Image source, EPA

We hope you enjoyed the live coverage of the launch of Nasa's rover Perseverance.

The robot is now on its seven-month journey to the Red Planet. In February next year, it should land in Jezero Crater to begin its search for evidence of ancient Martian life.

We'll continue to bring you any news about the mission. But for now, it's goodbye from Ritu Prasad, Helen Briggs, Jonathan Amos and Paul Rincon.

Next step: the Moon, says Jim Bridenstine.

"We need to go to the Moon sustainably to prove we can live and work on another world for long periods of time," he says. "We go to the Moon because it's always a three-day journey home and we can prove what we need to prove there so we can eventually send humans to Mars."

He says there are robotic precursor missions and human precursor missions at the Moon.

"We love Apollo. The challenge with Apollo is that it ended. And now we're going back to the Moon with commercial partners and international partners under the Artemis programme, learning how to use the resources of another world... so we can eventually apply that to our long-duration mission to Mars."

Bridenstine adds that when Congress considers Nasa's upcoming budget requests, they should think about what happened today and what will happen in February when Perseverance lands on Mars - as well as how US astronauts were launched on US rockets for the first time in nearly a decade.

"If we were to receive the budgets, I'm very confident that we could get there by the mid-2030s."

With that, the post-launch news conference ends.

Image source, NASA

Deputy project manager Matt Wallace responds to a question from Eric Berger from news outlet Ars Technica, who asks if the spacecraft is in "safe mode".

He said: "When we started this discussion, we weren't really sure, but it appears as though we came off the launch vehicle in our normal cruise mode. I'm just getting some indications that we had a minor temperature "transient" that's recovered, that may have put us into safe mode. If so, that's perfectly fine - the spacecraft is happy there.

"So the team is working through that telemetry, they're going to look at the rest of the spacecraft health. So far, everything I've seen looks good. And so we'll know more in a little bit."

Safe mode is an operating mode for spacecraft where all non-essential systems are shut down and only essential functions such as attitude control and radio reception are active.

Sometimes, it can be the response to some sort of system failure or to the detection of conditions outside the normal operating range of the spacecraft. However, we do not yet know about the circumstances in this case, if the spacecraft has indeed entered this state.

Jim Bridenstine is asked about how this latest astrobiology mission to Mars could serve as a bright light in these difficult times.

"I don't even know if 10 years ago we used that word [astrobiology]," Bridenstine says, adding that it's exciting that we've learned there are places that could be habitable in our own Solar System right now, not just in the ancient past.

He says Nasa is able to put together missions that not only inspire future generations, but all people.

"These are the kinds of things Nasa can do in very difficult times and we're very excited about it."

Nasa administrator Jim Bridenstine says there was "adversity all along the way" but that's expected with any projects like this. What was unexpected was the coronavirus pandemic.

He says a large fraction of Nasa, JPL and ULA teams were working from home, while smaller parts of the organisations kept functioning with personal protective gear, social distancing and staggered shifts.

"I'm not going to lie, it's a challenge, it's very stressful, but look - the teams made it happen and I'll tell you, we could not be more proud of what this integrated team was able to pull off here so it's very, very exciting."

Glaze answers a question about what the next steps to get to human exploration might be.

She says the upcoming sample return mission, which is the very next Mars mission following Perseverance, is a key step.

That mission will allow scientists to demonstrate the abilities of launching from the Martian surface as well as planning a rendezvous in space around another planet.

"I think with each robotic mission, we demonstrate those next capabilities that we're going to need... to human exploration," she says.

Image source, NASA

When Perseverance lands, cameras placed around the rover will allow us to watch a craft landing on another planet for the first time.

Nasa planetary science division director Lori Glaze says: "This mission has more cameras on it than any mission we've sent before. I think the images and the video we're going to get back form the Perseverance rover during entry, descent and landing and on the surface as well is going to be absolutely stunning."

She says it's going to "feel like we're actually there, riding along with Perseverance on the way down".

Image source, Nasa

Nasa Administrator Jim Bridenstine takes a question on how the public perceives these missions.

"Every single one of these missions gets more complex and more sophisticated and right now we have the single most sophisticated complex robot ever sent to another world, so we're all very excited about it," he begins.

"But I think the American people see the benefit of these activities, not just in terms of science but also in the development of technology that we all benefit from."

He says that there's a "lot of enthusiasm" among the public for these missions.

"And of course as far as children go, these are the kind of moments where young folks can decide 'Wow! that's something I want to do when I grow up'. I think all of America is very proud and excited about this mission."

The team is asked again about the signal issues with Perseverance.

Deputy project manager Wallace says the craft is very "inherently stable" and there's "plenty of time to work through the communication issues".

"There's nothing we need to do urgently...we've got plenty of time before ew have to make our first trajectory correction manoeuvre. Normally, it's 15 days after launch but we probably have time well beyond that based on how well we did [with the launch]."

Deputy project manager Matt Wallace answers a question on how landing will work when the rover enters Mars' atmosphere on 18 February 2021.

