Showing posts with label Moon. Show all posts
Showing posts with label Moon. Show all posts

Monday, November 01, 2010

Of the 75 artificial objects on the moon how many weren't put there by the US and USSR?

Surveyor 3 on the moon, photographed by Alan BeanImage via WikipediaThree years ago this week, China's first lunar probe, Chang'e 1, entered orbit around the moon. Roughly 15 months later, Change'e 1 was intentionally crashed into the lunar surface (after recording the most complete and accurate 3D survey of the moon ever made), adding yet another item to the growing list of man-made objects on the moon.

Humanity has been chucking technology at the moon for over 50 years. The first human creation to contact the lunar surface was the Soviet Luna 2 probe in 1959. Since then, a total of 75 man-made objects have achieved lunar touchdown (or impact). Most of those items are of American or Soviet origin, products of the Cold War space race. Twenty years ago, Japan broke the Russo-American duopoly on lunar littering by crashing the orbiter portion of the Hiten probe on the moon. Since then, four more non-US and and non-Soviet/Russian space agencies have placed objects on the moon -- but the rest of the world has a long way to go before it overtakes the American-Russian rivalry in lunar tech-tossing.

Of the 75 artificial objects on the moon how many
weren't put there by the US and USSR?

Tuesday, July 20, 2010

What did a 404 error signify in the Apollo 11 computer guidance system?

Buzz Aldrin removing the passive seismometer f...Image via Wikipedia
Today is the 41st anniversary of the Apollo 11 moon landing, and I'm too busy celebrating to write an original Truly Trivial piece. Thus, I leave you with one of my old Geek Trivia columns regarding some historically significant computer errors experienced during Apollo 11:
When Apollo 11 set forth for the moon in 1969, it carried with it what were then arguably the two most advanced computers ever built. The Apollo Guidance Computer — two of which went on every manned moon mission — was the first computer to use integrated circuitry and was thus the first modern embedded computer system ever put to use. ...
That isn’t to say the Apollo Guidance Computer — advanced as it was for its era — was error free. The AGC that ran the Apollo 11 lunar module’s Primary Navigation, Guidance, and Control System (PNGCS, pronounced pings) malfunctioned during the first lunar descent. Fortunately, the error codes 1201 and 1202 didn’t faze Buzz Aldrin and Neil Armstrong when they popped up, informing the astronauts of a critical buffer overflow. ... 
If the Apollo Guidance Computer had thrown a 404 error, it might have been a different story.

WHAT DID A 404 ERROR CODE SIGNIFY IN THE APOLLO GUIDANCE COMPUTER SOFTWARE SYSTEM?
Find out here.
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