Launch date and time: April 4, 2006 starting at 9:30AM
Launch location: Olathe, Kansas
Launch wind and weather: Cool temps with light winds
This is the third year that Ive been invited by the Olathe NW High School to observe their Team America flights. There were three teams the first year. There were eight teams last year (sorry, no write-up), and ten teams this year. Mr. Keiter has developed and entire curriculum around the Challange.
My co-worker, Kyle, came along this year to assist with the timing.
Last year, confronted with eight teams all trying to get in at least one flight, and sometimes two as time allowed, caused me to be swamped attempting to keep up with filling out the forms, doing the math, taking notes, etc. If it hadnt been for my friend Richard, and his uncanny ability to wield numbers in his head it might have been bad. As it was, we kept up but barely. So this year, learning from my mistakes, I asked for information about the teams entries in advance. This way I could take a look at the thrust to weight ratios, check the motors being used against the approved list, and even run a quick sim to find things such as rod exit speed and whos getting closest to 800-feet and so on. Having these pages of notes in advance improved the situation immeasurably. There was even time to take photos. The only possible problem, then, would be me writing the score(s) on the wrong sheet, so I tried very hard to remember to ask teams who they were when checking in and verify that their page was on top!
This worked pretty well, and there was only one time, when three teams were attempting to check in at once, that we were a little backed up. There was even time to take photos and chat a little with the team members.
When I arrived at the school, I checked in at the office, and went up to the classroom. The first hour class was there, already set to go. One of the teams hadnt forwarded their information to me so I collected that and spent a few minutes running the numbers using pRasp on my Palm T5. Each team was questioned regarding their rockets stability and thrust/weight ratio. We talked a little about stability, and then went out to the field.
First hour class.
Photo by Tim Burger
In the meantime, the news reporter chatted with some of the team members, looked over the rockets on camera, and discussed the Challange a little. He launched the sounding rocket sent up to gauge the wind on the air. The first team to make an attempt then loaded their entry on the pad and we held for a few minutes for the TV station to come back to us. They lit the first attempt on the air too, but unfortunately it didnt turn out well in fact it was one of the worst flights of the day as it happened (I believe its number 17 in the table below). The altimeter must have seen it coming and leapt in fear prior to impact since it wasnt found in the wreckage. Too bad they couldnt have had a more successful flight for the broadcast! Thems the breaks, I guess.
One of the local newspapers also sent over a photographer and reporter, and after that first flight was worried about where she had parked her car (it survived).
Launching commenced in earnest at this point, with teams preparing their entries, mounting them on the pad in turn, and lighting the motors. Some flights were a bit dicey, some went quite nicely, and one or two were catastrophies. Kyle and I timed the flights, made notes, and teams were expected to bring their egg-capsule to me when they were unpacked. I would also listen to the altimeter chirping out the altitude it measured on the flight at this time.
There were four teams in the first hour and six in the second. The news teams hung around for a little while after the first two flights, then packed up and left. Mr. K flew a rocket or two while we were waiting between classes.
The next six teams came out for the next hour. Each team was required to speak with me prior to flying. As with the previous teams, I wanted to know a couple things: I wanted to verify the weight, and ask about the stability. Most of the teams knew what I meant when asked about the margin, one team even knew the answer straight off and gave it to me in calibers. Most teams were only able to show me the center of pressure and center of gravity (Mr K. had them mark those two points on the rockets this year.) It was explained that the sim program they are using just indicates stable or unstable without showing the margin leaving it to the modeler to figure out. Most teams had a margin near two, but one or two teams were a bit lower and one a bit higher. One of the teams had a margin of about a half-caliber and their rocket flew as predicted (we suggested some nose weight to no avail).
I had no information on a couple of the rockets for this hour too, the Big Salad team being one of them. It turned out that their rocket was severely underpowered. We suggested that they redo the booster to handle two or even three motors in a cluster, or to switch to a larger motor in the sustainer and go single stage. Both of these suggestions would require redesign and rework of the model. We were reluctant to tell them they couldnt fly, but strongly suggested they fix it before they did. Mr Keiter suggested they mull it over for a while. In the mean time another team was ready to fly.
By this time, there were a lot fewer altimeters than before and Mr K. was picking teams who were likely to be successful to fly first, then the more dodgy entries were allowed to fly. And finally, teams still able and willing to make a second attempt were allowed to go again.
Eventually, it was Big Salads turn and they opted to fly, despite the warnings about a too low thrust/weight ratio. As expected, the rocket lumbered up the rod, hung above it for a half a second, then headed down range in cruise missile mode. It staged perfectly just before nosing in amid the groans of the team members and Mr K. who had realized hed just lost another altimeter.
The challange was really two problems this year. The first problem was to fly a raw large hens egg to an altitude of exactly 800-feet and recover it uncracked. Points were added to the score for every foot over or short. The second problem was to be in the air for exactly 45-seconds, measured from first motion to last (or until out of sight.) As with altitude, a point was added to the score for every second short or over. A score of zero is best. A cracked or scrambled egg results in a disqualified flight.
A couple of the teams were getting good altitudes; enough to get a good score, but for one reason or another the scores were disappointing problems such as chutes that didnt open or that were too large, or failure to lite all the motors, or in one case a separation.
