Laser-ion funnel mass spectrometry makes search for Martian life easier

Feb 08, 2011
NASA’s Mars Science Laboratory is part of one of many space exploration missions that have used mass spectrometry to analyze rocks and soils. But current techniques require samples to be heavily prepared, which can harm results. Recent research shows that adding a laser and an ion funnel to a mass spectrometer enables analysis on Mars’ surface without handling samples. Credit: NASA/JPL-Caltech

Finding life on Mars could get easier with a creative adaption to a common analytical tool that can be installed directly on the robotic arm of a space rover.

In a recent paper published online in the journal Planetary and Space Science, a team of researchers propose adding a laser and an ion funnel to a widely used scientific instrument, the mass spectrometer, to analyze the surfaces of rocks and other samples directly on Mars' surface. The researchers demonstrated that the combined system could work on the spot, without the sample handling that mass spectrometry usually requires.

"There are a lot of exciting discoveries about that have yet to be made," said the paper's lead author, Paul Johnson. "This technique could make understanding the composition of rocks and soils on Mars — possibly including evidence of life — much easier."

Johnson, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., came up with the idea after reading about an ion funnel technology for mass spectrometry developed by Keqi Tang and Dick Smith of the Department of Energy's Pacific Northwest National Laboratory. William Brinckerhoff of NASA's Goddard Space Flight Center in Greenbelt, Md., contributed his expertise in miniaturizing scientific instruments to the project, while Robert Hodyss, also of JPL, provided hands-on expertise during experimentation and testing.

Here on Earth, mass spectrometry is a common analytical technique scientists use to identify molecules, their elements and their isotopes in samples ranging from rocks to proteins. It works by turning a sample's molecules into electrically charged ions. A mass spectrometer then precisely measures the mass of ions and ion fragments to identify the sample's contents at a detailed molecular level.

Mass spectrometry isn't new to space exploration. It was used to analyze Martian soil for the first time as part of NASA's Viking program in the 1970s. And it's planned to be part of the Mars Science Laboratory's Curiosity rover, which will lift off for the Red Planet this November. But each time it's been used in space, the samples had to be extensively prepared before they could be analyzed.

With Viking, for example, soil had to be scooped up, placed into a chamber and heated to make the sample a gas before it could be analyzed. The Mars Science Laboratory will be able to do a more thorough sample analysis than Viking could, but it will still need to prepare its samples beforehand. The more a sample has to be handled, the greater chance there is for the equipment to malfunction or the analysis to fail.

On Earth, scientists do mass spectrometry within a vacuum chamber. But that requires either finding a small enough sample, or cutting down the sample to fit into the chamber. Any such efforts on Mars have to be done with a robotic rover that's controlled by human operators millions of miles away.

"Cutting rocks, picking them up and moving them around, all this adds complexity," Johnson said. "Complexity makes it more difficult to conduct experiments with a robotic rover. Plus, adding new tools so the instrument can do these extra tasks increase size, weight and power consumption. All this makes sending a mass spectrometer into space even more challenging."

Trying to simplify this work, Johnson and Hodyss at JPL, which manages NASA's Mars Exploration Project, turned to a technique called laser ablation. The method involves shooting a laser at the sample's surface, which creates a plume of molecules and ions that can then be analyzed by the mass spectrometer.

But how do you get the sample ions to enter the mass spectrometer? Even on our planet, that problem has plagued researchers for years. A large percentage of a sample was traditionally lost at this stage — until recently, that is. PNNL researchers Dick Smith and Keqi Tang developed a new technology for mass spectrometers in the late 1990s to address that challenge.

Their electrodynamic ion funnel is a series of conductive, progressively smaller electric ring electrodes that efficiently pull in and focus more ions into the mass spectrometer than without the funnel. This makes mass spectrometers tremendously more sensitive. Fortunately, the ion funnel works best when its surrounding environment has an air pressure of about 5 torr, which also happens to be the atmospheric pressure on Mars.

"We didn't specifically design the ion funnel for space exploration, but we're excited that it and Mars are a good fit," said Tang.

JPL asked PNNL to help test whether the combination of laser ablation and an ion funnel could make in situ, or "in place," possible on Mars. A standard laboratory mass spectrometer was equipped with laser and an ion funnel attachments, and the ion funnel end was placed inside a sealed chamber that matched Mars' atmospheric conditions. The researchers shot laser pulses at various samples, such as copper, stainless steel and gypsum. As they suspected, a small layer of each sample's surface atoms was transformed into ions and the ion funnel quickly pulled them into the , which identified the samples.

"This system could be developed into a 'point and shoot' instrument for space analysis," Johnson said.

The results are promising, but further work is needed to develop ion funnel-equipped mass spectrometers ready for space. The next step is to make the system as small and light as possible so it could be used on a space exploration rover. The authors plan to pare it down enough to fit onto a rover's .

Explore further: Curiosity brushes 'Bonanza king' target anticipating fourth red planet rock drilling

More information: Paul V. Johnson, Robert Hodyss, Keqi Tang, William B. Brinckerhoff, Richard D. Smith, The laser ablation ion funnel: Sampling for In Situ mass spectrometry on mars, Planetary and Space Science, online Jan. 11, 2011, DOI:10.1016/j.pss/2011.01.004

Related Stories

NASA's Mobile Mars Laboratory almost ready for flight

Oct 08, 2010

The Sample Analysis at Mars (SAM) instrument suite has completed assembly at NASA's Goddard Space Flight Center in Greenbelt, Md., and is nearly ready for a December delivery to NASA's Jet Propulsion Laboratory ...

