Monday, February 28, 2011

NASA wants spacecraft designed for Mars return trip

Getting home might prove to be as difficult. NASA today selected three companies -- Alliant Techsystems, Lockheed Martin and Northrop Grumman - to being the task of defining the spacecraft that will leave Mars, presumably at first loaded with red planet rock samples, then later possibly humans - for a safe trip back to Earth.
The engineering challenges those three companies face are immense.
From a NASA whitepaper on the challenges of a return trip from Mars: "Lifting geology samples off of Mars is both a daunting technical problem for propulsion experts and a cultural challenge for the entire community that plans and implements planetary science missions. The vast majority of science spacecraft require propulsive maneuvers that are similar to what is done routinely with communication satellites, so most needs have been met by adapting hardware and methods from the satellite industry. While it is even possible to reach Earth from the surface of the moon using such traditional technology, ascending from the surface of Mars is beyond proven capability for either solid or liquid propellant rocket technology. Miniature rocket stages for a Mars ascent vehicle would need to be over 80 percent propellant by mass. It is argued that the planetary community faces a steep learning curve toward nontraditional propulsion expertise, in order to successfully accomplish a Mars sample return mission. A cultural shift may be needed to accommodate more technical risk acceptance during the technology development phase. Achieving a small size and mass for the Mars Ascent Vehicle (MAV) is critical to mission affordability, because program budgets have been 1-2 million dollars per kilogram of useful mass landed on Mars."
NASA said of the MAV in the past, "of particular interest is a MAV design/architecture or supporting technologies that reduces the system mass as compared to the previous studies. Technologies should be applicable for, but are not limited to either a two-stage solid (primary interest) or a liquid propulsion system with three-axis stabilization."

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Friday, February 25, 2011

NASA investigator: Mars rover mission 'adventure of a lifetime'

It's cold, dry, dusty and desolate, said Steve Squyres, the principal investigator of NASA's Mars rover program.

"It is a terrible place," he said. "If you went there, you would hate it." However, Squyres said, evidence discovered during the mission indicates that Mars in the ancient past was a very different place from the one he and his team are exploring now.
Squyres delivered a guest lecture Wednesday evening at Oklahoma State University's Wes Watkins Center. Squyres' lecture was the featured event in the university's Research Week lineup.

Since the Mars rover mission began, scientists have uncovered evidence of erosion on the red planet, indicating liquid water once existed. Dry river and lake beds are scattered across the Martian surface, Squyres said. The rovers have also found minerals that can only form in the presence of water, he said.

"This is telling us that, in the past, Mars was different," he said.

The two rovers, Spirit and Opportunity, landed on Mars in January 2004. Originally, Squyres said, the rovers were designed to last about 90 days. He expected them to last longer -- maybe twice as long, he said. But the two rovers have outlasted even the most optimistic expectations, he said.

