Close to a Thor Simulation

Entering rocket details into RockSim is not my favorite task. Fortunately for me, I almost finished creating the Thor in RockSim - that means that I'll be able to start running simulations soon.



As for construction: Greg M provided the drill press and drilled the holes in the aft centering ring last night for the motor retainer. Joe at HobbyTown helped me find another forward centering ring since one of the rings provided with the kit was consumed by the motor retainer. I expect to set all the centering rings today and hope to do some glassing with Warren on the airframe tomorrow.

Clary, Rocket Man

i borrowed Rocket Man from the local library with the hope of learning a bit about Robert Goddard. The book was pretty difficult to read, so I don't expect to ever read it again. The biggest problem was that the author bounced around in time so it was confusing about what had happened versus what was going on at the time. Another confusing bit was that the author used different names for the same people, but there were so many names in the book that it became a blur.

A particularly interesting bit in the book was that they dispute a lot of Goddard's claims. Goddard was certainly an intelligent visionary, but he was exclusive and when he found people that were likely smarter or more qualified he either convinced them to work on his team or he shunned them. Goddard received more publicity than any other scientist, but he never published in scientific journals.

Launch Log 2007.09.22

We had 7 launches on this awesome late-summer afternoon. We pulled out the Renegade which hasn't flown in a while, melted the Stingray, and broke the fin on the Purple Rhino - again. Spencer wanted to fly the Firestreak SST but it has a broken fin from little boys playing with rockets so we'll have to wait for a replacement part.

• Firehawk | 1/2 A3 | straight flight, higher than usual on 1/2 A3, drifted in recovery to land 100 yards from pad


• Renegade | C6 | Isaac did most of the prep, some weather cocking, drifted in recovery to land 120 yards from pad


• Army Man | B6 | impressive flight on a B6; no weather cocking but drifted a lot in recovery; landed about 200 yards from pad - bounced in a parking lot


• Stingray | 1/2 A3 | Spencer thought about prep'ing the rocket, weather cocked just enough to land close to pad on streamer recovery


• Purple Rhino | 4 x A10 | beautiful flight - love this rocket; no weather cocking; light wind so landed pretty close to pad


• Firehawk | 1/2 A3 | neighborhood kid joined us and did the prep; chute got stuff in ejection so motor ejected; no damage to rocket (other than lost motor retainer


• Stingray | 1/2 A3 | the ejection charge blew the nose-cone off the rocket and melted / deformed the top 60% of the fuselage; fuselage and nose-cone both recovered but rocket is damaged beyond repair because of the deforming of the fuselage

Before the final Stingray flight, we attempted to launch Mighty Mouse 2. I didn't have anything to use for flash-in-the-pan ignition, so we tried using solar igniters. After 3 attempts of getting rocket to pad, count-down, fail, check connection and for shorts, we gave up. We're thinking we need to build or buy a bigger launcher (one that uses a bigger battery anyway).


Spencer can't hold down the launch key, so Isaac holds the key and Spencer pushes the button.


Team work - and the rocket lifts off. Note that it is the person pushing the launch button that does the count-down.


Spencer finishes off his launch by doing his own retrieval. Well done, Spencer.

Bullet Ground-Testing

I've been reading a lot lately that you need to always ground-test to make sure that the charge can separate the loaded rocket. I had actually planned to fly the Bullet without ground-testing but I'm ready to fly the Bullet and the next available date isn't until November so ground-testing sounded kinda fun.

I prep'd the rocket (without an engine) and fed the wire for the Main ejection canister through the static port hole. Some people, so I'm told, do their ground-testing using a tube taped to the static port hole and they suck on the tube and then when they release, the AV bay represurrized and the computer fires the charges. I manually tested the computer separately a few days ago using it's built-
in test sequences and am just testing the separation in my ground-testing here.

Isaac thought that the test failed; he knew that the rocket wasn't going to launch but he thought that the chute was supposed to open. I used the canisters that I built a couple weeks ago and calculated that I needed about 2.5 g of FFFFg black powder for the ejection charge. A failure would have either been the whole upper section shredding from too big a charge or the nose code not popping out with force from too small a charge. Looks to me like the 2.5 g was just right.