Invention could aid Mars probes' search for life

Aug 16, 2010

The next generation of Mars rovers could have smaller, cheaper, more robust and more sensitive life-detecting instruments, thanks to a new invention by scientists at DOE's Idaho National Laboratory.

Carnegie Mellon scientist to build unique mass spectrometer

Jan 11, 2006

Carnegie Mellon University's Mark Bier has received a $546,000 grant from the National Science Foundation's Instrument Development for Biological Research program to build a heavy-ion mass spectrometer. This one-of-a-kind ...

Next Mars rover stretches robotic arm

Sep 06, 2010

(PhysOrg.com) -- Curiosity, the Mars Science Laboratory rover that will be on Mars two years from now, has been flexing the robotic arm that spacecraft workers at NASA's Jet Propulsion Laboratory attached ...

Recommended for you

Australian amateur Terry Lovejoy discovers new comet

19 hours ago

It's confirmed! Australian amateur astronomer Terry Lovejoy just discovered his fifth comet, C/2014 Q2 (Lovejoy). He found it August 17th using a Celestron C8 fitted with a CCD camera at his roll-off roof ...

Students see world from station crew's point of view

Aug 19, 2014

NASA is helping students examine their home planet from space without ever leaving the ground, giving them a global perspective by going beyond a map attached to a sphere on a pedestal. The Sally Ride Earth ...

Mars deep down

Aug 19, 2014

Scarring the southern highlands of Mars is one of the Solar System's largest impact basins: Hellas, with a diameter of 2300 km and a depth of over 7 km.

User comments : 9

Adjust slider to filter visible comments by rank

Display comments: newest first

xrisxs
1.8 / 5 (8) Feb 08, 2011
I know this is silly but if you landed a robot dune buggy on mars then you just put life on it. I know the bot is not made up of a heart and whatnot but if you are the eyes of this thing and this thing was made of life on this planet earth then you have just put life on it. I know your looking for life in another means, but I just wanted to say something instead of saying nothing. thanx..lol, somehow I knew to copy this message because I knew it would not submit. let's try it again
xrisxs
1.3 / 5 (8) Feb 08, 2011
Even if we do not find one shread of evident life we still see one big rock and we all know we are not moving to jupiter or w/e is closer to the sun. But again mars is still unable to move away from danger. If I had ten bux to give to the mars thing or the spaceship thing, then it would be the spaceship. At least a spaceship can move out of danger and go to mars and earth.
Ogahr
1.3 / 5 (4) Feb 09, 2011
I know this is silly but if you landed a robot dune buggy on mars then you just put life on it. I know the bot is not made up of a heart and whatnot but if you are the eyes of this thing and this thing was made of life on this planet earth then you have just put life on it. I know your looking for life in another means, but I just wanted to say something instead of saying nothing. thanx..lol, somehow I knew to copy this message because I knew it would not submit. let's try it again


It all depends on your definition of life, I believe it is not life because it is not able to make a conscience decision by itself. Therefore I also believe you are wrong. To put it In simpler terms, so that you will probably be able to understand, you are putting commands into your computer do you also believe that it is "life".

On the topic at hand, this is interesting news.
Jonathan_Q
4.7 / 5 (3) Feb 09, 2011
Personally I would rather them see if they could build some habitat using robotics and local materials in case that day we do attempt a landing. I think robotics is the way to go especially with harsh environments like mars.

I would like to see how we can develop a local mining operation that is build solely from a robotic crew assisted by human operators.

The more we use robotics in such environments by the time we wish to travel to mars we would already have a functioning base of operations.
Going
5 / 5 (3) Feb 09, 2011
Ogahr said "I believe it is not life because it is not able to make a conscience decision by itself"

Conciousness is not life. Bacteria are not conscious but they are alive. Its very difficult to come up with a concise definition of what alive means. Bounded entities which reproduce themselves using local energy and material resources, perhaps.
soulman
1 / 5 (1) Feb 09, 2011
Going, I agree with your critique, if not your definition.

Jonathan_Q, sounds great, but we can't even to that on Earth, so I wouldn't hold my breath about doing it on another planet any time soon.
Beard
3 / 5 (1) Feb 09, 2011
@soulman

An automated Von Neumann style system, controlled by an AI is feasible as soon as our technology is advanced enough.

I feel that in 20-30 years AI will be advanced enough to administrate a base and adapt to problems on the fly. Self replication of components might prove difficult but who knows?
soulman
3 / 5 (1) Feb 09, 2011
An automated Von Neumann style system, controlled by an AI is feasible as soon as our technology is advanced enough.

Anything (well, almost) is feasible as soon as the technology is advanced enough. This is similar to asking how long is a piece of string? I certainly don't think it will be withing 20 or so years time.
Beard
3 / 5 (1) Feb 09, 2011
Just see how AI is coming along in 2020 and again in 2030, we'll have greater perspective then. Self replication of robots is not beyond our ability if we can find a way for them to refine raw material into usable parts.

If the system works; we could just launch it at a planet and have a base or whatever else we can program waiting for us.