Changes

}}

}}

'''SSI-86''' (project designation '''CY-2'''; also called ''BalBal'') was the second launch of [[Cycloon|Project Cycloon]] on May 18, 2019. It featured a legacy ballast mechanism from ValBal operated by Cycloon avionics and thus marked the beginning of ''#cy-flops'', or ''Cycloon flight operations''. The mission was noted for its low-altitude profile, interaction with inclement weather, pentagram traced out by RockBlock coordinates, and most remarkably, resumption of flight a full 24 hours after presumed flight termination, the only such occurrence in SSI history.

'''SSI-86''' (project designation '''CY-2'''; also called ''BalBal'') was the second launch of [[Cycloon|Project Cycloon]] on May 18, 2019. It featured a legacy ballast mechanism from ValBal operated by Cycloon avionics and thus marked the beginning of {{slack-channel|cy-flops}}, or ''Cycloon flight operations''. The mission was noted for its low-altitude profile, interaction with inclement weather, pentagram traced out by RockBlock coordinates, and most remarkably, resumption of flight a full 24 hours after presumed flight termination, the only such occurrence in SSI history.

==Project context==

==Project context==

After the lessons learned of [[SSI-83|CY-1]], a plan for the remainder of the year was decided upon on April 21. First, due to the avionics issues of CY-1, it was envisioned that a marine tether profile launch would be reattempted in early May. Because it was decided that a grounded tether would be a more suitable means of testing endurance, the requirement on launch windows became much less stringent. Then, on May 11, there was to be a HF communications test module as a payload on a ValBal. Finally, on June 4 there would be a fully altitude-controlled flight using the ValBal ballast mechanism, Apex Vent, and Cycloon avionics.

After the lessons learned of [[SSI-83|CY-1]], a plan for the remainder of the year was decided upon on April 21. First, due to the avionics issues of CY-1, it was envisioned that a marine tether profile launch would be reattempted in early May. Because it was decided that a grounded tether would be a more suitable means of testing endurance, the requirement on launch windows became much less stringent. Then, on May 11, there was to be a HF communications test module as a payload on a ValBal. Finally, on June 1 there would be a fully altitude-controlled flight using the ValBal ballast mechanism, Apex Vent, and Cycloon avionics.

Data from CY-1 had demonstrated that the floating coefficient of the system was very low and therefore the aerodynamic drag on the balloon very large; it was suspected that high aerodynamic forces during  winds led to the termination of that mission. Therefore, the first priority was to design a more effective and hydrodynamic floater. This was done by April 25. On April 28, however, the would-be second launch was cancelled due the ValBal controversy, and the would-be first launch was delayed to mid-May. Furthermore, due to continued delays in the HF transceiver parts supply chain and the overall lack of urgency, the communications test was delayed indefinitely. The mid-May launch would instead aim to test the full extent of the system in the absence of a venting mechanism --- that is, marine tether and ballast mechanism --- by starting as a marine tether, dropping ballast, popping, and landing on land, a so-called float-drop-pop profile.

Data from CY-1 had demonstrated that the floating coefficient of the system was very low and therefore the aerodynamic drag on the balloon very large; it was suspected that high aerodynamic forces during  winds led to the termination of that mission. Therefore, the first priority was to design a more effective and hydrodynamic floater. This was done by April 25. On April 28, however, the would-be second launch was cancelled due the ValBal controversy, and the would-be first launch was delayed to mid-May. Furthermore, due to continued delays in the HF transceiver parts supply chain and the overall lack of urgency, the communications test was delayed indefinitely. The mid-May launch would instead aim to test the full extent of the system in the absence of a venting mechanism --- that is, marine tether and ballast mechanism --- by starting as a marine tether, dropping ballast, popping, and landing on land, a so-called float-drop-pop profile.