In the same quote (copied below), what does "series" mean?
"These activities are part of a two–year extended mission that began Oct. 1, the newest in a series of extensions going back to the end of Opportunity's prime mission in April 2004."
"These activities are part of a two–year extended mission that began Oct. 1, the newest in a series of extensions going back to the end of Opportunity's prime mission in April 2004."
What does "international" mean?
"The agency’s long–running string of spacecraft is winding to a close, and international and commercial interests are on the rise."
Which phrase best describes what "[t]hroughout the 2000s" means?