Changes

==Aims==

==Aims==

Balloons platforms exhibit a very wide range of operating altitudes, making them uniquely well suited to study the [https://en.wikipedia.org/wiki/Tropical_cyclone#Physics_and_energetics primary circulation and energetics] of tropical systems. Understanding such aspects of tropical cyclones is key to improving forecast models of cyclone intensity, whose reliability has lagged significantly behind that of storm track forecasts. [https://en.wikipedia.org/wiki/Hurricane_Michael Hurricane Michael] is a prime example of a storm where poor intensity forecasts resulted in substantial loss of life and property and was a key inspiration for the project. Additionally, balloons platforms can be deployed at significantly lower cost than planes and buoys, and are therefore significantly more scalable.

Balloons platforms exhibit a very wide range of operating altitudes, making them uniquely well suited to study the [https://en.wikipedia.org/wiki/Tropical_cyclone#Physics_and_energetics secondary circulation and energetics] of tropical systems. Understanding such aspects of tropical cyclones is key to improving forecast models of cyclone intensity, whose reliability has lagged significantly behind that of storm track forecasts. [https://en.wikipedia.org/wiki/Hurricane_Michael Hurricane Michael] is a prime example of a storm where poor intensity forecasts resulted in substantial loss of life and property and was a key inspiration for the project. Additionally, balloons platforms can be deployed at significantly lower cost than planes and buoys, and are therefore significantly more scalable.

Key projects being undertaken within Cycloon (and their respective Slack channels) include:

Key projects being undertaken within Cycloon (and their respective Slack channels) include:

*'''Altitude control:''' Cycloon aims to master and extend the legacy of altitude control on latex balloons pioneered by previous SSI projects. This entails both mechanical and algorithmic aspects.

*'''Altitude control:''' Cycloon aims to master and extend the legacy of altitude control on latex balloons pioneered by previous SSI projects. This entails both mechanical and algorithmic aspects. Design and production of the primary vent and ballast mechanisms is undertaken in {{slack-channel|balloons-cy-platform}}.

*'''Marine tether:''' In order to extend the flight endurance beyond the inherent limitations of latex, Cycloon is developing an tether and floater to rest on the surface of the ocean for days at a time. This architecture was successfully demonstrated in [[SSI-83|CY-1]].

*'''Marine tether:''' In order to extend the flight endurance beyond the inherent limitations of latex, Cycloon is developing an tether and floater to rest on the surface of the ocean for days at a time. This architecture was successfully demonstrated in [[SSI-83|CY-1]].

*'''Simulations:''' The need to predict trajectories from California to the Pacific and Atlantic topical basins using the GEFS forecast ensemble has given rise to [[HABSIM]] and its associated work. See also {{slack-channel|balloons-cy-sims}}.

*'''Simulations:''' The need to predict trajectories from California to the Pacific and Atlantic topical basins using the GEFS forecast ensemble has given rise to [[HABSIM]] and its associated work. See also {{slack-channel|balloons-cy-sims}}.

*'''Payload:''' Ultimately, the purpose of the balloon platform will be to carry low-cost, lightweight radiosondes. See {{slack-channel|balloons-cy-payload}}.

*'''Payload:''' Ultimately, the purpose of the balloon platform will be to carry low-cost, lightweight radiosondes. See {{slack-channel|balloons-cy-dropsonde}}.

*'''Communications:''' To augment data uplink rates, Cycloon is developing a skywave communications system and protocol in {{slack-channel|balloons-cy-comms}}.

*'''Communications:''' To augment data uplink rates, Cycloon is developing a skywave communications system and protocol in {{slack-channel|balloons-cy-comms}}.

*'''Avionics:''' Core avionics work involving circuit board design and flight code is undertaken in {{slack-channel|balloons-cy-avionics}}.

*'''Avionics:''' Core avionics work involving circuit board design and flight code is undertaken in {{slack-channel|balloons-cy-avionics}}.

*'''ZPB:''' Polyethylene envelopes have intrinsically more desirable properties compared to latex envelopes. In-house manufacture of such envelopes is being explored in {{slack-channel|balloons-cy-zpb}} and was first demonstrated in [[SSI-90|CY-4]].

*'''ZPB:''' Polyethylene envelopes have intrinsically more desirable properties compared to latex envelopes. In-house manufacture of such envelopes is being explored in {{slack-channel|balloons-cy-zpb}} and was first demonstrated in [[SSI-90|CY-4]].

==Missions==

==Missions==

| April 17, 2019

| April 17, 2019

| Pigeon Point

| Pigeon Point

| 60.5 hours

| 60 hours, 33 minutes

| Demonstration of long-endurance marine tether. Float-only profile. Lost off the coast of San Luis Obispo county.

| Demonstration of long-endurance marine tether. Float-only profile. Lost off the coast of San Luis Obispo county.

|-

|-

| June 1, 2019

| June 1, 2019

| Le Grand

| Le Grand

|  

| 3 hours, 52 minutes

| Latex full altitude control. Recovered from near Firebaugh, California.

| Latex full altitude control. Recovered from near Mendota, California on June 1, 2019.

|-

|-

|4

|4

| August 5, 2019

| August 5, 2019

| Hollister

| Hollister

| 2 hours

| 2 hours, 0 minutes

| Second flight of in-house constructed polyethylene envelope. Final location near Tracy, CA; recovery pending.

| Second flight of in-house constructed polyethylene envelope. Recovered from near Tracy, CA on August 31, 2019.

| First polyethylene tubing envelope. First SSI ZPB flight with full telemetry. First interstate Cycloon flight. Final location near Alamo, NV.

| First ballast-controlled ZPB. Eventful launch and post-landing. Final location near Tulare, CA.

| Extensive ZPB ground tests.

|}

|}

[[Category: High Altitude Balloons]]

[[Category: High Altitude Balloons]]