Nickel-iron or Nickle-iron?

The text below is exactly as found at the Mars Rover Opportunity status page.

"This week Opportunity approached an interesting surface target, the meteorite "Oileán Ruaidh."

The rover performed an in-situ investigation of the nickel-iron meteorite prior to resuming the trek to Endeavour crater. On Sol 2370 (Sept. 23, 2010), Opportunity made a short 2-meter (7 foot) bump to a location where the south-southwest face of Oileán Ruaidh would be reachable by the instrument deployment device. On Sol 2371 (Sept. 24, 2010), the rover used the microscopic imager to collect imagery of two locations on Oileán Ruaidh. These locations were named "Mulroy A" and "Mulroy B."

After collecting the microscopic imagery, the alpha particle X-Ray spectrometer (APXS) was placed on Mulroy B for a series of three measurements over the three-sol weekend plan. The findings from the APXS confirmed that Oileán Ruaidh is a
nickle-iron meteorite."

I just happened to notice that both spellings of "nickel" were used in the above; "nickle" isn't incorrect, just rare, and more commonly used for the 5-cent coin.

Nickle is also a programming language. nickle.org (or it was; I'm not sure how popular it is anymore).