Today in History – February 7, 1984 – The first untethered spacewalks were made by Space Shuttle Challenger astronauts Bruce McCandless II and Robert L. Stewart. Each used a manned maneuvering unit (MMU) in an orbit 150 nautical miles above the Earth. McCandless was the first to leave the cargo bay untethered in space. They were both charged with checking out the equipment by maneuvering within the cargo bay, then flying away and returning. Data were collected to test and demonstrate the capabilities of the MMU flights with the goal of eventually using it for a planned retrieval of the Solar Max satellite on a later shuttle mission.

For more information, see the Engineering Pathway‘s resources on spacewalks and space exploration. For related educational resources, visit the Aerospace Engineering Education Community site. The Engineering Pathway also hosts Engineering Education communities in all ABET-accredited disciplines.

Also on this date in 1863, the Law of Octaves was used as the basis for the Periodic Table and the in 1935 the first Monopoly game was marketed. Don’t laugh, educational games can be an engaging and effective form of learning in engineering.

Today in History – January 31, 1958 – Explorer 1 became the United States of America’s first satellite to orbit the Earth after it was launched on January 31, 1958. After the Soviet Union’s successful launch of Sputnik I on October 4, 1957, the United States of America embarked upon a program to launch it own artificial satellite. The first American attempt to launch a satellite using a Vanguard 1 rocket occurred in December 1957 and failed miserably.

Following this failure, the U.S. Army Ballistic Missile Agency, located at Redstone Arsenal in Huntsville, AL, was directed to launch a scientific satellite using a Jupiter C rocket developed under Dr. Wernher von Braun. The artificial satellite was designed, built and operated by the California Institute of Technology’s Jet Propulsion Laboratory under the direction of Dr. William Pickering.

The satellite instrumentation of Explorer 1 was a cosmic ray counter designed by Dr. James Van Allen, a physicist at the University of Iowa. The cosmic ray counter experiment was designed to measure the radiation that surrounds the Earth. Once in orbit, the cosmic ray counter began to overload and measured a much lower cosmic ray count than previously assumed. Given this new information, Dr. Van Allen theorized that the cosmic ray equipment may have been exposed to very strong radiation caused by a belt of charged particles trapped in space by Earth’s magnetic field.

The data returned by Explorer 1 and another satellite launched in March 1958 prove the existence of intense belts of radiation that surround the Earth. These belts of radiation are now called Van Allen Belts and are considered to be the first major scientific discovery of the space age.

Check out the Engineering Pathway’s educational resources on the Explorer I and satellites. For more educational resources, see our aeronautical engineering education and electrical engineering education community pages. The Engineering Pathway also hosts Engineering Education communities in all ABET-accredited disciplines.

Today in History – January 28, 1986 – Space Shuttle Challenger explodes after launch, killing the entire crew. American’s stared in shock at their televisions watching the Challenger accident in full motion video. The 35th Challenger’s flight had been previously scheduled for January 22, but delayed because of bad weather, high winds and icicles on the launch apparatus. Never had there been a launch approved in freezing weather conditions, but NASA had assured the public that the conditions were safe. They were anxious to launch due to economic considerations and scheduling backlogs. Political pressure has been suggested as well due to NASA’s heavy publicizing of Christa McAuliffe as the first school teacher in space. She had been selected under a highly competitive process from among 10,000 entries for the opportunity. The Challenger disaster was a severe blow to the American space program, bringing manned flights to a halt for many years. It was also a blow to the American public who had come to think of the Space Shuttle as an important symbol of national identify.

Speaking before the launch, Christa McAuliffe said: “One of the things I hope to bring back into the classroom is to make that connection with the students that they too are part of history, the space program belongs to them and to try to bring them up with the space age.”

Morton-Thiokol, one of the contractors for the Solid Rocket Motor was convinced that the cold weather would cause problems and had briefed NASA about their concerns. Two engineers, Robert Ebeling and Roger Boisjoly had previously urged a redesign on the booster rockets due to O-ring erosion in the booster field joints. The lowest temperature experienced by the O-rings in any previous mission was 53°F in the January 24, 1985 flight; the temperature predicted for Florida on January 28th was much lower, in the low 20′s °F.

