SSI-87 - Revision history

Bjing at 10:11, 21 October 2019

2019-10-21T10:11:53Z

← Older revision		Revision as of 10:11, 21 October 2019
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	Before and around the time of the previous flight, CY-2, a reevaluation of project goals for the quarter had been underway. While a full apex vent equipped flight had originally been envisioned for the weekend of '''June 2''', delays on the project prompted a decision to focus more on quick iterations and numerous launches rather than awaiting longer term initiatives. In particular, it was decided that a legacy ValBal vent mechanism, while unlikely to suffice as a long-term solution, was sufficient and necessary for building altitude control expertise within Cycloon in the short term. Therefore, on '''May 19''', the day after CY-2, it was decided that two payloads would be launched on '''June 1''', alongside Spaceshot and onboarding, each with ballast, vent, and (winds permitting) tether and floater mechanism.		Before and around the time of the previous flight, CY-2, a reevaluation of project goals for the quarter had been underway. While a full apex vent equipped flight had originally been envisioned for the weekend of '''June 2''', delays on the project prompted a decision to focus more on quick iterations and numerous launches rather than awaiting longer term initiatives. In particular, it was decided that a legacy ValBal vent mechanism, while unlikely to suffice as a long-term solution, was sufficient and necessary for building altitude control expertise within Cycloon in the short term. Therefore, on '''May 19''', the day after CY-2, it was decided that two payloads would be launched on '''June 1''', alongside Spaceshot and onboarding, each with ballast, vent, and (winds permitting) tether and floater mechanism.

	The bulk of the avionics work for the two payloads was completed on May 27, followed by demonstration of vent control on May 29. As winds forecasts for favorable for a float-drop profile, a floater was confirmed for the final configuration. The bulk of the mechanics work occurred on May 29, though due to a lack of spare mechanics the second payload was cancelled. Finally, substantial system integration occurred on May 31.		The bulk of the avionics work for the two payloads was completed on May 27, followed by demonstration of vent control on May 29. As winds forecasts for favorable for a float-drop profile, a floater was confirmed for the final configuration. The bulk of the mechanics work occurred on May 29, though due to a lack of spare mechanics the second payload was cancelled. Finally, substantial system integration occurred on May 31. It was hoped that the flight would land safely in the Pacific, enabling controlled daytime hops throughout the following week.

	==Configuration==		==Configuration==
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	==Flight synopsis==		==Flight synopsis==

	[[File:~~Ssi86profile.png\|frameless\|800px\|center]][[File:Ssi86traj~~.png\|400px\|thumb\|~~Mission trajectory~~]]		[[File:Ssi87pred.png\|400px\|thumb\|Predicted flight trajectories before launch]]


	'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.		'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.
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	'''June 1, 2019, 1435 PDT:''' GPS began reporting coordinates of landing site. It remains unknown why this reset occurred. A recovery team was dispatched to the landing site.		'''June 1, 2019, 1435 PDT:''' GPS began reporting coordinates of landing site. It remains unknown why this reset occurred. A recovery team was dispatched to the landing site.
			[[File:Ssi87profile.png\|thumb\|center\|600px\|Flight profile from launch to loss of telemetry]]
			[[File:Ssi87Rates.png\|thumb\|center\|600px\|Ascent rate profile from launch to loss of telemetry]]

	{{balloon-footer}}		{{balloon-footer}}

	[[Category: High Altitude Balloons]][[Category: Balloon Launches]]		[[Category: High Altitude Balloons]][[Category: Balloon Launches]]

Bjing at 10:07, 21 October 2019

2019-10-21T10:07:06Z

← Older revision		Revision as of 10:07, 21 October 2019
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	==Flight synopsis==		==Flight synopsis==

			[[File:Ssi86profile.png\|frameless\|800px\|center]][[File:Ssi86traj.png\|400px\|thumb\|Mission trajectory]]

	'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.		'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.

