Embedded Files
Zephyrus Iota
Zephyrus Iota
Zephyrus Iota was launched on October 4, 2025, and consisted of two balloons, alpha and bravo. This mission was our second attempt at our previous mission (Zephyrus Theta), which aimed to simultaneously launch two balloons from the same location, at the same time, with identical payloads in order to observe variations between them and see how accurate our flight predictions were.
Preparations
Preparations
The tables on the left show the payload for Zephyrus Iota. In all, the balloons consisted of valves, parachutes, spot traces, LightAPRSs, Cosmic Watches, and airTags. The payload mass of Balloons Alpha and Bravo is 854 grams and 853 grams, respectively. Path predictions as well as burst calculations were also conducted in advance in order to prepare for Zephyrus Iota's retrieval and to give a rough estimate of the neck lift, which was adjusted later.
Burst calculation and path predictions for both balloons since they theoretically should have been on a similar path.
Launch Information
Launch Information
The two balloons for Zephyrus Iota were launched at approximately 10:32 am EST (16:32 pm UTC). Alpha took close to 19 minutes to fill up the balloon, while Bravo took close to 13 minutes to fill up. Balloon Alpha had a payload weight of around 854 g with a neck lift of 22.6 N, while Balloon Bravo had an approximate payload weight of 853 g and a neck lift of around 24.7 N.
IMG_8584.MOVFlight Information
Flight Information
The estimated total flight duration for Balloon Alpha of Zephyrus Iota was 1 hour and 35 min with an estimated maximum altitude of 104,008 feet (31,702 meters). Balloon Bravo had an estimated flight duration of 1 hour and 43 min with an estimated maximum altitude of 107,950 feet (32,903 meters). Balloon Alpha landed at approximately 12:07 EST (16:07 UTC) while Balloon Bravo landed at around 12:15 pm EST (16:15 UTC).
The paths taken by the balloons were fairly similar to each other, with the landing places of the balloons being 3.45 miles apart, which is within the 10 nautical miles expected error range. This distance, however, suggests that there is a lot more room to improve and, although it can be explained by the difference in payload mass and necklift, indicates there may be something else affecting the flights differently.
Page updated
Report abuse