Washington, July 10 : NASA engineers have attached its Mars rover to the top of the rocket that will send it toward the Red Planet as the US space agency now targets July 30 for its launch. Encased in the nose cone that will protect it during launch, the "Perseverance" rover and the rest of the Mars 2020 spacecraft -- the aeroshell, cruise stage, and descent stage -- were affixed to a United Launch Alliance Atlas V booster on July 7, NASA said on Thursday. "I have seen my fair share of spacecraft being lifted onto rockets," said John McNamee, Project Manager for the Mars 2020 Perseverance rover mission at NASA's Jet Propulsion Laboratory in Southern California. "But this one is special because there are so many people who contributed to this moment. To each one of them I want to say, we got here together, and we'll make it to Mars the same way." With the mating of spacecraft and booster complete, the final testing of the two -- separately and as one unit-- will be underway, NASA said. The targeted launch date of the mission has been pushed back three times so far Â? first to July 20, then to July 22 and now to July 30. NASA and United Launch Alliance recently also updated the mission's launch period Â? the range of days the rocket can launch in order to reach Mars. It now spans from July 30 to August 15. The launch period opening changed from July 17 to 30 due to launch vehicle processing delays in preparation for spacecraft mate operations. Four days were also added to the previously designated August 11 end of the launch period. NASA and United Launch Alliance Flight Teams were able to provide those extra days after final weights of both the spacecraft and launch vehicle became available, allowing them to more accurately calculate the propellant available to get Perseverance on its way. No matter what day Perseverance lifts off during its July 30 to August 15 launch period, it will land in Mars' Jezero Crater on February 18, 2021. NASA said. /IANS