Bjing at 09:10, 21 October 2019

2019-10-21T09:10:16Z

← Older revision		Revision as of 09:10, 21 October 2019
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	'''SSI-87''' (project designation '''CY-3''') was the third launch of [[Cycloon\|Project Cycloon]] on June 1, 2019. It featured a legacy ballast and vent mechanism from ValBal operated by Cycloon avionics and was the first such fully controlled Cycloon flight. The mission was noted for its eventful manual equilibration, early termination, and for being the last latex Cycloon before the project transitioned to polyethylene. The payload was recovered the afternoon of the launch.		'''SSI-87''' (project designation '''CY-3''') was the third launch of [[Cycloon\|Project Cycloon]] on June 1, 2019. It featured a legacy ballast and vent mechanism from ValBal operated by Cycloon avionics and was the first such fully controlled Cycloon flight. The mission was noted for its eventful manual equilibration, early termination, and for being the last latex Cycloon before the project transitioned to polyethylene. The payload was recovered the afternoon of the launch.

	The bulk of the avionics work for the two payloads was completed on May 27, followed by demonstration of vent control on May 29. As winds forecasts for favorable for a float-drop profile, a floater was confirmed for the final configuration. The bulk of the mechanics work occurred on May 29, though due to a lack of spare mechanics the second payload was cancelled. Finally, substantial system integration occurred on May 31.

	==Project context==		==Project context==
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	Before and around the time of the previous flight, CY-2, a reevaluation of project goals for the quarter had been underway. While a full apex vent equipped flight had originally been envisioned for the weekend of '''June 2''', delays on the project prompted a decision to focus more on quick iterations and numerous launches rather than awaiting longer term initiatives. In particular, it was decided that a legacy ValBal vent mechanism, while unlikely to suffice as a long-term solution, was sufficient and necessary for building altitude control expertise within Cycloon in the short term. Therefore, on '''May 19''', the day after CY-2, it was decided that two payloads would be launched on '''June 1''', alongside Spaceshot and onboarding, each with ballast, vent, and (winds permitting) tether and floater mechanism.		Before and around the time of the previous flight, CY-2, a reevaluation of project goals for the quarter had been underway. While a full apex vent equipped flight had originally been envisioned for the weekend of '''June 2''', delays on the project prompted a decision to focus more on quick iterations and numerous launches rather than awaiting longer term initiatives. In particular, it was decided that a legacy ValBal vent mechanism, while unlikely to suffice as a long-term solution, was sufficient and necessary for building altitude control expertise within Cycloon in the short term. Therefore, on '''May 19''', the day after CY-2, it was decided that two payloads would be launched on '''June 1''', alongside Spaceshot and onboarding, each with ballast, vent, and (winds permitting) tether and floater mechanism.

	The bulk of the avionics work for the two payloads ~~occurred~~ on May 27, ~~and first~~ demonstration of vent ~~motor~~ control ~~was achieved~~ on May 29. The bulk of the mechanics work occurred ~~that same day~~, ~~although~~ due to a lack of spare mechanics the second payload was cancelled. ~~Due to favorable wind forecasts~~, ~~a floater was confirmed. Substantial mechanical~~ integration ~~was finalized~~ on May 31~~, the day before the launch~~.		The bulk of the avionics work for the two payloads was completed on May 27, followed by demonstration of vent control on May 29. As winds forecasts for favorable for a float-drop profile, a floater was confirmed for the final configuration. The bulk of the mechanics work occurred on May 29, though due to a lack of spare mechanics the second payload was cancelled. Finally, substantial system integration occurred on May 31.