The Rogers commission confirmed the cause of the Challenger disaster explosion to have been caused by a leak through the faulty O-ring seal in one of the solid rocket boosters. According to testimony by Morton-Thiokol engineer Boisjoly, management put pressure on the engineers to OK the launch saying: “Take off your engineering hat and put on your management hat.” The recommendation was reversed, discounting the concern about the O-rings as being “inconclusive” and launch was recommended, “based on their engineering assessment”, even though the engineers had no part in this recommendation. In spite of concerns expressed by others, NASA managers decided to approve the boosters for launch despite the fact that the predicted launch temperature was outside of their operational specifications and any test conditions.

Engineers must learn from both the technical and organizational failures that led to the tragic Challenger accident. The Engineering Pathway digital library has information on several excellent case studies, lesson plans and other curricular materials that can be used in the classroom. The Texas A&M case, for example, leads to these discussions questions:

• “What could NASA management have done differently?
• What should Roger Boisjoly have done differently (if anything)? In answering this question, keep in mind that at his age, the prospect of finding a new job if he was fired was slim. He also had a family to support.
• What do you (the students) see as your future engineering professional responsibilities in relation to both being loyal to management and protecting the public welfare?”

For more information, see the Engineering Pathway’s resources on the Challenger accident or engineering ethics.

Today in History – January 14, 2005 – Huygens Probe Lands on Titan.

After spending seven years in space, the Huygens probe separated from the main Cassini spacecraft on December 24, 2004, and spent the next three weeks traveling to the moon Titan. After beginning its descent, it transmitted scientific data for nearly five hours before running out of power. The Huygens probe was named after the Dutch astronomer Christiaan Huygens. He is credited with the discovery of Titan and thus it was deemed fitting to name the probe after him.

For more information, see the Engineering Pathway’s related resources Saturn and Cassini. Or visit the Aerospace Engineering Education community site.

Today in History – January 4, 2004 – Spirit Rover Lands on Mars. The Jet Propulsion Laboratory’s  twin Mars rovers -  called Spirit and Opportunity – landed on January 4, 2004 and January 25, 2004, respectively. They were originally scheduled to operate for three months, but were actively collecting and transmitting data for over 6 years. The rovers have set the longevity record for broadcasting to Earth from a distant planet.   Although  Spirit got stuck in the sand (and had its last communication on March 22, 2010), Opportunity has been traveling towards the Endeavour crater on Mars since August 2008.

The next Mars rover Curiosity launched on November 26,  2011 and is a six-wheeler much like  Spirit, Opportunity and Sojourner. Unlike these earlier Mars rovers, however, Curiosity will also use its mobility system as a landing gear when rocket-powered down to the Martian surface on a tether in August 2012 (artist’s conception of Curiosity working on Mars below left).

I was honored to have served on the Advisory Board for the Engineering Division at JPL and was impressed with their “faster, better, cheaper” approach to space exploration. I was invited by JPL’s Director Charles Elachi as a VIP visitor to the Mars Science Laboratory Rover (official name for “Curiosity”) at the Kennedy Space Center. I brought my husband, daughter and doctoral student Kimberly Lau (photo, above right) with me. We visited the launch site and the mission hanger for the Mars Rover Curiosity at the Kennedy Space Center on November 25.  We inspected the launch pad for the Mars Rover Curiosity as well and the Hanger and local Command center for the launch. During the pre-launch tour we were also shown the Vehicle Assembly Building where the Space Shuttle Endeavor was being decommissioned. We attended the scheduled launch for the successful Mars Rover on Saturday, November 26, 2011. Several dignataries gave briefings before the launch, including NASA chief Charles Bolden. “We are very excited about sending the world’s most advanced scientific laboratory to Mars,” NASA Administrator Charles Bolden said in a statement. “MSL will tell us critical things we need to know about Mars, and while it advances science, we’ll be working on the capabilities for a human mission to the Red Planet and to other destinations where we’ve never been.“  See more photos on the launch.

