picture of the encyclopedia
previous next
Version 0.81 comes with a new web design! Please allow popups for navigation.


Student Nitric Oxide Explorer, also called STEDI 1 and UNEX 01; pronounced "snowy"


Designation 25233 / 98012A
Launch date 26 Feb 1998
Country of origin United States
Mission Scientific:
Perigee/Apogee 536/580 km
Inclination 97.7°
Period 95.8 min
Launch vehicle Pegasus XL #20

Built at the University of Colorado's Laboratory for Atmospheric Research and Space Physics. It will analyse and measure the contributions of nitric oxide from the Sun and magnetoshpere to the lower atmosphere. First satellite of the Student Explorer Demonstration Initiative program.

Worth $4.4 million

End of life

Out of service  
Decay planned in Dec 2003

External resources

sat-index articles

Technical data


Prime contractor  
Mass at launch 132 kg
Mass in orbit  
Dimension 99 x 91 cm
Solar array  
DC power 35 W consumption
Design lifetime  

It carries 3 instruments: an ultraviolet spectrometer to measure nitric oxide altitude profiles, a two-channel auroral photometer to measure auroral emissions beneath the spacecraft, and a five-channel solar soft X-ray photometer.

downlink: 2272.9 MHz
downlink rate: 128 kbps

© TBS Internet, all rights reserved. All reproduction, copy or mirroring prohibited. Legal notice
francais anglais contact