If you look at the very early Estes multi-staging technical report, they didn't yet "do" taped-together motors. Plans for the Aries II showed a considerable gap between stages, with a balsa thrust ring used as a coupler.

The Apogee "I" may have used a system like that.

The booster was indeed shorter. Here's a comparison drawing I extracted from the various catalog pics. But I'm quite sure the Apogee 1 used regular length motors.

FWIW, Estes had shorties by 64. Looks like Centuri had them in 65, but carried only some of the available types. The 61 Estes catalog shows no shorties. No more Estes data until 64. The 62 and 64 Centuri catalogs show no shorties. (No 63 catalog available.)

It's never been clear why Estes stretched the Apogee (into the 2), but I suspect the booster was stretched (+~0.85") to encase the motor thus ensuring the booster stage separated along with the motor at staging - ie, to avoid fried boosters.

Doug

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YORF member #11

The third kit to use the PNC-55EX was the Neptune.

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SAM # 0011

The story that I read was that the original Apogee design was unstable. I'm sure that I saw that explanation here on this forum, some years ago.

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SAM # 0011

I wanna say I've heard that, too. But I was a little skeptical - with the Bertha style fins, it's a little hard to believe.

That said, maybe, with some of the then new motors coming, they were anticipating stability problems as the new motors entered the market.

Doug

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YORF member #11

One way to find out is to try to build one, estimating the part dimensions as closely as possible.

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SAM # 0011

Looking at the 1960 catalog, there were only A8 and B8 engines available. Even by 1961, the largest engines were B8's and B16's. But, in 1964, the first C8's were introduced. A C engine is heavier, so it would have placed more mass behind the CP. With the shorter airframe, it might have become unstable, with or without the payload section. Remember, in the 63 ad, it was suggested the rocket could fly without the payload section, and I'll bet someone tried it with a C-C or a C-B combination, and got a whirlygig...

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Craig McGraw

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SAM 0044
AMA 352635

Oddly, no engines are listed in the 1963 Estes catalog.

From their introduction in 1964 until 1968, the only Estes C engine was a booster.

(Weird thing about the 1968 Estes catalog on Ninfinger: there is no link on the Contents page to the Rocket Engine Selection Chart. In order to find it easily, click on the link to the Electro-Launch page. Then hit "Previous page" twice. Then hit "Next page" once. If you hit "Next page" again, it will reveal another "hidden" page from the catalog. Bizarre. You can get those pages if you are moving forward through the catalog, but not if you are moving backward through it.)

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SAM # 0011

I believe the reason C engines might have been boosters only during that time is that they may have been the "thick wall" Mabel I casing. This would not have left room for the delay/ejection charge.

Anyone with first hand knowledge to confirm or rebut this?

The early C-booster engines were thick walled, and had quite a bit less total impulse than the C6 we have now.
Can't remember what the catalog quoted as the impulse but seem to recall they were like only 7n-sec in reality.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !