The technical issue which occurred shortly after the launch of NASA's latest Mars rover Perseverance was not serious, the agency has confirmed.
Matt Wallace, the mission's deputy project manager, said the issue was not overly concerning, adding: "We'll know more in a bit."
A United Launch Alliance Atlas V rocket took off on schedule at 7.50am (11.50 GMT) from Cape Canaveral, Florida.
About an hour later, the spaceship carrying Perseverance broke away from the upper-stage Centaur rocket and headed for Mars at 25,000 mph (40,000 kph).
But it was experiencing technical difficulties after passing through the Earth's shadow which briefly caused its temperature to drop and triggered a "safe mode" that switched off all but essential systems, NASA said.
Perseverance was launched on an astrobiology mission to look for signs of ancient microbial life - and to fly a helicopter-drone on another world for the first time.
If all goes to plan and no other issues occur, Perseverance will reach Mars on 18 February 2021, becoming the fifth rover to complete the voyage since 1997.
So far, all have been American. China launched its first Mars rover last week, which should arrive by May 2021.
By next year, Mars could have three active rovers, including NASA's Curiosity, which landed in 2012.
Perseverance was launched on an astrobiology mission to look for signs of ancient microbial life and to fly a helicopter-drone on another world for the first time.
It soared into the sky under clear, sunny and warm conditions carried by an Atlas 5 rocket from the Boeing-Lockheed joint venture United Launch Alliance.
The launch took place after the Jet Propulsion Laboratory in California where its mission engineers were located was rattled by an earthquake.
This marked NASA's ninth journey to the Martian surface.
A physics lecturer at Technological University Dublin has said the NASA mission is very exciting and Perseverance is the by far the most sophisticated rover ever to be sent into space.
Kevin Nolan said its mission is to find any evidence of the origin of life because Mars was "very earth like in its beginning".
He said the rover will land in a dry river delta, around the size of Dublin Bay, and will drive around there for two to three years, adding that if there is any original microbial life to be found it will find evidence of it.
Speaking on RTÉ's Morning Ireland, he said this is the first of a whole new breed of missions and the objective of the mission is to lay down the precursor steps to "get people there".
If all goes to plan, Perseverance will reach the Red Planet on 18 February 2021, becoming the fifth rover to complete the voyage since 1997.
All so far have been American.
China launched its first Mars rover last week, which should arrive by May 2021.
By next year, Mars could have three active rovers, including NASA's Curiosity, which has traversed 23km of the Red Planet since it landed in 2012.
"It's without question, a challenge. There's no other way to put it," NASA chief Jim Bridenstine said yesterday.
"That being said, we know how to land on Mars, we've done it eight times already. This will be the ninth," he added, referring to the total of previous rover and lander missions.
Perseverance, which was developed at the storied Jet Propulsion Laboratory in Pasadena, California, is an improved version of Curiosity.
It is faster, with a tougher set of six wheels, has more computing power, and can autonomously navigate 200 meters per day.
About the size of a small SUV, it weighs a metric tonne, has 19 cameras, and two microphones - which scientists hope will be the first to record sound on Mars.
It also has a two-metre-long robotic arm, and is powered by a small nuclear generator.
Once on the surface, NASA will deploy the Ingenuity Mars Helicopter - a 1.8 kg aircraft that will attempt to fly in an atmosphere that is only 1% the density of Earth's.
The idea is to lay down a proof of concept that could one day revolutionise planetary exploration, since rovers can only cover a few dozen kilometres in their whole lifespans and are vulnerable to sand dunes and other obstacles higher than 40cm.
Perseverance's primary mission is to scour the planet for evidence of ancient life forms.
Scientists believe that more than three billion years ago the planet was much warmer than now and was covered in rivers and lakes, conditions which could have led to simple microbial life.
The reasons for it becoming the cold, barren world we know today are not fully known.
In another first, Perseverance's drill will collect around 30 intact rock cores and place them in test tubes, to be collected by a future joint US-European mission.
Indisputable proof of past life on Mars will most likely not be confirmed, if it exists, until these samples are analyzed next decade, NASA chief scientist Thomas Zurbuchen said on Tuesday.
"What we are looking for is likely very primitive life, we are not looking for advanced life forms that might be things like bones or fern fossils," explained project scientist Ken Farley.
NASA has chosen the Jezero crater as its landing site, a giant impact basin just north of the Martian equator.
Between three and four billion years ago, a river flowed there into a large body of water.
Scientists believe the ancient river delta could have collected and preserved organic molecules and other potential signs of microbial life.
If conditions are harsh on the sand-swept planet where night temperatures dip to minus 90C, it does have one major advantage: no plate tectonic activity.
On Earth, it is extremely difficult to find landscapes that have remained the same for three billion years.
"Mars preserves on the surface of some incredibly complex and diverse geology," said Lori Glaze, NASA Planetary Science Division director.
More than 350 geologists, geochemists, astrobiologists, atmospheric specialists and other scientists from around the world are taking part in the mission.
It is set to last at least two years, but probably much longer given the endurance shown by previous rovers.