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Thursday, February 24, 2011

Cave hope for moon house

moon cave
A giant volcanic cave beneath the moon’s surface discovered by Indian scientists last year through an analysis of archived images from the Chandrayaan-1 spacecraft may be a candidate site for a future human habitat.
Researchers at the Space Applications Centre, Ahmedabad, analysed 3D images from Chandrayaan-1’s Terrain Mapping Camera to identify the 1.7-kilometre long cave in a region of the moon called Oceanus Procellarum.
The hollow structure created by ancient volcanic lava flows on the Moon may provide lunar explorers a natural shelter from radiation storms and extreme variations between day and night temperatures encountered on the lunar surface, the SAC scientists said.
Their image analysis has revealed a hollow lava tube with a cavernous mouth — about 120-metres high and 360-metres wide —- and a roof estimated to be 40-metres thick. Details of the lava tube will appear tomorrow in the journal Current Science .
“This is a monster cave,” Ashutosh Arya, a senior geologist at the SAC, told The Telegraph .
The images also show two narrow trench-like structures that appear to lead into and out of the lava tube — a 4-km stretch aligned northeast-southwest appearing to move into the lava tube, and a 2-km stretch extending on the other side. The scientists believe these trenches, called rilles by geologists, represent the collapsed portions of what was once a much longer lava tube.
“The hollow tube-like structure is similar to lava tubes observed on the islands of Hawaii,” said Arya. “But but we don’t find a lava tube on the Earth as large as this one.”
Such buried lava tubes are expected to protect human explorers as well as instruments from radiation storms as well as extreme variations in temperatures on the Moon’s surface. The radiation is not expected to penetrate beyond 6 metres of the roof thickness. While the day and night temperatures on the moon swing from +120°C to -180 °C, temperatures inside the lava tube are expected to be near-constant -20°C.
“Such natural protection will help cut down the bill for future human habitats,” said A.S. Kiran Kumar, a physicist at the SAC and the principal investigator for Chandrayaan-1's Terrain Mapping Camera.
The SAC team plans to continue using the archived images from Chandrayaan-1 to look for more such structures in different areas of the Moon. “We’re trying to generate a database for future generations of space explorers," Kiran Kumar told The Telegraph.
While the global space science community has shown a renewed interest in the moon, sections of scientists caution that it would be unrealistic to expect any long-term habitation efforts within the next two decades.
The SAC scientists had announced their discovery of the lava tube at lunar science conferences in Ahmedabad and Houston, US, last year, but have described their results in greater detail in the journal Current Science this week.
The Terrain Mapping Camera was among several scientific payloads aboard Chandrayaan-1, India’s first lunar orbiter, launched in October 2008, but which was lost several months later due to instrument failures.

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Wednesday, February 23, 2011

Meteorites yield Mars water clues

Rare fragments of martian meteorites have revealed evidence of how water once flowed near the surface of that planet, U.K. researchers say.
Scientists at the University of Leicester have examined five samples of nakhlite -- a form of meteorite known to have originated on Mars and named after the Egyptian village of el-Nakhla where the first one was found in 1911 -- using an electron microscope, a university release said Wednesday.
The samples showed veins created during an impact on Mars and filled with clay, carbonite and other materials probably carried there by water from ice melted in the impact, John Bridges of Leicester's Space Research Center says.
The discovery closely ties in to recent geological discoveries of clay and carbonate on the surface of Mars made by NASA and European Space Agency probes, and suggests how some of it probably formed.
"We are now starting to build a realistic model for how water deposited minerals formed on Mars, showing that impact heating was an important process," Bridges said.
"With models like this we will better understand the areas where we think that water was once present on Mars."

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Tuesday, February 22, 2011

Canada to play important role in Mars mission


A Canadian-built device aimed at testing the Martian landscape for signs of "habitable" environments from the planet's past -and perhaps its present -is being readied at a California space institute for launch later this year.

The latest version of the Alpha Particle X-Ray Spectrometer -designed by University of Guelph physicist Ralf Gellert and built by B.C.-based aerospace firm MacDonald, Dettwiler and Associates -will be mounted on the Mars rover Curiosity as part of NASA's upcoming Mars Science Laboratory mission, scheduled for takeoff on its 55-million-kilometre journey to the red planet as early as Nov. 25.

If all goes according to plan, the probe and its APXS instrument, partly funded by the Canadian Space Agency, will land on Mars in August 2012.

Then the Canadian-built sensor -a smarter, faster and more durable version of similar devices used on previous NASA missions to Mars -will be put to use as Curiosity roams the Martian surface scanning rocks in search of geological evidence that the planet might have sustained life in the distant past, and perhaps still could today.

Gellert's device is "one of 10 that will help the rover in its upcoming mission to determine the past and present habitability of a specific area on the red planet," NASA's Jet Propulsion Laboratory, based at the California Institute of Technology in Pasadena, said in a newly issued update on launch preparations.

"Scientists will use information from APXS and the other instruments to find the interesting spots and to figure out the present and past environmental conditions that are preserved in the rocks and soils," JPL stated. "Identifying the elemental composition of lighter elements, such as sodium, magnesium or aluminum, as well as heavier elements, like iron, nickel or zinc, will help scientists identify the building blocks of the Martian crust."

Gellert and members of his research team have been preparing the upgraded APXS device for years. It is being twinned with an identical instrument that will remain at the University of Guelph to run simulations corroborating surface-ofMars findings during the mission.

