Where does this come from, and can I check it?

1202 and 1201 program alarms meant the guidance computer was shedding low priority work. The figure is taken from NASA History, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a space fact?

Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Apollo 11 landed through a cascade of computer alarms

1202 and 1201 program alarms meant the guidance computer was shedding low priority work A radar switch left in the wrong position flooded the computer with data during descent. The software recovered by restarting lower priority tasks, and controller Jack Garman recognised the alarm codes as recoverable. The Eagle touched down with about 25 seconds of fuel left. It sits in Mondo's space collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NASA History

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Space & Astronomy trivia

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Falcon 9 landed its first booster in 2015The rocket touched down upright in Florida after an orbital launch Chandrayaan-3 landed near the lunar south poleIndia's 2023 mission set a lander and rover down at high southern latitude Moon dust smelled like spent gunpowderAstronauts reported the odour inside the cabin after dust came back on their suits Each Saturn V fuel pump produced 55 megawattsThe five F-1 engines burned kerosene and oxygen at about 13 tonnes a second A Moonwalking spacesuit weighed about 127 kilogramsOn the Moon it pressed down with only about a fifth of that Apollo brought back 382 kilograms of Moon rockSamples from six sites are still being analysed today

Tags: apollo, landing, software

Apollo 11 landed through a cascade of computer alarms: the short answers

Where does this come from, and can I check it?: 1202 and 1201 program alarms meant the guidance computer was shedding low priority work. The figure is taken from NASA History, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a space fact?: Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.