Stanford SSI Wiki - User contributions [en]

MediaWiki:Sidebar

2015-10-18T06:05:57Z

Stanfordssi:

MediaWiki:Sidebar

2015-10-18T06:05:16Z

SSI-20

2015-10-18T05:20:48Z

Stanfordssi:

SSI-19

2015-10-18T05:01:48Z

Stanfordssi:

File:Ssi19rec.jpg

2015-10-18T05:00:59Z

Stanfordssi:

SSI-19

2015-10-18T01:39:10Z

Stanfordssi:

SSI-19

2015-10-18T01:33:23Z

2015-10-18T01:29:01Z

Stanfordssi:

SSI-19

2015-10-18T01:28:07Z

Stanfordssi:

{{balloon-launch
| header = SSI-19
| img link = File:rsz_11ssi_19.png
| launch date = May 16th 2015, 6:32 PM PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 15 hrs, 11 minutes
| landing date = May 16th 2015, 9:39 AM PDT
| landing coordinates = 37°50.87' N 119°5.28' W
| last = 18
| next = 20
}}

SSI-19 was the 19th launch of SSI Balloons. SSI-19 flew for just over 15 hours and to an altitude of 119,932 ft - breaking SSI's altitude record. The launch was a demonstration of the physical feedback found at high altitude with a precision filled latex balloon. The payload maintained an altitude of approximately 118,000 feet merely by passive feedback and no active control - it was degraded by UV radiation and descended shortly after sunrise. SSI-19 landed in Yosemite just east of Grant Lake after a flight of 15 hours.

== Flight Profile ==

SSI-19 was based on a flight method that was first successfully flown by the California Near Space Project (CNSP). The principle of the launch is inflating a large latex balloon (In the case of SSI-19, a 1600g) to a very low lift capacity (365g payload, ~140g free lift) to launch a very light payload. By barely filling the balloon and providing a very light payload, the balloon is able to ascend to a very high altitude (110,000-120,000 ft) where there is a positive feedback loop, allowing the balloon to equilibrate due to natural phenomena (no active control mechanism).

== Payload Specifications ==

[[File:ssi191.jpg | thumb | <center> SSI-19 Payload </center>]]

The SSI-19 payload was, as needed, a very barebones set of electronics. It included an APRS BigRedBee transmitter using the callsign of balloons team member Iskender Kushan (KK6MIR), a GPS for position reporting, a sizable lithium-ion battery, and a heater made of nickel-chromium (nichrome) wire. In total, the payload had a mass of about 365g. It was the first balloon to be launched during the launch of SSI-19, SSI-20, and SSI-21. CNSP graciously brought their mass-flow meter to fill the SSI-19 latex balloon to a precise lift capacity (a mission-critical aspect of this launch).

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, a site frequented by the balloons team. The team left campus at 10 am, arriving just after 11:30 am. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. The APRS transmitter was verified for flight-readiness by ensuring transmission on the ground, the payload was sealed, and just prior to launch, the heater was hard-wired to the battery pack (for constant heating).

Filling of the 1600g Hwoyee balloon began at around 5:30 pm. Filling was coordinated in conjunction with CNSP personnel, who used their mass-flow meter to fill the balloon with the appropriate volume of Helium as calculated and verified by SSI members. Filling was challenging due to higher than expected ground wind speeds. After filling, launching was additionally challenging due to powerful east-bound winds, which pushed the balloon nearly into the ground on multiple occasions. During a moment of south-bound winds, the balloon was released from the north end of Laird Park (in order to clear the southern tree line) and ascended at a nominal velocity.

[[File:ssi193.jpg | thumb | <center> Winds during Filling </center>]]

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

As expected, the balloon had a fairly slow ascent velocity due to its low free lift. It ascended at an average velocity of around 1.5 m/s, initially with a southbound heading until hitting north-bound winds 10 minutes into flight. Following ascent to approximately 10,000 feet at 7:07 PM PDT, SSI-19 had a East-Northeast heading for the majority of its flight. It reached critical altitude at around 8:00 AM PDT on May 17th, just south of Mono Lake in the Yosemite National Park. As the sun rose, the balloon began being degraded by UV radiation.

