The Smith & Williamson Boomerang Balloon Flight Control System completed its second year of flights for the Balloon Asian Tropopause Aerosol Layer (BATAL) campaign. Lead by Jean-Paul Vernier of NASA’s Airborne Science Program, the BATAL research campaign includes researchers from India’s National Atmospheric Research Laboratory and the Banaras Hindu University in Varanasi. BATAL’s science goal is to “study the summertime layer of tiny particles floating 9 to 12 miles high, in the zone where the troposphere fades into the stratosphere”1. In situ measurements from Boomerang will help researchers understand aerosol processes in the atmosphere as well as data from other platforms such as the CALIPSO satellite2.
Jed Smith of Smith & Williamson traveled to India to support BATAL 2016 using the the Boomerang system. Boomerang was attached to a 2000g latex balloon and lifted an 8kg (17.6lb) payload suspended 30m (100ft) below to an altitude of 19km (62,000ft). The sensors in the payload included a COBALD3 backscatter sonde, iMet radiosonde, optical particle counter, ozone sonde, and three-stage particle impactor.
Boomerang flight profiles in this second year of field operations utilized a rapid ascent (approx. 6m/s) to 13km in order to minimize surface wind influences and airplane flight path interference. Once at 13km, much slower ascent and descent rates increased flight times in the altitude region of interest. To easily achieve this stepped vertical flight profile, a second ‘tow’ balloon was used to provide the necessary free-lift during the initial high-ascent ascent. The tow balloon was cutaway at 13km to reduce overall buoyancy using a Smith & Williamson Doongara balloon cut-down device. Boomerang gas venting and ballast dropping was then used to fine-tune system buoyancy in real-time. Boomerang also provided continuous positioning telemetry and flight termination which minimized recovery distances.
The flights this year were successful in demonstrating Boomerang’s support of high-altitude atmospheric research payloads. All the equipment was recovered without damage and was flown multiple days in a row.
3 Made by the Swiss Federal Institute of Technology
Many thanks to the following to help make the campaign so successful: Dr. Jean-Paul Vernier (NASA), Prof A.K. Singh (BHU), Amit Kumar Pandit (NARL), Vishnu, Shani, Sravan, Akhilesh, Aravidn, Sasi, Mustafa, and everyone else.