Date 3.7.05

Project: First launch of Rocket OPSA 1

Chosen location: Location B Oddown Playing fields

Weather Report: As of Sunday July 3, 2005 12:44pm

Sunrise 4:57 (BST)
Sunset 21:28 (BST)
Max Day Temp19°C
Min Night Temp 12°C
Wind 4mph
Visibility good 
Barometric Pressure 1016 
Relative Humidity 46 

Measurements achieved

Flights were used to achieve new personal altitude record.

Previous record: 0 ft

New Record: 517.91 ft (157.86m)

Altitude Calculations

1. 30m x Tan(70 degrees = 2.74) = 82.2 metres (269.69 ft)

2 20m x Tan (83 degrees = 8.14) = 162.8 (534.12 ft)

3. 20m x Tan (85 degrees =11.43) 228.6 (750 ft)

Average of 3 flights =

157.86 (517.91 ft)

First test of OPSA ALTITRACK Mark 1 Altitude recording device as built by Jon Bobbins

Flights were filmed for web site purposes and we successfully filmed a total of two launches and have a selection of stills from the day which will be put on the website in due course.

Flights have prepared the team for the next stage, which will include an electronic altimeter test.

We have made the following observations from this launch.

Parachute failed to open fully on 1st and 3rd launch. Parachute needs work, either in replacing the string with thin fishing wire or some other twine.
Launch Rings fell off prior to first launch so we needed to purchase Sellotape before we could start to secure the launch runner. A solution would be to redesign launch runner to be more substantial.
Altitrack System worked well but was not particularly accurate. In doing trigonometric calculations it was observed that the Tan gradient increases drastically between 85 and 90 degrees and we can assume from this that far greater accuracy is required to get a visual reference.
It should be common practice on all launches to get the mode average from a series of three launches wherever possible.

A solution for this would be to prepare for Altitrack MKII based on the ESTES Altitrack system and also buy or build an electronic altimeter that connects to a laptop. Therefore a more accurate reading of flights can be achieved and results can be obtained at the launch site.

Summary of schedule

The day was a success. All three flights were successful apart from a couple of parachute failures. Wind speed meant that launches might have lost a little height from drift of approx 50 meters.

Team Members Present

Jon Bobbins, Bob Jobbins, The Levitator.