GPS: part one

© Mark Ollig

Today’s Global Positioning System (GPS) had its roots with the US Navy developing the first satellite-based navigation system, known as Transit, in the late 1950s.

The Transit system’s initial purpose was to provide navigation for US Navy submarines.

The system was named “Transit” because it tracked the time it took for satellites to move into and out of view, helping to pinpoint locations on the ground or water.

The US Navy launched the first experimental navigation satellite, Transit 1A, using a three-stage Thor-Able rocket.

The third stage failed to ignite, and the satellite payload fell back to Earth after reaching an altitude of 400 miles.

Although the Transit 1A mission was unsuccessful, it marked the initial attempt at a space-based satellite navigational system.

Launched April 13, 1960, Transit 1B became the first successful US navigation satellite, demonstrating the feasibility and potential accuracy of satellite navigation in determining positions.

Although its orbit around Earth was not perfectly circular, it successfully transmitted radio signals that laid the foundation for today’s GPS.

Transit satellites, operational from 1960 to 1967, were primarily solar-powered. However, early models Transit 4A and 4B used nuclear battery power via a radioisotope thermoelectric generator.

These satellites weighed between 264 and 308 pounds, and they communicated using radio signals at 150 MHz.

Their navigation data is encoded using a pseudorandom noise (PRN) binary code, which serves as a unique identifier for each satellite.

Devices on the ground use this code to calculate their position in relation to the satellites.

A ground-based receiver detects, decodes, and processes signals from orbiting navigational satellites to determine its exact location.

The Transit satellite system, although designed for military navigation, became valuable for scientific research and civilian use.

In 1973, the US Department of Defense began the Navigation System with Timing and Ranging (NAVSTAR) program.

The program officially became known as the Global Positioning System (GPS) in 1978, the same year the first NAVSTAR satellite (OPS-5111/NAVSTAR 1) was launched Feb. 22 using an Atlas F rocket.

The satellite, weighing 845 pounds and measuring 5.3 feet in diameter by 6.7 feet tall, was the first of eleven Block I experimental GPS satellites.

NAVSTAR was powered by solar panels and batteries, and it communicated via L1 (1575.42 MHz) and L2 (1227.60 MHz) radio signals, using PRN codes.

The L1 frequency (1575.42 MHz) transmitted both the Coarse/Acquisition (C/A) code for civilian use and the Precision (P) code.

The P-code, also available on the L2 frequency (1227.60 MHz), was restricted to authorized users.

Due to Selective Availability (SA), a US government policy implemented for national security reasons, the civilian C/A code’s accuracy was intentionally degraded to approximately 328 feet.

The military had exclusive access to an encrypted version of the P-code, known as the Y-code, providing enhanced security and accuracy.

GPS satellites transmit navigation messages containing essential timing and orbital information (ephemeris, almanac, clock corrections, status messages) at a constant rate of 50-bps (bits per second).

This standardized transmission rate ensures compatibility across all subsequent generations of GPS satellites and allows older GPS receivers to function seamlessly with newer satellites.

The frequency at which a GPS receiver updates its position varies depending on the application.

Consumer-receiving devices typically update their position once per second (1 Hz), which aligns with the 50-bps transmission rate.

Pilotless aerial vehicles (UAVs) and autonomous vehicles require much faster update rates, sometimes reaching ten times per second (10 Hz) or even faster, to ensure precise tracking and navigation.

The GPS Block I satellite’s Precise Positioning Service (PPS) signal offered military users location accuracy within a range of approximately 10 to 20 feet.

In comparison, the civilian Standard Positioning Service (SPS) signal accuracy was intentionally degraded to 328 feet due to Selective Availability (SA).

SA, a US government policy, intentionally degraded civilian GPS accuracy by manipulating satellite data, including timing and location information.

While the military retained access to a more precise signal, civilian accuracy via SA was limited to about 328 feet.

The launch of this NAVSTAR satellite marked an essential step in developing the modern GPS.