Launch Log 2007.09.20

We met up with some friends at the park at 6p to play and launch some rockets. We had 5 launches and ended the evening by losing Mighty Mouse - yes, the original. Very sad.

By the time we all ate, it was after 6:30p - that means the sun was about to go down. The field had been in use by a bunch of soccer teams, so we weren't just waiting to finish eating. We performed a rapid setup and prep on the Firestreak SST and launched it for a nearly perfect flight on a 1/2 A3.

The second flight was the Firehawk on an A3, but we had intended to use a 1/2 A3. With dusking coming and a bit of a break, we needed to keep landings close to the pad and that meant lower flights. The Firehawk is a great flyer and it went out of sight on the A3. There was almost no weather cocking so a long walk crossed my mind; fortunately, the chute only opened about 70% so decent was quick but not destructive.

Third flight was the Firestreak SST again but this time with Sam pushing the button. Another great flight on a 1/2 A3 - Spencer loves his rocket and set it asside with the intention of us launching it again right after launching the Stingray. The Stingray was unexciting on a 1/2 A3 - just too small to see in the near dusk conditions.

The Firestreak SST wasn't ready for a flight yet, so I loaded up Mighty Mouse for a flight on a C6. What was I thinking? Bad choice - so long Mighty Mouse. After spending some time looking for Mighty Mouse, we cleaned up and went home.

Recovery Canisters

When I built the Bullet, I went with a common canister for storing the recovery charges: a PVC cap attached to the AV bay. Now that I've watched many people prep for flights, I've decided to switch to these Polyethylene tubing-based canisters. I'm hoping to do ground tests tomorrow for separation for main chute deployment so I made some canisters today.

In the pictures above, you can see the first couple steps I use. Since the glue takes a moment to set and the ROL article is light on details on technique, I decided to record my steps for future reference. I found it easiest to put a partial ring of glue around the bottom before involving the e-match. There would be just a little gap open to get the e-match in. After the partial ring set, I put the e-match in and put just a small drop of glue in to hold the match and then let that set. Finally, I'd put in the final bit of glue and fill it out at the bottom.

The reason for the multiple steps was that putting too much glue in at once made it too difficult to manage the e-match. For the separation tests tomorrow, I'll need to add 3g of black powder to the canister and cap it with masking tape but the hard part is done now.

Launch Log 2007.09.09

Mom and I briefly attended the Tripoli Colorado commercial launch on Saturday (2007.09.08) but we didn't launch anything. We got to see an impressive flight on a SkyRipper K motor - that was the first flight I'd seen on a hybrid (other than a couple Alpha Hybrid test flights that blew up the rockets). I attended the Tripoli Colorado research launch on Sunday (2007.09.09) for about 5 hours and got to see some static tests, more Alpha Hybrid tests (yes, again, they destroyed the rocket), and some big launches on home-built motors.

When we got home from our trip in the mountains, we all went over to the field by our house and launched a few rockets of our own. The first flight was Spencers new purple rocket: the Firestreak SST. The Firestreak SST was purchased to replace Spencer's previous favorite: the 'silver nose' Outlaw which finally broke a fin and is no longer flyable. The Firestreak SST used a A3-4T for its first flight and flew great but recovery was not ideal: it uses a streamer for recovery but the streamer didn't appear to slow the rocket much.

Our second flight was Isaac's new Firehawk. Isaac built and put the decals on the Firehawk himself but I assisted with the glueing. Isaac even tied the shock cord on. We flew the Firehawk on an A3-4T but recovery here was also a bit of a problem: chute didn't open right and got tangled up. We'll have to watch it closely on the next flight - perhaps we didn't pack the chute good enough on this first flight.

It was a bit windy: we had to tilt the launch rod quite a bit to keep the rockets coming down within walking distance.

We flew Mighty Mouse on a B4-2 and Army Man also on a B4-2. Might Mouse landed in a pine tree but was recovered and had no damage. Great straight flight and drifted a bit in recovery. Army Man landed behind the school; Shanelle was hoping it was on the school but the boys recovered it without trouble. It flew great on the B4 with very little weather cocking (which is why it landed so far away :) ).

