New Mars Forums

Terraformer, maybe I am mistaken, but what you describe sounds similar to a nickel-iron battery, though they use a nickel cathode instead of carbon (obviously), and usually employ a potassium hydroxide solution (though it appears sodium hydroxide can also be used).

https://en.wikipedia.org/wiki/Nickel%E2 … on_battery

It seems some researchers have recently worked on updating this old technology by adding carbon to the mix:

https://news.stanford.edu/news/2012/jun … 62612.html

So it seems that you have hit upon a good idea, and the details are in the engineering.

Thanks for the invite! Yes, I'm in Colorado and it would be easy for me attend those Boulder meetings now that I know where they are (or it would be, if my Mondays weren't so busy with regular meetings!). I know the campus well. I will have to see if I can work it into my schedule.

How do you prefer to be referred to on the forum?

There were some talks on the status of the methane problem at the American Geophysical Union meeting in December, and I managed to see some of them. The hint of seasonality just adds to the list of things we can't adequately explain. I think the only detection that has information about a geographic localization is still Mike Mumma's Earth based observations. Some of the current lines of interest are discussed in a recent Science article that you may be interested in: link. One of my colleagues on MAVEN is quoted. We will indeed be taking the observations on January 24 mentioned in the article to test the cometary source hypothesis. If we see something (we're not hopeful, but you gotta try, right?) there would certainly be a press release. I would be sure to bring it to the forum as soon as the embargo lifted.

I expect we'll start getting closure on the methane mystery when Trace Gas Orbiter starts their science mission this year. Or maybe things will just get more complicated. Either way, I'm very much looking forward to that!

With regard to the magnetic field, might you be referring to this work led by Jim Green? It's a fascinating idea, but there are some inaccurate verbal statements that sort of muddied the media coverage.

Thanks, guys!

We have already started collecting data with a few instruments, and hope to make a press release in the near future. The primary business this week is lowering the period of our 35 hour orbit capture to our nominal 4.5 hour science orbit. After that we'll deploy the booms and start running tests over the next few weeks. There will be a break in mid-October to make some special observations of Comet Siding Spring and its effect on Mars as it flys by. By early November we will start our nominal science operations and start getting back a constant stream of data on the upper Martian atmosphere.

Hi, GW! I have noticed it's been on the quiet side here lately...I'm guessing the start of a new semester is preoccupying the users who are students or teachers.

Be sure to tune into NASA TV tomorrow at 1pm ET for the MAVEN Pre Mars Orbit Insertion News Briefing. Should be a good way to gear up for the weekend!

Soccer is the sport I most enjoy playing, but I've ever followed the professional leagues very closely. That said, I have been keeping track of the scores this World Cup, and watching the highlights after the fact. I might even try to watch the elimination round live.

The proposals for instruments are in review right now, and while I know some people who submitted, they were more of the remote sensing variety. At this stage in the process you have to personally know someone directly involved to have an idea of what's on the table.

One decent guess would be a drilling instrument similar to that on MSL, which can only penetrate up to 5 cm into a target. I know that quite a few Europeans have submitted proposals, so there may be the possibility of an ExoMars type drill which could sample down to 2 meters.

These depths may seem somewhat inadequate given that you need to dig about 3 meters on Mars to get to a depth where organics could be stable against cosmic radiation over geologic time scales. However, one of the discoveries of MSL is that by driving up to the foot of a scarp undergoing active erosion ("active" being on a geologic scale) and digging to a relatively shallow depth you should be able to sample very old material that hasn't been exposed to cosmic radiation for very long. For more details you can check out this video from last year's AGU meeting, starting at 27:18 at watch for a few minutes:

http://mars.jpl.nasa.gov/msl/news/whats … ewsID=1564

The MAVEN mission was originally slated for 1 Martian year to sample full seasonal variability, however it was cut back to 1 Earth year during the proposal process to improve the chances of selection (e.g. less money) since it could still achieve its primary objectives in that timeframe. The other reason for the relatively short nominal mission is that MAVEN will have its periapsis considerably lower than most Mars orbiters (150 km, as mentioned above), and those deep dips to 125 km are essentially aerobraking altitudes. That is why the solar panels have a swept look to them, to make the craft more aerodynamic at those altitudes. It takes a considerable amount of fuel to raise the orbit after each dip, and even keep it in its nominal orbit over the course of a year, so fuel limitations translate into mission duration limitations.

After the nominal mission we will ultimately raise periapsis to ensure an orbit with long term stability. This is key, because MAVEN's main purpose after being a Mars science mission is to serve as a communications relay for future surface missions (our current fleet of birds is getting a bit long in the tooth...). In fact, this aspect is so critical to NASA's Mars Program that it was what allowed MAVEN to continue preparing for launch in the midst of the government shutdown last year.

SpaceNut, humans are not going to significantly effect the thickness of Mars' atmosphere through making rocket fuel any time soon. For one thing, the exhaust is ejected back toward the planet in order to make the spacecraft leave it (Newton's 3rd Law). Also, a fun number to put the magnitude of the atmosphere in perspective: it would take humans close to 1000 years at current CO2 production rates to generate the mass of CO2 that makes up the current Martian atmosphere. It's pretty substantial.

It's been a busy month here on MAVEN...time for an update!

I can now proudly say that every instrument aboard MAVEN has been successfully turned on and demonstrated full capability. The NGIMS saw residual atmospheric gas in their chamber, the Particles and Fields package observed the solar wind and interplanetary magnetic field, and IUVS took thousands of images of the Lyman-alpha spectral feature of interplanetary hydrogen across part of the sky.

As of January 1st we are now in Phase E of the project, meaning that money is now being shifted from engineering to science.

We are now looking forward to transitioning to "late cruise" and exercising the instruments a bit more. At the beginning of April the IUVS will pick some UV bright stars to look at (for example, B-type stars like Spica). This will help us calibrate the instrument and prepare for stellar occultation observations of Mars' atmosphere.

Thanks everyone!!!

I just got back with friends and family from viewing the launch from the causeway. It was truly thrilling. Feeling the rockets' rumbling resonate in your chest at a distance of a couple miles is quite the experience. And such a bright exhaust, like there was a miniature sun mounted on the bottom of the rocket. It really was an awesome sight.

In the next few days we will take MAVEN out of safe mode and begin the "cruise" phase of the mission. We'll be doing instrument checkout the first week of December, and after that the IUVS instrument will see about snapping a few shots of comet ISON as it passes by Earth. Hopefully we'll get some spectacular results...even before getting to Mars!