Apollo 13's Slickest Trick, "The Entrance"

Originally posted by intrptr
reply to post by Saint Exupery

 

Thank you for that most in depth and informative reply. You helped me answer an old mystery and I will clarify my spelling mistake about "helo carrying a helo" up front. It was too late to go back and edit. I meant a helo, I was told a Chinook, carrying a "standby capsule" suspended beneath it to drop in case of reentry failure. Ok, that is the heresy part told second hand to me in my youth.

Ooooh! Ooo-ooo-ooo-ooo-ooo! I GET IT!

If someone said, "Back when they were recovering Apollo missions, I saw a Chinook carrying what looked like an Apollo capsule." I can confidently tell you that this statement was accurate.

...but not in the context of an ATS conspiracy fantasy.

North American Aviation, builders of the Apollo CSM, built a bunch of boilerplate capsules for various purposes. Several of these were used to train the recovery teams (helo crews, swimmers, etc.) to safe a landed spacecraft and bring it on board (one of these was "lost at sea" and recovered by the Soviet Union). If your friend's dad was stationed at Hickam AFB in Hawaii in the late '60s/early 70's, he very likely saw a helo hauling an Apollo boilerplate off-shore for training. The Naval Base and the Diver piers are right next to Hickam.

That solves THAT mystery.

Originally posted by Saint Exupery
I'd like to know how it was reported at the time.

Originally posted by intrptr
Just like I saw and you say.

I found unedited video of the CBS News Coverage of Apollo 13 in ~10-minute chunks.
Part 11 has the re-entry and chute deployment.
Part 12 has the splashdown.
Part 13 and Part 14 show the swimmers safe-ing the capsule. As you can see, the process is involved, and would be quite tricky in rougher sea (necessitating the a fore-mentioned training).
Part 15 shows crew-egress and Part 16 shows the helo arriving at the Iwo Jima.

My memory about when they saw the chute is that that appeared on screen just after the "we read you" from the capsule. Then the response was almost immediate. "we see you on the mains" and massive cheering in the control room. The screen in the control room showed the capsule suspended from chutes. Did they hold back cheering till then to be sure? Dunno.

As you can see, the reaction at MCC to re-establishing radio contact is cool & professional - so much so that I think a lot of viewers didn't realize that blackout had, in fact, ended (Cronkite clearly gets it - You can hear him chuckling with relief, though he is still tense until he sees the main chutes). When the mains opened, we finally get the first big emotional release. Others follow at splashdown & crew egress. Per MCC tradition, flight controllers do not celebrate in earnest until the crew is on the recovery ship.

Did anyone test those depleted batteries or measure signal strength...

You might check the mission reports.

or explain how the manual corridor adjustment to reentry glide slope was made with such precision, before firing of explosive bolt(s) to jettison LEM prior to reentry?

That one is easy. To put it delicately, the US & USSR had invested a great deal, in the 10+ years before the Moon landings to refine the accuracy of inertial guidance systems to land a "payload" within a mile or less of a target thousands of miles away (Video 1, Video 2 and bizarre-in-its-cheerfulness Video 3). The early Atlas & Titan-I ICBMs deployed in the early '60s used radar & Doppler to track the missile and send it course-corrections from launch to horizon. Apollo turned that around and had ground stations feeding accurate position & velocity data to the spacecraft's guidance system up until just a few minutes before re-entry (the previously-referenced transcript shows this). The pilot (equipped with the world's finest inertial navigation system) was thus quite capable of tracking his position and flying "on instruments" to his designated target.

(Continued...)

Originally posted by intrptr
reply to post by Saint Exupery

 

At this point, the Apollo capsule was generating aerodynamic lift (it really was an honest-to-god "flying saucer" - even if it was only gliding) and Command Module Pilot (CMP) Jack Swigert was flying it towards the recovery target area.

Wait. What? He was flying it after reentry and prior to chute deployment? How could he know where they were? And what on the capsule provided aerodynamic control? You lost me there.

The first manned capsules - Mercury, Vostok & Voskhod -were pretty much purely ballistic. Cannonballs, if you will. However, subsequent space capsules - Gemini, Apollo & Soyuz (which is still in service today) - actually generated lift and were (to a limited extent) maneuverable. This allowed for more accurate landings and also easing the G-loads on their crews.

It worked by offsetting the capsules' center-of-mass from the center-of-drag (I may be using the wrong terminology here - Sorry!). Sort of in the same way that a surfer or a snow-boarder can change his speed & direction by shifting his feet on the board, the pilots of these capsules could use its thrusters to rotate & pitch the CoG around to provide lift and turning moment. I tried to find an easy primer on this, but all I found was this paper on the AERODYNAMIC STABILITY CHARACTERISTICS OF THE APOLLO COMMAND MODULE which was written by aeronautical engineers for aeronautical engineers (i.e. way over my head).

Every so often you hear about a Soyuz making a ballistic re-entry:

The baseline descent rolls the entry module in a way that offsets its center of mass to create a small lift force. This keeps the shallowly descending vehicle higher in thinner air, limiting the deceleration forces to 3 to 4 g's. The maneuver also helps steer the path toward a desired landing region.

If the normal shallow descent isn't possible, the autopilot performs what is called a ballistic, or nonlifting, entry, falling more quickly into thicker air and consequently enduring as much as twice the peak deceleration.

Scary stuff.

I've got to get to work. Hope this helps!