Launch Log 2007.09.01

We launched at the NCR North Site which is in the Pawnee Grasslands. The launch ceiling was around 20,000 or 25,000 feet but none of our rockets were sent to even 1/10th that altitude today. We launched the Purple Rhino, Migthy Mouse, Army Man, and then Mighty Mouse 2.

Our first flight was a flash-in-the-pan ignition of the Rhino. It flew 4 A10-3T's which carried it high and straight even though only 3 of the 4 motors lit. The second flight was the Mighty Mouse on a C6-7. The 7 second delay was nice because that kept the Mighty Mouse pretty close to the pad even though it was a nice, high boost. The third flight was Army Man with the split set for the center of the rocket. Past flights of Army Man suggested that it was heavy or not aerodynamic so we used a C6-3; I'm pretty sure it hadn't hit apogee when the chute opened. We had to walk quite a ways to recover Army Man but we did find it. Finally, we launched Might Mouse 2 for the first time. We used 3 A3-4T's with a flash in the pan (but the pan in this case was a Cherry Coke can rather than our usual ceramic dish). I was worried that the flash wouldn't light all motors because the can wasn't as close as I usually like but all motors did light and it was high and straight.

We saw a couple dozen other flights. There were quite a few problems - more than I've seen at a public launch. One rocket got tangled on the rod, caught fire, and then knocked the launch pad over. Two rockets went unstable immediately and landed in the viewing area. Quite a few recovery failures; this one in particular was interesting:

This bowling pin and ball was pretty and flew nicely, but recovery failed completely. It went ballistic and fortunately landed quite a ways away from the launch line because was a big, fast impact.

Launch Log 2007.06.21

Isaac woke me up at 6:30a this morning to go launch some rockets. Unfortunately, I had a production deployment at 2a this morning, so I was slow to get out of bed. We finally hit the launch site around 7:45a and had some nice launches. It was a beautiful, warm morning; winds were calm.

Our first launch was a new Estes Bandit that the local hobby show, Mile Sky Hobbies, gave us. The owner had hosted a build 'n take booth at an air-show recently and we weren't able to attend so he gave us the model that he had built for demonstration. The rocket is an E2X kit and flies nice and straight. Our first flight was on an A8-3 just to verify that it would fly straight.

Second flight was the tiny, yellow Estes Sting Ray. Isaac did all the prep including the motor install and launch connection and then launched. We launched with a 1/2A3 and the tiny thing still went high and far.

Mighty Mouse took a turn on a B6-6 and had a great flight, as always. Next, Isaac prep'd the Estes Swift for it's first flight. Using a 1/2A3, the rocket went far out of site up and a little to the north. We heard the motor ejection, but couldn't see any trace of the rocket or smoke. Isaac is convinced that the Swift is orbitting earth at this very moment.

The String Ray flew next on a B6-4. The glide from powered flight to apogee was impressive. Mighty Mouse flew on a B6-6 and then we flew the String Ray one more time on a B6-6.

That's 7 flight... I think we had 8 launches... I'm forgetting something. I better start carrying paper or a computer to the launch to record! Launch prep was far better this time and I remembered all launch rods and parachutes today :)

Under Construction: Talon 2 and Rhino II

In the smallish rockets that I build, the motor mounts have been pretty fun lately. The two main rockets that I'm working on at the moment are the Talon 2 and the Rhino II. The Rhino II is my second Rhino: the first is a cluster with 4 13mm motors; the Rhino II will fly with 5 13mm motors.

The Talon 2 my first Talon kit - it just has a 2 in the name because Giant Leap makes a bunch of different sizes of the kit. This kit is a 'high power' kit similar to the Bullet, but far more complex to build. The motor mount is shown below just before I assembled it into the rocket. The black on the one end is the motor retainer that uses snap rings rather than a screw-on cap like the retainer on the Bullet. The wire loop on the motor mount is the shock-cord mount - again, different from the U-bolt used by the Bullet.

