托福阅读材料之超级航空器

美国NASA的航空器发射成功

The US National Reconnaissance Office has launched what is reputed to be the largest satellite ever sent into space.

The spacecraft was put into orbit on a Delta-4 Heavy rocket from Cape Canaveral Air Force station on Sunday.

The NRO gave no details about the payload but it is understood the satellite will be used to eavesdrop on enemy communications.

For comparison, the largest commercial satellite ever launched was the seven-tonne Terrestar-1 telecoms spacecraft.

It had an 18m antenna-reflector to relay phone and data traffic.

US websites have speculated that the mesh antenna on the new NROL-32 satellite would exceed this, and could even be substantially bigger than the 22m-diamater structure orbited last week on another commercial platform called Skyterra-1.

The Delta-4 Heavy rocket, the largest unmanned American launch vehicle, lifted off at 1758 local time (2258 GMT).