Yes, Jay... I knew that already.
Yes, I figured you did. Sorry for the non-answer; I was winding down for the night.
What I don't know is, how were these things designed/assembled/packed/created so that they operated the way that they did.
I can't give you specifics about how I learned about parachute design. It's one of those things that's too far back to remember specific sources, although I like to think I retained all the knowledge. That said, the Preliminary Mission Report for Apollo 15 might prove helpful. As you may recall, one of their parachutes collapsed because the RCS safing procedure cut one of the reefing lines. Because the RCS fuel is toxic, as much of it as possible is burned off during the descent once it's no longer useful for control. This requires burning all the jets until the fuel is exhausted, leaving only a residue. One of the jets impinged on a reefing line and cut it.
As an aside, this is a great example of failure in integration engineering and testing. The RCS and Earth Landing System were considered "orthogonal" systems in that one had nothing to do with the other -- supposedly. The team that designed the ELS is thinking about aerodynamics and structural mechanics. Aerodynamics because the center of drag is computed by knowing the attach points for the suspension lines. The parachute exerts its drag at those points, and that in turn determines how the spacecraft will orient itself under the drag load. Conversely the drag has to be communicated safely to the structure via those attach points. They aren't thinking about RCS, because that's not the part of the mission they deal with. They just sit patiently until the last ten minutes.
Similarly, the RCS team is thinking about optimal jet placement. But most importantly, when the CM drogue deploys, their job is done. They aren't nominally responsible for anything that happens beyond that point. The integration engineers and testing team are supposed to think at a higher level and investigate the interactions between systems that are well designed individually to work. That's one of several examples from space engineering that I use when I teach workshops on design engineering and project management.
But I digress. The report has a brief description of the Apollo mechanism.
The science of parachutes is pretty straightforward. You need materials with considerable and predictable tensile strength and low mass, and methods of reliably distributing tension to the rim. Those distribution networks incidentally offer the advantage of stopping rips. Another way of mitigating the tension is the ribboning method, which cuts holes or slits in the canopy to let some of the air through. Materials science governs most of what we consider innovative in parachute design.
The idea of variations in the canopy aperture producing different degrees of drag is as old as parachuting itself. In the early 1900s practitioners were able to measure its effect also on canopy tension. That was when the bright idea emerged that variable-drag parachutes might be a useful thing. I can only remember two types of reefing mechanisms off the top of my head: the ring method and the skirt method.
The ring method uses a frangible or detachable ring around the suspenders near the aperture. This forms an apex far above the risers or hoist point and keeps the aperture closed. Via various release mechanisms, the ring is detached at the right time and the parachute opens fully.
The skirt method is far more common. Rather than attach the suspenders at a single point on the canopy rim, you run it through an eyelet and then along several adjacent eyelets and then back down to the hoist point. Interleaving this arrangement around the rim allows you vary the circumference of the aperture by taking in or paying out suspenders. The modern variation on that method separates reefing lines from suspenders so that you don't have the drag tension on the reefing lines. To mimic the one-time reef-open behavior of the ring method, the reefing lines are initially regulated to a short fixed length by a frangible or pyrotechnic restraint. At the appropriate time this restraint is fired and the line pays out to longer fixed length.
In practice, any automatic method of reeling will serve as the actuator for a controllable reef. The rest becomes straightforward control-system design. Any number of inputs (ram air pressure, barometric altitude, radar altitude, timers, manual control) can be translated into commands to an addressable winch. These days such things are quite sophisticated and very reliable. For safety nets in fall applications we actually use a constant-tension digitally addressable winch. It will pay out line under load in order to maintain a constant tension. Control systems can be as simple as relay-based combinatorial logic (i.e., the reef cutter signal is just a combination of sensor outputs), or as sophisticated as a full PID controller (equivalent to full-fledged airplane flight control).
Packing the chute is an art. Which is to say, there's a science to it, but also great skill in executing it. The big problem, as you've probably guessed, is avoiding everything getting all tangled up during deployment. The basic element of the art is the accordion pleat. Rather than coiled, the lines are laid out side-by-side on the ground, then carefully serpentined so as to produce a bulk of cord that can be pulled from one end without a loop forming around the standing mass of line. Similarly for the canopy fabric. At the very end is the pilot chute, which pulls at the top of the canopy and unfolds it from the package. This method appeals to common sense, but was worked out through trial and (sometimes fatal) error.
The secondary problem is going instantly from fully confined to fully free. You don't want everything to have to come through an opening in the packaging such that some of it might get hung up. Engineering has a whole bunch of methods for instantly and simultaneously "failing" all the seams in a container.
As you can guess, the skill required to pack parachutes and the need (in the military) to provide braking chutes for each flight of some aircraft led to the notion of componentized parachute packages. As part of preparing the aircraft for flight, the ground crew installs a pre-packaged parachute assembly. After use, the assemblies are removed and sent to a specialized shop for repacking.
Wind tunnel testing has been the mainstay of investigating behavior in parachutes. As with much engineering, you learn a lot just by trying it and seeing how it behaves.
What I'm obliquely referencing is some documentary I may or may not correctly recall seeing when I was a pre-teen...
I sympathize. I saw a film when I was young called
Pack Your Own Chute. (It's searchable on YouTube.) While it got me interested in parachutes and how they work, the film itself tells very little of the story.
Something that specifically dealt with recovery systems, and how the future shuttle would not need them. I'd like to have my memory refreshed, but 35 years is a long time.
If it's specifically about the shuttle, I can help you look around. Because of the STS's high landing speed, runway braking isn't generally sufficient. Large airframes stretch our skill at brake design. We use multiple friction layers and so forth, but the problem is often literally where the rubber meets the road. Early in the shuttle program they experimented with different tire designs and different runway surfacing methods to provide enough grip without risking shredding the tires. While especially acute for STS, it was a problem all through the early jet age for high-performance military jets. They just couldn't get enough grip on the runway to slow down. Modern airliners, as you've seen, not only use reversible thrust but they deploy their spoilers automatically to allow the full weight of the airframe to ride on the wheels and also provide additional down force.
I think the most exciting thing (at least for space) is the combination parachute and retro rocket method. This requires less reefing from the parachute because it allows a faster descent rate until just before landing, when rockets at the riser ring fire at the very last second to apply a smooth terminal deceleration.
Here is the Apollo 15 mission report.
http://history.nasa.gov/alsj/a15/ap15mr.pdf The relevant section begins on PDF page 187.
This is the Apollo Experience Report on the Earth Landing System, including the parachutes.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740003586.pdf It goes into substantial detail about Apollo's parachutes. And in general, the AERs are a very good source of technical information on all aspects of Apollo design and operation.
