NASA has announced that the first launch attempt of the Mars 2020 mission has been pushed back from the scheduled July 22 launch date, and will take place no earlier than July 30. The operation team found an issue with the rocket during the rehearsal stage and wants to have time to investigate it thoroughly.
“A liquid oxygen sensor line presented off-nominal data during the Wet Dress Rehearsal, and additional time is needed for the team to inspect and evaluate,” explained NASA in a statement.
The Mars 2020 mission includes the rover Perseverance and the Mars Helicopter drone Ingenuity, the first aircraft to attempt flight on another planet. The mission will launch on an Atlas V rocket operated by the United Launch Alliance. The new delay has people concerned that the issue might be significant and the mission might be delayed further.
“Flight analysis teams have expanded the mission launch opportunities to August 15 and are examining if the launch period may be extended further into August,” the statement continued.

The pressure is certainly on because if the mission cannot be made ready for the slim launch window, it will have to be postponed by over two years. July and August 2020 are the perfect launch window for a trip to Mars from Earth. Given the relative position of the two planets, launching in this period guarantees the shortest trip, which means the least amount of energy to cross interplanetary space. This launch window repeats every 780 days. So if the mission doesn't make it now, it will have to wait until 2022.
This is what happened to the European Space Agency-Roscomos Rosalind Franklin rover, which was scheduled to launch this summer but due to parachute issues has been postponed until the next launch window. Fingers crossed the issue with the rocket is resolved presently and that NASA's mission launches this summer. Two other missions from China and the United Arab Emirates are scheduled to launch this summer too.
All going well, Perseverance and Ingenuity are expected to reach the Red Planet in late February 2021, touching down inside Jezero Crater. Perseverance will search for signs of past microbial life and Ingenuity will be a technology demonstration of how drones could be used as robotic explorers on Mars.