Lift Gas Cracker
The Lift Gas Cracker (LGC) is a new method for extending the duration of high-altitude scientific balloon flights and for enabling the launch of balloons from remote locations. The LGC produces balloon lift gas by catalytic steam reforming of methanol to generate hydrogen and carbon dioxide.
A portable LGC methanol reforming system was prototyped by Pioneer Astronautics during a NASA SBIR Phase I project. The LGC demonstrated lift gas generation for launching meteorological balloons from remote locations where heavy helium cylinders are not available. The LGC can also generate hydrogen for fuel cells by incorporating a gas separation step.
During Phase II, the LGC is being developed for extending high-altitude balloon flight duration. For this application, an on-board LGC produces lift gas at night. During the day, some of the lift gas (which is predominantly hydrogen) is burned at low pressure with atmospheric air to produce water ballast. The water ballast can be dropped or can be recycled to the LGC for steam reforming of methanol at night. These techniques can extend the duration of high-altitude flights by a factor of three or more compared to conventional methods of dropping ballast at night and venting gas during the day.
Phase I Lift Gas Cracker Technical Accomplishments
- Demonstrated a portable, methanol-heated LGC producing 100 standard liters per minute of lift gas,
- Demonstrated membrane separations to produce lift gas with an average molecular weight of about 6,
- Demonstrated catalytic hydrogen/air combustion and trapping of water ballast at about 40 millibar, thus enabling a significant technology for extension of flight duration.
- Filled and launched a 1500-gram latex balloon (~560m3 at burst). The carrier balloon lifted smaller zero-pressure helium and lift gas balloons along with a camera plus telemetry, altitude, and temperature sensors to 100,000 feet to collect valuable information regarding the performance of the lift gas cracker system as well as the effect of carbon dioxide on balloon temperatures.
- Conducted mission analyses demonstrating significant extension of high-altitude flight duration using LGC.
Phase II Lift Gas Cracker Tasks
- Stratospheric flight test of lift gas cracker, and
- Stratospheric flight test of low-pressure combustor.
NASA applications of the Lift Gas Cracker include greatly extending scientific balloon flight duration. Use of the LGC to provide nighttime makeup gas during flight can nearly double the duration of a stratospheric zero-pressure balloon flight over what is now possible. If, in addition, the excess lift gas in the balloon during daytime is reacted with air to produce water ballast instead of simply being vented, the flight duration can be tripled. This is an extraordinary benefit for all types of stratospheric scientific ballooning. The LGC is also applicable to balloon flight on Mars, Venus, and Titan.
Non-NASA Commercial Applications
The LGC can produce lift gas in remote areas, such as the Arctic, Antarctic, and remote regions where conventional gas cylinders are difficult and costly to obtain. Such gas is needed in large quantities to support meteorological campaigns and flight service stations that provide winds aloft data to pilots. In addition, winds-aloft information is needed by military units, such as artillery, which fire projectiles through high altitudes. In remote regions, the provision of compressed helium bottles to field units could prove difficult, and the LGC offers corresponding logistic advantages.
Debora Fairbrother was the NASA Contracting Officer’s Technical Representative at the Goddard Space Flight Center during Phase I. Dr. Robert Zubrin is the Principal Investigator for Pioneer. Mark Berggren is Pioneer’s lead engineer for the LGC project. Jerry Sterling is the COTR at Goddard for the Phase II Lift Gas Cracker program.