In 1983, President Ronald Reagan approved the development of GPS as a dual-use (military and civilian).

The first Block II satellite, a NAVSTAR satellite, was successfully launched into orbit using a Delta II rocket Feb. 14, 1989. It represented the second generation of GPS satellites. It used solar panels and batteries for power and communicated via radio signals at 1227.60 MHz (L2 frequency) and 1575.42 MHz (L1 frequency), transmitting timing and orbital information.

At the outset, only the US military had access to the more accurate PPS signal on both the L1 and L2 frequencies.

In May 2000, the US government ended Selective Availability, improving GPS accuracy and reliability for civilian use worldwide.

Today, the Global Positioning System is owned by the US government and operated by the US Space Force.

Although I use the GPS in my car, I still keep a folded paper highway map in the glove compartment – just in case.

Next week – GPS: part two.

(Image created by Meta AI)

Mission Control: ‘Stay or No-Stay’

© Mark Ollig

The Apollo 11 mission made history with the first moon landing 55 years ago Sunday, July 20, 1969.

That day, the lunar module named Eagle slowly descended toward the lunar surface with a five-foot aluminum rod extending from the footpad of the descent stage.

When the rod’s contact sensor touched the moon, it triggered an amber light inside the lunar module crew cabin.

“Contact light. Okay. Engine stop,” announced lunar module pilot Buzz Aldrin.

Apollo 11 astronauts Neil Armstrong and Buzz Aldrin landed the Eagle Sunday, July 20, 1969, at 3:17 p.m. CDT (Minnesota time), in a region of the moon called the Sea of Tranquility.

“We copy you down, Eagle,” radioed capsule communicator (CapCom) Charlie Duke (Charles Duke Jr.) from Mission Control in Houston, TX.

“Houston. Tranquility Base here. The Eagle has landed,” confirmed Armstrong.

“Roger, Tranquility. We copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again, thanks a lot,” answered CapCom.

“Thank you,” replied Armstrong.

“Very smooth touchdown,” Aldrin added.

Inside mission control, the flight controllers were cheering loudly.

Gene Kranz, flight director, knew that it was not the right time to be uproarious and said in a raised voice, “OK, keep the chatter down in this room,” as T1, the one-minute mark after landing, neared.

T1 was the last point at which an immediate abort was possible if conditions aboard the Eagle were unsafe.

Kranz, known for his calm demeanor and unwavering focus, depended on his team’s quick analysis of telemetry data.

He required confirmation from each flight controller’s status board that conditions in and outside the Eagle were safe enough for the astronauts to stay on the moon.

Each confirmed the lunar module’s systems were functioning correctly.

“CapCom, we’re stay for T1,” Kranz told Charlie Duke.

“Eagle, you are stay for T1,” CapCom radioed Armstrong and Aldrin.

If the “no-stay” orders were issued, the astronauts would ignite the engine on Eagle’s ascent stage (containing the crew compartment), lift off from the moon, rendezvous with the command module, and head back to Earth.

“Roger. Understand, stay for T1,” Armstrong replied.

“Eagle is at Tranquility,” Duke reported to Michael Collins, who was orbiting 60.27 miles above the moon in the command module named Columbia.

“Yes, I heard the whole thing. Fantastic!” replied Collins.

“Be advised there are a lot of smiling faces in this room, and all over the world,” CapCom told the astronauts.

“There sure are two of them up here,” Armstrong replied.

“Don’t forget the one in the command module,” quipped Collins.

I remember CBS News anchor Walter Cronkite being at a loss for words after the Eagle touched down on the moon.

“Wally. Say something; I’m speechless,” Cronkite said as he turned to Wally Schirra, a former astronaut who was co-anchoring the moon landing as a consultant.

“Kind of nice to be aboard for this one, isn’t it?” Schirra replied with a grin to a smiling Cronkite.

That evening, Armstrong became the first person to walk on the moon.

