Wingtip vortices are a result of the finite length of a wing. Airplanes generate lift by having low-pressure air travelling over the top of the wing and higher pressure air along the bottom. If the wing were infinite, the two flows would remain separate. Instead, the high-pressure air from under the wing sneaks around the wingtip to reach the lower pressure region. This creates the vorticity that trails behind the aircraft. I was first introduced to the concept of wingtip vortices in my junior year during introductory fluid dynamics. As I recall, the concept was utterly bizarre and so difficult to wrap our heads around that everyone, including the TA, had trouble figuring out which way the vortices were supposed to spin. A few good photos and videos would have helped, I’m sure. (Photo credits: U.S. Coast Guard, S. Morris, Nat. Geo/BBC2)
Paying Tribute to Madiba on Mandela Day
Nelson Mandela was only 33 years old when a speech he gave incited a protest in Durban and first landed him in jail. Over the next 10 years, Mandela would be arrested three more times for his work fighting South Africa’s oppressive apartheid regime until a 1962 conviction for sedition sent him to prison for the next 27 years.
“I was hoping to capture some sense of the hardships he suffered,” retired Johannesburg math lecturer Vivien Budge (@vivbudge) says of the young Mandela portrait she painted, “the anger he must have felt at the injustices he witnessed and the relentless tenacity, determination and courage with which he fought for his beliefs.”
After his release in 1990, Mandela helped bring an end to apartheid in South Africa and became the country’s first black democratically elected President. Mandela, who died last December but would have been 96 today, continues to inspire South Africans and others around the world to this day.
Here, we have the Saturn V rocket, housed inside the Apollo/Saturn V Center at Kennedy Space Center near Titusville, Florida, just a few miles from Launch complex 39, where these beasts once roared into the sky.
When we look at the enormous first stage of the Saturn V rocket, called an S-IC, we think “spaceship”. Truthfully, the Saturn V first stage never actually made it into space. The stage only burned for the first 150 seconds of flight, then dropped away from the rest of the rocket, all while remaining totally inside Earth’s atmosphere. The S-IC stage is merely an aircraft.
Even more truthfully, the S-IC stage displayed here at the Apollo/Saturn V Center at the Kennedy Space Center in Florida, never flew at all. It is a static test article, fired while firmly attached to the ground, to make sure the rocket would actually hold together in flight. Obviously, these tests were successful, (e.g. she didn’t blow up), and she sits on our Apollo museum today. I wrote more about this particular stage in a previous post, (click here to view.)
The rest of the rocket, the second and third stages, called the S-II and S-IVB stages, did fly into space. The S-II put the manned payload into orbit, and the S-IVB was responsible for initially propelling that payload from earth orbit to the moon, an act called “trans-lunar injection” (TLI).
The particular rocket in this display, except for the first stage, is called SA-514. 514 was going to launch the cancelled Apollo 18 and 19 moon missions.
The command/service module (CSM) in the photos is called CSM-119. This particular capsule is unique to the Apollo program, because it has five seats. All the others had three. 119 could launch with a crew of three, and land with five, because it was designed it for a possible Skylab rescue mission. It was later used it as a backup capsule for the Apollo-Soyuz Test Project.
A M A Z I N G
This novel fuel cell technology uses liquid methanol as a fuel to produce electrical energy, and does not require any fuel processing. Pure water and carbon dioxide are the only byproducts of the fuel cell, and no pollutants are emitted.