Mars Rovers Return to Exploration

inkslinger77 writes "The two Mars rovers that have been carefully conserving critical power supplies since June, when the summer dust-storm season began on the red planet, are now springing back to work as the storms subside. Typically, the solar panels on each rover produce about 700 watt-hours of electricity per day — enough to light a 100-watt bulb for seven hours, according to NASA. But this year's dust storms reduced that to as little as 128 watt hours per day. When daily power generation is down to less than 400 watt-hours, the rovers suspend their driving on the planet and stop using their robotic arms, cameras and other instruments. But they are back in action now!"

Not "Defective by Design"

[D4C5CE]

Fortunately they are not into consumer electronics. Otherwise there'd be a DRM [wikipedia.org] on these rovers, one they would have retired 3 years ago in a cruel, wanton act of planned obsolescence [theinquirer.net].

Crazy units

[Ed Avis]

700 watt-hours per day

Since a watt is just a short way of saying one joule per second, this means

700 joules per second per hour per day

Do NASA really do their energy computations in this unit? Given their past problems getting to grips with the metric system, perhaps they might.

Surely it would be clearer to say 'the rover's solar panels have an average power output of about 29 watts'. Anyone could see that this is enough power to run a 100 watt lightbulb nearly one-third of the time.

Software Never Dies

[curmudgeon99]

We as software developers here should take note of this. The code you're writing and putting into production has the potential to last for decades. For example, out of college my first programming job was for Mutual of Omaha. They had lots of code that was written in the late 1960s in Assembler or in (gag) COBOL. Well, although someone like me would have loved to have rewritten those systems, it was not happening. Then, take another point. I myself wrote a large system for them that--according to friends who are still there--and that system has not been changed much since then. So, folks, the point is this: you write a lot of applications. Some won't survive a year. Others... they may be doing their job in twenty years. Machines wear out but--properly designed and maintained--software never does. Bravo to Spirit & Opportunity and the teams that built those kickass pieces of hardware/software.

"700 watt-hours of electricity per day"

[Anonymous Coward]

"700 watt-hours of electricity per day -- enough to light a 100-watt bulb for seven hours, according to NASA"

Do you really have to be a rocket scientist to figure that out?

Q: Why do NASA engineers buy their shoes much too big?
A: They think their feet are one meter long.

Re:Software Never Dies

[chill]

Not to rain on your parade, but I just fixed some veterinary office software for a local animal hospital that was written in COBOL. Yes, it was on a PC and I thank the Gods it was interpreted and thus included the source code. It had been 20 years since I've worked with COBOL.

I was fixing it because the original programmer -- and I am NOT making this up -- committed suicide. Hmmmm...I wonder if there is a connection?

Author Shill

[Frosty Piss]

Looks like IDG (ComputerWorld) is really hitting Slashdot HARD, either that or they have a deal with Slashdot. Here's a partial list of the shills that regularly show up and have almost 100% article acceptance rates:

inkslinger77

narramissic

jcatcw

If it's all OK and everything with the corporate ownership of Slashdot to be played by IDG, I suppose that's their business, but one would hope that they are actually getting PAID for being part of IDG's advertising program. And of course there should be disclosure so that visitors to Slashdot realize they are reading advertisements and not an article submitted by a "real" user...

Re:It runs and runs and runs...

[OriginalArlen]

The rovers normally do a sun stare (through thick h-a filters I believe) to measure tau, the fraction of sunlight that's making it through the atmosphere. Here's a mosaic of those sun stares [planetary.org] from the last month or so, corrected to show the light as it would actually appear to the rover. The dramatic darkening of the sun is obvious. The feat of building rovers that not only live (at time of writing) thirteen times over their design lifetime, but survive on less than half the power that was originally expected to kill them both stone-dead, is going to be a legend in unmanned spaceflight for a long time to come... (For the last 3 years, those of us following the rovers on a daily basis believed the official line that less than 280Wh/day would mean bricked rover after a couple of days. The minimum Oppy received was 128 W/h - and (thanks partly for the nice warm summer weather) it didn't even trip the emergency heaters which come on at 39*C below. Kudos to Emily Lakdawala of the Planetary Society, who got an awesome congrats note from Jim Bell, the MER imaging lead [postcardsf...rsbook.com].

The untold story of the MER rovers is the triumphant vindication of Steve Squyres' then unprecedented decision to allow the raw imagery to be automatically thrown up on the net virtually as they came in - so that in some cases, the amateur mosaics, panoramas and other post-processed images were sometimes out before the official JPL team had even seen the raw data. Indeed someone even wrote an application [blogspot.com] specifically to pull down, process and render the raw data. (Yeah, it's GPL'd :) )

Mars Rovers Budget

[iamlucky13]

This is a concern, but NASA considers the work the rovers are doing valuable enough to keep funding it.

NASA's budget for 2007 provides $85 million for rover operations, communications, and data processing. Obviously that's a non-trivial amount (roughly enough to employ 350 people full-time, standard cost ratios), even compared to the $820 million spent on designing, building, launching, and operating for the first year.

For comparision, Hubble is receiving $340 million this year. The entire NASA budget for Mars exploration for 2007 is about $700 million. Almost half of that goes towards building the 2009 Mars Science Laboratory rover. The rest is divided between the Spirit and Opportunity, Mars Global Surveyor (which died a couple months ago), Mars Odyssey (orbiter), Mars Reconnaissance Orbiter, the US contributions to Mars Express (orbiter), Phoenix Polar Lander (lander, en route), and a Scout-class mission scheduled for 2011.

* My numbers came from NASA's 2007 budget request. Some of them were changed for the actual allocation.