Mariner 1 was die eerste onbemande vlug van die Mariner-program en is ontwerp vir 'n verbyvlug van Venus. Dit het $18.5 miljoen VSA gekos in 1962. Die ruimtetuig was gelanseer op 22 Julie 1962 met 'n Atlas-Agena vuurpyl. Kort na lansering het die vuurpyl nie korrek gereageer op bevele van die grond beheer rekenaar nie, dit was blykbaar toe te skryf aan aan 'n sagteware fout in die beheerstelsel. Met die ruimtetuig feitlik buite beheer, het die veiligheids beampte die selfvernietiging bevel gestuur na 294.5 sekondes. Volgens NASA se laaste verslag uitgereik aan die publiek: The booster had performed satisfactorily until an unscheduled yaw-lift (northeast) maneuver was detected by the range safety officer. Faulty application of the guidance commands made steering impossible and were directing the spacecraft towards a crash, possibly in the North Atlantic shipping lanes or in an inhabited area. The destruct command was sent 6 seconds before separation, after which the launch vehicle could not have been destroyed. The radio transponder continued to transmit signals for 64 seconds after the destruct command had been sent.