The balloon reached a peak altitude of 119,932 ft at 9:15 AM PDT, May 17th, breaking the former SSI altitude records for latex balloons. It burst shortly after this position report, indicating a descent of nearly 1,000 feet. Unequipped with a parachute, SSI-19 descended from altitude in a matter of approximately 30 minutes. It landed just east of Grant Lake, a few hundred feet off the California 395.

[[File:aprs.png|frameless|600px]]

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

{{balloon-footer}}
[[Category: High Altitude Balloons]][[Category: Balloon Launches]]

SSI-19

2015-10-18T01:17:38Z

Stanfordssi:

{{balloon-launch
| header = SSI-19
| img link = File:rsz_11ssi_19.png
| launch date = May 16th 2015, 6:32 PM PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 15 hrs, 11 minutes
| landing date = May 16th 2015, 9:39 AM PDT
| landing coordinates = 37°50.87' N 119°5.28' W
| last = 18
| next = 20
}}

SSI-19 was the 19th launch of SSI Balloons. SSI-19 flew for just over 15 hours and to an altitude of 119,932 ft - breaking SSI's altitude record. The launch was a demonstration of the physical feedback found at high altitude with a precision filled latex balloon. The payload maintained an altitude of approximately 118,000 feet merely by passive feedback and no active control - it was degraded by UV radiation and descended shortly after sunrise. SSI-19 landed in Yosemite just east of Grant Lake after a flight of 15 hours.

== Flight Profile ==

SSI-19 was based on a flight method that was first successfully flown by the California Near Space Project (CNSP). The principle of the launch is inflating a large latex balloon (In the case of SSI-19, a 1600g) to a very low lift capacity (365g payload, ~140g free lift) to launch a very light payload. By barely filling the balloon and providing a very light payload, the balloon is able to ascend to a very high altitude (110,000-120,000 ft) where there is a positive feedback loop, allowing the balloon to equilibrate due to natural phenomena (no active control mechanism).

== Payload Specifications ==

[[File:ssi191.jpg | thumb | <center> SSI-19 Payload </center>]]

The SSI-19 payload was, as needed, a very barebones set of electronics. It included an APRS BigRedBee transmitter using the callsign of balloons team member Iskender Kushan (KK6MIR), a GPS for position reporting, a sizable lithium-ion battery, and a heater made of nickel-chromium (nichrome) wire. In total, the payload had a mass of about 365g. It was the first balloon to be launched during the launch of SSI-19, SSI-20, and SSI-21. CNSP graciously brought their mass-flow meter to fill the SSI-19 latex balloon to a precise lift capacity (a mission-critical aspect of this launch).

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, a site frequented by the balloons team. The team left campus at 10 am, arriving just after 11:30 am. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. The APRS transmitter was verified for flight-readiness by ensuring transmission on the ground, the payload was sealed, and just prior to launch, the heater was hard-wired to the battery pack (for constant heating).

Filling of the 1600g Hwoyee balloon began at around 5:30 pm. Filling was coordinated in conjunction with CNSP personnel, who used their mass-flow meter to fill the balloon with the appropriate volume of Helium as calculated and verified by SSI members. Filling was challenging due to higher than expected ground wind speeds. After filling, launching was additionally challenging due to powerful east-bound winds, which pushed the balloon nearly into the ground on multiple occasions. During a moment of south-bound winds, the balloon was released from the north end of Laird Park (in order to clear the southern tree line) and ascended at a nominal velocity.

[[File:ssi193.jpg | thumb | <center> Winds during Filling </center>]]

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon proved to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km, as this range of altitudes was chosen to optimize the wind conditions the balloon would experience (fastest winds, most predictable, and most appropriate direction). After the balloon roughly levelled off, the team armed the ballast mechanism over satellite comms. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a subpar ~ 4km accuracy).

The payload flew at considerable speed, crossing into Nevada after two hours in the appropriate altitude range. The flight continued through Nevada northward, cutting through the southeastern corner of Oregon before entering Idaho around 2:20 am PDT. The payload spent considerable time in central Idaho, and transmitted data suggesting considerable venting and ballast dropping occurring in this area. Unbeknownst to the team until the balloon was out of Idaho airspace, the balloon flew through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to autonomously maintain its altitude within its defined range, at the cost of considerable gas and ballast.

