The MIA chute

One year ago yesterday, the SpaceShipOne landed in a fine tall oak tree after drifting too far under its 24" chute. Five days later, the body of the rocket fell back down, undamaged. Two weeks later, the nose cone followed.

However, the orange parachute stayed. And stayed.

Finally, last week, the wind blew it away. After over 350 days in the tree.

History Day!

It's been over a year since I did a proper History Day post. Which means it's time for the tradition to start again...

1804: John Deere - yes, *that* John Deere - was born.

1812: The strongest (Magnitude 8.3) of the New Madrid earthquakes destroyed the town of New Madrid, toppled buildings in St. Louis, made waterfalls on the Mississippi and changed it course, caused a wave to run UPSTREAM on the Mississippi, and rang church bells all the way to Boston.

Also 1812: Charles Dickens, great and intolerably boring Victorian writer, was born.

1867: Pinoneering pioneer writer Laura Ingalls Wilder was born.

1889: Harry Nyquist, a founding informational theorist, was born.

1906: Oleg Antonov, Soviet aerospace engineer, designer of planes from small biplanes to the monster An-225, and the founder of the eponymous Antonov design firm; was born.

1926: Konstantin Feoktistov, cosmonaut and spacecraft designer, was born.

1932: Apollo 15 command module pilot Al Worden was born.

1935: Monopoly is invented. Rainy Sunday afternoons become a little less boring.

1959: Baseballer extraordinaire Nap Lajoie died at 84.

1960: Igor Kurchatov, father of the Soviet atomic bomb but also an advocate of peaceful nuclear power, died at 57.

1979: For the first time since Pluto's 1930 discovery, its orbit brought it closer to the sun than Neptune.

1984: On the Shuttle mission STS-41B, astronauts Bruce McCandless and Robert L. Stewart performed the first untethered spacewalks using the MMU.

1990: The Soviet Union ended when the Central Committee of the Soviet Communist Party relinquished its power.

1999: King Hussein of Jordan, a skilled diplomat, peacemaker, democratic and civil rights activist, ameteur radio operator, pilot, and all-around awesome guy; died at age 63 after having ruled Jordan since age 17.

2010: A large explosion at a power plant in Middletown, CT - near where I live - killed at least 5 workers.

All information except the last item from Wikipedia.

Marie Curie Quotes

Not only was Marie Sklodowska-Curie an incredible scientist and quite possibly the single person who ended science being a misogynistic 'old boy's club', but she also said a number of very profound things:

• "Be less curious about people and more curious about ideas."
• "You cannot hope to build a better world without improving the individuals. To that end each of us must work for his own improvement, and at the same time share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful."
• A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale. We should not allow it to be believed that all scientific progress can be reduced to mechanisms, machines, gearings, even though such machinery also has its beauty. Neither do I believe that the spirit of adventure runs any risk of disappearing in our world. If I see anything vital around me, it is precisely that spirit of adventure, which seems indestructible and is akin to curiosity."
• "Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less."
• "I am one of those who think like Nobel, that humanity will draw more good than evil from new discoveries."
• "And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."
• "One never notices what has been done; one can only see what remains to be done.

"I am among those who think that science has great beauty."

Contacting me

I've added a new page with blogger, to list my email addresses. It's here, and I'll improve it eventually. I might also add pages for listing stuff like the blogs I follow, or my most informative posts.

Viper building part III

I've got some more building done over the last few days, mostly using my wonderful epoxy clay.

First I installed the shock cord mount. It's an 18" length of 1/8" nylon cord. The instructions say to tape the ends to the inside of the body tube about 4" down from the forward end and slather with epoxy. I used epoxy clay instead, but it's still very strong.

Second is the cluster mount assembly. I epoxyied two nuts between the four 24mm tubes, and used a threaded rod to get them an exact distance apart. I also epoxied a washer to a 2" length of threaded rod. Now, all I have to do to retain all four motors is to thread the rod-with-washer into the middle of the cluster and the washer holds all four motors.

New Quest D motors certified

Comments in bold are mine. 4.45N = 1 pound

R133: NAR S&T New Motor Certifications:

D8-0,3,5
24mm x 70mm
18.59Ns total impulse
28.88N peak thrust
8.44N average thrust
22g propellant mass

This is basically a lower-thrust D12. Same size, same delays, and just a hair more impulse. The 29N spike, though, should be enough to get decent-sized rockets off the pad.

