News from Mars: Spirit Rover’s Tenth Anniversary

opportunityTwo days ago, another major milestone passed for one of NASA’s famed rovers. But this time around, it wasn’t the spotlight-hogging Curiosity or the die-hard Opportunity rover that was the subject of interest. It was the Spirit rover, the other half of NASA’s now legendary Mars Exploration Rovers (MER) that landed on the Red Planet over a decade ago.

Yes, January 3rd of this year marks the 10th anniversary since the safe landing of NASA’s renowned Spirit rover on the plains of Mars, making her the oldest rover in operation on the planet’s service. Opportunity, her twin sister, landed on the opposite side of the Mars three weeks later – on Jan. 24, 2004. The goal was to “follow the water” as a potential enabler for past Martian microbes if they ever existed.

mars_roverTogether, the long-lived, golf cart sized robots proved that early Mars was warm and wet, billions of years ago – a key finding in the search for habitats conducive to life beyond Earth. It was these findings that have since been followed up on by Curiosity rover in its ongoing search for water and organic particles in the soil, and MAVEN’s planned surveys of the Martian atmosphere.

And it was a decade ago that the famous robot survived the 6 minute plunge through the thin Martian atmosphere, which involved scorching atmospheric heating, and then bounced some two dozen times inside cushioning airbags before coming to a stop. It then gradually rolled to a stop inside 161 km (100 mile) wide Gusev Crater. This landing was known as the “6 minutes of Terror”.

spiritrover_landerThe three petaled landing pad then opened and Spirit was deployed in what was a milestone event. This deployment will be forever remembered in the annuls of history, mainly because of the groundbreaking scientific discoveries that ensued, not to mention the unbelievable longevity of the twins. And while Spirit did not make it past 2010 – effectively remaining in service for six years – she accomplished quite a bit in that time.

Before they were launched atop a series of Delta II rockets in the summer of 2003 from Cape Canaveral, the dynamic, solar powered robo duo were expected to last for only 90 Martian days (Sols). NASA engineers firmly believed that dust accumulation on the life-giving solar panels, an engineering issue or the extremely harsh Martian environment would terminate them before long.

SpiritAndOpportunity_ByTheNumbers1-580x423But in reality, both robots enormously exceeded expectations and accumulated a vast bonus time of exploration and discovery in numerous extended mission phases. In part, the harsh Martian winds occasionally cleaned their solar panels to give them both a new lease on life. And more importantly, the rovers’ components just kept working miraculously.

And she kept working faithfully for six years until communications officially ceased in 2010. Altogether, Spirit drove 7.73 kilometers (4.8 miles) across the Martian surface – about 12 times more than the original goal set for the mission – and transmitted over 128,000 images. And shortly after landing, Spirit scaled Husband Hill and found evidence for the flow of liquid water at the Hillary outcrop.

Columbia_Hills_from_MER-A_landing_site_PIA05200_br2This was especially impressive, seeing as how the rovers were not designed to climb hills. But eventually, she managed to scale the 30 degree inclines and collect a series of rock samples using her Rock Abrasion Tool (RAT). The samples were then inspected using her on-board spectrometers and a microscopic imager. Eventually she drove back down the hill and made even greater scientific discoveries.

These occurred in 2007 in an area known as “Home Plate”, where she unexpectedly got mired thanks to an ancient volcanic feature named ‘Home Plate’ that prevented the solar arrays from generating. In the process, her right front wheel churned up a trench of bright Martian soil that exposed a patch of nearly pure silica, which was formed in a watery hot spring or volcanic environment.

Spirit-Sol-2175c-_Ken-KremerThree years later, in February of 2010, Spirit once again got mired and took her last panorama (pictured above), which was stitched together from raw images by Marco Di Lorenzo and Ken Kremer. After several attempts to save her, NASA eventually declared Spirit dead in the water, her last resting place being the same as where she made her landing – the Gustev Crater in the Aeolis quadrangle.

At one time, many billions of years ago, the Ma’adim Vallis channel – a natural river-like depression running from the crater – probably carried liquid water and/or ice into Gutev. NASA scientists believe this has left sediments in the crater that could be up to 915 meters (3000 feet) thick. Spirit all but confirmed this when her tire turned up a patch of silica in 07, thus providing the first conclusive evidence of this theory.

Mosaic image taken on Jan. 4, 2004 after deployment
Mosaic image taken on Jan. 4, 2004 after deployment

The rovers’ principal investigator, Steve Squyres of Cornell University, Ithaca, N.Y., described some of the key findings in a NASA statement, starting with what Spirit found after driving from the crater floor where it landed into the Columbia hills to the east:

In the Columbia Hills, we discovered compelling evidence of an ancient Mars that was a hot, wet, violent place, with volcanic explosions, hydrothermal activity, steam vents — nothing like Mars today.

At Opportunity’s landing site, we found evidence of an early Mars that had acidic groundwater that sometimes reached the surface and evaporated away, leaving salts behind. It was an environment with liquid water, but very different from the environment that Spirit told us about.

When Opportunity got to the rim of Endeavour Crater, we began a whole new mission. We found gypsum veins and a rich concentration of clay minerals. The clay minerals tell us about water chemistry that was neutral, instead of acidic — more favorable for microbial life, if any ever began on Mars.

Because of the rovers’ longevity, we essentially got four different landing sites for the price of two.

maven_orbitMeanwhile, NASA’s new Curiosity rover just celebrated 500 Sols on Mars and is speeding towards Mount Sharp from inside Gale Crater – which is about the same size as Gusev crater. And a pair of newly launched orbiters are streaking towards the Red Planet as we speak – NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) and India’s Mars Orbiter Mission (MOM).