	==Configuration==		==Configuration==

Bjing at 09:09, 21 October 2019

2019-10-21T09:09:51Z

← Older revision		Revision as of 09:09, 21 October 2019
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	\| launch coordinates = 37.226, -120.251		\| launch coordinates = 37.226, -120.251
	\| flight duration = 3h:52m		\| flight duration = 3h:52m
	\| flight length =		\| flight length = unknown
	\| flight profile = Ballast and vent control		\| flight profile = Ballast and vent control
	\| landing time =June 1, 2019, 14:27 ODT		\| landing time =June 1, 2019, 14:27 ODT

Bjing at 09:09, 21 October 2019

2019-10-21T09:09:14Z

← Older revision		Revision as of 09:09, 21 October 2019
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	\| launch site = Le Grand Elementary School, Le Grand, CA		\| launch site = Le Grand Elementary School, Le Grand, CA
	\| launch coordinates = 37.226, -120.251		\| launch coordinates = 37.226, -120.251
	\| flight duration =		\| flight duration = 3h:52m
	\| flight length =		\| flight length =
	\| flight profile = Ballast and vent control		\| flight profile = Ballast and vent control
	\| landing time =		\| landing time =June 1, 2019, 14:27 ODT
	\| landing site=		\| landing site= 13 km SW of Mendota, Fresno County, CA
	\| landing coordinates =		\| landing coordinates = 36.692, -120.518
	\| last = 86		\| last = 86
	\| next = 90		\| next = 90
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	'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent, as the balloon was nearing the danger zone. Following this, a slight descent was observed after a peak altitude of 22.100 km, and equilibration was declared.		'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent, as the balloon was nearing the danger zone. Following this, a slight descent was observed after a peak altitude of 22.100 km, and equilibration was declared.

	'''June 1, 2019, 1409 PDT:''' It was noticed that the GPS coordinates and altitude had frozen at the launch site. The cause for this remains unknown, and hence no detailed trajectory of this flight is available. ~~Simulatenously~~, the barometer began reporting a negative altitude. This is when the balloon probably popped, after spending only three communication intervals between 22.0 and 22.1 km.		'''June 1, 2019, 1409 PDT:''' It was noticed that the GPS coordinates and altitude had frozen at the launch site. The cause for this remains unknown, and hence no detailed trajectory of this flight is available. Simultaneously, the barometer began reporting a negative altitude. This is when the balloon probably popped, after spending only three communication intervals between 22.0 and 22.1 km.

	'''June 1, 2019, 1427 PDT:''' Iridium triangulation began reporting consistent coordinates. It is believed that this was payload impact.		'''June 1, 2019, 1427 PDT:''' Iridium triangulation began reporting consistent coordinates. It is believed that this was payload impact.

Bjing at 09:06, 21 October 2019

2019-10-21T09:06:29Z

Bjing at 09:02, 21 October 2019

2019-10-21T09:02:55Z

← Older revision		Revision as of 09:02, 21 October 2019
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	\| landing site=		\| landing site=
	\| landing coordinates =		\| landing coordinates =
	\| last = 87		\| last = 86
	\| next = 90		\| next = 90
	}}		}}
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	'''June 1, 2019, 1341 PDT:''' 80 seconds of vent were sent, successfully slowing ascent to around 0.8 m/s.		'''June 1, 2019, 1341 PDT:''' 80 seconds of vent were sent, successfully slowing ascent to around 0.8 m/s.

	'''June 1, 2019, 1347 PDT:''' 80 more seconds were sent.		'''June 1, 2019, 1347 PDT:''' 80 more seconds were sent with the intention of stopping ascent entirely.

	'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent. Following this, a slight descent was observed after a peak altitude of ___, and equilibration was declared.		'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent, as the balloon was nearing the danger zone. Following this, a slight descent was observed after a peak altitude of ___, and equilibration was declared.

			'''June 1, 2019, 1409 PDT:''' It was noticed that the GPS coordinates and altitude had frozen at the launch site. The cause for this remains unknown, and hence no detailed trajectory of this flight is available. Simulatenously, the barometer began reporting a negative altitude. This is when the balloon probably popped.

			'''June 1, 2019, 1427 PDT:''' Iridium triangulation began reporting consistent coordinates. It is believed that this was payload impact.

			'''June 1, 2019, 1435 PDT:''' GPS began reporting coordinates of landing site. It remains unknown why this reset occurred. A recovery team was dispatched to the landing site.