Here's a simple question... Independent researches have reviewed the camera used on the first million to the moon. It has NO SPECIAL PROTECTION measures what so ever. That means the film would be subject to endless radiation, heat from the sun as high as 200 degrees and cold. How would the film stay in tact. And how would they come back with such exact picture perfect images considering they had very little experience taking pictures, and the clumbsy apperatus that didn't allow for easy picture taking. I don't see this being reasonable, even if they did somehow make it there.

reply to post by r2d246


Aside from being off-topic for this thread, pretty much EVERYTHING IN YOUR POST IS WRONG

Originally posted by r2d246
Here's a simple question...

No question mark follows.

Independent researches have reviewed the camera used on the first [mission] to the moon.

No they didn't, otherwise they would not have made the following statement:

It has NO SPECIAL PROTECTION measures what so ever.

It was given a highly reflective surface to moderate thermal absorption & emmisivity.

That means the film would be subject to endless radiation,

There is not "endless radiation" on the Moon any more than there is in low Earth orbit (which is at the same distance from the Sun as the Moon is, and is subject to the same cosmic rays). Are all photographs from the ISS fake?

heat from the sun as high as 200 degrees and cold.

Read this post carefully.

How would the film stay in tact (sic).

Because it uses the same Estar base that Kodak developed for high-altitude reconnaissance.

And how would they come back with such exact picture perfect images...

Like this one - crooked & off-center? The next one on the roll is even better.

...considering they had very little experience taking pictures...

They practiced with the cameras before the mission.

...and the clumbsy apperatus that didn't allow for easy picture taking.

The cameras were fitted pistol-grip shutter triggers that were quite easy to use, even in gloves, and the lens focus & aperture rings were modified with paddles & detents to make setting them easy in gloves. Additionally, each photo magazine had an exposure guide printed on top for easy reference.

I don't see this being reasonable...

It's a good thing "this" (the things you list) are not true then.

...even if they did somehow make it there.

Which is the most thoroughly documented event in human history.

Originally posted by intrptr

post by Saint Exupery
At this point, the Apollo capsule was generating aerodynamic lift (it really was an honest-to-god "flying saucer" - even if it was only gliding) and Command Module Pilot (CMP) Jack Swigert was flying it towards the recovery target area.

Wait. What? He was flying it after reentry and prior to chute deployment? How could he know where they were? And what on the capsule provided aerodynamic control? You lost me there.

As Saint Exuery pointed out in his post above, the Apollo capsule had a limited ability for "guided Entry".

The latest mars Rover -- Curiosity -- employed a version of guided entry as it went through Mars' atmosphere. The shape and angle-of-attack (the entry vehicle's "attitude) of the craft added lift, and reaction control thrusters were used to control the entry somewhat...

MSL (Curiosity) Guided Entry

...Which all means that Curiosity had the ability to steer and change its flight path as it entered the atmosphere. Apollo could do similar things.

Apollo Command Module Earth Entry (directly links to a < 1MB pdf file)

excerpt:

As the Earth's atmosphere was entered aerodynamic forces created torques that were determined by the CM's shape and centre of mass location. In the correct attitude these torques were in the direction of a stable trim orientation with the heat shield forward and flight path nearly parallel to one edge of the conical CM surface.The guidance system commanded the reaction jets to dampen out oscillations about this trim orientation. The resulting angle of attack of the entry shape caused an aerodynamic lift force which was used to control the entry path by rolling the CM about the wind axis under control of the guidance system. Range control was achieved by rolling such that a part of the aerodynamic lift was either "up or down". Across-range control was achieved by choosing which side the horizontal lift component was to be on. The maneuver footprint was 2870 miles by 345 miles.The early part of the entry phase is concerned with safely reducing the high velocity by dissipating the energy effects of the drag forces. At lower velocity ,later in the entry descent, the guidance system was more concerned with controlling the descent to achieve the desired landing (splashdown) area.

reply to post by Saint Exupery


Let me ask you this. How would they even take a dump on the moon? There's no outhouse and no leaves to wipe. so you're saying they held it in the whole time?

reply to post by r2d246

Let me ask you this. How would they even take a dump on the moon? There's no outhouse and no leaves to wipe. so you're saying they held it in the whole time?

One word: diapers.

reply to post by Saint Exupery

Sorry for the delay. I wanted to review your links and stuff before responding.

To be sure the YouTube video of that day is a walk down memory lane for me. Almost just like I remembered it. Almost. To be sure, the record will always be more accurate than memory (read my signature). Pretty good otherwise. I did get the mains opening, Cronkite, and the control room view with screen in background of ship board camera. Once I saw it, I even remembered all the worlds peoples transfixed by the event. I was off on the applause...

Times have changed. I love visual events records, they are so revealing. Thanks again so much for taking the time to converse on this and bring the data for my mind to absorb. Thats why I come to ATS.

PS: Good thing I kept personal that recounting of a Helo carrying a capsule in the area during recovery operations quiet all these years, huh?

I still will.

reply to post by Soylent Green Is People

Thanks to you Soylent Green and Saint Exupery for helping me to understand the reentry capabilities of cannonballs (lol) and guided merteroic manned capsules. The links were revealing.

I always liked the questions about why all the photographs are perfect.Well in the days before digital probably 2/3 of a professionals pictures were trash at least mine were. Nowdays I bet it's more like 80% perhaps 90% have no value so you don't show them to anybody

you seem to be under the impression the board takes your seriously as an engineer

speaking for myself, that is incorrect

good day

Originally posted by mikellmikell
I always liked the questions about why all the photographs are perfect.Well in the days before digital probably 2/3 of a professionals pictures were trash at least mine were. Nowdays I bet it's more like 80% perhaps 90% have no value so you don't show them to anybody

Very true (he says, while taking a break from wading through 5 GB of vacation pix).
What's funny is that when you look at the complete rolls of film, most of them are, as you say, either badly composed of simply unmemorable. Neil Armstrong, for example, had a habit of tilting the camera to the left.