D5-4,6
20mm x 96mm
17.61Ns total impulse
16.80N peak thrust
3.82N average thrust
24.0g propellant mass

This is an interesting development. It's their D5 motor, originally designed for rocket gliders, but with delays and an ejection charge. It's got decent oompf - 16.8N (3.78 lbs) for liftoff - but it's otherwise a long-burning motor with low thrust. Good for gliders that need an ejection charge I suppose, but it doesn't fit in 18mm kits, is too low-thrust for most 24mm kits, and it's not useful for most contest rockets.

Long delays

I noticed on TRF today that Aerotech actually has three delays certified for the E20W: 4, 7, and 10 seconds. However, where they're for sale, I've only seen the -4 and -7 motors.

I've noticed this before with certain reloadable motors. There are often three delays listed on the packaging - short, medium, and long - but only the short and medium delays are certified and available. This includes most of their 24/40 loads plus a few others:

24mm:
D9-10
D15-10
E11-5*
E18-10
E28-10
F24-10
F39-12

29mm:
E16-10
E23-11
F22-10

However, a number do have long delays available:
18mm: D13-10 and D24-10

24mm: F12-5*, F35-11

29mm:
F40-10
F52-11
G53-10
G64-10
G71-10
G76-10

* The weird ones are the E11 and F12. Both are long-burn Black Jack motors. The E11-3 is widely available, but the listed E11-5 is not certified, and there's no true long delay at all. The F12-3 (certified as -2) and F12-5 are both available; however, once again no long burn time is listed at all.

Changes in the Rules

Recently, there's been some nastiness over having certified G sparky motors. It appeared to some that the NAR was trying to ban sparkies under 160Ns total impulse. It appears, though, that recommendations made by the NAR panel to the NFPA (National Fire Protection Agency) will likely become part of NFPA 1125 (Code for the Manufacture of High-Power Rocket Motors) in 2011.

First, they decided to raise the upper limit of propellant in 'model rocket' motor from 62.5g to 125g. This simply means that full G motors, like the Aerotech G75J, that are under the 80N average thrust limit but over 62.5g propellant are officially model rocket motors. A good thing, though technically all motors over 62.5g (and reloadables) cannot be sold to those under 18, though it's clear that no one really pushes the issue.

Second, model rocket motors are restricted to solid propellant. That means that the 3 hybrid motors (West Coast Hybrids G55 and Skyripper G63 and G69) out there that are under 160Ns and under 80N average thrust are now grouped as high-power motors, along with all the other hybrids.

Third, model rocket motors had their maximum particle size shifted from 150 microns (0.15mm / 0.006") to 74 microns (0.074mm / 0.003"). This puts most sparkies firmly in the HPR category; however, sparkies with impulses under 160Ns will still be allowed, and new ones can be certified.

Fourth, any motors under 160Ns (G size or smaller) that violate the particle size, solid-propellant, or 80N limits will be certified as high-power motors and have 'HP' added to their motor designation. This includes about 25 G motors which will have their designations changed.

Fifth, there were a few certification changes. Maximum motor casing temperature was increased from 200 C (392deg; F) to 220 C (428° F). Provisions will be made for testing motors with interchangable and user-set delay systems, and manufacturer designations must reflect average thrust to within 10N or 20%, whichever is greater. I'm not sure why these changes were needed, but they all make sense.

These changes are not official yet, but stand a high chance of becoming so. They seems to me to do a good job of clearing the issue and making everything fair.

Story from Rocketry Planet
Dick Stafford reports and comments

From the RP story: a great picture that speaks a thousand words. Gary Rosenfield (L) of Aerotech and Anthony Cesaroni of CTI at the meeting. Competitors in business, but partners in making the rules good.

No time

The EGE has a 3-page paper due tomorrow monrning. Hence, nothing to say, sorry.

That's a lot of motor

I ordered just 13 motors that came on friday, and 9 of them were blackpowder. But they pack quite a punch:

The 9 D12 motors, at 16.8 Ns (Newton-seconds) each, have a total of 151.2 Ns. That's in the upper range of 'G' motor impulse - one more D12 would push it into the high-power range. In fact, At 10.2 N average thrust, 9 motors equals 91.8 N average thrust, and 9 motors with 21g of propellant each equals 189g of propellant; both of those figures would make it a 'High-Power' rocket if they were lauched as a 9-motor cluster.

Fortunately, I only use 4 at a time, which equals a mid-range (67.2 Ns) F41 motor.

2 F35Ws at 57.1 Ns and 30g of propellant each, 1 G53FJ at 60g and 90.9 Ns, and 1 G64W at 63g and 118.8 Ns equals 323.9 Ns (just into 'I' range) and 183g of propellant of composite motors.

Added to the 9 D12s, that's a whopping total of 372g (13.1 oz) of propellant with a total impulse of 475.1 Ns, which works out to the total equivalent of a mid-range I motor.

Now that's a lot of motor.