Bjing at 08:55, 21 October 2019

2019-10-21T08:55:55Z

@@ Line 3: / Line 3: @@
 | img link =
 | designations = '''CY-3'''
-| launch date =June 1, 2019, 10:20 PDT
+| launch date =June 1, 2019, 10:35 PDT
 | launch site = Le Grand Elementary School, Le Grand, CA
 | launch coordinates = 37.226, -120.251
@@ Line 43: / Line 43: @@
 ==Flight synopsis==

Bjing at 08:43, 21 October 2019

2019-10-21T08:43:36Z

← Older revision		Revision as of 08:43, 21 October 2019
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	'''Tether and floater:''' 30m paracord tether from balloon to payload and 30m paracord tether from balloon to floater. Total tether mass: 0.34kg. Hydrodynamic floater of mass 0.785 kg.		'''Tether and floater:''' 30m paracord tether from balloon to payload and 30m paracord tether from balloon to floater. Total tether mass: 0.34kg. Hydrodynamic floater of mass 0.785 kg.

	'''Avionics:''' BMP280, TinyGPS, Teensy 3.2 reporting all data at ~~regular, fixed~~ intervals via RockBlock modem~~. 2 solar-charged LED modules~~. Ballast motor controlled by N-type MOSFET.		'''Avionics:''' BMP280, TinyGPS, Teensy 3.2 reporting all data at modifiable intervals via RockBlock modem. Ballast motor controlled by N-type MOSFET. Vent motor controlled by breakout motor driver.

	'''Power:''' 18 L91 lithium AA batteries~~. In comparison with the standard ValBal complement of 12 L92 batteries, this was thought to be more than sufficient under the most optimistic conditions~~.		'''Power:''' 18 L91 lithium AA batteries.

	'''Mass budget:''' 3.42 kg. ~~Counterweight was designed~~ to ~~balance 3~~.1 kg of ~~total~~ lift~~, after which ballast would be removed. In actuality, target fill resulted in nearly perfect buoyancy and no significant ballast was removed~~.		'''Mass budget:''' Total mass under balloon 3.695 kg. Total mass 5.195 kg. Target fill to 1.4 kg of tension at top of tether, translating to 275 kg free lift.

	==Flight synopsis==		==Flight synopsis==

Bjing at 08:42, 21 October 2019

2019-10-21T08:42:00Z

← Older revision		Revision as of 08:42, 21 October 2019
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	==Configuration==		==Configuration==

			'''Balloon:''' Kaymont 1500g latex.

			'''Mechanics:''' ValBal-style cylindrical polycarbonate sheeting, ValBal ballast and vent mechanism. Parachute in parachute tube. Total payload mass (without ballast, tether or floater) 1.07 kg.

			'''Ballast:''' 1.5 kg.

			'''Tether and floater:''' 30m paracord tether from balloon to payload and 30m paracord tether from balloon to floater. Total tether mass: 0.34kg. Hydrodynamic floater of mass 0.785 kg.

			'''Avionics:''' BMP280, TinyGPS, Teensy 3.2 reporting all data at regular, fixed intervals via RockBlock modem. 2 solar-charged LED modules. Ballast motor controlled by N-type MOSFET.

			'''Power:''' 18 L91 lithium AA batteries. In comparison with the standard ValBal complement of 12 L92 batteries, this was thought to be more than sufficient under the most optimistic conditions.

			'''Mass budget:''' 3.42 kg. Counterweight was designed to balance 3.1 kg of total lift, after which ballast would be removed. In actuality, target fill resulted in nearly perfect buoyancy and no significant ballast was removed.

	==Flight synopsis==		==Flight synopsis==

← Older revision		Revision as of 09:06, 21 October 2019
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	'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.		'''June 1, 2019, 1035 PDT:''' Launch. A fitting between the neck of the balloon and the vent had to be improvised on site. The target ascent rate was 1.7 - 2 m/s, and the flight plan was to equilibrate at 19-22km, with the first vents occurring at 14km.

