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Technology innovations spin NASA's SMAP into space

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It's active. It's passive. And it's got a big, spinning lasso.

Scheduled for launch on Jan. 29, 2015, NASA's Soil Moisture Active Passive (SMAP) instrument will measure the moisture lodged in Earth's soils with an unprecedented accuracy and resolution. The instrument's three main parts are a radar, a radiometer and the largest rotating mesh antenna ever deployed in space.

Remote sensing instruments are called "active" when they emit their own signals and "passive" when they record signals that already exist. The mission's science instrument ropes together a sensor of each type to corral the highest-resolution, most accurate measurements ever made of soil moisture -- a tiny fraction of Earth's water that has a disproportionately large effect on weather and agriculture.

To enable the mission to meet its accuracy needs while covering the globe every three days or less, SMAP engineers at NASA's Jet Propulsion Laboratory in Pasadena, California, designed and built the largest rotating antenna that could be stowed into a space of only one foot by four feet (30 by 120 centimeters) for launch. The dish is 19.7 feet (6 meters) in diameter.

"We call it the spinning lasso," said Wendy Edelstein of NASA's Jet Propulsion Laboratory, Pasadena, California, the SMAP instrument manager. Like the cowboy's lariat, the antenna is attached on one side to an arm with a crook in its elbow. It spins around the arm at about 14 revolutions per minute (one complete rotation every four seconds). The antenna dish was provided by Northrop Grumman Astro Aerospace in Carpinteria, California. The motor that spins the antenna was provided by the Boeing Company in El Segundo, California.

"The antenna caused us a lot of angst, no doubt about it," Edelstein noted. Although the antenna must fit during launch into a space not much bigger than a tall kitchen trash can, it must unfold so precisely that the surface shape of the mesh is accurate within about an eighth of an inch (a few millimeters).

The mesh dish is edged with a ring of lightweight graphite supports that stretch apart like a baby gate when a single cable is pulled, drawing the mesh outward. "Making sure we don't have snags, that the mesh doesn't hang up on the supports and tear when it's deploying -- all of that requires very careful engineering," Edelstein said. "We test, and we test, and we test some more. We have a very stable and robust system now."

SMAP's radar, developed and built at JPL, uses the antenna to transmit microwaves toward Earth and receive the signals that bounce back, called backscatter. The microwaves penetrate a few inches or more into the soil before they rebound. Changes in the electrical properties of the returning microwaves indicate changes in soil moisture, and also tell whether or not the soil is frozen. Using a complex technique called synthetic aperture radar processing, the radar can produce ultra-sharp images with a resolution of about half a mile to a mile and a half (one to three kilometers).

SMAP's radiometer detects differences in Earth's natural emissions of microwaves that are caused by water in soil. To address a problem that has seriously hampered earlier missions using this kind of instrument to study soil moisture, the radiometer designers at NASA's Goddard Space Flight Center, Greenbelt, Maryland, developed and built one of the most sophisticated signal-processing systems ever created for such a scientific instrument.

The problem is radio frequency interference. The microwave wavelengths that SMAP uses are officially reserved for scientific use, but signals at nearby wavelengths that are used for air traffic control, cell phones and other purposes spill over into SMAP's wavelengths unpredictably. Conventional signal processing averages data over a long time period, which means that even a short burst of interference skews the record for that whole period. The Goddard engineers devised a new way to delete only the small segments of actual interference, leaving much more of the observations untouched.

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Technology innovations spin NASA's SMAP into space

NASA hacks Mars Rover to cure system amnesia

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January 2, 2015

Eric Hopton for redOrbit.com Your Universe Online

In December, NASA reported that its Mars rover Opportunity, which has been working the surface of Mars for over 10 years, was experiencing continuing Flash memory problems. As a result, the project team decided to operate the rover without using the non-volatile Flash storage system. Instead, they had to rely on the volatile random access memory (RAM) for temporary storage of telemetry and rover data. NASA said at the time that its longer term plan was to implement a strategy to mask off the troubled sector of Flash and resume using the remainder of the Flash file system in normal operations.

The fault, thought to be due to the robots age, has resulted in the six-wheeled vehicle resetting unexpectedly.

According to the BBC, NASA now believes it has found a way to hack the rovers software which will enable it to disregard the faulty part. NASA project manager John Callas told Discovery News how his team intended to solve the issue.

Callas explained that the rover has two key types of memory volatile and non-volatile. Non-volatile memory remembers information even when powered down. This makes it perfect for longer term storage. Volatile memory is more like PC RAM data is lost when power is lost or turned off.

Opportunitys memory fault means that it cannot save telemetry data to the flash memory. It then writes it to the volatile memory instead and any data is lost when the rover powers down.

Callas describes this problem as amnesia. Essentially, each time it powers down it forgets what it has done. The problem was relatively minor and benign at first but is now becoming much worse. NASA now reports that the fault is causing the rover to reset itself. On occasions, it even stops communicating with mission control altogether. The rover keeps attempting to save data to the flash memory but repeatedly fails. As a consequence, its software keeps forcing the rover to reboot time and time again and to forget what the previous command instructed it to do. Callas likens this to your car stalling every five minutes on a family day out. The situation took a turn for the worse when Opportunity failed to communicate with mission control over the Christmas period.

NASAs hack involves persuading the rovers software to ignore the faulty part of its flash memory and to write to the healthy hardware instead. The fix will probably take around two weeks. Longer term prospects for Opportunity are not great, however, and its life on Mars may be coming to an end. Callas believes that it could suffer terminal failure at any time. Nevertheless, the rover has lasted much longer than its expected three months on the Red Planet. In its ten years on Mars, Opportunity has roamed over 26 miles across the surface of Mars surface. The data it has gathered has provided vital understanding of the biological make-up of Mars.

