A dust-off broom for Mars
Romanian engineers have developed a small plasma jet capable of blowing Martian dust from solar panels and other equipment that can be used by future missions.
The “plasma broom” solution developed by Ticoş and colleagues uses bursts of plasma jet produced by a simple plasma accelerator. When a large current is passed through two electrode plates separated by a field of rarefied gas, the voltage difference between the two electrodes ionizes the gas, creating the plasma. In the broom, this is done with a coaxial gun – the two metal electrodes are arranged as an inner rod within a hollow cylindrical shell. The discharge current flowing through the central rod electrode produces a magnetic field, which, together with the electric field, exerts a Lorentz force on the ionized gas that expels it. “The trick is that you need a quite high current in order to produce a reasonable magnetic field and this can be achieved more conveniently in a pulsed operation,” Ticoş explains. “For a fraction of a second (100 µs) the current is very high (several kiloamps) and the force pushing the plasma is quite strong.” During a pulse, the plasma is expelled at a very high speed – several kilometres per second – and so can simply blow dust away from an area two to four times bigger than the diameter of the jet.
An advantage of the plasma broom is that it uses low-pressure CO2 as the gas between the electrodes. This is particularly ideal for operation on Mars as the atmospheric pressure there is 150 times lower than on Earth and the atmosphere is 96% CO2. This means the gun will be able to function in “open” Martian atmosphere without the need for a pump or gas bottle. Ticoş and colleagues have also considered the energy required for the cleaner to function on Mars. This depends on the voltage the gun operates at and can vary between a few hundred to a few thousand Joules per pulse. “We did an energy budget estimate taking into account the solar irradiance on Mars,” says Ticoş, “and it appears perfectly feasible to fire a few shots even on a daily basis for cleaning the solar panels, which will boost considerably the energy production rate.”
Essentially, they are using ion engine concepts to create a can of dust-off, using the Martian atmosphere itself as the can.
Hat tip Mike Buford.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Romanian engineers have developed a small plasma jet capable of blowing Martian dust from solar panels and other equipment that can be used by future missions.
The “plasma broom” solution developed by Ticoş and colleagues uses bursts of plasma jet produced by a simple plasma accelerator. When a large current is passed through two electrode plates separated by a field of rarefied gas, the voltage difference between the two electrodes ionizes the gas, creating the plasma. In the broom, this is done with a coaxial gun – the two metal electrodes are arranged as an inner rod within a hollow cylindrical shell. The discharge current flowing through the central rod electrode produces a magnetic field, which, together with the electric field, exerts a Lorentz force on the ionized gas that expels it. “The trick is that you need a quite high current in order to produce a reasonable magnetic field and this can be achieved more conveniently in a pulsed operation,” Ticoş explains. “For a fraction of a second (100 µs) the current is very high (several kiloamps) and the force pushing the plasma is quite strong.” During a pulse, the plasma is expelled at a very high speed – several kilometres per second – and so can simply blow dust away from an area two to four times bigger than the diameter of the jet.
An advantage of the plasma broom is that it uses low-pressure CO2 as the gas between the electrodes. This is particularly ideal for operation on Mars as the atmospheric pressure there is 150 times lower than on Earth and the atmosphere is 96% CO2. This means the gun will be able to function in “open” Martian atmosphere without the need for a pump or gas bottle. Ticoş and colleagues have also considered the energy required for the cleaner to function on Mars. This depends on the voltage the gun operates at and can vary between a few hundred to a few thousand Joules per pulse. “We did an energy budget estimate taking into account the solar irradiance on Mars,” says Ticoş, “and it appears perfectly feasible to fire a few shots even on a daily basis for cleaning the solar panels, which will boost considerably the energy production rate.”
Essentially, they are using ion engine concepts to create a can of dust-off, using the Martian atmosphere itself as the can.
Hat tip Mike Buford.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I must resist with all my might the urge to face palm. The job of cleaning the solar arrays of a rover or lander could much more easily be accomplished with a simple, cheap, light weight and energy efficient compressor. No fancy high voltage systems, no plasma, just compressed Martian atmosphere. You build up a few PSI of CO2 from the atmosphere and then use a solenoid valve to dump the pressure through a tube to the end of what ever arm you have on the rover/lander. Maybe add in a filter to ensure ambient dust doesn’t get into the works.
But plasma? Really?
Everything to do with outer space must be complicated with engineering problems that simple solutions could solve for a fraction of the money for a reason, money.
The old story ( true?) of the micro gravity pen developed by NASA- the Soviets used a pencil
Chris: The story is not true. NASA never spent millions to develop a zero gravity pen. The reason everyone believes it, however, is that it is totally believable, considering what we all know of NASA.
