Would Be Done...

I'd be done cutting out the wraps except that...

I got the extra Interstage wrap, so I could patch over the removed ullage rockets. It makes sense to cut out the extra, use the better for the rocket and cut up the other. So, one more (complicated) wrap to cut, then ullage rocket patching, and then it'll be time to decide whether to try the CA technique for attaching the wraps or the tape technique.

Wraps, Wraps, and More Wraps—and a Launch

I talked with Tony Cooper at today's LUNAR launch; Tony has a built but not-yet painted Apogee Saturn V. He cautioned that many CAs dissolve the thin wraps. I told him about the online cautions about certain brands of paint being incompatible with the wraps.

Punch line: test the CA, test the paint.

As to the launch: 2400' overcast kept temps down, but skies gray. Fun launch nonetheless. I was able to get Alpha 3 to accept a motor (last month, it wouldn't go in), and the ~55th flight was a nice affair on an A8-5. Bertha flew twice, on a D12-5 and on a C6-5; the D flight landed on the runway, chipping and cracking a fin (certainly repairable). 4TNC flew twice, on a C6-5 each time: it's a fun little rocket, though I'm concerned about the tangling parachute shrouds.

Meantime, this afternoon, I've started cutting out the last of the main tube wraps.

I'd Like Paper, Please

Wow: these plastic wraps are a pain. Seemingly pretty fragile, difficult to figure out just where to cut, nerve-wracking while cutting. I remember the paper wraps from the Estes Saturn V: much easier to work with those, and I've not even begun attaching the wraps to the tubes.

Extra Wrap Arrived

Cutting is slow: perhaps this particular wrap came from a mold nearly at the end of its life, and so worn? Sometimes, it's hard to find the little scribe lines that are supposed to be convenient cutting guides. Regardless, the extra wrap's arrived, and once I get the wrap cut out I'll remove the S-II ullage rockets and cut replacement stringers from the second wrap.

Decision to Cut

S-IC retro rocket issues are now sorted out: they were installed on the inside of the S-IC engine fairings, and blew a piece of the fairing off when they fired. One decision down (doesn't have to be made!).

The S-II ullage rockets are a different story: model Apollo 15, for example, and they should come off (the S-II wrap has four of them, Apollo 15 had none). Tim had a suggestion: get a second S-II wrap, cut out the ullage rockets, and cut pieces from the second wrap to replace the stringers.

I'm ordering a second S-II wrap, and I'll cut-and-piece.

Sorting Ullage Rockets and Retro Rockets

Which craft do I model: Apollo 8, 9, 11, 13, or 15? Not so trivial a decision, if I really want to have a reasonably accurate model.

The S-IC stages had retro rockets. All of these missions used 8, except for Apollo 15, which used only 4.

Some of the S-II stages used ullage rockets: 4 on all of these except 15, none on 15.

If I model Apollo 15, how much will I need to muck with the wraps ("2nd Stage Aft Skirt and Interstage" wrap for the ullage rockets, "Thrust Structure" wrap for the retros)? Can I even make these mods, or is it 4 ullage rockets and 8 retros, period?

4TNC Flight Report

4TNC turned out pretty well!

A B4-2 had the right delay, but not quite enough thrust. The flight seemed to be, well, mushing (in the sense that an airplane can be mushing: descending on the back side of the power curve, not stalled, but not exactly flying well) for about 10m after clearing the launch rod.

A C6-5 produced a nice flight: good altitude, good speed off the launch rod.

A note on flying at Moffett: build those fins strong: that concrete's pretty hard!