The team would dearly love to keep the mission going a little longer. Callas says that the most exciting part of the mission is still ahead. The rover is only about 650 meters away from Marathon Valley, so-called because, if the rover ever makes it there, it will have exceeded the length of a marathon while on Mars. Marathon Valley contains a variety of clay minerals from a time when Mars held pH-neutral water on its surface. The Valleys geology could give fascinating clues to the potential for life on the ancient Mars environment. Whatever happens though, Opportunity already holds the current off-world record forarover.

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NASA hacks Mars Rover to cure system amnesia

Eric Powell: NASA Championships PTD race and track record at Sonoma GoPro – Video

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Eric Powell: NASA Championships PTD race and track record at Sonoma GoPro
Fun race. I was able to work my way to the front rather lazily while taking care of the car and put it on cruise control. My 97 miata was driving wonderfully! I had minimal break pad material...

By: MrEpowell1

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Eric Powell: NASA Championships PTD race and track record at Sonoma GoPro - Video

NASA working to fix Opportunity's memory

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NASA's Opportunity rover landed on Mars in 2004 and its 90-day mission has now lasted almost 11 years. Unfortunately, its age is beginning to show with the unmanned robotic explorer beginning to display signs of memory loss. Mission control at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, reports that Opportunity's computers have been resetting as its flash memory banks suffer fits of "amnesia," which engineers back on Earth are trying to repair.

Opportunity may be an extremely sophisticated piece of rolling scientific hardware, and it may be functioning a decade beyond its specifications, but its "brain" is still a computer relying on much the same components as any PC circa 2003. As anyone who uses computers on a regular basis knows, these components have a limited service life, which is why junk drawers inevitably fill up with dead tech. Worse, the Martian environment is extremely hostile to electronics, and microelectronics especially, because the incredibly dry, dusty climate generates static electric charges, and the thin atmosphere and almost non-existent magnetic field lets in dangerous levels of cosmic radiation.

Whether due to time or radiation, NASA says that Opportunity is now suffering from bouts of computer senility. Like most computers, the rover's uses a combination of volatile Random Access Memory (RAM), and a non-volatile memory in this case, a set of seven flash memory banks. The latter are especially important because Opportunity is solar powered. This means that it can't spare the power to keep the RAM operating at night because the batteries are needed to keep the electronics warm, so data collected during the day is stored in the flash memory until it can be transmitted to Earth.

This arrangement has worked fine until now, but in recent weeks the flash memory has refused from time to time to record new data, causing the computers to reset like a cranky tablet. To prevent this from happening again and to avoid lost data, mission control tried re-formatting the flash memory, but with little success, so in early December it ordered Opportunity to carry out a more extensive repair, including using the RAM to collect data and transmitting it to Earth before sunset. However, the space agency says that the main problem has been located in one of the seven flash banks, which NASA plans to isolate.

"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," says Mars Exploration Rover Project Manager John Callas of JPL. "While we're operating Opportunity in that mode, we are also working on an approach to make the flash memory usable again. We will be sure to give this approach exhaustive reviews before implementing those changes on the rover."

Launched on July 7, 2003, Opportunity is the twin of the now defunct Spirit rover. It landed on January 25, 2004, three weeks after Spirit, in the Meridiani Planum region of Mars for a mission scheduled to last 90 Martian days, but ten years later, it's still going strong. It continues to study Martian soil and provide surface calibration for orbital observations by the Mars Reconnaissance Orbiter, and has traversed over 25 miles (40 km).

Source: JPL

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NASA working to fix Opportunity's memory

NASA exhibit blasts off at River Falls library

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In many exhibits, the rule is "look, don't touch." But that's not the case with the River Falls public library's new NASA exhibit in the downstairs gallery.

Gallery and event coordinator Katie Chaffee said kids are welcome to touch most items on display -- unless, of course, they're locked in a glass case.

"(Kids') moms say, 'You can't touch that,' " Chaffee said. "I say, 'Actually, you can.' "

The items, on loan from NASA's Houston and Cleveland offices, include a 1/25-scale model of a space shuttle, which stands about 9 feet high. That's high enough that Chaffee and her helpers had to dislodge a ceiling tile to fit the model shuttle into the gallery.

Other items include a "photo opportunity space suit," which is a model of a real space suit with steps in back so people can have their photos taken "in" the suit. There also are replica moon rocks, a space glove and the back tire from a space shuttle.

The space shuttle tire, Chaffee said, doesn't seem very impressive at first, especially not when compared to tractor tires that can stand taller than the average person. The shuttle tire doesn't initially appear much larger than an average truck tire.

However, the shuttle tire can handle a lot more than a truck tire. With very thick walls, and inflated to 340 pounds of air per square inch, it has a 142,000-pound load rating. That means it can carry three times the load of a Boeing 747 jet.

About 146 people went through the exhibit during the first three days. About 100 people attended a program by Jon Montgomery, a River Falls native and director of NASA's Mission Support Office.

"There's a lot of interest, and it's fun because there's something for everybody," Chaffee said.

The exhibit can be exciting for kids -- especially the space food display and the space suit. It's also educational, and kids can touch most of the items.

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NASA exhibit blasts off at River Falls library

Images From The National Aeronautics and Space Administration (NASA – Video

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Images From The National Aeronautics and Space Administration (NASA
The National Aeronautics and Space Administration (NASA) is the United States government agency that is responsible for the civilian space program as well as for aeronautics and aerospace research ...

By: Samuel Cernuto

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Images From The National Aeronautics and Space Administration (NASA - Video


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