The Penquin Team gets ready.
Photo by Tim Burger
The Penguin team would have done better, except their first attempt separated, causing the part with the egg to float for a lot longer than it would have, and their second attempt resulted in no chute for a DQ.
Team V2 also has high potential; their main problem being too much motor! Perhaps a D12 or even C11 upper stage motor would have brought them closer to 800-feet.
Another team worth mentioning is the Silver Bullet team. Their first flight was over 3-minutes long! Their altitude was a tad low on both flights, and coupled with an over-large chute resulted in disappointing scores. A touch more motor, and little more tuning on the recovery system would get them in the ball-park at least. They did have two of the prettiest flights we witnessed during the day though. The rocket flew true, and staged beautifully.
Standard Dress might be more of a threat with F50 motors; the F20 is about 50% F while the F50 is a bit more powerful at 72%. The increase in altitude would get a little longer time as well.
The clinker of the day had to be the Big Salad flight (term flight used loosely). As already mentioned, the slow majestic lift off followed by the apparent hovering above the rod until a breath of air tipped it downwind and the grinding furrow it plowed was painful to watch.
Even so, overall, it was a pretty good day of launching. Most of the teams made a pretty good showing. Two or three teams are on track and could have a good score with a bit of tuning. Four more seem to know what they are doing and would be major threats with some minor changes to motors and recovery. And the remaining teams, well one at least, needs to return to the design stage and try again. I noticed that most of the teams staged but that the three top scores were accomplished with single stage rockets. Theres really no reason to stage this year; you can, but it isnt really necessary. Better to use a good solid cluster, or figure out a way to make F impulse Econojets work for the purpose. None of the rockets transitioned to different size tubing which would improve overall performance due to lower static drag and if done well lower dynamic drag too.
The time was well spent; Kyle and I enjoyed meeting the teams and witnessing the flights. Im already looking forward to next year!
And now some statistics: there were 10 teams making a total of 17 flights, of those 5 were disqualified for one reason or another. Total impulse was 1056.21 or mid-J in 49-total motors. There were 11 staged flight(s) (4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17), and 10 that were both clustered & staged (4, 5, 6, 10, 12, 13, 14, 16, 17). There were no single stage clusters.
In order of score
|1||Scrambled Eggs||Black with White Twist||F42-4||57.11
|2||Scrambled Eggs||Black with White Twist||F42-4||19.63
|733||92.33||Good flight except chute didnt open. Egg survived!|
|3||Blitzkrieg||Blue Fading to Silver||F50-6||57.20
|4||Silver Bullet||All Silver Rocket||2 x D12-0 to D12-7||62.57
|659||158.61||Good flight! Return to top|
|5||Penguin||Red Rocket with Sickle & Hammer Logo||3 x D12-0 to E9-4||103.38
|937||194.33||Staged OK though one booster motor didnt lite. Separated. Return to top|
|6||Silver Bullet||All Silver Rocket||2 x D12-0 to D12-7||201.66
|719||237.66||Good flight! Floating . . floating . . Return to top|
|7||Standard Dress||Red with White Cone||F20-4||32.80
|570||242.32||Good flight late deployment.|
|8||Standard Dress||Red with White Cone||F20-4||32.05
|566||247.87||Squirrelly late deployment.|
|9||Blitzkrieg||Blue Fading to Silver||F42-6||29.14
|10||V2||Black with Silver Specks Cone & Fins||3 x C11-0 to E9-4||73.87
|1264||493.48||Beauty of a flight, over achievers! Return to top|
|11||Top Fliers||White With Black Bands & Fins||3 x D12-0 to 3 x C6-5||18.60
|320||498.58||Staged OK; long arching flight with late (just in time) ejection. One booster motor & two sustainer motors didn't lite. Egg OK. Return to top|
|12||Top Fliers||White With Black Bands & Fins||3 x D12-0 to 3 x C6-5||5.14
|94||745.86||Classic unstable flight! Eggs survived! Return to top|
|13||Penguin||Red Rocket with Sickle & Hammer Logo||3 x D12-0 to E9-4||35.69
|-||DQ||No chute Return to top|
|14||Cash Money||Black & Silver Rocket||3 x D12-0 to C11-5||12.01
|-||DQ||Didnt lite upper stage Return to top|
|15||Big Salad||Pink Nose & Fins||D12-0 to E9-6||6.10
|-||DQ||SERIOUSLY underpowered. Return to top|
|16||Cash Money||Black & Silver Rocket||3 x D12-0 to D12-5||5.34
|-||DQ||Bound on the rod just enough to clear it only one motor of three lit and it hung up on the clips Return to top|
|17||Wildfire||Yellow Top, Orange Bottom||2 x D12-0 to E9-6||-
|-||DQ||Staged OK; long arching flight into the dirt! Rocket trashed; altimeter lost. Return to top|
The Scrambled Eggs Team makes a last check before flying
Photo by J. Kyle Sallee
Blitzkrieg places their entry on the pad
Photo by J. Kyle Sallee
Top Fliers install the altimeter
Photo by J. Kyle Sallee
Submitted by Tim Burger, NAR 78486 L1.
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Page created on April 10, 2006.
Last updated on April 12, 2006.