By the middle of the 21st century we (to build) will have built space stations which (to circle) ………. the earth and probably (to circle) ………. the moon, too. We (to establish) ………..bases on planets like Mars. At present, we use radar to ‘watch’ nearly 8,000 objects in space. In addition, there are at least 30,000 bits of rubbish from the size of marbles to the size of basket balls flying round the earth. These (to increase) ……….in number by the year 2050 and (to orbit) ……….the earth. All these bits and pieces are watched by NORAD (North American Radar Defense Command). NORAD (to have) ……….more and more rubbish to watch as the years go by. Some bits fall back to earth, like the Russian satellite C954, which crashed in the Northern Territories of Canada in 1978. Crashing junk could give us a bad headache. Most of the staff (to stay) ……….up there we hope! The sad fact is that we who are alive today (not / to clear up) ……….our own junk tomorrow. Perhaps we just (to watch) ……….from some other safe place as it goes round and round the earth!
Revision Test on Future Perfect