With my young eyes transfixed on the living room television, I, along with 650 million others, watched the ghost-like video images of Neil Armstrong descending the ladder of the lunar module.

At approximately 8:56 p.m. CDT Sunday, July 20, 1969, Armstrong stepped onto the lunar surface, saying, “That’s one small step for [a] man, one giant leap for mankind.”

Nineteen minutes after Armstrong stepped onto the lunar surface, Aldrin descended the ladder and described the scene as “magnificent desolation.”

After joining Armstrong on the surface, they carefully assembled the flagpole, planted it in the lunar soil, and unfurled the American flag, marking this historic moment.

From Houston, CapCom patched through a 238,855-mile long-distance call from the Oval Office of the White House to the moon.

President Nixon, speaking on an olive-green Western Electric 2500 telephone, congratulated the astronauts on their remarkable achievement.

Armstrong and Aldrin spent two hours and 31 minutes outside of the lunar module, where they collected rock and soil samples, conducted experiments, and placed measuring and sensor devices on the lunar surface.

After spending 21 hours and 36 minutes on the moon, the Eagle’s ascent stage lifted off, carrying Armstrong and Aldrin to rendezvous with Columbia for their return to Earth.

Minnesota played a significant role in the Apollo 11 mission in 1969.

Honeywell Inc., headquartered in Minneapolis, contributed through its Bendix Division by building two lunar surface experiments: the passive seismic experiment package (PSEP) and the lunar dust detector (LDD).

Additionally, Honeywell’s Aerospace Division in Minneapolis developed the stabilization and control system (SCS) for the Apollo command module, crucial for attitude control and maneuvering during the mission.

Today, several members of the Apollo 11 mission are still with us, such as Gene Kranz, who is 90, Buzz Aldrin, who is 94, and Charles Duke Jr., who is 88 and walked on the moon during the Apollo 16 mission in April 1972.

Neil Armstrong, the first person to walk on the moon, died Aug. 25, 2012, at the age of 82.

Michael Collins, who piloted the Apollo 11 command module, passed away April 28, 2021, at the age of 90.

The Apollo 11 astronauts left a stainless-steel commemorative plaque on the moon, attached to the ladder on the lunar module’s descent stage.

It reads, “Here, men from the planet Earth first set foot upon the moon July 1969, A.D. We came in peace for all mankind.”

From sand to silicon wafers

© Mark Ollig

High-purity silica sand is the starting point for the tiny integrated circuits, commonly referred to as microchips, powering our digital devices.

This extraordinary level of purity (exceeding 99.9999% silicon dioxide) is crucial in manufacturing, as even minuscule impurities can interfere with the electron flow in a microchip’s complex circuitry.

The journey of creating microchips begins with the extraction of raw sand, which is transformed into thin, round wafers that serve as the foundation for these intricate electronic components.

According to the United States Geological Survey, the US remained a major producer of industrial sand and gravel in 2023.

High-purity quartz sand, a type of silica sand and a key component in microchip manufacturing, is found in specific deposits across the country, like those in Minnesota.

Minnesota is known for its high-quality quartz sand deposits, primarily located in the southeastern and south-central parts of the state and the Minnesota River Valley.

Silica sand is used in a variety of applications, including concrete and mortar production, metal casting, sandblasting, and even recreational settings like golf courses and volleyball courts.

While silica sand has various industrial and recreational uses, only high-purity quartz sand, a specific type of silica sand, meets the strict requirements for microchip manufacturing.

The process of transforming silica sand into high-purity silicon involves extracting and purifying the sand, followed by melting and carefully growing a large cylindrical crystal of silicon. The resulting crystal is then sliced into thin, round wafers.

During the 1980s and 1990s, these wafers were six inches (150mm/millimeters) in diameter.

Today, they are 12 inches (300mm), allowing for a significantly greater number of chips per wafer.

