11.   And it took four attempts before they actually got there, because the first three times they had to turn back because of stormy weather at the landing site.

12.   Because material at the landing site is thought to be ancient, it should provide evidence for early environmental conditions on the planet that could have supported microbial life.

13.   Boeing engineers were then at work designing a unique vehicle that could carry future astronauts across the moon miles from their landing site.

14.   Both orbiters are to map the planet and search for good landing sites.

15.   A much improved forecast for both landing sites Wednesday reduced the urgency some.

16.   But already, scientists are forming tentative conclusions about the rocks near the landing site.

17.   But because of treacherous ocean currents and the lack of a suitable landing site for boats, the French government has banned travel to this island.

18.   But crosswinds had been unacceptably stiff at the trans-Atlantic landing sites.

19.   But scientists, wanting to make the most of the opportunity, chose a landing site that promised scientific dividends.

20.   But there is a gap in the middle, covering such activities as looking for groundwater, charting magnetic anomalies and scouting out future landing sites.