The U.S. Government's Official Web Portal National Aeronautics and Space Administration
NASA Banner  
Go button
Advanced Search
About NASA About NASA Glenn Exploration Systems Mission Directorate
Space Flight Systems @ GRC
News & Events
Orion Project Office
Launch Systems Project Office
Ares I Upper Stage
Announcement Background
Avionics
 
Upper Stage Electrical Power

The Upper Stage’s Electrical Power System (EPS) provides redundant sources of 28 volt direct current (VDC) electrical power to the integrated Avionics subsystems, the J-2X engine interface, the Upper Stage Reaction Control System, the First Stage Roll Control System, the TVC electronics, and the Main Propellant System (including the liquid oxygen and liquid hydrogen recirculation pumps), from the time ground power is removed prior to launch until the end of the mission.

The EPS has equipment located both in the Instrument Unit (top of the Upper Stage) and on the Aft Skirt (bottom of the Upper Stage). In addition, there is an independent EPS located in the Interstage (in between the Upper Stage and First Stage) to power the First Stage Roll Control System thrusters.  EPS system components include power sources (batteries), power distribution and control units, DC-to-AC Inverter Units (to drive the recirculation pumps), and cabling.

Development Flight Instrumentation

The Upper Stage Developmental Flight Instrumentation (DFI) is a stand-alone subsystem that collects data for engineering analysis of the performance of Ares I. DFI is a Glenn-led, in-house effort. DFI hardware mounted in the Instrument Unit will include Data Acquisition Units, a Battery Module Unit, a Telemetry System, cable harnesses (power and data) and sensors of various types. 

The primary purpose of the Development Flight Instrumentation is to acquire data in early flights and use it to verify the performance of the vehicle, based on modeled data that was previously gathered. The project team plans to collect and analyze this data for the first five flights of Ares I.

Sensors

Glenn’s sensor development work is composed of two component tasks: Sensor Data Qualification System (SDQS) and Smart Leak Detection Sensors (SLDS). 

The SDQS team is developing advanced algorithms (software) to qualify the validity of key data measured by sensors embedded in various Upper Stage systems. This sensor data validation uses a variety of analytical methods (e.g., analytical redundancy models, Bayesian belief networks, and statistical limit filters) to ensure that the health management and control systems use data that accurately reflect the state of the Upper Stage systems. The sensor data qualification software developed by the Glenn team will be incorporated into flight software, which will be used to monitor the health of the Upper Stage while in flight.

lick stick 1
Significant miniaturization of leak sensor technology from  legacy Space Station systems (right) to CLV implementation  (left)
lick stick 2

“Lick  and stick” miniaturized smart leak detection  system

Glenn’s SLDS team is developing a miniature, electronic, hydrogen leak detection sensor that will be used to monitor the concentration of flammable hydrogen gas in the Upper Stage’s closed compartments. At present, there is no other means of measuring hydrogen gas concentration levels while the Upper Stage is in flight. The Glenn-developed electronic hydrogen sensor will fly as part of the Development Flight Instrumentation on the first few test flights of the Upper Stage.




 

 

 

Contact at NASA Glenn Research Center
Lead, Upper Stage, Avionics: Amy L. Jankovsky
Space Flight Systems Directorate / Launch Systems Project Office
216-977-7498

 

Ares I-X Upper Stage Simulator
Ares V
Upper Stage Engine & Engine/Stage Testing
Vehicle Integration
Constellation Office
Advanced Capabilities Project Office
Space Operations Project Office
National Center for Space Exploration Research
External Partners
Education/Outreach
Space Exploration Benefits
Program Support
 
Space Flight Systems Links
 
 
 
 
 
 
 
   
 
SFS Internal (NASA GRC only)
 
 
 
Launch Systems Links







 

 

 

 



Footer seperator
FirstGov Logo

+ Freedom of Information Act
+ Privacy Policy and Important Notices
+ President's Commission on Moon, Mars and Beyond (PDF)

NASA Logo

Webmaster:
Tim Reckart
Technical Writer: Emily Owens
NASA Official: Jana VanHorn
Last Updated: March 7, 2008
Footer spacer
Footer spacer