Posts Tagged ‘rovers’

NASA Twittering

Posted: 30 October 2008 in Uncategorized
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@MarsPhoenix is a twitter success story.  It’s also a NASA success story.  Oh and also a scientific success for all it has done on Mars.  As six months of night approach, the Phoenix probe was slowly shutting down systems to finish analyses.  A couple of days ago, a dust storm diminished the day time charging cycle enough that it caused the lander to go into hibernation.  NASA is going to try to revive the it this weekend, but the prospects are grim.  Even more grim are the chances that the probe will awake come spring.  Temperatures at the Martian poles go so low in the winter, they exceed the minimum tolerance for electrical circuits.

But back to the Twitter success story.  As of right now, @MarsPhoenix has 37,284 followers.  That makes it one of the most followed users on Twitter.  For the past few months, NASA has been posting updates posing as the probe.  The updates take the form of first-person snippets of information and answers to questions from users.  Overall, it has been great PR, keeping people up-to-date on space exploration in a completely new way.  We can’t exactly have a live feed from Mars, but by personifying the probe and getting people involved, NASA has really done a lot for improving public involvement in the mission.

NASA has expanded their twittering to a whole host of other missions.  Most notable (to me) amongst them are the Cassini probe (which is orbiting Saturn),  the Lunar Reconnaissance Orbiter, and the Spirit and Opportunity rovers.  So if you twitter, they might be worth some of your time.

@MarsPhoenix posted the following earlier today:

I should stay well-preserved in this cold. I’ll be humankind’s monument here for centuries, eons, until future explorers come for me ;-)

In honor of its imminent passing, Wired is running a contest to find the best epitaph for Phoenix.  My current favorite is:  ”Every robotic lander dies. Not every robotic lander truly lives.”  I’m getting a little choked up..

Venutian Rover Bomb

Posted: 12 November 2007 in Uncategorized
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There is a cool article today in New Scientist that describes an old cooling method with a bleeding edge application: a rover to Venus. Venus is a picture of the greenhouse effect gone wild. Average temperatures are about +260 degrees Celsius (500 degrees Fahrenheit). This is hot enough to melt lead and destroys most modern electronics. Previous rover attempts to Venus by the US and Russia lasted less than 2 hours. So if we are to put a rover on Venus for the kind of time we have spent on Mars, we’ll need to find a way to cool the onboard electronics long enough that they can operate well.

Enter two NASA boffins, Geofferey Landis and Kenneth Mellott. By applying a refrigeration technique invented by a clergyman nearly two centuries ago, they have found a way to keep a rover cool for about fifty Earth days (a Venutian day is 243 Earth days, about 19 days longer than its year!). The Stirling cooler (invented by Reverend Robert Stirling) works by compressing a gas with a piston. As it compresses, it gets hotter. The temperature is dissipated with a radiator (which would be placed on the back of the probe). As the gas expands, it gets cooler (causing the refrigeration effect). In order for this to work, the radiator must be hotter than the outside air.

Interestingly, the Stirling cooler is energy efficient and is being incorporated into some of the newer energy efficient refrigerator models. To power the cooler on the rover, they propose using a plutonium battery. This type of device is known as a radioisotope thermoelectric generator. As the radioactive material decays, it release heat, and this heat is converted into electricity. These batteries are common on satellites and in unmanned situations where a long duration power source is necessary and solar cells are not viable (the massive cloud cover on Venus prevents solar cells from being very effective, plus the atmosphere is very caustic and I think it would probably damage them).

Well, if there is somehow intelligent life on Venus, let’s hope they don’t confuse this rover for the first case of interplanetary terrorism.

New X Prize cooler than ever

Posted: 13 September 2007 in Uncategorized
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Buzz has been building over the past few days about what will be the next X Prize. If you don’t know what the first X Prize was all about, skip down a bit. The new Google Lunar X Prize was announced today. The prize purse is $20 million for the grand prize winner, $5 million to a second place winner and $5 million split amongst several bonus prizes. The goal is a soft-landing on the moon with a robotic craft which then must signal back to Earth. The rover must roam around for at least 500m before sending the “Mooncast”.

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