In short, we are not finished with Mars yet. And the past, ongoing and future efforts of our many rovers, orbiters and (someday) astronauts are likely to keep providing us with a slew of new discoveries and revelations about our celestial neighbor.

Source: universetoday.com

News from Space: Chang’e-3’s Landing and 1st Panorama

Change-3-landing-site_1_ken-kremer-580x344China accomplished a rather major technological and scientific feat recently with the recent soft landing of its Chang’e-3 robotic spacecraft on Dec.14th. This was the nation’s first attempt at landing a spacecraft on an extra-terrestrial body, and firmly established them as a competitor in the ongoing space race. What’s more, the event has been followed by a slew of fascinating and intriguing pictures.

The first were taken by the descent imaging camera aboard the Chang’e-3 lander, which began furiously snapping photos during the last minutes of the computer guided landing. The Chinese space agency then combined the photos to create a lovely compilation video, with the point of view rotated 180 degrees, to recreate what the descent looked like.

Change-3_lunar_landing_site-580x470The dramatic soft landing took place at 8:11 am EST (9:11 p.m Beijing local time) with the lander arriving at Mare Imbrium (Latin for “Sea of Rains”) – one of the larger craters in the Solar System that is between 3 and 4.5 billion years old. The precise landing coordinates were 44.1260°N and 19.5014°W – located below the Montes Recti mountain ridge.

The video begins by showing the Chang’e-3 lander approaching the Montes Recti mountain ridge. At an altitude of 15 km (9 miles), the Chang’e-3 carried out the rocket powered descent to the Moon’s surface by firing the landing thrusters starting at the altitude of 15 km (9 mi) for a soft landing targeted to a preselected area in Mare Imbrium.

chang'e3_landingThe vehicles thrusters then fired to pivot the lander towards the surface at about the 2:40 minute mark when it was at an altitude of roughly 3 km (1.8 miles). The powered descent was autonomous, preprogrammed and controlled by the probe itself, not by mission controllers on Earth stationed at the Beijing. Altogether, it took about 12 minutes to bring the lander onto the surface.

Roughly 7 hours later, on Sunday, Dec. 15 at 4:35 a.m. Beijing local time, China’s first ever lunar rover ‘Yutu’ (or Jade Rabbit) rolled down a pair of ramps and onto the Moon’s soil. The six wheeled ‘Yutu’ rover drove straight off the ramps and sped right into the history books as it left a noticeably deep pair of tire tracks behind in the loose lunar dirt. This too was captured by the lander’s camera and broadcast on China’s state run CCTV.

chang'e3_egressThe next bundle of footage came from the rover itself, as the Jade Rabbit took in its inaugural photographs of the landing site in Mare Imbrium. The photos were released by Chinese state TV on Dec. 15th, not long after the rover disembarked from the lander, and were then pieced together to form the lander’s first panoramic view of the lunar surface.

Marco Di Lorenzo and Ken Kremer – an amateur photo-astronomer and a science journalist who have composed panoramas from the Curiosity mission in the past – also composed the images together to create a series of mosaics. A sample of the 1st panorama is pictured below, with the Yutu rover in the center and tire tracks off to the left.. Click here to the see the full-size image.

Change-3-1st-Pano_1b_Ken-Kremer--580x203The individual images were taken by three cameras positioned around the robotic lander and captured the stark lunar terrain surrounding the spacecraft. The panoramic view shows ‘Yutu’ and its wheel tracks cutting a semi circular path at least several centimeters deep into the loose lunar regolith at the landing site at Mare Imbrium, located near the Bay of Rainbows.

Liu Enhai, Designer in Chief, Chang’E-3 Probe System, has this say about the images in a recent CCTV interview:

This picture is made of 60 pictures taken 3 times by the rover. The rover used three angles: vertical, 15 degrees tilted up, and 15 degrees down…so that we get an even farther view

chang'e3_portraitThe 140 kilogram Yutu rover then turned around so that the lander and rover could obtain their first portraits of one another. The first is visible above, showing the Jade Rabbit rover (in better resolution), with the image of the Chang’e 3 lander below. Liu Jianjun, Deputy Chief Designer of the Chang’E-3 Ground System, was also interviewed by CCTV, and had this to about that part of the mission:

The rover reached the point of X after it went down from the lander, then it established contact with the ground. Then it went to point A, where the rover and lander took pictures of each other. Then it reached point B, where it’s standing now.

These are just the first of what is expected to be a torrent of pictures produced by the rover, which according to Chinese officials, will spend the next year conducting in-situ exploration at the landing site. Beyond that, the rover will use its instruments to survey the moon’s geological structure and composition on a minimum three month mission to locate the moon’s natural resources for use by future missions.

chang'e3_lander_portIn addition to accomplishing a great scientific feat, China has now joined a very exclusive club, being only one of three nations that has successfully conducted a soft landing on the Moon. The United States was the first, reaching the Moon with its Apollo 11 mission on July 20th, 1969. The Soviet Union followed less than a decade later, having reached the Moon with its unmanned Lunik 24 spacecraft in 1976.

And now, almost forty years later, the space race is joined by one of the world’s emerging super powers. Soon, we can expect the European Space Agency, India, Pakistan, and possibly Iran to be reaching the Moon as well. And by that time, its likely the spaceships will be carrying colonists. Hopefully we’ll have some infrastructure set up to receive them!

In the meantime, be sure to check out the Chang’e 3 descent video, and stay tuned for more updates from the Jade Rabbit and it begins its exploration of the Lunar surface.


Source:
universetoday.com, (2)