NASA launched the largest-ever helium balloon on 25 August, when it flew a 1.7 million m3 (60 million ft3) single-cell disposable balloon to 161,000ft (49,000m) from Lynn Lake, northern Manitoba, Canada. The balloon carried 690kg (1,500lb) Low Energy Electrons for the University of Delaware as part of the sixth in a series of flights to observe cosmic electrons from sub-orbital altitudes. The 328m-tall balloon, built by Texas-based Raven Industries, is made from polyethylene film only 0.02mm (0.0008in) thick. It is partially filled with helium at launch and expands as it rises, taking two to three hours to reach its float altitude. It flew for over 24h, before a command was sent from the ground to tear the balloon and return the payload to Earth by parachute, where data tapes were recovered. NASA hopes that high-altitude, heavy-payload balloons will establish a new platform for ultraviolet and X-ray astronomy.
Source: Flight International