Q: How is communication initiated and maintained with spacecraft?


Read this paragraph and choose the correct option from the provided answers:

Radio waves are used for communicating with spacecraft. A round-trip communication from Earth to Mars takes anywhere from 6 to 42 minutes. What challenges might this present for sending unmanned spacecraft and probes to Mars?.

 Choices:

- sonar

- telegraph

- wi-fi

- radio waves


A:
radio waves