Some quick numbers from the 2022 TARC Finals...

The 2021-2022 TARC Finals were held last weekend in northern Virginia. No Huntsville teams made it into the top 100, though 6 teams from Alabama (5 from north Alabama) did compete at the Finals. Of these 6, four were in the top 42 of round one and advanced to round 2. Alabama ended up with two teams in the top 25 - Tharptown, which finished in the money at #10, and Muscle Shoals, which was #20. These teams will receive invitations to participate in the NASA Student Launch Program next year, and I wish them well - it will be a very busy time for those students!

Trip Barber just sent out the stats of the flights conducted at the Finals - 1st round had 810 feet as the altitude goal and 860 feet was the target of the second. My natural instinct is to fiddle with numbers and that PDF full of stats was just too tempting for me to pass up. It also gave me an excuse to try extracting tables from PDF documents - something that I had never tried before. Turns out it's pretty easy - at least on a Mac. Anyway, on to the graphs...

Motor choices of the TARC teams attending the 2021-2022 Finals (Click to enlarge).

The above plot shows the breakdown of motors used by the 100 teams attending the Finals. Note that the Aerotech F39 was the most popular motor, accounting for 25% of the motors flown in round 1. It was followed by the Cesaroni F59, with Duane's favorite TARC motor, the Aerotech F32, coming in a distant 3rd. Exactly two-thirds of the finalists used reloads and 70% of the motors were made by Aerotech. This changes a bit when we look at the same information for the 42 teams making it to round 2:

Motor choices of the final 42 at the 2021-2022 TARC Finals (Click to enlarge).

Here the number of F39's increases to 33% of the total. Reloads account for nearly 74%, and the Aerotech share increases to 76%.

Ever since TARC instituted two altitude goals at Finals (one high and one low), I have always wondered whether it was easier for the teams to go higher or lower. I suspected that it would be easier to hit the low mark, as TARC teams making it into the top 100 would have had plenty of practice adjusting weight, etc. to bring their rockets' altitudes down. Not so much the other direction. The 2021-2022 Finals data give me a chance to see if my guess was right, at least for the recent season.

Altitude scores of the teams attending the 2021-2022 TARC Finals (Click to enlarge).

Looking at the above plot we see that the mean difference between the altimeter altitudes and the 810 foot goal was about 6 feet on the low side (i.e., average altitude was 804 feet). The dashed red lines give the one standard deviation bounds, which correspond to 38 feet above and below the average. In computing these numbers, I have thrown out flights with absurd altitudes or those that were disqualified.

Now let's look at the same data for the final 42:

Altitude scores of teams in the final 42 at the 2021-2022 TARC Finals (Click to enlarge).

In round 2 the average difference was also low, but by 25 feet - 4 times the round 1 difference. The scatter is also larger; 55 feet as opposed to 38 for the opening round. I noticed that 860 feet - 25 feet is 835 feet, meaning that the round 2 average is the same as the altitude mark the teams had to hit for their qualification flights. This implies that most of the teams in the second round did not really know how to adjust their rocket to make it go higher; perhaps they fell back on the configurations that got them to the Finals in the first place? The round 2 scores were certainly worse, by almost a factor of 2 (average of 95 in round 2 versus 55 in round 1) - which lends some support to my hypothesis. However, the weather was pretty bad at Finals this year, and it's hard to rule out worse conditions in round 2 as a cause.

I guess I am going to have to see if the trend is there next year...