Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U-M scientist says Mars winds could pose challenges

31.07.2007
—but manageable ones—for NASA's Phoenix lander team

Martian winds probably won't cause serious problems for NASA's upcoming Phoenix Mars Lander mission but could complicate efforts to collect soil and ice at the landing site, according to University of Michigan atmospheric scientist Nilton Renno.

New results from U-M wind tunnel tests suggest that winds could blow away some of the laboriously collected soil and ice, but probably not enough to affect onboard laboratory experiments, said Renno, a member of the Phoenix science team.

"Basically, my conclusion is that if you do the delivery properly and plan it well, you can guarantee that a large fraction of the sample is going to fall inside the instrument intake," said Renno, an associate professor in the U-M College of Engineering's Department of Atmospheric, Oceanic and Space Sciences.

Set for launch from Florida as early as Aug. 3, the Phoenix spacecraft will land on the planet's northern arctic plains, analyzing soil and ice to see if it could support microbial life. An 8-foot robotic arm will scoop up the soil and dump it into onboard science instruments.

With funding from NASA, Renno and his graduate students have been studying the possibility that Martian winds could blow away bits of falling soil and ice as the samples are dropped.

Winds of up to 11 mph are expected much of the time at the Phoenix landing site during the three-month main mission, which begins with arrival on May 25, 2008. Renno calculated that if the soil samples were dropped from a height of 10 centimeters (4 inches)—as called for in the original mission plan—the vast majority of the particles wouldn't make it into the instrument intakes under windy conditions.

Based in part on Renno's work, the Phoenix team decided to move the Phoenix scoop closer to the science-instrument intakes before dropping the soil, he said.

Robert Bonitz, lead engineer on the robotic arm team at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said the new plan is to dump the samples from 2 cm (0.8 inches). And Washington University in St. Louis researcher Raymond Arvidson, lead scientist on the robotic arm team, said the goal is to deliver samples to the instruments during calm periods.

"With Nilton's tests and Bob's ability to deliver at 2 cm., we should be OK," Arvidson said. "I am not particularly concerned about wind dispersal of our samples. Just another issue to keep in mind."

To test his wind-dispersal calculations, Renno and his graduate students completed about a dozen wind-tunnel experiments at his Ann Arbor laboratory in recent weeks. They placed a model of the Phoenix robotic-arm scoop inside the cylindrical, 10-foot-long test chamber.

The scoop contained wood grains of various densities to represent bits of martian dust, soil and ice. The grains were released from a height of 5 centimeters into simulated cross winds ranging from 1 to 10 meters per second (2.25 to 22.5 mph), and their trajectories were photographed with a high-speed camera.

Based on the wind-tunnel results, Renno concluded that only about one-third of the Phoenix samples would make it into the science-instrument intakes when dropped from 5 centimeters into winds of a few meters per second.

But losing two-thirds of a hard-won sample during a $420 million mission isn't as calamitous as it might sound, Renno said. The Phoenix instruments need about 1 gram per test, and the scoop will deliver several grams during each dump. So even if two-thirds of the sample blows away, there would be enough soil and ice to complete the test, he said.

And the recent decision to dump from a height of 2 centimeters, along with the plan to deliver samples during calm weather, should further reduce sample losses.

"We will deliver more volume than needed, in case of lateral transport," Arvidson said. "And we will deliver in calm conditions, based on examination of the meteorology data we collect."

Renno leads the Phoenix science team's atmospheric sciences theme group. His main research goal during the mission is to better understand the water cycle at the landing site. Mars is a frigid desert, and liquid water can't survive at the surface.

But subsurface ice exists in the Martian arctic. Some scientists suspect that near-surface ice periodically melts, during warmer parts of long-term climate cycles.

Since liquid water is required by all known forms of life, the melted ice could provide a home for hardy, opportunistic microorganisms. The Phoenix spacecraft is not equipped to detect current or past life, but it can determine if the prerequisites for life are present.

"The main goal of the mission is to see if there are conditions that could allow life to evolve on Mars, Renno said."Understanding the water cycle will help us answer that question."

Additional U-M tests concerning the dust cloud likely to be kicked up by the Phoenix landing engines have been delayed until September.

NASA's Phoenix mission is led by Peter Smith of the University of Arizona, with project management at the Jet Propulsion Laboratory and development partnership at Lockheed Martin, Denver. International contributions are provided by the Canadian Space Agency; the University of Neuchatel, Switzerland; the University of Copenhagen, Denmark; the Max Planck Institute, Germany; and the Finnish Meteorological Institute.

Jim Erickson | EurekAlert!
Further information:
http://www.umich.edu

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>