After spending a few hours in the thunderstorm, the balloon entered Montana at around 8:00 am PDT, continuing on a north/northeast trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the North Dakota/Montana border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift as night was arriving and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

{{balloon-footer}}
[[Category: High Altitude Balloons]][[Category: Balloon Launches]]

SSI-19

2015-10-18T01:17:10Z

Stanfordssi:

{{balloon-launch
| header = SSI-19
| img link = File:rsz_11ssi_19.png
| launch date = May 16th 2015, 6:32 PM PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 15 hrs, 11 minutes
| landing date = May 16th 2015, 9:39 AM PDT
| landing coordinates = 37°50.87' N 119°5.28' W
| last = 18
| next = 20
}}

SSI-19 was the 19th launch of SSI Balloons. SSI-19 flew for just over 15 hours and to an altitude of 119,932 ft - breaking SSI's altitude record. The launch was a demonstration of the physical feedback found at high altitude with a precision filled latex balloon. The payload maintained an altitude of approximately 118,000 feet merely by passive feedback and no active control - it was degraded by UV radiation and descended shortly after sunrise. SSI-19 landed in Yosemite just east of Grant Lake after a flight of 15 hours.

== Flight Profile ==

SSI-19 was based on a flight method that was first successfully flown by the California Near Space Project (CNSP). The principle of the launch is inflating a large latex balloon (In the case of SSI-19, a 1600g) to a very low lift capacity (365g payload, ~140g free lift) to launch a very light payload. By barely filling the balloon and providing a very light payload, the balloon is able to ascend to a very high altitude (110,000-120,000 ft) where there is a positive feedback loop, allowing the balloon to equilibrate due to natural phenomena (no active control mechanism).

== Payload Specifications ==

[[File:ssi191.jpg | thumb | <center> SSI-19 Payload </center>]]

The SSI-19 payload was, as needed, a very barebones set of electronics. It included an APRS BigRedBee transmitter using the callsign of balloons team member Iskender Kushan (KK6MIR), a GPS for position reporting, a sizable lithium-ion battery, and a heater made of nickel-chromium (nichrome) wire. In total, the payload had a mass of about 365g. It was the first balloon to be launched during the launch of SSI-19, SSI-20, and SSI-21. CNSP graciously brought their mass-flow meter to fill the SSI-19 latex balloon to a precise lift capacity (a mission-critical aspect of this launch).

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, a site frequented by the balloons team. The team left campus at 10 am, arriving just after 11:30 am. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. The APRS transmitter was verified for flight-readiness by ensuring transmission on the ground, the payload was sealed, and just prior to launch, the heater was hard-wired to the battery pack (for constant heating).

Filling of the 1600g Hwoyee balloon began at around 5:30 pm. Filling was coordinated in conjunction with CNSP personnel, who used their mass-flow meter to fill the balloon with the appropriate volume of Helium as calculated and verified by SSI members. Filling was challenging due to higher than expected ground wind speeds. After filling, launching was additionally challenging due to powerful east-bound winds, which pushed the balloon nearly into the ground on multiple occasions. During a moment of south-bound winds, the balloon was released from the north end of Laird Park (in order to clear the southern tree line) and ascended at a nominal velocity.

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon proved to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km, as this range of altitudes was chosen to optimize the wind conditions the balloon would experience (fastest winds, most predictable, and most appropriate direction). After the balloon roughly levelled off, the team armed the ballast mechanism over satellite comms. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a subpar ~ 4km accuracy).

The payload flew at considerable speed, crossing into Nevada after two hours in the appropriate altitude range. The flight continued through Nevada northward, cutting through the southeastern corner of Oregon before entering Idaho around 2:20 am PDT. The payload spent considerable time in central Idaho, and transmitted data suggesting considerable venting and ballast dropping occurring in this area. Unbeknownst to the team until the balloon was out of Idaho airspace, the balloon flew through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to autonomously maintain its altitude within its defined range, at the cost of considerable gas and ballast.

