Space Matter is a weekly column that delves into space science and the mechanics of spaceflight. From the latest discoveries in the universe around us to the fits and starts of rocket test flights, you’ll find analysis, discussion and an eternal optimism about space and launching ourselves into the cosmos.
Cape Canaveral (called Cape Kennedy for a time after President Kennedy’s death) is our nation’s spaceport. Sure, we have launch facilities at other sites, such as Wallops Island, VA, Vandenberg Air Force Base in California, and a whole host of commercial launch facilities currently licensed or in development, but the Cape is where all our manned launches happen—our gateway to the stars.
Last year, NASA made headlines within the space community by announcing that SpaceX would be taking over Launch Pad 39A, a historic launch site to be sure. Its first flight is scheduled (at the time of this writing) for February 18. The first launch from pad 39A was the unmanned Apollo 4, the first test of the Saturn V rocket, on November 9, 1967. Pad 39A saw use through the Apollo and shuttle era—it was the launch site of both the first shuttle flight (STS-1) and the last (STS-135). It also played a part in the first and only possible dual shuttle launch in the program’s history.
STS-125 was a risky mission to service the Hubble Space Telescope in 2009. It was originally cancelled by NASA in the wake of the Columbia accident investigations because it was seen as too dangerous—the high orbit of Hubble meant that the shuttle couldn’t do a required ISS flyby to inspect the thermal tiles that comprised the orbiter’s heat shields. (Columbia was destroyed upon reentry in 2003 because of damage to its thermal tiles). But NASA managers were able to work around the problem, and Space Shuttle Atlantis launched from Pad 39A on May 11, 2009, ensuring that Hubble would be able to function through, at minimum, 2014. Just as a precaution, for the first time in the shuttle program’s history, a second orbiter—Endeavour—was prepped and ready on Launch Pad 39B in case a rescue mission was needed.
Space Shuttle Atlantis sits on Pad 39A, while Endeavour waits on Pad 39B in case a rescue is needed for STS-125. Photo courtesy of NASA/Troy Cryder
Launch Pad 39A isn’t the only launch site with interesting history. Most people probably don’t give launch pads a second thought. They’re a tool we use to get to space—the interesting stuff is what happens as and after the rocket lifts off the launch pad, not the pad itself. But actually, the history of Cape Canaveral as a spaceport is more interesting than it first appears.
To start with, there’s not just one launch pad, or two, or even ten. There’s a reason the area surrounding Kennedy Space Center and Cape Canaveral is called The Space Coast—it’s littered with launch pads (the vast majority of which are inactive). There are over 40 launch complexes on the Space Coast, divided between the civilian Kennedy Space Center and the military Cape Canaveral Air Force Station. Kennedy only has three launch pads—39A, 39B, and 39C, two of which became inactive after the space shuttle era. Launch Pad 39B is still in an inactive state, but as mentioned, 39A has been updated to serve SpaceX launches. Pad 39C is new, designed for small satellite launches, rather than ISS resupply missions and eventual manned missions. Only four of the launch pads at Cape Canaveral are active; one of those, Launch Complex 40, was heavily damaged in the SpaceX Falcon 9 explosion last year, accelerating NASA’s plans to lease Pad 39A to the company.
You’ll notice I often use the term launch complex, rather than launch pad. The pad is the actual physical site where the rocket is placed, while the launch complex is a broader term. It encompasses all the facilities that service the launch pad and rocket—each Launch Complex can have multiple pads. For example, Launch Complex 39 has three pads (the afore mentioned 39A, 39B, and 39C), the Vehicle Assembly building, or VAB, the crawlerway that crawlers use to move vehicles from the VAB to the designated launch pads, maintenance hangars (called Orbiter Processing Facilities), the Launch Control Center (mission control for launches), and the press site with the iconic countdown clock.
Apollo 14 rolls out of the VAB with its Saturn V rocket, equivalent in size to a 36-story building Photo courtesy of NASA
But why are there so many launch pads? It’s a great question, especially considering how many launch pads are no longer being used. Why build a new launch pad, for example, at Launch Complex 39 instead of using one of the existing launch pads that is currently inactive? (Pad 39C was originally conceived of as an Apollo launch site, but was never built—the design was modified and construction completed in June 2015.)
The short answer is that different rockets have different demands of their launch pads, and the requirements for a launch complex differ based on what kind of mission is being launched (for example, manned Apollo launches required a White Room, where astronauts could enter the spacecraft. Clearly that’s not necessary if a rocket is not designed for human spaceflight.) You can’t launch a Falcon 9 rocket, for example, from a launch pad designed for small, lightweight satellite launches.
How much a rocket can carry depends on its thrust: the heavier the cargo, the more thrust is needed to get the rocket off the ground. As a result, launch pads need to be specifically designed around the rocket that’s launching from the site. Engineers need to make sure that the pad can withstand what the rocket will do it. For example, SLS (the Space Launch System) is currently being built by NASA and Boeing, and when it’s ready, it will be the largest rocket ever built. Launch Pad 39B at Kennedy is currently being modified to service SLS because the largest rocket ever built means a lot of potential launch pad damage.
Though the launch pads at Cape Canaveral Air Force Station were primarily for military use (some of the launch pads are subterranean—missile silos), they also have a rich history in regard to our manned space program. Launch Complex 14 hosted all the Mercury missions, while Launch Complex 26 was the launch site of Gemini (the oft-overlooked bridge between Mercury and Apollo). Launch Complex 34 has a tragic, but also triumphant, history, as the site of the Apollo 1 fire. However, it also is the launch site of Apollo 7, which finally saw manned Apollo missions successfully take flight. And the missile silo at Launch Complex 31 is the resting place of the debris of the Space Shuttle Challenger.
The remains of Challenger are lowered into the missile silo at Launch Complex 31. Photo courtesy of NASA
Launch pads might not be the most exciting subject, but they hold so much interesting history. Etched (and scorched) on their concrete surfaces is the history of our space program—the triumphs and tragedies that echo through time, reminding us of our history and holding so much promise for our future.
Top photo courtesy of Nasa/Troy Cryder
Swapna Krishna is a freelance writer, editor, and giant space/sci-fi geek.