"K" Class Altitude Record
Who: Mark Sims
What: 25,158 feet
When: July 14, 2002
Where: Amarillo,TX
Mark's flight took place at the LDRS 21 launch near his home turf of Amarillo, Texas. This was the second time Mark had notched the "K" record with this rocket. He previously held a tie for the "K" record at 20,000 something feet, but he broke well through at LDRS. He credits losing his launch lug and using a tower, plus the fact that this launch site was at a higher elevation, thus giving him thinner air.
The rest of the photos and descriptions on this page refer to his previous record flight. I am expecting updated descriptions and altimeter downloads shortly, but it all should remain informative until then:
The rocket was 2.3" diameter by 68" long with an ogive nose, using the same motor as Kurt's flight shown above; an Aerotech K250W. Mark built this rocket two years in advance of the flight, and had Texas style weather problems that scratched every launch until he was finally "go" in Oct.2001. Mark is also known for his flying tetrahedrons. He was kind enough to send me some photos and altimeter data from the flight, as well as a nice description of the flight, quoted verbatim below:
'The rocket is a 2.3 inch minimum diameter rocket. It is constructed of Red Arrow flexible phenolic tubing that has been laminated with 1.0 oz carbon fiber mat from Aerospace Composite Products. West Systems marine epoxy was used throughout the rocket (105 resin, 207 hardener, 404 High Density Filler).
Overall length is 68 inches. Total weight is 42 ounces. The rocket can be flown on F motors to small L class motors.
The rocket is composed of four sections:
1) The booster section is 34 inches long and can handle a 29 inch motor. The fins are made from 0.032 inch G10 laminate and weigh 5 grams each. They are surface mounted to the tube with 3.9oz woven carbon fiber from ACP that extends over about 1/2 the fin, across the tube, to the other adjacent fin. A layer of 1 oz carbon mat then covers the total fin and body tube area.
A two inch long collar made of laminated Kevlar is used for the motor retainer. This collar is epoxied to the end of the booster section and extends about 3/4 inch below the end of the booster. A ring made up of pieces of body tubing material and coupler tube is inserted into the retaining collar and is held in place with dome head screws behind each fin.
A coupler is epoxied into the top of the booster section. This coupler serves as the motor thrust bulkhead, the booster section shock cord mount, and the coupler to the altimeter section. The coupler is constructed from two layers of PML coupler tube laminated together with a layer of 2 oz carbon fiber mat.
The shock cord mount is a piece of 0.25 inch diameter internally threaded aluminum standoff inserted through two holes drilled through the booster section body and coupler.
A removable spacer made of PML phenolic coupler tubing was used to fill the space between the "K" motor and the booster section coupler.
The rocket is launched from a 12 foot long BlackSky ProRail. Two rail guide buttons are used. The top guide is screwed into the booster section shock cord mounting rod with an 8-32 stainless screw. The bottom guide screws into the motor retaining ring.
2) The altimeter section is a 10 inch long piece of laminated tubing that has a single 1/4 inch thick centering ring glued 3.5 inches up from the bottom. This centering ring is backed up by a 1/2 inch wide piece of PML coupler tubing.
The electronics module consists of an Adept OBC2-50K altimeter mounted to a piece of plywood bulkhead with right angle brackets. This plywood bulkhead is epoxied to a 2 inch tall section of PML coupler tubing. This avionics coupler also contains a loud sonic locater beeper that is wired into one of the altimeters, the altimeter power switches, and a stainless U-bolt shock cord mount. A Walston Retrieval Systems tracking transmitter fits into a 24 inch long piece of 5/8 inch tubular nylon that connected to the shock cord mounting U-bolt with a quick link.
This electronics module slides into the altimeter section tube. The altimeter power switches are armed through the altimeter section 0.25 inch vent holes. The switches are wired in parallel and are mounted horizontally in opposing directions such that any spin to the rocket will force them on or any lateral shock could only turn one switch off.
3) The main chute section is a 10 inch long section of 1 oz carbon mat laminated tubing. The main chute section connects to the altimeter section via a reinforced coupler. This coupler consists of two layers of PML phenolic coupler tubing with a layer of 2 oz carbon in between. The top of the coupler is closed with a 1/4 inch thick plywood bulkhead. A stainless U-bolt is used for shock cord attachment. Three set screws are used to attach the main chute section to the altimeter section.
The main chute is a RocketMan R3 fired at 750 feet. There is no drogue chute. Shock cords are 2000 lb test woven Kevlar fish tape. Flash bulbs with 1/2 gram black powder charges are used for ejection. Nomex cloth is used to protect the chute and shock cords from the hot ejection gases. Stainless steel quick links are used for all shock cord attachments.
4) The nose cone is a PML thermoplastic nose. Booster section and nose joints are friction fit with masking tape.'
If you've got a broadband internet connection, you can watch a video of Mark's flight that is posted on the DARS website. Go to "Gallery" and then "Sights and Sounds from Shoot for the Stars, Windom Texas, October 2001".