Little Joe and Little Joe II launch angle
 

I have a curious question about the Little Joe and Little Joe II. I notice that most of the videos and pictures I see of the real Little Joe rockets, they are almost always seem to be launched at a slight angle. Does anyone know why?

David

I would suppose, essentially, so that post-flight vehicle debris would land down range and not back in the launch area.

In the older photo, which is a Mercury escape capsule test at Wallops Island, I believe the landing zone for the capsules (and any booster debris, etc.) was the Atlantic Ocean.

In the color photo of the Little Joe II (Apollo escape tower test) at White Sands, NM many of those test involved some type of deliberate destruction or malfunction of the booster to simulate a real booster malfunction on a Saturn launch vehicle, so there would be Little Joe booster debris raining down, as well as recovery of the capsule post flight.

All that stuff needed to come down well away from the launch area, so hence the launch angle you see in the photos. In one famous Little Joe II test at White Sands, the booster went into an unplanned, early very fast roll-rate when one of the fin elevons used to control the flight went into a full hard-over deflection (as I recall) and the booster was spinning very fast as it zoomed up towards altitude. Around 11,000 feet or so the booster disintegrated in a spectacular sequence of photos, but the malfunction system of the Launch Escape System DID detect the malfunction and pulled the capsule away from the disintegrating Little Joe II booster. Booster motors, still burning, came raining to the ground down range, creating quite a debris field.

There is a famous sequence of stills of the vehicle failure that maybe you have already seen before, or could probably find on-line with a quick search. Maybe even the film sequence as well.

Earl

LJII Image Sequence
 

Here's the photo sequence.....

Earl

Why were they called "Little Joe"?

I'm not sure where that name originated.....I seem to recall an early Mercury-Atlas test mission called 'Big Joe', so possibly there is some connection there.

But honestly, beyond just whimsical name labeling on the part of project engineers and such, I don't really know where the name came from.

Earl

According to Google the Little Joe name came from the fact that the original drawings of the four seargent rocket motors resembled two dice rolling deuces in a game of craps

Interesting sidebar on the Little Joe name. Current crop of folks runnung the Orion Abort System tests refuse to designate them Little Joe III flights. They were content to call the Orion Pad Abort test "PA-1", same as the Apollo PA-1. They even duplicated the Apollo tests' capsule markings. But for no apparent reason that I can discover the abort system flight tests will not be called "Little Joes."

Of note, however, is that the MLAS test, of an alternative escape system, was run and named by folks who were very historically aware and interested. That flight, the "Max Launch Abort Test" was named after Max Faget, the engineer who designed the Mercury abort system.

Correct about the dice analogy in the naming of the Little Joe tests...

It's a pair of two's when shooting dice that's called a "Little Joe". As someone mentioned, the engine arrangement of solid motors inside the rocket resembled a "Little Joe" when viewed end-wise so it stuck...

The MUCH larger Apollo test vehicle got the moniker "Little Joe II" by extension-- the same sort of interim vehicle consisting of clustered solid motors in a shell body with fins used solely for the escape system test series.

Seems rather snobbish for the modern NASA folks to refuse to honor tradition with the naming conventions... what would be the harm in it?? It's just their "we gotta be different" attitude showing I guess...

Later! OL JR :)

I know, I know, pick me, pick me!

Cause Little John was taken! :chuckle: :D :p :rolleyes:

And here's a link to a Youtube video of the breakup. I've seen this full documentary before some years back, but forgot the name.

As you look at the launch and tracking footage, keep in mind this is high frame rate footage, which means that in the normal playback speed, it is at a slow-motion pace. So while you can see the vehicle IS spinning, it 'appears' in this clip to not be spinning too very fast. Actual real-time spin rate is likely 3-4 times the apparent spin rate in the footage you'll see.

In any event, it's pretty spectacular footage. Clip is a couple minutes long with some interview soundbites....actual launch footage is towards the end of the clip.

Earl

http://www.youtube.com/watch?v=AqeJzItldSQ