157
edits
Changes
Jump to navigation
Jump to search
mLine 19:
Line 19: + + + + Line 28:
Line 32: − +
no edit summary
==Project context==
==Project context==
The launch plan at the beginning of the quarter had called for a fully controlled ZPB flight coincident with onboarding on '''October 26, 2019'''. However, the unavailability of a vent mechanism and the surprising endurance of [[SSI-92]] motivated the decision to do a long-endurance ballast-controlled ZPB instead. The analysis of data from that previous flight had suggested a thermal difference of 10% during the day; given this, it seemed possible to aim for a multi-day flight with a reasonable amount of ballast. Briefly, on October 18, a floater was considered as the forecast appeared to show winds going towards the ocean, but this was temporary. The primary upgrades, in addition to the vent mechanism, was a heating mechanism and a GPS reset mechanism, lessons learned from the last flight.
Construction of the payload was a streamlined process by this time. Avionics were produced in an October 15 worksession; on October 18 a large number of balloons were manufactured for Onboarding; and on October 20, the payload was integrated, marking launch readiness a week ahead of time. The integration of the payload was tricky, as no top piece was suitable for the legacy ballast piece, and furthermore thermal insulation was a concern.
==Configuration==
==Configuration==
'''Power''': 12 L91 lithium AA batteries. 3 L91 lithium AA batteries on resistive heater and cutdown.
'''Power''': 12 L91 lithium AA batteries. 3 L91 lithium AA batteries on resistive heater and cutdown.
'''Ballast''': Legacy valbal mechanism with 300 g ballast.
'''Ballast''': Legacy valbal mechanism with 500 g ballast, theoretically enough for two nightfalls.
'''Payload''': Half valbal-style polycarbonate cylinder within styrofoam enclosure. Mass 1.25 kg including ballast.
'''Payload''': Half valbal-style polycarbonate cylinder within styrofoam enclosure. Mass 1.25 kg including ballast.