NASA's HETE Coming Down

terrymr writes "NASA expects the High Energy Transient Experiment spacecraft which failed to successfully detach from the third stage of its launch rocket in 1996 to fall to earth within the next few days. While most of the spacecraft will likely burn up in the upper atmosphere there is a good chance that the spacecraft's batteries (weighing 33lbs each) may reach the ground intact. Current predictions put re-entry at 4:41 EDT Sunday April 7 (+/- two days)."

Comments

33 pounds TOTAL, not each

[wowbagger]

Initial analysis indicates that only four small stainless-steel batteries, weighing a total of 15 kilograms (33 pounds) will survive re-entry.

In other words, the weight of all 4 batteries is 15 kilos, not the weight of each battery. Still, 3.5 kilos at terminal velocity is nothing to sneeze at - perhaps I should buy a large number of pillows from Yahoo!....

Nothing nuclear here. These are NiCad.

[Christopher Thomas]

'Stainless steel batteries? ' I think not. More likely that they are plutonium or some other nuclear material

Um, you might want to actually read about the satellite before assuming it uses radiothermal generators.

The great big solar panels in the picture of the satellite might have been a hint that it didn't use nuclear power.

From the HETE pages (describing HETE-2, an exact duplicate of the HETE-1 craft whose launch was unsuccessful):

The HETE-2 power system hardware consists of

• 
  
• four solar panels, made of honeycomb aluminum with silicon substrate, each supplying 42W.
  
• power box with power point tracker,~90% efficient
  
• 6 battery packs, each made up of a string of 24 1.5V NiCd cells, and each with 1.2 A-hrs capacity
  

You can find more information on the specs of the HETE satellites at http://space.mit.edu/HETE/spacecraft.html .