Count me as someone who could believe, NASA would, blow money, at ANY opportunity.
The Truth About the Million-Dollar Space Pen
–The Fischer Pen Company Model “AG-7”
https://youtu.be/LbYOdS9_vo0
(4:24)
Wayne, you are truly a fountain pen of knowledge…… ;-)
Steve–
HAR!
What can I say… “I’m a ‘TV-Baby,’ & they showed us a lot of a films in elementary school. (A lot, of films, and film-strips.)
I vaguely recall the whole pen-thing.
Pivoting to urban-legend’s…
What, is the Truth, about NASA & TANG?
When NASA was a brand that everyone wanted to be associated with, I remember Tang, Gulf oil company, and a few others that celebrated NASA and the moonshot and the good that NASA did for the country as a whole, lately, not so much.
Joe–
Good stuff.
(tangentially-whatever happened to all that “muslim outreach” that NASA was doing? Have all those people been fired yet?)
On a more serious note—been reading Sky & Telescope magazine for 1966 & 1967.
>Non-stop Space activity, constant rocket launches (all sizes) & probe missions, every school & College in the Country is building an observatory, Radio telescopes are getting yuuge, etc., etc., etc. It’s absolutely amazing.
NASA definitely had a Brand, and I’m seeing where they pumped a lot of money into basic research & hardware, literally “everywhere.”
–As I’m want to do, this reminds me of a movie…
Armageddon–
“You guys are NASA” scene
https://youtu.be/_B7MzBmjaJ8
(0:32)
Off to see Wonder Woman with the g-daughter.
The article suggests that it isn’t as simple as blowing them off with pressurized gas.
From the article: “Unfortunately, it isn’t a simple case of tipping the particles off or brushing them away with a standard broom. The dust sticks strongly to surfaces due to factors such as electrification caused by high electric fields during storms, and chemical composition – the high iron content is easily magnetized, for example. … ‘The problem appears when you have large dust grains, which are quite heavy,’ explains Ticoş, ‘Even if they are electrically charged it becomes very challenging to lift them off and transport them over tens of centimetres.’ … During a pulse, the plasma is expelled at a very high speed – several kilometres per second – and so can simply blow dust away from an area two to four times bigger than the diameter of the jet.”
Joe,
There are plenty of unsung things that came from NASA development money. Little known is the integrated circuit chip, because NASA needed a small and lightweight computer, and there was a university that was experimenting with building microscopic electronics components on semiconducting material. NASA hired them to make that a practical reality.
Add to the list quartz-crystal clocks, MRIs, cordless power tools, and solar panels. Here is more:
https://spinoff.nasa.gov/Spinoff2008/pdf/spinoff2008.pdf
(As an aside, in 1977 I interned at a NASA department that had just completed some research for improving mine safety.)
That was from 2008, before ISS was declared operational. More is coming out of science conducted on the ISS, but that science is often kept fairly proprietary for as long as NASA permits (five years).
As for solutions in space being complicated and expensive, often a solution to a problem in space must work the first time, because it is impractical to send someone to fix it if it does not work. There is often redundancy built in as part of the solution (the backup plan — thanks, wayne), but redundancy costs money, adds weight (which reduces the weight available for additional science), and complicates the overall system. A simple solution on Earth seems like it would be just fine in space, but on Earth you can fix it, tweak it, or try another solution when it does not work. You can pull your faulty car to the side of the road and call for a tow, but on Mars, the auto club does not provide roadside service; otherwise Spirit would likely still be running just as strongly as Opportunity.
I still see the occasional advertising that relates a product to NASA in some way, so while NASA is not in the glory days of yore, it is still pretty awesome. I wish Congress would put it to good use on technical solutions and on exploration rather than squander the talents of so many talented scientists and engineers on political solutions. JPL is the only part of NASA that still has a stellar reputation for science and exploration. I hope that our president will convince Congress to put the rest of NASA to good use, too.
I don’t know if it’s useful, but useful things often come from crazy ideas. Plus, it’s always good to have a back up plan.
Good stuff.
On a more optimistic note, brand new JPL, von Karman lecture:
“The Golden Age of Exploration”
6-1-2017
https://youtu.be/gcsgz8wF_ZA
(1:19:35)
“Charles Elachi, Caltech professor and JPL director (2001-2016), describes the excitement and impact of discoveries made by JPL’s robotic missions at destinations around the solar system and beyond over the past 15 years—from rovers and orbiters at Mars to Cassini at Saturn to discoveries about planets around other stars.”