Previously, the Sojourner Rover (above), carried by the Pathfinder spacecraft, rolled onto the Mars’ surface on July 6, 1997. Click on the image above right to see a video of its initial positioning. Sojourner was designed as a six-wheeler that used a rocker-bogie suspension system; each wheel having its own drive motor, and the corner wheels also have independent steering motors.

Launched on December 4, 1996, Pathfinder impacted the surface of Mars earlier on July 4, 1997 at a velocity of  18 m/s (40 mph) and then bounced into the air 15 times at a maximum height of  15 meters (50 feet), before rolling and coming to rest  1 km from the initial impact site. The lander and landing site was named the Carl Sagan Memorial Station.  Pathfinder was designed, built and operated by the Jet Propulsion Laboratory (JPL) for NASA.

The project ended on March 10, 1998 when the lander failed to respond to communicate with controllers at JPL. The mission operated three times longer than its original 30-day planned lifetime.

The images from Pathfinder-Sojourner are spectacular, ranging from videos of Martian sunsets (click on image above left to see movie), data on the composition of the Martian rocks and the role of water on Mars. Quoting from a NASA press release of June 29, 1998:

The current assessment of data from this instrument suggests that all of the rocks studied by the rover resemble a type of volcanic rock with a high silicon content known on Earth as andesite, covered with a fine layer of dust. All of the rocks appear to be chemically far different from meteorites discovered. on Earth that are believed to have come from Mars.

For more information, see the Engineering Pathway‘s resources on the Pathfinder mission, Mars rovers and space exploration. For related educational resources, visit the Aerospace Engineering Education, Engineering Mechanics Engineering Education, Computer Engineering Education or the Mechatronics Engineering Education Community sites.

Also on this date in 1863, 4 wheeled roller skates were patented by James Plimpton of NY. On this date in 1962,
First automated subway train in New York City.

Today in History – January 2, 1959 – the first lunar space ship shot to escape the Earth’s gravitational pull. The unmanned Luna I was launched by the Soviet Union less than two years after their launch of Sputnik, the Earth’s first artificial satellite. Luna 1 passed to within 4,600 miles of the moon before moving on to a solar orbit.

Later in 1959 on September 14, the Soviets were successful in reaching the moon with the Luna 2. The Luna 2 spaceship fell out of the lunar sky and hit the ground near the Sea of Serenity. Although the ship itself was shattered, the mission was considered a success, making Luna 2 from the Soviet Union the first manmade object to “land” on the Moon. The U.S. lunar orbiters came next, followed by Japan’s Hiten spacecraft.

It does seem like a big waste, but crash landing was the main mode of landing for the next decade of moon landings. NASA’s series of Rangers in the 1960′s had five crashes, but were able to transmit the first detailed images of lunar craters, rocks and soil before being destroyed by the crash. These images beamed back to Earth provided information critical for the success of later Apollo missions.

Alas this means that the Moon has become a graveyard for old satellites and spaceships, including all five of NASA’s Lunar Orbiters (1966-1972), four Soviet Luna probes (1959-1965), two Apollo sub-satellites (1970-1971), Japan’s Hiten spacecraft (1993) and NASA’s Lunar Prospector (1999).

The Japanese were the third country that we know of on the moon. I find it interesting that their spacecraft was named the “Hiten” after the Buddhist flying angel, pictured below playing the flute in a sculpture by Okita Toshiki.

The first attempted soft landing wasn’t until May 1965 with the Soviet’s Lunar 5; but it failed and crashed in the Sea of Clouds area of the moon. The Luna 9 (center photo above) was successful a year later, transmitting data from the Ocean of Storms lunar area. Later in 1966, NASA’s Surveyor 1 (right photo) was the first soft-landed robotic laboratory, landing in the Ocean of Storms area.

For more information, see the Engineering Pathway’s related resources on the Luna Missions and other lunar spacecraft. Or visit the Aerospace Engineering Education community site.

Also on this date in 1923 Thomas Midgley’s ethyl gasoline was first marketed. On this date in 1975 the U.S. Department of Interior designates the grizzly bear a threatened species in the Lower 48 States.

