Could you run a moon mission from your smartphone?
21 September 2022
Many older people who experienced the first moon landing will vividly remember seeing Neil Armstrong’s famous words of wisdom when he said, ” A small step for man, but a giant leap for mankind.” Half a century later, this event remains one of the greatest achievements of humanity. Despite rapid technological advances since then, no astronaut has returned to the moon since 1972.
This seems surprising. After all, when we look back on this historic event, it is often said that “we currently have additionally computing power in our pockets than the computers on Apollo 11. But is that true? If so, how greatly more powerful are our cell phones?
The Apollo 11 was equipped with the Apollo Guidance Computer (AGC). This computer had 2048 words, which was used to store “temporary results” (data that would be lost if the power went out). This sort of memory is called RAM (Random Access Memory). Each word consists of 16 binary digits (bits), with one bit being 0 or 1. This means that the “Apollo” computer had 32,768 bits of RAM.
In addition, it had 72 KB of ROM (Read Only Memory), equivalent to 589,824 bits. This memory is programmed and cannot be changed once it is determined.
More specifically, modern cell phones typically have 4 GB of RAM. This equates to 34,359,738,368 bits. This is more than a million times (1,048,576 times to be exact) more memory than the RAM that the Apollo computer had. The iPhone also has up to 512 GB of ROM memory. That’s 4,398,046,511,104 bits, more than 7 million times more than a guidance computer.
But memory is not the only thing that matters. The Apollo 11 computer had a processor (an electronic circuit that performs operations on external data) that operated at 0.043 MHz. The processor in the latest iPhone is estimated to run at about 2490 MHz. Apple has not disclosed this processing speed, but others have calculated it. This means that the iPhone in your pocket has more than 100,000 periods of the processing capacity of the computer that landed a man on the moon 50 years ago.
