-
-
---------------------- 2275 - Mars - What did we learn?
-
- We have learned that Mars was likely wetter and warmer in the past. These conditions could have served as a cradle for life on Mars at a time when life first emerged on Earth.
-
- Opportunity's measurements showed that sedimentary rocks formed on the surface in ancient ephemeral playas. Opportunity also discovered small spheres of hematite nicknamed "blueberries" that formed later from rising, acidic groundwater.
-
- Once Opportunity rover reached the rim of Endeavour crater it found white veins of the mineral gypsum, a telltale sign of water that traveled through underground fractures.
-
- Opportunity also found more clay minerals that formed in neutral-pH (not too acidic, not too basic) water. This environment at the crater had the friendliest conditions for ancient microbial life.
-
- Opportunity worked longer on the surface of Mars than any other robot, more than 14 years. This far exceeded the original 90-day mission planned for Opportunity and Spirit.
-
- During Opportunity's time on Mars, it also drove a total of 28.06 miles.
-
- Opportunity didn't survive for over 14 years because its mission was easy. It encountered challenges that required its engineers to be resourceful. The rover's right-front wheel sometimes drew more current than the other wheels, so engineers often drove the rover backward to extend the right front wheel's life.
-
- The terrain was treacherous. After the rover landed at Eagle Crater, its wheels slipped on the loose slopes when it first attempted to drive out of the crater. Rover planners had to come up with creative driving strategies to get out. They did this again at Endurance Crater, where slopes were as steep as 31 degrees.
-
- On April 26, 2005, Opportunity's wheels dug into a soft, wind-sculpted sand ripple and got stuck for several nail-biting weeks at "Purgatory Dune." But after extensive testing in a Mars-like sandbox at the Jet Propulsion Laboratory, the team was able to carefully shimmy out of the Martian sand trap.
-
- Opportunity encountered two mission-threatening dust storms that blocked sunlight from reaching its solar panels. It survived a dust storm in 2007 by minimizing activities and maintaining enough power in its batteries to recover when the skies cleared. Unfortunately, the 2018 dust storm blotted out even more sunlight and kept the skies above Opportunity dark about a month longer.
-
- The two rovers returned over 342,000 raw images, which were promptly posted online for everyone's enjoyment. These two rovers also produced 31 stunning 360-degree color panoramas.
-
- The most memorable images Opportunity took included ripples of sand that resembled waves on water, patches of jumbled rock on a crater rim, whirling dust devils and its own tracks along a ridge.
-
- The success of the Mars Exploration Rovers helped drive the growth of NASA's Mars program, building support for orbiters and new kinds of rovers. Spirit and Opportunity showed how mobile robots on Mars could communicate reliably with Earth (either directly or by employing orbiters around Mars as relays back to our home planet), use 3-D vision to navigate the Martian terrain and make autonomous science observations.
-
- Opportunity's twin, Spirit, got stuck in soft Martian dirt in 2009, and NASA eventually gave up trying to free it. Both rovers were designed to operate for just 90 days, however, and exceeded expectations. They were launched separately in 2003 and landed on Mars in 2004.
-
- Another NASA spacecraft is on its way to Mars and should land in November. Named InSight, this robotic explorer has solar panels.
-
- Insight will have a tough act to follow. Opportunity kept going for 60 times its planned mission life, has traveled 28 miles and found evidence of water on Mars and conditions that may have been suitable for sustaining microbial life.
-
- Even though it is hobbled, having lost the use of its front steering and 256-megabyte flash memory, not everyone is ready to give up so fast.
-
- NASA is the only space agency to have successfully landed a robotic vehicles on Mars.
Its larger, newer vehicle, Curiosity, touched down in 2012 and has been largely unaffected by the dust because it operates using a nuclear-powered battery.
Martian dust storms are common, and can be more easily whipped up there than on Earth because Mars has a thinner atmosphere. They typically last between a few weeks and a few months.
-
- Spirit and Opportunity have been a fertile training ground for the many hundreds of engineers and planetary scientists who have learned at their robotic pioneers.
-
- Other Reviews available:
-
- 2123 - Is there water for life on Mars?
-
- 2029 - Exploration started In 2004. Since then there have been over 20 successful missions. 20 more did not make it.
-
- 1905 - The water source is believed to be salt water frozen down 1 meter below the surface.
-
- 1877 - Can we find oxygen on Mars?
-
- 1860 - Lists the discoveries and several more Reviews about Mars the forth rock from the Sun.
-
- 24 - Does the math.
-
- February 15, 2019
----------------------------------------------------------------------------------------
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
- to: ------- jamesdetrick@comcast.net ------ “Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
-------------------------- Friday, February 15, 2019 --------------------------
------------------------------------------------------------------------------------------
No comments:
Post a Comment