Semiconductor industry leaders like the Taiwan Semiconductor Manufacturing Company (TSMC) and Intel are already experimenting with larger 18-inch (450mm) wafers for future production.

Larger wafers offer significantly more surface area compared to the current 12-inch standard and, with continued advancements in miniaturizing chip components, could dramatically increase chip output per wafer.

Building and operating microchip fabrication plants (fabs) are incredibly costly, often requiring investments of tens of billions of dollars.

These expenses arise from the need for strict cleanroom environments, specialized equipment, ongoing research and development, highly skilled labor, and substantial energy consumption.

GlobalFoundries, a major US chipmaker, has invested heavily in their New York Fab 8 facility, with more than $15 billion already spent and an additional $11.6 billion planned.

The company also received $1.5 billion from the US government’s CHIPS and Science Act to boost domestic chip production.

Additionally, they are investing $1 billion to modernize Fab 9 in Vermont to produce next-gen gallium nitride (GaN) semiconductors, a material enabling faster and more efficient electronics for high-performance applications like electric vehicles, renewable energy systems, and 5G or 6G infrastructure.

Samsung is developing a $17 billion semiconductor fabrication complex in Taylor, TX, which is expected to be operational in 2025 or later.

In Arizona, TSMC is investing $40 billion to build multiple fabs, with the first one expected to be operational in 2025.

Thin silicon wafers serve as the foundation for constructing the intricate circuitry of microchips.

Billions of transistors, diodes, and resistors are meticulously patterned and layered onto the wafer’s surface through a complex fabrication process.

Finally, the wafer is diced into individual integrated circuits using a diamond saw, resulting in tiny chips packed with microscopic components that power our electronic devices.

Some central processing units (CPUs) consist of multiple cores, with each core acting like a “miniature brain” within the central “brain” of the CPU.

These cores work together, like different parts of the brain, to process information, execute instructions, and perform calculations, ultimately delivering faster and more efficient performance.

High-performance processors, found in data centers and used for demanding applications like artificial intelligence, can have dozens or even hundreds of cores.

Beyond CPUs, the intricate design of various other integrated circuits, such as memory chips, graphics processors, and communication chips, enables the wide array of features and capabilities found in our smartphones, computers, and other electronic devices.

The fabrication of advanced integrated circuits involves an intricate process of layering and patterning various materials onto a silicon wafer, analogous to constructing a microscopic layer cake, where each layer serves a distinct purpose.

In each layer, conductive materials like copper or aluminum form complex wiring, while semiconductors like silicon create transistors that function as switches.

Additionally, insulators like silicon dioxide are used to separate and protect the semiconductor components, ensuring their proper functioning and preventing electrical interference.

Photolithography, a technique employing light to precisely transfer patterns onto the wafer, is a crucial step in this intricate process.

Using light, manufacturers etch intricate patterns onto the silicon wafer, creating the complex circuitry of the microchip.

Circuit sizes are measured in nanometers (nm), a unit of length equal to one billionth of a meter.

The smaller the circuit sizes, the more transistors can be packed onto a single chip, leading to increased processing power and performance.

Intel has projected that by 2030, a single chip could contain a trillion transistors, which would dramatically impact computing and AI, and unlock extraordinary technological possibilities.

As always, stay tuned.

One diced six-inch (150mm) silicon wafer displays small squares,
each representing an individual chip or die that can
 be separated (cut) and packaged.
 (Photo taken by me) 

A zoomed-in view of the wafer, revealing
a detailed pattern of scored microchips.
(Photo by me) 

Wish I could get a brick or two

© Mark Ollig

The Winsted Holy Trinity elementary grade school building, constructed in 1907 for $30,000, was torn down in 2010.

The two-story brick building was dedicated in 1908 and originally served as both a school and a home for the Franciscan nuns who taught there.

One side of the building was the convent, and the other side had the grade school classrooms.

The convent area contained a first-floor chapel, living room, and guest reception area, while the second floor housed bedrooms and a study.