After spending a few hours in the thunderstorm, the balloon entered Montana at around 8:00 am PDT, continuing on a north/northeast trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the North Dakota/Montana border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift as night was arriving and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

{{balloon-footer}}
[[Category: High Altitude Balloons]][[Category: Balloon Launches]]

File:Ssi193.jpg

2015-10-18T01:16:20Z

Stanfordssi:

File:Ssi191.jpg

2015-10-18T01:16:07Z

Stanfordssi:

SSI-19

2015-10-18T01:14:29Z

Stanfordssi:

{{balloon-launch
| header = SSI-19
| img link = File:rsz_11ssi_19.png
| launch date = May 16th 2015, 6:32 PM PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 15 hrs, 11 minutes
| landing date = May 16th 2015, 9:39 AM PDT
| landing coordinates = 37°50.87' N 119°5.28' W
| last = 18
| next = 20
}}

SSI-19 was the 19th launch of SSI Balloons. SSI-19 flew for just over 15 hours and to an altitude of 119,932 ft - breaking SSI's altitude record. The launch was a demonstration of the physical feedback found at high altitude with a precision filled latex balloon. The payload maintained an altitude of approximately 118,000 feet merely by passive feedback and no active control - it was degraded by UV radiation and descended shortly after sunrise. SSI-19 landed in Yosemite just east of Grant Lake after a flight of 15 hours.

== Flight Profile ==

SSI-19 was based on a flight method that was first successfully flown by the California Near Space Project (CNSP). The principle of the launch is inflating a large latex balloon (In the case of SSI-19, a 1600g) to a very low lift capacity (365g payload, ~140g free lift) to launch a very light payload. By barely filling the balloon and providing a very light payload, the balloon is able to ascend to a very high altitude (110,000-120,000 ft) where there is a positive feedback loop, allowing the balloon to equilibrate due to natural phenomena (no active control mechanism).

== Payload Specifications ==

The SSI-19 payload was, as needed, a very barebones set of electronics. It included an APRS BigRedBee transmitter using the callsign of balloons team member Iskender Kushan (KK6MIR), a GPS for position reporting, a sizable lithium-ion battery, and a heater made of nickel-chromium (nichrome) wire. In total, the payload had a mass of about 365g. It was the first balloon to be launched during the launch of SSI-19, SSI-20, and SSI-21. CNSP graciously brought their mass-flow meter to fill the SSI-19 latex balloon to a precise lift capacity (a mission-critical aspect of this launch).

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, a site frequented by the balloons team. The team left campus at 10 am, arriving just after 11:30 am. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. The APRS transmitter was verified for flight-readiness by ensuring transmission on the ground, the payload was sealed, and just prior to launch, the heater was hard-wired to the battery pack (for constant heating).

Filling of the 1600g Hwoyee balloon began at around 5:30 pm. Filling was coordinated in conjunction with CNSP personnel, who used their mass-flow meter to fill the balloon with the appropriate volume of Helium as calculated and verified by SSI members. Filling was challenging due to higher than expected ground wind speeds. After filling, launching was additionally challenging due to powerful east-bound winds, which pushed the balloon nearly into the ground on multiple occasions. During a moment of south-bound winds, the balloon was released from the north end of Laird Park (in order to clear the southern tree line) and ascended at a nominal velocity.

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon proved to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km, as this range of altitudes was chosen to optimize the wind conditions the balloon would experience (fastest winds, most predictable, and most appropriate direction). After the balloon roughly levelled off, the team armed the ballast mechanism over satellite comms. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a subpar ~ 4km accuracy).

The payload flew at considerable speed, crossing into Nevada after two hours in the appropriate altitude range. The flight continued through Nevada northward, cutting through the southeastern corner of Oregon before entering Idaho around 2:20 am PDT. The payload spent considerable time in central Idaho, and transmitted data suggesting considerable venting and ballast dropping occurring in this area. Unbeknownst to the team until the balloon was out of Idaho airspace, the balloon flew through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to autonomously maintain its altitude within its defined range, at the cost of considerable gas and ballast.

After spending a few hours in the thunderstorm, the balloon entered Montana at around 8:00 am PDT, continuing on a north/northeast trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the North Dakota/Montana border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift as night was arriving and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

{{balloon-footer}}
[[Category: High Altitude Balloons]][[Category: Balloon Launches]]

SSI-19

2015-10-18T00:33:29Z

Stanfordssi:

High Altitude Balloons Team

2015-10-18T00:24:26Z

Stanfordssi:

The Balloon team constructs and launches high altitude latex balloons with experimental payloads. To date, the team has launched and recovered 22 high altitude balloons to as high as 120,000 feet with thermal controls, satellite communication, and scientific payloads. They have launched a balloon halfway across the continental United States and are currently working on a full cross-country launch by the end of 2015. The HAB team has launched 22 payloads over the course of two years - all but three of which have been recovered fully intact, yielding an 87% success rate.

