Flight Log Sheet Instructions v1.0

The Far Horizons Flight Log sheet is used during the assembly, launch and chase portions of the flight. All sections need to be filled out properly to ensure good post-flight analysis. A copy of the log sheet has been labeled with numbers below, and that is followed by an explanation of each section. To record your own data download a PDF version or an editable ODS spreadsheet version of this flight log.

0: The "FLIGHT NUMBER" in this section is used as an ID for the flight. This can be based on the number of each launch that you ever do, starting from 1 for the first. That number can then be associated with not only the log sheet, but all video and data files as well.

1: "MISSION OBJECTIVES" are goals for the mission. Examples would be "Highest altitude ever achieved" and "Provide platform for student data logging payload". The idea is that you are making the investment to fly a HAB mission, so what is it for?

2: The "PARTICIPANTS" section holds the names of everyone who takes part in the flight from HAB assembly through recovery. Additionally, it is helpful to list what task each person performed. Personal and emergency contact information should be collected for each participant prior to a mission, but should not be included in this section.

3:"LAUNCH CONDITIONS" refer to the ground level weather conditions at the launch site. If there is not an Internet connection at the launch site and there is no way to measure the conditions directly, someone will need to look them up prior to travelling to the site.

4: "PAYLOAD WEIGHTS" - In the United States, the FAA (Federal Aviation Administration) requires that the total weight of a HAB system at launch be no more than 12 pounds total. In addition to that, no single component of the HAB platform may exceed 6 pounds. This portion of the sheet helps ensure that the the FAA requirements are met and provides information that is used to calculate total lift later.

5: "BALLOON STATS" refer to the balloon itself, and not the rest of the HAB system. The "Balloon Size" is the weight of the balloon in grams. There are 3 lines for "PSI Dispensed X" because a typical sized balloon for a HAB launch will require multiple tanks of lift gas (typically Helium where available). The number of tanks will vary depending things like balloon weight, target ascent rate, maximum altitude, etc. The "Measured Lift" is found by measuring the upward pull of the balloon using a hanging scale. The "Fill Tube Weight" is added to this value to compensate for the fact that the balloon will still have the fill tube attached when the measurement is taken, and so is already lifting the tube's weight. When added, these two items give you "NOZZLE LIFT".

6: The "LIFT/ASCENT CALCULATION" section allows you to find the difference between the "NOZZLE LIFT" (section 5) and the "PAYLOAD TOTAL" weight. Subtracting these two values will give you the amount of net "TOTAL LIFT" that the balloon is providing. This amount of lift has an affect on ascent rate and maximum altitude.

7: "MISSION TIMES/STATS" - The "Depart Adler" field is to record the time that the HAB team leaves for the launch site, and "Site Arrival" is when the team arrives. The "Launch" time is recorded, and the altitude of 625 should be replaced by the altitude above mean sea level (MSL) of your launch site. Readings are then taken periodically from approximately 10,000 feet (2048 meters) to 70,000 feet (21336 meters) in increments of 20,000 feet (6096 meters). Record the time and the actual altitude for each of these. The "Brust/Cut Down" field is used to record when the balloon starts descending. You then reverse the process that was done for the ascent, taking readings for each section of the descent. Lastly, you will record the landing time and altitude, and then the time when the HAB platform is actually found and recovered. These two times can vary significantly depending on where the HAB lands and how long it takes to reach it.

8: The "ASCENT/DESCENT SPEEDS" section is filled out in a similar way to "MISSION TIMES/STATS" except that you will need to take two altitude/time readings a minute or more apart for each target altitude (if the information is available). You then calculate the ascent/descent rates using the following formula:

abs(Altitude1 - Altitude2) / abs(Time1 - Time2)

abs means that you take the absolute value of the subtraction so that the difference between the two values is always positive. An example would be that if you took a got data from the balloon that said it was at 11,223 feet at 09:38:14, and then got another reading of 11,325 at 09:39:14, your ascent rate would be:

abs(11223 feet - 11325 feet) / abs(38 minutes - 39 minutes) = 102 feet per minute

This ascent rate is just an example. Your ascent/descent rate will vary.

9: The "INSTRUMENTS" section is used to record the activation times for equipment such as GoPro cameras and data loggers. This allows all of the data on the HAB platform to be tied to a common time base. An example would be that for a camera, you would write down the camera number (if using multiple cameras), and the time when the record button was pressed. Then if a data logger is activated 10 seconds later you know the location in the video to sync with the data from the logger.

Far_Horizons_Flight_Log_Markup.png (82 kB) Jeremy Wright, 10/18/2012 08:08 pm

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