appoint (v)
/əˈpɔɪnt/

to choose someone officially for a job or responsibility

artificial (adj)
 /ˌɑː.tɪˈfɪʃ.əl/ 

made by people, often as a copy of something natural

aspiration (n)
 /ˌæs.pɪˈreɪ.ʃən/ 

something that you hope to achieve

astronaut (n)
 /ˈæs.trə.nɔːt/ 

a person who has been trained for travelling in space

bid goodbye (phrase)
/bɪd ɡʊdˈbaɪ/

to say goodbye to someone

biography (n)
/baɪˈɒɡ.rə.fi/ 

the life story of a person written by someone else

breakthrough (n)
 /ˈbreɪk.θruː/

an important discovery or event that helps to improve a situation or provide an answer to a problem

caption (n)
/ˈkæp.ʃən/

words that are printed underneath a picture, cartoon, etc. that explain or describe it

challenge (v)
/ˈtʃæl.ɪndʒ/

to invite someone to compete or take part, especially in a game or argument

Congress (n)
/ˈkɒŋ.ɡres/ 

the name of the group of people who are elected to make laws, in the U.S. consisting of the Senate and the House of Representatives

conquest (n)
/ˈkɒŋ.kwest/ 

the process of gaining control of something through great effort

extreme (adj)
/ɪkˈstriːm/

very large in amount or degree

feat (n)
/fiːt/

something impressive and often dangerous that someone does

gravity (n)
 /ˈɡræv.ɪ.ti/

the force that attracts objects towards one another, especially the force that makes things fall to the ground

leap (n)
 /liːp/

a long or high jump

mission (n)
 /ˈmɪʃ.ən/

an important job, especially a military one, that someone is sent somewhere to do

orbit (n)
/ˈɔː.bɪt/ 

the curved path through which objects in space move around a planet or star

pioneer (n)
 /ˌpaɪəˈnɪər/ 

a person who is one of the first people to do something

pressure (n)
/ˈpreʃ.ər/

the force you produce when you press something

shuttle (n )
/ˈʃʌt.l̩/ 

a vehicle or aircraft that travels regularly between two places