The motor mount in the Talon 2 is 29mm in diameter and about 18" long: that's pretty big for as small a rocket as it is. It uses G-10 fins which is a new material for me to work with. G-10 is necessary for bigger, faster rockets because it is a lot stronger and less flexible than plywood. One curiousity is that it uses a nylon shock-cord with kevlar sleeve rather than a simple kevlar shock-cord - I'm not sure why that is yet.

NCR June Launch

No - I didn't launch the Bullet this weekend. It was an awesome weekend of rocketry, though.



In the picture above, the two rockets were supposed to drag-race. I believe that the rules are the winner has the best 2 out of 3 of: first to altitude, highest altitude, and first to land. Art, with his BAMF, was the obvious winner in this launch because Dougs camera rocket didn't fire. The next day, they tried again and both rockets launched, but Doug's rocket was only thinking about getting to the ground first: it went up, turned over and went back down. I'm pretty sure it was super-sonic by the time it landed because it was really screaming and I was well over a mile away and could here it quite loudly. The nose cone was buried 2 feet in the hard-packed desert dirt. Art won again.

Later on the day, after dozens of other cool flights, this 14 foot long Saturn V launched. Most impressive:

Launch Log 2007.05.28

Isaac, Jeremiah, Luke, Emma, and Megan launched rockets today. We had 5 launches total with 2 of them being first flights. We need to start tracking how high the rockets go, but at this point we just see them as low, high, or really high.

The first launch was Might Mouse I with an A8-5. The Mighty Mouse is good to fly on a C, but I wanted to start with an A to introduce the girls to rockets. I think we should stick to A8-3 or just go with B or bigger in the future because the 5 second delay put the chute opening about 16 feet above ground (I was nervous).

Our second launch was the recently completed SpaceShip ONE. We used an A8-3, but that didn't work out so well. I think we'll try it again on a C, but I may not have gotten the wings straight because this launch was just kart-wheeling off the rod. We did a first flight of the UNNAMED: it flew decent and then melted the chutes on deployment. It recovered fine (fortunately, one of the chutes fully opened), but I'll have to figure out how to properly pack the chutes.

We finally launched the Alpha and the Outlaw. Both had great flights. The Alpha flew on a C6-7 and the Outlaw flew on a C6-5. Both were recovered in the same field, thanks to the calm weather. The paint on the Alpha is bubbled, so Luke and I suspect that the heat is causing it some problems. We may have to retire this one and get a new one for future flights.

Alberto Santos-Dumont

I've not read about Alberto until now. From the little information that I have read so far in Wikipedia I suspect at least a few of the early Tom Swift books were based around this man and his achievements. I'll have to find a book about him.

It was while I was looking for information about personal blimps that I saw Alberto's name. I was reading the FAQ about the Alberto airship from SkYacht and they pointed out that they named the ship after this pioneer of aviation.

Isn't it beautiful:

Launch Log 2007.03.10

Today was our first time launching a cluster. This one was the FlisKits Rhino with a 4-motor cluster built with centering rings from Jon's Colorado Rocketry Components.

The Rhino had two flights and both were amazing. The first flight was on 4 A3 motors and the rocket proved to flight straight. I did a quick clean-up, regreased, reloaded, and took a second flight with 4 A10's.

After flying the Rhino, we flew Isaac's Alpha on a C6-7... we were sure we lost the rocket because there was no sight of it even a couple minutes after the launch. While Spencer and I were over in the field to the east of the launch field, we noticed the Alpha decending over the field to the south of the launch field. Wowsers - we'll have to get a pico altimeter and beacon installed in the Alpha before another flight on a C motor!

Launch Log 2007.03.04

We had a beautiful day for a launch at the school by our house today. It was a little breezy, so we started the launch with a C6 in the Outlaw to get an idea what to expect. It was a very pretty flight because the motor was extra smoky and went nice and high.

Those were the last launches of Pipes and Pencil: Pipes got tangled up in power lines and I have no idea when the power company will get it down and I doubt they'll bring it to us; Pencil was flying without a chute (because we forgot all of our chutes at home) and it turns out it doesn't do tumble-recovery so well. BTW, Pipes and Outlaw do tumble-recovery perfectly.

