Companies develop 270V flight battery system

Advanced Battery Technology,  Apr 2003  

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AZ Technology Inc. and Symmetry Resources Inc. have developed and qualified a 270V flight battery system for NASA's X-38/crew return vehicle to the International Space Station. This is the first 270V battery system approved for human spacecraft. It powers flight control surfaces's electromechanical actuators and parafoil winches.

It uses a self-contained ground support equipment (GSE) unit to provide fast charge/discharge control and battery diagnostic functions using 120VAC input. The GSE performs battery diagnostics and provides battery status information such as temperature, effective internal resistance, voltage, and capacity. The GSE provides analog outputs and digital input/output via an RS 232 port. The GSE and battery have safety interlocks that enable dead-face cable connections.

The 270V battery uses commercially available sealed nickel-cadmium cells and has a rated capacity of 9.6Ah. The battery consists of four 210-cell strings with individual control electronics and protection circuits. The cell string design will deliver up to 2,870W/L or 1,120W/kg, in a pulsed duty cycle application. During mission profile, the battery easily delivers the required 36kW- 100 millisecond pulses over a 220-second duration at 50 % state of charge.

The battery design qualification was completed for NASA-JSC in July 2002. The qualification testing consisted of 20-G mechanical shock and 9.05Grms random vibration while under load, thermal performance (10 deg C to 70 deg C) while discharging to the mission profile, overpressure and vacuum exposure, thermal cycling from (-31 deg C to 45 deg C), radiation, and various other tests. One battery/GSE and four flight batteries/GSE have been produced.

Visit www.aztechnology.com.

Tiny Scroll Compressor Delivers Big Blast of Air

Air Squared's tiny P18H36 high-pressure air compressor lives up to its design roots in an artillery piece by delivering a big shot of air - 12 CFM at 130psig - from a compact package. Originally created to clean a laser window for the Army's crusader mobile howitzer, the new oil-free unit offers designers a clean, quiet, and reliable source of compressed air for medical equipment, fuel cells, and natural gas boosters.

Contact Air Squared Inc., 7014 Rock Springs Dr., Hamilton, OH 45011, phone: (513) 755-2559, fax: (513) 755-2533, or www.airsquared.com.

Copyright Seven Mountains Scientific, Inc. Apr 2003
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