Today in History – December 31, 1968 – The Russian TU-144 is the first commercial supersonic airliner flown. Building on their supersonic military jets, the Russians developed the first supersonic commercial airliner called the Tupolev 144. Decades later the U.K. developed the Concorde supersonic passenger jet. Athough successful as a collaborative technical effort, it did not survive the marketplace; it was too expensive to maintain, demand was not high enough at the prices required and the public put many constraints on flight paths due to the noise pollution of the sonic boom.

For more information, see the Engineering Pathway‘s resources on the Concorde, supersonic flight and aerospace engineering. Curricular resources and events can be found on the Aerospace Engineering Education Community site.

Today in History – December 30, 1924 – Edwin Powell Hubble announces his discovery of a galaxy outside the Milky Way. Edwin Hubble was one of the leading astronomers of the twentieth century. His discovery that not only one, but countless galaxies, exist beyond our own Milky Way galaxy forever changed our understanding of the universe. Prior to his discovery, most astronomers believed that the universe was limited to our galaxy. Hubble also discovered enough galaxies that he was able to create a system for classifying them into ellilptical, sprials and barred spirals. The Hubble Space Telescope was named in his honor.

For more information, see the Engineering Pathway‘s resources on Hubble, space telescopes, astronomy and aerospace engineering. For curricular resources, visit the Aerospace Engineering Education community site.

Today in History – December 27, 1571 – Birth of Johannes Kepler.  When Kepler made his calculations from measurements taken by Tycho Brahe and himself, at the turn of the seventeenth century, they had to create many of the instruments that they used.  The types of tedious observations and measurements taken by Brahe and Kepler had never been attempted before.  Thus when Kepler first published his results in 1609, writing what would later become the first two laws of planetary motion, he was in the best position to determine whether the Ptolemaic Earth-centered system was correct or the Copernican heliocentric system.

In 2009 NASA plans to launch the Kepler Mission, a space telescope designed to search for other planets outside our own solar system.  To date, astronomers have only been able to find gas-giant planets, such as our own Jupiter, with the current technology.  The Kepler mission will place a telescope in space that will focus on a specific area long enough to be able to find the presence of smaller Earth-like planets.  Once one has been located, the telescope will be able to study it well enough to determine whether or not it would be able to sustain life.

400 years after Kepler published the results of his studies of the planets from relatively crude observations, NASA will have sent a telescope into space to find and study planets outside our own solar system.

For more information, see the Engineering Pathway’s related resources planetary motion and Kepler’s Laws or general astronomy. Or visit the Aerospace Engineering Education or the Engineering Mechanics Education community sites.

Today in History – December 24, 1979 – Launch of the Ariane rocket. In the 1970s, in the middle of the Cold War, the state of European aeronautics was in disarray. After Europa, Europe’s latest rocket, failed 11 times, many were skeptical that Europe could match the power that Russia and the USA had over outer space. However, in 1973, the French decided to take on the job that nobody else would by building the Ariane I, the 210,000 kg (462000 lb) rocket named after the character Ariadne from Greek mythology. Despite tremendous skepticism and several delays, the first launch of the Ariane Rocket on December 24th, 1979 was successful. Since then, the French company Arianespace continued to launch Ariane rockets from the Guiana Space Center in Kourou, French Guiana, carrying along numerous satellites for orbit.

Since its birth, the Ariane Rocket has had its setbacks, such as the booster failure in 2002 that led to the craft’s self-destruction three minutes into flight. However, such failures have not been able to undermine the Ariane Rocket’s reliability; Twenty-eight years later, after 5 versions and hundreds of liftoffs, the Ariane rocket continues to be one of the premier commercial satellite launching systems in the world today.

For more information, see the Engineering Pathway‘s resources on rockets and aerospace engineering. For curricular resources, visit the Aerospace Engineering Education community site.

Also on this date in history in 1975, first radioactive isotope medicine administered, Berkeley, California. This event at Lawrence Berkeley Laboratory is acknowledged as the birth of nuclear medicine. For more information, see the Engineering Pathway‘s resources on nuclear medicine. For curricular resources, visit the Nuclear Engineering Education and Biomedical Engineering Education community sites.