"APXS was modified for Mars Science Laboratory to be faster so it could make quicker measurements," Gellert said in the JPL statement. "On the Mars Exploration Rovers (Spirit and Opportunity), it took us five to 10 hours to get information that we will now collect in two to three hours. We hope this will help us to investigate more samples."

Monday, February 21, 2011

Cassini to Sample Magnetic Environment around Titan

NASA's Cassini spacecraft is set to skim close to Saturn's moon Titan on Friday, Feb. 18, to learn about the interaction between Titan and Saturn's magnetosphere, the magnetic bubble around the planet.

The closest approach will take place at 8:04 a.m. PST (4:04 p.m. UTC) and bring Cassini within about 3,650 kilometers (2,270 miles) of Titan's surface.

As Titan makes a complete 360-degree orbit around Saturn, the relative influence of the sun's illumination and the hot ionized gas trapped in the magnetic bubble changes. These factors are important for understanding the relationship between Titan and Saturn's magnetosphere. It is important to make measurements at a variety of locations in the Saturn magnetosphere, so this flyby will occur in a part of the magnetosphere that has been poorly sampled so far.

Previous flybys have shown the magnetic environment near Titan to be rather variable and unpredictable. For 12 hours before and after closest approach, the Cassini plasma spectrometer instrument will be pointing in a direction to capture ionized gas in the region.

At the same time, Cassini's radio science subsystem will be gathering sensitive gravity data from Titan to improve understanding of the structure of the interior. Collecting data like these will eventually enable scientists to determine whether Titan has an ocean under its crust.

Other instruments will also be collecting data, much of it pertaining to seasonal change. Titan is currently in northern spring, approaching northern summer, and scientists want to know what has changed with the north polar winter vortex weather pattern. The composite infrared spectrometer, for instance, will be mapping temperatures in Titan's stratosphere. The imaging science subsystem will also be monitoring the lakes, clouds and transport of aerosols in the Titan atmosphere.

This latest flyby is dubbed "T74," though planning changes early in the orbital tour have made this the 75th targeted flyby of Titan.

Wednesday, February 16, 2011

New Planet Believed to Have Been Found at Edge of Solar System

While some people may still argue otherwise, most of us have come to accept the unfortunate realization that Pluto is not a planet. But just because we’ve lost Pluto as a planet doesn’t mean that we’re down to eight. NASA scientists are working to see if a mass that was found by NASA telescopes is, in fact, the long-believed-to-exist-but-as-of-yet-unprovable planet of Tyche.

Tyche (pronounced “tie-key”) is believed to be a gas giant located some 1.35 trillion miles from the Sun, which is equivalent to 15,000 AU. In layman’s terms, it would take light from Tyche roughly thre months to reach Earth. Tyche is also believed to be between three-and-four times the size of the current champion of the solar system, Jupiter, and have a surface temperature of -73C.

Even if Tyche is proven to exist, which seems to be a foregone conclusion, there’s no guarantee that it will ultimately be classified as a planet in our solar system. Many scientists believe that Tyche was not formed in our solar system, but was formed around another star and was later captured by the gravitational pull of our own Sun. According to Professor John Matese of the University of Louisiana at Lafayette, the International Astronomical Union (IAU, the organization that determines what is and isn’t a planet), the organization may not include Tyche as a new planet but create a new category specifically for Tyche.

Monday, February 14, 2011

Jupiter’s Moon Helps Peek Below Planet’s Belt

Astronomers have a new view of the chaos brewing beneath Jupiter’s cloud belt, thanks to some help from its icy moon Europa.

This new image, captured Nov. 30, 2010 with the 10-meter Keck II telescope in Hawaii, shows heat escaping from Jupiter’s interior, giving astronomers a peek into the roiling turmoil inside Jupiter’s missing red stripe.

The image shows Jupiter at four wavelengths of infrared light, which is beyond the range that human eyes can see. Three of those wavelengths show reflected sunlight. But one wavelength, 5 micrometers, can sense breaks in the cloud cover.

Jupiter’s famous red stripe mysteriously faded in late 2009 and vanished altogether by May, 2010. Observations with Hubble and other telescopes showed that the ruddy band was hiding beneath a layer of high, bright clouds made from icy ammonia crystals.