Balloon payloads are launched with state-of-the-art equipment constantly re-envisioned by the team. Recent additions include altitude control mechanics for latex balloons, including a gas venting valve and ballast dispenser, as well as a custom flight control system, two-way satellite communications, an intelligent altitude control algorithm, and more. The current goal of the team is to push the bounds on its current latex balloon flight hardware, both in terms of flight time and flight distance.

The current team leads are Iskender Kushan and [[User:ksafin|Kirill Safin]].

{{balloon-footer}}
<noinclude>[[Category:High Altitude Balloons]]</noinclude>

User:Ksafin

2015-10-18T00:23:46Z

Stanfordssi: Created page with "Kirill Safin is the current co-leader of SSI's Balloons Team, as well as being the SSI Chief Marketing Officer & Space Manager. He is a sophomore in Electrical Engineering."

Kirill Safin is the current co-leader of SSI's Balloons Team, as well as being the SSI Chief Marketing Officer & Space Manager. He is a sophomore in Electrical Engineering.

SSI-22

2015-08-29T19:18:38Z

Stanfordssi:

{{balloon-launch
| header = SSI-22
| img link = File:rsz_ssi-22.png
| launch date = May 31 2015, 8:32pm PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 24 hrs, 3 minutes
| landing date = June 1 2015, 8.35pm PDT
| landing coordinates = 49.88690, -104.50746
| last = 21
| next =
}}

SSI-22 was the 22nd launch of SSI Balloons. Flying for a over 23 hours through 5 US states and southern Canada, it was SSI Balloons' first international flight. The launch was a phenomenal demonstration of the [[Valve Ballast Altitude Control | ValBal technology]] that had been in development for months within SSI. The payload maintained altitude within 12km and 14km as per pre-programmed instructions, and managed to do so autonomosuly - not to mention maintain this altitude in the midst of a thunderstorm without a hitch. SSI-22 landed in Saskatchewan after an approximately 24 hr flight.

== Pre-Launch ==

After being recovered from the SW Nevada Desert, ValBal (previously launched as [[SSI-21]]) required some slight repairs due to cracks in acrylic upon landing. After about a week of modifications, repairs, and improvements, the payload was once again flight ready. Some additional adjustments were also made from observations of ValBal's first flight. The team inferred that the valve seal was not airtight (based on data transmitted over satellite communications during SSI-21 and over data logged to SD cards). In response, a latex seal was added to the valve such that closure of the valve would result in compression of the latex seal, producing an airtight fit. This was predicted to help dramatically with gas leaking that was observed during the previous flight.

Some additional features were added to ensure that less power was needed for payload heating. Motor/servo mounts on the payload interior received additional insulation and an enhanced latex seal was attached around the stem connecting the valve to a servo within the payload. Additionally, changes were made in the flight control software to allow enhanced user-to-payload communication and the data sent from the payload was modified to be more useful and descriptive.

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, the same site used for ValBal's previous flight. The team left campus at 4 pm, arriving just after 5:30 pm. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. Fishing line used for the cutdown mechanism was added to the valve, code was re-uploaded and verified, GPS lock was attained, and satellite communications were tested and verified. Although the payload was exempt from regulations requiring FAA tracking, the FAA was notified of the launch and gave a green light to proceed.

Filling of the 1600g Hwoyee balloon began at around 7:45 pm. Filling was more challenging than normal given substantial ground winds, but still concluded successfully. The latex seal on the neck adapter also posed problems as it was not fully considered in the design of the fill valve. An improvisation was made using duct-tape that allowed successful filling of the balloon. Once filled, the balloon and the neck adapter were locked onto the valve mechanism, the ballast hopper was filled, and the balloon was ready to be launched. The balloon was quite overfilled, and hence ascended at faster than most balloons the team has launched.

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon proved to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km, as this range of altitudes was chosen to optimize the wind conditions the balloon would experience (fastest winds, most predictable, and most appropriate direction). After the balloon roughly levelled off, the team armed the ballast mechanism over satellite comms. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a subpar ~ 4km accuracy).

The payload flew at considerable speed, crossing into Nevada after two hours in the appropriate altitude range. The flight continued through Nevada northward, cutting through the southeastern corner of Oregon before entering Idaho around 2:20 am PDT. The payload spent considerable time in central Idaho, and transmitted data suggesting considerable venting and ballast dropping occurring in this area. Unbeknownst to the team until the balloon was out of Idaho airspace, the balloon flew through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to autonomously maintain its altitude within its defined range, at the cost of considerable gas and ballast.

