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Batteries and other components that are not designed to survive cold martian nights |
reside in the warm electronics box. Nighttime temperatures may fall as low as minus |
105 C (minus 157 F). The batteries need to be kept above minus 20 C (minus 4 F) for |
when they are supplying power, and above 0 C (32 F) when being recharged. Heat |
inside the warm electronics box comes from a combination of electrical heaters, eight |
radioisotope heater units and heat given off by electronics components. |
Each radioisotope heater unit produces about one watt of heat and contains about 2.7 |
grams (0.1 ounce) of plutonium dioxide as a pellet about the size and shape of the |
eraser on the end of a standard pencil. Each pellet is encapsulated in a metal cladding |
of platinum-rhodium alloy and surrounded by multiple layers of carbon-graphite com- |
posite material, making the complete unit about the size and shape of a C-cell battery. |
This design of multiple protective layers has been tested extensively, and the heater |
units are expected to contain their plutonium dioxide under a wide range of launch and |
orbital-reentry accident conditions. Other spacecraft, including Mars Pathfinder's |
Sojourner rover, have used radioisotope heater units to keep electronic systems warm |
and working. |
The computer in each Mars Exploration Rover runs with a 32-bit Rad 6000 micro- |
processor, a radiation-hardened version of the PowerPC chip used in some models of |
Macintosh computers, operating at a speed of 20 million instructions per second. |
Onboard memory includes 128 megabytes of random access memory, augmented by |
which allows the system to retain data even without power. |
Program/Project Management |
The Mars Exploration Rover Project is managed by the Jet Propulsion Laboratory, |
Pasadena, Calif., for NASA's Office of Space Science, Washington, D.C. At NASA |
Headquarters, Dr. Edward Weiler is associate administrator for space science, Orlando |
Figueroa is Mars program director, Dr. Jim Garvin is the lead scientist for the Mars |
Exploration Program, David Lavery is Mars Exploration Rover program executive and |
Dr. Catherine Weitz is Mars Exploration Rover program scientist. |
At the Jet Propulsion Laboratory, Dr. Firouz Naderi is the Mars program manager, Dr. |
Dan McCleese is Mars chief scientist, Peter Theisinger is Mars Exploration Rover pro- |
ject manager and Dr. Joy Crisp is Mars Exploration Rover project scientist. |
At Cornell University, Ithaca, N.Y., Dr. Steve Squyres is principal investigator for Mars |
Exploration Rover's Athena suite of science instruments. |
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General Question |
newtscamander's avatar |
Your best learning techniques? |
Asked by newtscamander (2743 points ) October 24th, 2012 |
I’m asking for your most effective ways of gaining knowledge when studying for exams or deepening your expertise on any topic. For me (I seem to be a visual and auditive learner) it’s easiest to work with flashcards, write the facts down repeatedly, write them onto walls or big pieces of paper that I walk by throughout... |
Observing members: 0 Composing members: 0 |
14 Answers |
tom_g's avatar |
Record yourself (using your phone or digital recorder) either explaining a subject or describing relevant information. Then go back and listen to these recordings later. |
Adirondackwannabe's avatar |
I don’t do well with straight memorization. But tell me why something works the way it does, and I’ll get it instantly and retain it. So with me, it depends on the subject. |
@scuniper What subjects are you studying? |
wonderingwhy's avatar |
Repetition, three times spread out during the day, then get a good nights sleep and refresh first thing in the morning. Then application, application, application. Also turning it over in my head during the day poking at and exploring different aspects of it helps a lot. And of course there’s always the hear/do(apply)/... |
newtscamander's avatar |
@Adirondackwannabe English, German (I live in germany), Biology and social studies. Basically, I have to know the topics we looked at in class during the last 3 years off by heart. |
Adirondackwannabe's avatar |
@scuniper For biology and social studies try the cause and affect angle. That works best for me. For the languages if I understand the root of words I grasp them easier, if that helps at all. |
newtscamander's avatar |
English and German won’t be a problem- I just need to freshen up my memory by reading the books we worked on. How exactly do you look at something from the cause and affect angle? How is that done in practice, could you give me an example with a theoretical topic? |
@wonderingwhy Application? How does that work? Do you mean testing yourself? |
I seem to be rather narrow-minded right now… I guess I should take a break from studying and clear my head a little ;) |
Adirondackwannabe's avatar |
@scuniper Okay, How are bacteria and viruses different and how do you treat a person suffering from an infection from either? Antibiotics will kill bacteria, but not touch a virus. Then how do you prevent an infection? Why does a vaccine work on one and not the other? Why is anthrax so deadly? The cells contain a toxin... |
lifeflame's avatar |
Explain the concept to someone who is unfamiliar to the subject. |
snowberry's avatar |
For memorization of several sentences or even a long passage, I write down the first letter of each word of a sentence and put each string of letters on a separate line. |
So if I were to memorize this famous passage by Robert Frost, it would look like this: |
Here’s the text |
Stopping by Woods on a Snowy Evening |
By Robert Frost |
Whose woods these are I think I know. |
His house is in the village though; |
He will not see me stopping here |
To watch his woods fill up with snow. |
My little horse must think it queer |
To stop without a farmhouse near |
Between the woods and frozen lake |
The darkest evening of the year. |
I begin to memorize with the last line and say it using the first letters of each word as a clue. Then I learn the next line above that. It works quite well because the new material is always the stuff you say first. Does this make any sense to you? |
newtscamander's avatar |
@Adirondackwannabe I get it, that sounds logical, basically like a question and answer game ;) Thank you! |
@snowberry That’s what I use to memorize biological processes, like the conduction of nervous stimuli, just a series of letters, easy to remember, thanks! |
wundayatta's avatar |
I read. Or attend a lecture. Or both. Take notes. Write a synthesis. Discuss it with someone. Write it again (in an exam, when I was younger). |
Jeruba's avatar |
I treat content knowledge and process knowledge differently. Most of my classes have involved content knowledge. Some are cumulative, and that makes a difference too. |
With content knowledge, such as philosophy or the social sciences, when I read the material through the first time, I mark, highlight, and annotate with care and thought so that my notations will serve as a good review tool. At review time I can concentrate on the things I’ve marked. |
I pay attention to what the instructor emphasizes and write down anything that amounts to guidance about the exams. Writing practice essays is a good strategy for me. So is finding an accommodating audience and trying to explain major themes and topics aloud. A review session with a few other serious students has been ... |
Coming at the material from different angles and working it over from a number of points of view helps to cement it, especially when I do it in writing. Creating lists and tables and filling in their contents by hand makes me process the material in different ways and see useful relationships. |
With languages, it’s always the vocabulary that I have to work the hardest on, so flash cards do help. Grammar seems to come very easily to me. |
With process knowledge I’d like to say that I practice problem-solving, which is what I ought to have done, but in truth I always just abandoned myself to chance. I haven’t taken a process-knowledge course in a very long time and most likely never will again. |
colinross's avatar |
Weightlifters work and progress at the same rate. To learn, work and compete with another student. It becomes a game. |
newtscamander's avatar |
Thanks everyone, I’m getting on rather well with my learning, interesting to hear some fresh ideas! |
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