clarity, including the planet’s polar ice caps. On August 27, the two planets will only be 56 million km apart; the closest they’ve been for 60,000 years. The planet is currently visible in the morning sky, but over the course of the summer it will move to the point that it’s easy to spot in the evening sky – it’ll be hard to miss since it’ll be nearly the brightest object in the sky.

Count slowly: one one-thousand, two one-thousand, three one-thousand…. You just got about 30 km closer to the planet Mars.

Earth and Mars are rapidly converging. On August 27, 2003–the date of closest approach–the two worlds will be 56 million km apart. That’s a long way by Earth standards, but only a short distance on the scale of the solar system. NASA, the European Space Agency and Japan are all sending spacecraft to Mars this year. It’s a good time to go.

Between now and August, Mars will brighten until it “blazes forth against the dark background of space with a splendor that outshines Sirius and rivals the giant Jupiter himself.” Astronomer Percival Lowell, who famously mapped the canals of Mars, wrote those words to describe the planet during a similar close encounter in the 19th century.

Already Mars is eye-catching. You can see it this month in the morning sky–bright, steady and remarkably red. Only Venus near the sun is brighter.

Amateur astronomers looking through backyard telescopes have reported in recent days great views of Mars’s south polar cap. Made of frozen water and carbon dioxide (“dry ice”), it reflects sunlight well. “I can see the polar ice vividly using my 8-inch telescope,” says Ron Wayman of Tampa, Florida. He’s also spotted “some faint darker-shaded areas on the surface.”

Such markings will become clearer in the weeks ahead. On June 1st Mars was 12.5 arcseconds across and it glowed like a -1st magnitude star. On August 27th it will be twice as wide (25 arcseconds) and six times brighter (magnitude -2.9).

Much has been made of the fact that the August 27th encounter with Mars is the closest in some 60,000 years. Neanderthals were the last to observe Mars so favorably placed. This is true. It’s also a bit of hype. Mars and Earth have been almost this close many times in recent history.

Some examples: Aug. 23, 1924; Aug. 18, 1845; Aug. 13, 1766. In each case Mars and Earth were approximately 56 million km apart.

Astronomers call these close encounters “perihelic oppositions.” Perihelic means Mars is near perihelion–its closest approach to the sun. (The orbit of Mars, like that of all planets, is an ellipse, so the distance between the sun and Mars varies.) Opposition means that the sun, Earth and Mars are in a straight line with Earth in the middle. Mars and the sun are on opposite sides of the sky. When Mars is at opposition and at perihelion–at the same time–it is very close to Earth.

August 27th is indeed the best perihelic opposition since the days of the Neanderthals, but it scarcely differs from other more recent ones. That’s fine because all perihelic oppositions of Mars are spectacular.

Mars is a morning planet now. You have to wake up early to see it. Soon, though, it will be more conveniently placed. By mid-July Mars will rise in the east around 11 p.m. local time. In late August it will appear as soon as the sun sets. It won’t be long before everyone can see Mars at a civilized hour.

We’ll be telling more stories about Mars in the weeks ahead. This one, though, is finished. Did you make it to the end? Congratulations! You’re now 2000 km closer to Mars.

Original Source: NASA Science Story