Lastest Surface Grinding Aluminum News


Image by jurvetson
On July 16, 1969, Apollo 11 took flight to the moon. In the days that preceded the launch, the U.S. scrambled to pull together the messages from Earth that would be left behind on the moon. This is the Apollo Goodwill Disc, and it was engineered to last lengthy following the U.S. flag was destroyed.

This silicon disc includes etched letters (scanned and reduced 200x) from the leaders of the world’s nations. This is one of the discs created by Sprague and retained by a Sprague manager a second resides in the Smithsonian, and a third rests on the Moon’s Sea of Tranquility, deposited there by Buzz Aldrin.

(Does anybody know if other builds remain intact? A Sprague press release says that of the handful of discs made, a single was given to President Nixon and 1 to President Johnson).

It is a tricky topic matter for photography. I wanted to capture the angle-dependendent iridescence of the semiconductor thin films. The overhead light source reflects off the leather seat cushion, revealing the shift from green to purple that happens at oblique angles.

This comes from the early days of the semiconductor market, when Apollo consumed 50% of international production, and wafers had been just 2” wide (the ultimate disc was cropped around the 1.5” metallized ring and placed in a aluminum case).

The notion of using lithographic thin films to produce a extended-term option to microfiche was novel at the time, earning Sprague a patent (#3,607,347). I used those techniques to develop a multi-colored Devo hat on a chip I designed at HP in 1988.

The story of the rushed creation of the disc is fascinating, as are the messages embedded in this interplanetary time capsule.

The notion started in June, 1969, and it was a politically charged project, in the midst of the Cold War and the Vietnam War. On June 27, NASA telephoned the state division, and got the unprecedented permission to make contact with the foreign chiefs of state to deposit a message on the moon. This was 19 days before launch. They had been asked to compose and send typed and scribed letters to the U.S. (they came by telegram and mail).

But NASA did not know how they would shop the messages so that they could last thousands of years in the harsh temperatures, solar radiation, and cosmic rays on the lunar surface. So they approached the supplier of some of the most sophisticated technologies on Apollo – the nascent semiconductor business.

Sprague manufactured 53,000 components on the Apollo 11 spacecraft and many much more for the ground assistance equipment. The engineers chose silicon for the storage medium since of the density of storage and the stability of silicon more than temperature in a vacuum.

“Crash course is an understatement. We had practically no time to put this together!”
— John Sprague, head of the semiconductor division

NASA officials delivered the goodwill letters on the July 4 vacation, and Sprague finished the first printing on July 5 at three a.m. Each and every letter was photographed, and optically reduced to the point where every single letter was ¼ the width of a hair. The image was transferred to a glass photomask which was then employed to image the silicon, considerably like the early days of IC manufacturing.

“It was a rush to get it accomplished. We slept on lab benches for two days in a row.”
— Ray Carswell, Sprague Engineer

Nevertheless, on July 9, the business was asked to commence over and develop a new disc with eight added messages. It was completed and sent to Houston at 3:30 a.m. on July 11, five days prior to launch.

In the comments under are some of the messages that caught my eye, such as the Vatican and Estonia (recognized in spite of their Soviet occupation at the time).

The letters had been written independently at a historic epoch in exploration abroad and conflict at home. Most of them reference God or peace on Earth.

“The Silicon disc represents a historic time when many nations looked beyond their variations to come with each other to accomplish this historic first.”
Charlie Duke, Apollo 16 moonwalker