STRATEX #2 (Eustace)

The StratEx mission, officially known as the Stratospheric Exploration project, aimed to develop a system enabling an individual to ascend to, explore, and safely return from the stratosphere. This system was analogous to a SCUBA suit designed for underwater exploration, focusing on simplicity, safety, and lightweight design compared to traditional capsule-based systems. Conceptualized in December 2011 by Alan Eustace, Senior Vice President of Knowledge at Google Inc. pilot and an avid skydiver in collaboration with Paragon Space Development Corporation, the mission sought to address the feasibility of creating a self-contained system for human stratospheric exploration.

The StratEx mission employed an intricate array of hardware to ensure a successful and safe stratospheric flight and descent. In the image at left can be seen the suit in launch position (click for more details). Central to the system was the Pressure Suit Assembly (PSA), which encompassed a pressure suit, equipment module (EM), and the flight recovery system. The suit was designed to maintain a pressurized environment at 37.2 kPa, protect the pilot from extreme stratospheric conditions, and integrate with environmental control and life support systems (ECLSS). It featured a Dual Suit Controller (DSC) to manage internal pressure, a Demand Helmet Regulator (DHR) for oxygen delivery, and a liquid thermal garment (LTG) to regulate temperature. The helmet bubble included anti-glare features and ensured clear visibility. Mounted on the pilot's chest, the EM housed high-pressure oxygen tanks, batteries, and a heat exchanger system to manage temperatures, alongside avionics for navigation, telemetry, and communication.

The flight recovery system, critical for descent, included a drogue parachute for stabilization, a main parachute for controlled landing, and a backup parachute activated either manually or via an Automatic Activation Device (AAD) in emergencies. The innovative Stiff Anti-Entanglement Bridle Ejecting Rod (SAEBER) system prevented entanglement during drogue deployment. Ground support was facilitated by the Ground Cart (GC), which provided oxygen, cooling, and electrical power before liftoff, maintaining consumables and system functionality until launch.

The Flight Vehicle, a helium balloon, was engineered to lift the pilot to the stratosphere. Its envelope, constructed of specialized polyethylene, included a servomotor-controlled crown valve for helium venting and a reinforced base fitting for equipment attachment. The Balloon Equipment Module (BEM), suspended below, housed avionics, radar reflectors, and telemetry systems. It featured a destruct system for safe decommissioning post-mission, using a weighted tear mechanism or a fuse-activated release. The BEM also carried ballast to adjust ascent rates and housed video transmission systems to relay real-time visuals.

The Launch System involved extensive ground-based support infrastructure, including the balloon support equipment for safe handling and inflation, helium supply systems, and a ''Spork" vehicle to raise the balloon into position. A launch plate and sedan ensured the balloon and pilot were securely stationed during the launch process, with equipment enabling controlled lateral movement as the balloon ascended.

Mission Control integrated hardware and software for real-time monitoring and coordination, with personnel overseeing pilot health, ECLSS performance, and flight trajectory. Redundant communication systems ensured continuous connectivity. The Chase and Recovery system utilized helicopters, trucks, and fixed-wing aircraft, supported by GPS navigation, to track and recover the pilot and equipment efficiently. The medical team and technicians were equipped to handle contingencies, including pilot extraction and post-landing support.

The StratEx mission hardware demonstrated a sophisticated balance of innovation, redundancy, and operational precision, enabling groundbreaking exploration of the stratosphere.

Balloon launched on: 10/15/2014
Launch site: Roswell Industrial Air Center, New Mexico, US  
Balloon launched by: PARAGON
Balloon manufacturer/size/composition: Zero Pressure Balloon 1.700.000 cuft
End of flight (L for landing time, W for last contact, otherwise termination time): 10/15/2014
Landing site: In New Mexico, US

This was the second crewed flight aimed to reach 106,000 ft. The 48,000 m³ helium balloon was launched on October 15, 2014, from Roswell International Air Center in New Mexico, carrying pilot Alan Eustace, equipped with a custom space suit integrated with essential life-support systems. This flight further increased demands on the flight system from both an aerodynamic loading on descent and a consumables standpoint.

Freefall duration was increased by nearly a minute and a half over the previous flight and maximum freefall speed more than doubled. A noteworthy achievement for this flight was that it broke the unofficial world altitude record for a drogue assisted skydive set by Joe Kittinger in 1960 as part of the Air Force Excelsior program. For this flight the only anomaly associated with the pressure suit assembly occurred pre-flight and during suit donning operations when the pilot had difficultly donning one of the pressure suit gloves. Subsequent investigation revealed that tapes used to index the glove bladder to the glove restraint had allowed slippage between these two layers, likely due to storage at elevated desert temperatures over an extended period of time. These layers were carefully re-indexed in the field and were successfully used for this flight, however the tapes were completely replaced and the bladder/restraint layers completely re-indexed prior to the subsequent and final flight.

• StratEX project website Paragon SDC
• Medical Support and Outcomes Of a Manned Stratospheric Balloon and Free-Fall Parachute Flight Test Program 45th International Conference on Environmental Systems, July 2015
• StratEx Environmental Testing 45th International Conference on Environmental Systems, July 2015
• StratEx Mission Overview 45th International Conference on Environmental Systems, July 2015
• StratEx Pressure Suit Assembly Design and Performance 45th International Conference on Environmental Systems, July 2015
• The Design and Development of an Extravehicular, Stratospheric Exploration (StratEx) Pressure Suit 45th International Conference on Environmental Systems, July 2015