After spending a few hours in the thunderstorm, the balloon entered Montana at around 8:00 am PDT, continuing on a north/northeast trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the North Dakota/Montana border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift as night was arriving and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

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

SSI-22

2015-08-29T19:17:13Z

Stanfordssi:

{{balloon-launch
| header = SSI-22
| img link = File:rsz_ssi-22.png
| launch date = June 1 2015, 8:32pm PDT
| launch site = Laird Park, Modesto, CA
| launch coordinates = 37.56158, -121.14993
| flight duration = 24 hrs, 3 minutes
| landing date = June 1 2015, 8.35pm PDT
| landing coordinates = 49.88690, -104.50746
| last = 21
| next =
}}

SSI-22 was the 22nd launch of SSI Balloons. Flying for a over 23 hours through 5 US states and southern Canada, it was SSI Balloons' first international flight. The launch was a phenomenal demonstration of the [[Valve Ballast Altitude Control | ValBal technology]] that had been in development for months within SSI. The payload maintained altitude within 12km and 14km as per pre-programmed instructions, and managed to do so autonomosuly - not to mention maintain this altitude in the midst of a thunderstorm without a hitch. SSI-22 landed in Saskatchewan after an approximately 24 hr flight.

== Pre-Launch ==

After being recovered from the SW Nevada Desert, ValBal (previously launched as [[SSI-21]]) required some slight repairs due to cracks in acrylic upon landing. After about a week of modifications, repairs, and improvements, the payload was once again flight ready. Some additional adjustments were also made from observations of ValBal's first flight. The team inferred that the valve seal was not airtight (based on data transmitted over satellite communications during SSI-21 and over data logged to SD cards). In response, a latex seal was added to the valve such that closure of the valve would result in compression of the latex seal, producing an airtight fit. This was predicted to help dramatically with gas leaking that was observed during the previous flight.

Some additional features were added to ensure that less power was needed for payload heating. Motor/servo mounts on the payload interior received additional insulation and an enhanced latex seal was attached around the stem connecting the valve to a servo within the payload. Additionally, changes were made in the flight control software to allow enhanced user-to-payload communication and the data sent from the payload was modified to be more useful and descriptive.

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, the same site used for ValBal's previous flight. The team left campus at 4 pm, arriving just after 5:30 pm. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. Fishing line used for the cutdown mechanism was added to the valve, code was re-uploaded and verified, GPS lock was attained, and satellite communications were tested and verified. Although the payload was exempt from regulations requiring FAA tracking, the FAA was notified of the launch and gave a green light to proceed.

Filling of the 1600g Hwoyee balloon began at around 7:45 pm. Filling was more challenging than normal given substantial ground winds, but still concluded successfully. The latex seal on the neck adapter also posed problems as it was not fully considered in the design of the fill valve. An improvisation was made using duct-tape that allowed successful filling of the balloon. Once filled, the balloon and the neck adapter were locked onto the valve mechanism, the ballast hopper was filled, and the balloon was ready to be launched. The balloon was quite overfilled, and hence ascended at faster than most balloons the team has launched.

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon proved to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km, as this range of altitudes was chosen to optimize the wind conditions the balloon would experience (fastest winds, most predictable, and most appropriate direction). After the balloon roughly levelled off, the team armed the ballast mechanism over satellite comms. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a subpar ~ 4km accuracy).

The payload flew at considerable speed, crossing into Nevada after two hours in the appropriate altitude range. The flight continued through Nevada northward, cutting through the southeastern corner of Oregon before entering Idaho around 2:20 am PDT. The payload spent considerable time in central Idaho, and transmitted data suggesting considerable venting and ballast dropping occurring in this area. Unbeknownst to the team until the balloon was out of Idaho airspace, the balloon flew through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to autonomously maintain its altitude within its defined range, at the cost of considerable gas and ballast.

After spending a few hours in the thunderstorm, the balloon entered Montana at around 8:00 am PDT, continuing on a north/northeast trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the North Dakota/Montana border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift as night was arriving and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The ability of the balloon to maintain altitude on its own through almost the entire flight to such precision was a testament to the resilience of the technology. Nevertheless, problems were encountered, including the following:

*The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. Proposed improvements included more battery storage and, more importantly, solar panels for power regeneration.