Shanelle went home to get chutes and then we were able to fly some more. Isaac did the prep on his Alpha rocket from Seth. The Alpha had a nice launch, but on its first flight the chute was tangled so it bounced.

Afer the Alpha launch, Spencer decided he was ready to launch his rocket from Seth - the Mighty Mouse. Mighty Mouse flew a couple times and as always it flew beautifully.

The flight was great, but got a little scary because it looked like it was coming down in a tree. It must have been just past the tree or flew through the branches.

The Alpha taking a second flight - the recovery pictures are interesting because we replaced the usual rubber shock-cord with Kevlar thread. The thread is often used in contest models because it is light.

Spencer did the count-down and pushed the button on 3 launches: 1 launch of the Pencil and 2 launches of the Mighty Mouse. He even recovered Mighty Mouse after its second flight.

March Launch Scrubbed

We went to the launch site today. The launch was 'go' as of last night, but a dozen or so of us arrived at the launch site this morning at 9a and high winds made it clear we wouldn't be launching. We waited until about 10:30a to see if the winds would die down but they didn't so the club president officially scrubbed the launch and sent the equipment trailer away :(



Above is a picture of the rockets that I took with me to the launch. I had expected to make my first high-power flight with the bullet today. While I didn't get to fly, I did get a chance to ask another club member to look over the rocket. The red and yellow is an Estes Baby Bertha kit that we've named Mighty Mouse - I actually took two of those today: one with a since 18mm motor mount and one with a cluster of 3x13mm motor.

The Astronaut Farmer

I first heard about the Astronaut Farmer while looking at the CP Technologies Web site (my quest for ideas on small-scale strap-on booster designs). There was a lot of information there about the movie and skimming the info, I decided that I'd like to go to the movies on Feb 23 (opening night). It worked out that I was able to go a screening of the show today - great movie, in my opinion.

There was a point in the movie where there is a failure and I was horrified: I thought that the BATFE had worked with the Polish Brothers to help the public see the 'light' on their current case affecting rocket propellant and ignitors used by hobbyists. In the movie, it is the FBI rather than the BATFE, but a similar idea (Farmer was fine building his rocket - it was when he attempted to buy fuel that he got into trouble - even though he had attempted to follow known regulations).

There is a lot of family focus in the movie - the kind that I like because it helps me consider my role as a parent and gives me some things to think over. Some details are ignored - again, a nice thing - for example, Farmer allows the public to come into his garage and see the rocket and the line goes on for miles (apparently, these were only the most well behaved humans on the planet because there was no mess and no fights). I believe that the movie was filmed in New Mexico - I only mention it because the house, the ranch, etc. were so pretty that they really complimented the story / experience.

Good stuff.

Feb launch scrubbed but...

I'm not too down: on Monday, January 29th, I'll be attending a screening of The Astronaut Farmer and when we do get to launch, I'll be attempting my L1 cert on my second flight of the Bullet. I've been assisting with some PHP on the club Web site and one of the members showed me the casing and motor I'll be using for my L1 :) I'll have to pay for the H73 motor, but I'll be able to borrow the casing.

building a few cluster models

We have a rocket day coming in the next month or two at church, so I'm building a couple models size rockets for launching there. These are my first venture into clusters - and they are tiny clusters. The tall rocket is a Rhino and the shorter one is a Baby Bertha.

Both rockets use BT-60 size tubes, so I picked up a couple cluster mounts from a local rocket guy. The Baby Bertha will use 3 tiny A motors and the Rhino will use 4; this will give the Baby Bertha about 6.6 N-s and the Rhino 8.8 N-s of total impulse (equivalent of mid-C).

Jan 6 launch scrubbed

Disappointing :(

Regrettably but sensibly, NCR will NOT attempt to launch on Saturday the 6th. Our equipment trailer remains buried in deep snowdrifts and is pretty much in-accessible, as is the Atlas Site.

- from http://www.ncrocketry.org/