Your class and teacher obviously do not understand the importance of having aerospace. You can always have the last laugh.
We need machines to transport us to destinations within a month, days or even hours - planes, trains, buses, cars and ships.
The fastest, furthest machines that can take us across sea/oceans within hours are planes.
Aerospace experts/ engineers are part of aerospace to build, repair or maintain expensive civlian and military planes daily. Without them (no constant maintenance), our planes can go haywire and crash.
These people are the ones who design the planes and ensure maxmium safety of passengers abroad the planes - over hundreds of planes are in air daily!
The number of people travelling under normal circumstances (i mean no economic crisis to ground the travellers) is increasing rapidly - leads to increase in purchase of planes and renewal of fleet.
Aging passenger planes are being either scrapped or extended their life to serve other function such as cargo transport or even re-fuelling transport plane. So you need aerospace people to design better, faster planes with modern fuel-saving system to replace aging inefficent planes.
Aerospace is truly amazing but millions of people worldwide have taken for granted. We have wide variety of planes serving mankind very very well!
Space shuttle is considered part of aerospace - although it travels in space - it still guides in air and lands like any planes. The space shuttle looks like any plane but it is very special plane that is capable to go up to space and come back to Earth safely.
Travelling in space would help to keep aerospace alive. It won't take long before we finally see first prototype passenger plane that can transport humans to space and come back to Earth within 2 hours - imagine u take this plane from New York and land in Singapore less than an hour!
Concorde, no doubt, is the most magnificent machine ever built. However the lifespan of the concordes are reduced to few years left to serve us - probably end before 2010 or even earlier. They have been around for more than 30 years already.
But the next generation of supersonic passenger planes would arrive within decades eventually although we probably may not be able to see the new generation SST before year 2010 is out.
You can shoot back to teacher or class:
"Without aerospace, you would not be able to go within hours from one destination to another one - over 10, 000 km apart.
You would be struck with the ships that would take you several days to travel across mighty oceans to your destination - not within hours. Hence aerospace is not dead, sir."
You can end it with a big smile.
After all, aerospace is still alive.