*This flight offered an indication of how far the preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but the fact that this occurred suggested that significantly more ballast would be required for longer journeys.

*Gas venting can also be amended; a 3-inch neck was used to allow for high volumes of gas to be vented, but this could have been reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

*Better payload insulation is needed. [[SSI-18]] used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that its heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit the team to put Aerogel on this flight, but its potential value to future payload containers was demonstrated.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons (as of September 2015)
* Longest ground distance traveled by any SSI Balloons mission (as of September 2015)

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>

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

File:Ssi 22 altitude.png

2015-08-25T05:31:24Z

Stanfordssi:

File:Ssi 22 gpath.jpg

2015-08-25T05:31:15Z

Stanfordssi:

File:Ssi 22 storm.png

2015-08-25T05:31:04Z

Stanfordssi:

SSI-22

2015-07-06T04:21:20Z

Stanfordssi: Created page with "{| class="wikitable" style="float:right; margin-left: 10px;" !colspan="2"| File:rsz_ssi-22.png |- | Launch date | May 31 2015, 8.32pm PDT |- | Launch site |..."

{| class="wikitable" style="float:right; margin-left: 10px;"
!colspan="2"| [[File:rsz_ssi-22.png]]
|-
| Launch date
| May 31 2015, 8.32pm PDT
|-
| Launch site
| Laird Park, Modesto, CA
|-
| Launch coordinates
| 37.56158, -121.14993
|-
| Flight duration
| 24 hrs, 3 minutes
|-
| Landing date
| June 1 2015, 8.35pm PDT
|-
| Landing coordinates
| 49.88690, -104.50746
|}

SSI-22 was the 22nd launch of SSI Balloons. It outperformed all expectations, launching at 8:52 pm PDT and flying for a over 23 hours through 5 states and 2 countries. It was SSI Balloons' first international flight. The launch was a phenomenal demonstration of the ValBal technology that has been in development for months within SSI. The payload maintained altitude within 12km and 14km as per pre-programmed instructions, and managed to do so autonomosuly - not to mention maintain this altitude in the midst of a thunderstorm without a hitch. SSI-22 landed in Saskatchewan after an approximately 24 hr flight.

== Pre-Launch ==

After being recovered from the SW Nevada Desert, ValBal required some slight repairs (nothing serious) due to cracks in acrylic upon landing. After about a week of modifications, repairs, and improvements, the payload was once-again flight ready. It required only slight repairs due to its fortunately soft landing (~ 1 m/s). Some additional adjustments were also made from observations of ValBal's first flight. The team inferred that the valve seal was not airtight (based on data transmitted over satellite communications during SSI-21 and over data logged to SD cards). In response, a latex seal was added to the valve such that closure of the valve would result in compression of the latex seal, producing an airtight fit. This was predicted to help dramatically with gas leaking that was observed during the previous flight.

Some additional precautions were taken with respect to thermal insulation in order to ensure that less power was used for heating of the payload. This consisted mostly of better insulation of motor/servo mounts on the payload interior, and an enhanced latex seal for the valve servo stem. Additionally, changes were made in the flight control software to allow enhanced user-to-payload communication (allowing us to send more advanced instructions) and the data sent from the payload was modified to be more useful and descriptive.

== Launch site ==

The launch was conducted at Laird Park, just west of Modesto, CA, the same site used for ValBal's last flight. The team left campus at 4 pm, arriving just after 5:30 pm, and beginning set up and preparations. The payload was essentially flight-ready, requiring only minor pre-flight additions and verification of system fidelity. Fishing line used for the cutdown mechanism was added to the valve, code was re-uploaded and verified, GPS lock was attained, and satellite communications was tested and verified. Although the payload was exempt from regulations requiring FAA tracking, we notified the FAA of the launch and were given a green light to proceed.

Filling of the 1600g Hwoyee balloon began at around 7:45 pm. Filling was more challenging than normal given substantial ground winds, but still concluded successfully. The latex seal on the neck adapter also posed problems as it was not fully considered in the design of the fill valve. An improvisation was made using duct-tape (hurrah for engineering!) that allowed successful filling of the balloon. Once filled, the balloon and the neck adapter were locked onto the valve mechanism, the ballast hopper was filled, and the balloon was ready to be launched. The balloon was quite overfilled, and hence ascended at faster than most balloons we have launched.

