Computer Network

1.How can you make a connectionless protocol reliable? (You may not be able to answer this question, but try.)

2.Spacecraft exploring the outer planets need reliable data transmission. However, the acknowledgments would take hours to arrive. This makes an ACK-based reliability approach unattractive. Can you think of another way to provide more reliable data transmission to spacecraft without using acknowledgments? (You may not be able to answer this question, but try.)