An artist's depiction of one of the twin Mars Exploration Rovers, nicknamed Spirit and Opportunity. Opportunity has been offline for weeks due to low power caused by a massive dust storm. Engineers have a rockin' playlist of wake-up songs for the rover.

Engineers with NASA's Mars Exploration Rover program have been left hanging on like a yo-yo for 61 days now, after the space agency's Opportunity rover lost power during a Martian dust storm — but they've started greeting each new Martian day the rover may call with a themed song.

On Aug. 4 — Opportunity's 5,165th day on Mars — the rover was still asleep. But mission staff at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, hoped to inspire the robot to turn back on by playing Wham!'s "Wake Me Up Before You Go-Go" in the control room, beginning of a new tradition to wait out the storm.

"Morale has been a little shaky," Michael Staab, an engineer for the program at JPL who helped initiate the themed daily wake-up song for the humans waiting for Opportunity's long and nerve-wracking nap to end, told Space.com. "This is the first time she [Opportunity] has stopped talking to us and not resumed communication when we expected." [The Epic Mars Dust Storm of 2018 Explained]

The musical initiative in the control room isn't entirely new: Mission team members celebrated a daily wake-up song when Opportunity first landed on Mars nearly 15 years ago, in January 2004, Staab said. The rover's mission was originally planned to last just 90 days, but once it became clear that Opportunity would be staying in business on the Red Planet, the tradition faded.

Then, in May, came a dust storm to end all dust storms, which roiled around the entire planet and blotted out the sun — an awfully hazardous situation for a solar-powered robot. Opportunity hasn't produced so much as a chord, much less more substantive data, since June 10, according to NASA. (NASA's Curiosity Mars rover, by contrast, is nuclear-powered and thus has not suffered the same ill effects from the dust storm as the Opportunity rover.)

"That's a long time to not hear from your rover, and we don't know what it's doing," Staab said. And the engineers are feeling the change. "We still have things to do; we still have work to get done. But it's definitely slowed down a bit."

So mission team members have seized a few opportunities to keep their spirits up, Staab said. An informal betting pool is tracking guesses of when the rover will finally call home — dates range from early July to mid-September.

And they've started building a themed playlist to mark each new Martian day in the control room. For instance, Opportunity didn't respond as the team listened to Kansas' "Dust in the Wind" — although the band itself did. "The band actually reached out and was really excited that we were using one of their songs to wake up a Mars rover," Staab said. (We've gathered all the songs the team has already listened to while waiting for the rover, plus future options they're considering, in a Spotify playlist in case you'd like to listen along.)

Opportunity didn't chime in as its controllers listened to The Beatles' "Here Comes the Sun" or Elton John's "Rocket Man," either, but the engineers aren't out of songs yet. "We'll just keep playing until she decides to talk to us," Staab said.

Maybe in the coming days the opening line "Hello, I've waited here for you everlong" will be the magic charm that revives (robotic) "Life on Mars," music fans on the team hope.

Although the dust storm has been clearing for about two weeks, NASA can't tell how long it might take Opportunity's batteries to charge up enough for the rover to finally call its humans — or whether Opportunity will sleep forever, for that matter.

"It could take weeks — hopefully not months," Staab said. "I wish we had something to share; I wish we had good news. But we keep listening every day."

And, fingers crossed, the rover will take to heart another upcoming suggestion: Gloria Gaynor's "I Will Survive."

Email Meghan Bartels at mbartels@space.com or follow her @meghanbartels. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.