== The Flight ==

[[File:ssi_22_storm.png | thumb | <center> The storm </center>]]

The fast ascent rate of the balloon was going to be an immediate test of the resilience and fidelity of the autonomous altitude control algorithm. As soon as the balloon was launched, the team began to pack up while waiting for the first message from the payload. The first message confirmed that the payload was slowly being incentivized to vent gas (by the algorithm) and slow its ascent. By the time the team had packed up and started driving out, the payload had vented gas a total of 7 times, decreasing its ascent rate to < 1.5 m/s. The algorithm was pre-programmed to maintain an altitude between 12km and 14km (that is, when approaching 14 km, gas would be vented to drop altitude, and when approaching 12 km, ballast would be dropped to ascend altitude). This range of altitudes was chosen due to the optimal wind conditions (fastest winds, most predictable, most appropriate direction). The balloon approximately levelled off, and the team armed the ballast mechanism over satellite comms. Once the ballast was armed, the system was in full swing. The GPS lock was lost at exactly 12:00 am PDT (due to a snippet of code in the GPS library relying on date, and being unable to cope with the month turnover of May to June). Nonetheless, the satellite communications module transmitted GPS coordinates (albeit with a ~ 4km accuracy).

The payload flew at remarkable speed, making it to Nevada in a mere two hours in the appropriate altitude range. The flight continued a path through Nevada northward, cutting through the SE corner of Oregon before making it into Idaho (around 2:20 am PDT). The payload spent considerable time in central Idaho, and transmitted data suggested considerable venting and ballast dropping occurring in this area. It was not known until the balloon was out of Idaho airspace, but it turned out that the balloon crossed through a class 3 thunderstorm, experiencing considerable turbulence. Despite the tremendous up and downdrafts, the balloon was able to, autonomously, maintain its altitude within our defined range (at the cost of considerable gas and ballast).

After spending a few hours in the thunderstorm, our balloon flew out and into Montana at around 8:00 am PDT, continuing on a north/north-east trajectory. At 2:39 pm PDT, and at over 1,000 miles from the launch site, the balloon entered Canadian airspace in Saskatchewan province. At this point the balloon began a more prominently eastward flight path along the Canadian border. At around 6:36 PDT, the balloon began a steady descent just north of the ND/MT border. Based on data transmitted from the balloon, it was clear that the system had ran out of ballast material and was thus unable to drop weight to compensate for lost lift (as night was arriving) and hence began to fall. The ballooon fell slowly for about an hour, finally terminating its flight at around 8:35 pm EDT, landing in a field.

== Debriefing ==

The launch was phenomenal by any standard; the ability of the balloon to maintain altitude on its own through almost the entire flight to such precision is a testament to the resilience of the technology. However, problems were encountered, and will be amended in the next iteration of ValBal.

The power draw for heating was quite high; the battery started at a voltage of ~ 4.34 V and was around ~ 3.40 V upon landing. 3.20 V is the point at which the flight control system ceases to function; thus, for longer flights, more power is needed. This will necessitate both more battery storage and, more importantly, solar panels for power regeneration.

Additionally, we got a good sense of how far our preloaded quantity of ballast was able to take the balloon. Granted, the turbulence experienced over Idaho resulted in considerable usage of ballast, but it is still clear that significantly more ballast will be required for longer journeys.

Gas venting can also be amended; we have used a 3-inch neck to allow for high volumes of gas to be vented, but this can likely be reduced to a neck diameter as small as 1 inch and compensated for with a larger vent time. Venting for 5 seconds at a time with a 3 inch neck caused unnecessarily large volumes of gas to be vented.

We also intend to better insulate the payload. SSI-18 used a payload wrapped in AeroGel Cryogel blanket, which was so insulative that our heaters did not need to turn on for over 10 hours. A shrinking budget and smaller timeframe did not permit us to put Aerogel on this flight, but it will be a definite component of future payload containers.

== Milestones ==

* First international launch of SSI Balloons
* Longest flight of SSI Balloons
* Longest ground distance traveled by any SSI Balloons mission

== Gallery ==

<gallery widths=300px heights=300px>
File:ssi_22_gpath.jpg | <center> Ground path </center>
File:ssi_22_altitude.png | <center> Altitude data </center>
</gallery>