WASHINGTON — NASA’s Mars 2020 rover mission, one of the agency’s highest priorities during the coronavirus pandemic, remains on schedule for a launch in mid-July, officials said April 15.

The $2.4 billion mission, which will search for evidence of past life on Mars and cache samples for return to Earth by future missions using a rover named Perseverance, is a top priority because of its narrow launch window. The spacecraft must launch between July 17 and Aug. 5 in order to achieve its landing on Mars in February 2021. If Mars 2020 does not launch by Aug. 5, it will have to wait until the next launch window opens more than two years later.

That immovable deadline has meant NASA has gone to great lengths to keep mission preparations going when many other agency activities have slowed or stopped because of the pandemic. That effort has, so far, paid off.

“We’ve made every effort to try and put the health and safety of the individuals first, and yet still try to keep things on schedule,” Lori Glaze, director of NASA’s planetary science division, said during a virtual meeting of NASA’s Mars Exploration Program Analysis Group (MEPAG) April 15. “Right now the rover is at the Kennedy Space Center and is on schedule.”

Glaze described Mars 2020 as one of the two top priorities in NASA’s Science Mission Directorate, alongside the James Webb Space Telescope. However, JWST work slowed down in late March after the departure of many NASA personnel assigned to the Northrop Grumman facility where the spacecraft is going through final testing, and project officials said at the end of March that full-scale work won’t resume until the full NASA and industry teams can return.

The rover arrived at KSC in February for final launch preparations. In a later presentation at the MEPAG meeting, Jim Watzin, director of NASA’s Mars Exploration Program, said about 80 people are working on the Mars 2020 spacecraft at KSC, with another 80 at the Jet Propulsion Laboratory wrapping up work on the last set of hardware for the mission. The JPL personnel, he added, are “rapidly transitioning” to telework at the hardware is completed.

The personnel working at KSC have kept launch preparations on track. “We are green across the board in all aspects of the mission,” including schedule, Watzin said. Recent work has included installing the Mars Helicopter, a small helicopter that will be deployed from the rover after landing, as well as fueling the spacecraft’s descent stage.

“The team is working and has been able to maintain schedule,” he said. “We’ve been doing everything that we can to try to protect and support that team at the Cape.” One example of those efforts involves using additional office space at KSC so that personnel, when not working on the spacecraft in the clean room, can maintain adequate physical distancing.

At a NASA science town hall meeting in March 20, Thomas Zurbuchen, NASA associate administrator for science, said that the agency was considering using NASA aircraft to transport hardware and personnel to KSC if the use of commercial aviation was no longer considered safe, a proposal he dubbed “Perseverance Airlines.” Watzin confirmed at the meeting that NASA had adopted that proposal.

“We’ve been able to secure the use of NASA research aircraft to shuttle the personnel back and forth between the Cape and California, so we’ve been able to keep them away from public places and public airlines, which I think has contributed mightily not only to morale but also to their safety and exposure to COVID-19,” he said.

Besides being a top priority for NASA’s science program, Mars 2020 has emerged as a major priority for the agency overall. NASA Administrator Jim Bridenstine has on several occasions identified it and the upcoming crewed test flight of SpaceX’s Crew Dragon spacecraft as the two key programs for the agency in the next few months.

“What we are going to do this summer will absolutely stun the world,” Bridenstine said in an April 2 video thanking NASA employees for their continued work during the pandemic. “We’re going to launch American astronauts on American rockets for the first time since the retirement of the space shuttles back in 2011, then we’re going to turn around and launch Mars Perseverance.”

Bridenstine reiterated the importance of Mars 2020 in an interview published April 15 by The Planetary Society, a space advocacy group, saying commercial crew and Mars 2020 were “the two big mission-essential functions that we have as an agency right now.”

Bridenstine also acknowledged that Mars 2020 was a priority because of the cost NASA would incur if the mission doesn’t launch this summer. “If we miss that launch window, it will cost us upwards of $500 million over the course of two years, if not wreck the mission altogether, which we do not want to have happen,” he said.