The lower level of the building included a kitchen, dining room, and a bathroom with two tubs.

Until 1953, when Melinda Kappel, the first lay teacher, was hired, nuns and priests taught at the school.

In 1957, a new convent was built north of the grade school.

In 1958, the area of the grade school the nuns had occupied was converted into extra classrooms.

An underground tunnel connecting the grade school and the high school was constructed in 1965.

I attended school there from the first through the eighth grade, but as the years (and decades) passed, I lost contact with many of my classmates.

Some stayed in Winsted or traveled to other areas of Minnesota, while others moved out of state or, sadly, passed away.

The new elementary school, built nearby, opened in November 2006.

On June 26, 2010, I went to see the empty grade school building one last time before it was demolished.

I brought along my camera and took several photos, many of which I shared on Facebook.

Among the outdoor photos was one of the school’s southeast corner, where the 1907 cornerstone had been removed, leaving a hole and scattering dozens of red-orange “Lake Mary bricks” on the ground.

Several older buildings in downtown Winsted, including City Hall (built in 1895), used the red-orange bricks from the nearby Lake Mary brickyard, which operated from 1882 to 1917.

Upon seeing the photos posted on Facebook, former classmates began reminiscing and sharing their memories of the old grade school.

I have clear memories of my first-grade classroom located on the northeast side of the first floor of the school.

Sister Mary Cyril (Order of St. Francis) led our homeroom class.

The homeroom held around 50 students, and we sat in rows of wooden desks attached to wooden runners.

Across the hallway was the 8th-grade homeroom.

On Facebook, we shared memories of classes and our teachers, most of whom were nuns.

Many recalled the daily rituals of school life: reciting the Pledge of Allegiance after lunch, hanging our coats and gym bags on our assigned hooks in the cloakroom, the chalkboards and cleaning the chalk erasers by clapping them together outside.

We shared stories of pranks that earned a trip to the principal’s office, and of the fun we had during recess.

The 103-year-old grade school building was torn down on July 9, 2010.

The next day, I returned to Winsted to photograph what was left after the wrecking ball had demolished most of the building.

Not much remained except for the stone foundation with a few internal walls, and piles of rubble and red-orange bricks that were scattered about the area.

While standing near the foundation debris, I saw the now exposed underground tunnel entrance going east to connect with the high school.

I recall teachers instructing us to “get into single-file and walk slowly” through the tunnel to the high school cafeteria for lunch, pep rallies, or to take shelter in during tornado warnings and drills.

At the point where the demolished tunnel walkway interconnected with the high school, I observed the entrance was now sealed with concrete blocks.

“It looks very strange to see our grade school gone,” wrote a former classmate under one photo.

“Wish I could get a brick or two,” was mentioned many times.

While surveying the old grade school’s ruins, something immediately caught my attention in the northwest corner of the school’s foundation: it was exposed among the broken bricks, pieces of plaster, and busted wood laths.

I aimed, zoomed in my camera lens, and photographed a dusty and slightly damaged plastic cover case from a vinyl record player.

The case still contained the paper jacket from a children’s 33-rpm LP vinyl record with the words, “Holt Music Demonstration Record—Grades K-6.”

The record jacket showed a picture of seven singing school children with the words “Music!” written five times in bold colors above them.

A reverse image search on Google revealed that the record was released in 1984. It featured 11 songs, was published by Holt, Rinehart, and Winston Inc., and was manufactured by CBS Records in New York City.

The sight of the paper song jacket with the music it once held resting upon the remnants of my old school, undoubtedly sung by students decades ago, stirred feelings of melancholy.

As I stood there alone during that hot afternoon, it was eerily quiet.

I glanced over at the present elementary school, where a new generation of students are creating memories, they will someday look back on.

Holy Trinity School uploaded a 10-minute YouTube video at bit.ly/3RL8hsr of the demolition, which begins with a prayer led by Father Tony Hesse.

And yes, I saved a brick.