	'''June 1, 2019, 1109 PDT:''' Due to slow ascent of 1.4 - 1.8 m/s, a first ballast command of five seconds was sent.		'''June 1, 2019, 1109 PDT:''' Due to slow ascent of 1.4 - 1.8 m/s, a first ballast command of five seconds was sent. Balloon altitude was around 3.6 km.

	'''June 1, 2019, 1143 PDT:''' Further 5 seconds of ballast were sent, titrating successfully at 1.7 - 2.2 m/s.		'''June 1, 2019, 1143 PDT:''' Further 5 seconds of ballast were sent, titrating successfully at 1.7 - 2.2 m/s at around 7 km in altitude.

	'''June 1, 2019, 1236 PDT:''' First vent command of 5 seconds at an altitude of 14 km.		'''June 1, 2019, 1236 PDT:''' First vent command of 5 seconds at an altitude of 13.9 km.

	'''June 1, 2019, 1259 PDT:''' A communications gap was noted due to issues with HABMC. For the remainder of the flight, monitoring was performed through the RockBlock website.		'''June 1, 2019, 1259 PDT:''' A communications gap was noted due to issues with HABMC. For the remainder of the flight, monitoring was performed through the RockBlock website.
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	'''June 1, 2019, 1309 PDT:''' In response to consistent ascent, a total of 25 seconds of vent were sent at an altitude of 17.8 km.		'''June 1, 2019, 1309 PDT:''' In response to consistent ascent, a total of 25 seconds of vent were sent at an altitude of 17.8 km.

	'''June 1, 2019, 1324 PDT:''' With ascent still maintaining around 2 m/s, a total of 64 seconds of vent was sent.		'''June 1, 2019, 1324 PDT:''' With ascent still maintaining around 2 m/s at nearly 20km, a total of 64 seconds of vent was sent.

	'''June 1, 2019, 1334 PDT:''' With ascent only barely below 2 m/s and altitude ~~exceeding 20~~ km, 96 seconds of vent were sent.		'''June 1, 2019, 1334 PDT:''' With ascent only barely below 2 m/s and altitude nearing 21 km, 96 seconds of vent were sent.

	'''June 1, 2019, 1341 PDT:''' 80 seconds of vent were sent, successfully slowing ascent to around 0.8 m/s.		'''June 1, 2019, 1341 PDT:''' 80 seconds of vent were sent, successfully slowing ascent to around 0.8 m/s at around 21.5 km.

	'''June 1, 2019, 1347 PDT:''' 80 more seconds were sent with the intention of stopping ascent entirely.		'''June 1, 2019, 1347 PDT:''' 80 more seconds were sent with the intention of stopping ascent entirely. Altitude approaching 22 km.

	'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent, as the balloon was nearing the danger zone. Following this, a slight descent was observed after a peak altitude of ~~___~~, and equilibration was declared.		'''June 1, 2019, 1355 PDT:''' To play it safe, yet 96 more seconds were sent, as the balloon was nearing the danger zone. Following this, a slight descent was observed after a peak altitude of 22.100 km, and equilibration was declared.

	'''June 1, 2019, 1409 PDT:''' It was noticed that the GPS coordinates and altitude had frozen at the launch site. The cause for this remains unknown, and hence no detailed trajectory of this flight is available. Simulatenously, the barometer began reporting a negative altitude. This is when the balloon probably popped.		'''June 1, 2019, 1409 PDT:''' It was noticed that the GPS coordinates and altitude had frozen at the launch site. The cause for this remains unknown, and hence no detailed trajectory of this flight is available. Simulatenously, the barometer began reporting a negative altitude. This is when the balloon probably popped, after spending only three communication intervals between 22.0 and 22.1 km.

	'''June 1, 2019, 1427 PDT:''' Iridium triangulation began reporting consistent coordinates. It is believed that this was payload impact.		'''June 1, 2019, 1427 PDT:''' Iridium triangulation began reporting consistent coordinates. It is believed that this was payload impact.