Ikaros 2

Near-Space Balloon Mission

Around 8am on Friday, April 15th, we launched Ikaros II equipped with several video cameras, temerature and pressure sensors, and an APRS GPS transmitter from Morgan Territory Regional Park, east of the San Francisco Bay Area. After ascending for an hour and 6 minutes, the balloon burst at 83,772 feet, nearly 16 miles above the Central Valley. With a malfunctioning tracking system, we were afraid the equipment was lost, but after falling for 27 minutes, a 6-year-old girl in Turlock, California saw it parachute to the ground in front of her house. The family called us, and before noon we were able to pick up Ikaros II 57 miles ESE of the launch site.

Ikaros II flight path

Photos via flickr:

Flight Info

Launch Date
April 15, 2011 8:01am PDT
Flight Duration
1 hour 33 mintues
Ascent Time
66 minutes
Descent Time
27 minutes
Distance Traveled
92 km (57 miles)
Initial Ascent Rate
4.8 m/s (950 ft/min)
Final Ascent Rate
6.6 m/s (1300 ft/min)
Maximum Descent Rate
39 m/s (88 mph)
Impact Speed
7.6 m/s (17 mph)
Maximum Altitude
25,534 m (83,772 ft)
Lowest Temperature
< -60° (-76°F)
Lowest Pressure
2.3 KPa (.02 atmospheres)

Please read the press release for an overview of the project. Additional details are included below.

Project Details

Ikaros 2 Payload Arrangement

Balloon and inflation

We bought a 1300 gram balloon from Army surplus, filled it with enough helium to lift 60 Newtons. We cut off the skirt because it was unnecessary weight. We bought a regulator to use to measure the amount of helium we put in the balloon. However, the regulator limited the flow too much, so we didn’t use them. Instead we used party balloon filling regulators which release helium when bent.

We used two helium tanks which combined into one tube with a barbed plastic T. This allowed us to fill the balloon quicker.

We used a spring powered force meter to measure the number of Newtons the balloon was applying to the payload. The load was out of the spring scale's range, so we estimated lift with various heavy objects in a milk crate--something to plan better next year, along with remembering a wrench for the regulators. We used a spreadsheet designed by Dr. Piccioni and last year's students to find the number of Newtons our balloon needed to lift. It took about 20 minutes to fill because we used the dual tank system with a better piping system than the year before when it took over an hour.
Balloon inflation
Balloon burst
Balloon inflation apparatus


Apparatus to deploy parachute and retract balloon after balloon burst
Parachute deployment and balloon retraction mechanism
Parachute deploying

Data collection

We used a Vernier LabQuest with gas pressure and internal and external temperature sensors. The balloon cam was mounted to this, the top package. This was the only 808 camera with additional batteries (3 AA lithium) allowing it to record till the memory card was full after balloon burst and parachute deployment. Data module
Data collection components
Chart of Data


We used a Go Pro HD ($300) and a Flip mino ($60 discontinued.) We then put them in a 4x4x6-inch box surrounded by custom-cut Styrofoam. We also attached three 808#3 keychain cameras ($15 each) to the outside of the boxes in their own styrofoam/metal-tape enclosures.Video module
Video components


The tracking system consisted of a GPS connected to an amateur radio frequency APRS transmitter with a quarter-wave ground plane antenna.

Tracking module
Inside tracking box
Tracking components
Ground-plane antenna core

Launch Site

Morgan Territory Regional Preserve Staging Area, southeast of Mt. Diablo

KGO channel 7 coverage.

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