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 MEMS chips get metatlenses
21.02.2018 | American Institute of Physics

nachricht International team publishes roadmap to enhance radioresistance for space colonization
21.02.2018 | Biogerontology Research Foundation

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: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Decoding the structure of the huntingtin protein

22.02.2018 | Life Sciences

Camera technology in vehicles: Low-latency image data compression

22.02.2018 | Information Technology

Minimising risks of transplants

22.02.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>