"Basically we start prepping for it maybe eight days out or so," he says. As the craft approaches, more and more processes become autonomous.

It will land in a similar manner to the Curiosity rover.

"We come in on the order of 12,000 miles an hour, our entry capsule will slow us down, we'll steer that entry capsule hypersonically so we aim right at our landing site and then when we're still moving at about Mach 2 we inflate our big supersonic parachute. That's an exciting moment in the mission and that'll slow us down to maybe 150 miles an hour or so."

The heatshield will then drop off and here's where things get different. Perseverance has a new capability called Terrain Relative Navigation, which has allowed it to aim for the Jezero Crater landing site with very great precision.

"We take a picture as we're coming down, and then we find ourselves in a map we've stored on board from orbital imagery and once we know where we are in that map, we essentially divert the spacecraft away from the hazards."

The American GOES-16 weather satellite sits 36,000km above Earth's equator and caught the vapour trail from Perseverance's Atlas rocket.

Lori Glaze, Nasa's Planetary Science Division director, shares a video of children around the world who helped with Nasa's "countdown to Mars" campaign.

Deputy project manager Matt Wallace is next. He describes today, like Bridenstine, as a "perfect launch", and then explains more about the signal issues.

"The one problem we had is the terminology we use - we couldn't lock up our telemetry," he says.

"Basically it allows us to read the information and the data coming from the spacecraft. It turns out the Deep Space Network is really designed to talk to spacecraft that are a long, long way away...they have very sensitive receivers, very big antennas, and to configure them in fact to talk to a spacecraft that is this close to the Earth is a little out of the ordinary."

For the last hour or so, he says, engineers have been working on configuring the ground station to get this signal. He adds that he just got a text during the conference that the team would get more information soon.

Nasa administrator Jim Bridenstine speaks first, and says everything is still going to plan.

Addressing the communications issues with Perseverance, Bridenstine says: "We do need to fine tune our receiving stations on the ground and do some things to capture that signal and lock down but I think we're in great shape."

He adds that "it couldn't have gone any better from a launch perspective".

Nasa officials are hosting the post-launch briefing at the Kennedy Space Center.

We're hearing from Nasa administrator Jim Bridenstine, Thomas Zurbuchen, associate administrator for science, Lori Glaze of the planetary science division, Matt Wallace, deputy project manager at JPL, Omar Baez, launch director, and Tory Bruno, president of United Launch Alliance.

Paul Rincon
Science editor, BBC News website

Image source, NASA

Nasa's rover missions have detailed extensive evidence pointing to Mars being hospitable to life billions of years ago. But there's an intriguing phenomenon on Mars that could point to possible life today.

In 2004, the European Space Agency's (Esa) Mars Express spacecraft detected methane in the atmosphere of Mars in the parts per billion range. Nasa scientist Michael Mumma also presented evidence from ground telescopes of the gas in Mars' thin air.

The finding was of interest because the vast majority of methane on Earth is produced by life.

But it's not the only way methane can be produced, and so the methane can't be taken as solid evidence of microbial life. There are many ways it could be produced without biology, including a series of chemical reactions called serpentinisation, which could be taking place below the Martian surface.

Nasa's Curiosity rover has detected irregular "burps" of atmospheric methane from its landing site at Gale Crater.

Esa's Trace Gas Orbiter has been gathering long-term observations of gases such as methane in the Martian atmosphere. The results could provide a better idea of what's going on.

Could Martian bugs be eking out an existence deep beneath the Martian surface, producing methane as a by-product of their life cycle? It's a possibility, but not the only one.

Image source, Nasa

Seven months from now, as it prepares to land on Mars, Perseverance will face what Nasa engineers call the "seven minutes of terror".

This is the period of time it takes for the craft - which will enter Mars at high speeds - to slow down and gently land, wheels-down.

But since parachutes aren't fully effective in the thin Martian atmosphere, Perseverance will need to slow down with rockets and be lowered on to the surface with a "sky crane".

In addition, the rover will need to execute these manoeuvres on its own since there'll be a more-than 10-minute delay in signals reaching Earth from Mars.

Wherever you go, it's difficult. The atmosphere is thick enough to cause severe heating on your spacecraft when you enter at high speed, but not so thick that you get all the help you need to slow down. This means what they term Entry, Descent and Landing, or EDL, has bitten many of those who've tried to make the drop to the surface.

The Soviet Mars-3 mission was the first to get down intact, in 1971, but died very soon after. We all remember the British-European Beagle-2 lander. Satellite images suggest that also made it to the ground intact but, again, died soon after.

Only the Americans have managed long-lived surface missions, starting with the Viking probes in the mid-70s, and continuing with Pathfinder-Sojourner in 1997, Spirit and Opportunity in 2004, Phoenix in 2007, Curiosity in 2012 and Insight in 2018.

Hopefully, Perseverance and the Chinese Tianwen-1 rover will get down safely next year. And then, fingers crossed, Europe's ExoMars "Rosalind Franklin" rover will do the same in 2023.

There seem to be some communication issues between Nasa and the spacecraft.

Nasa Administrator Jim Bridenstine says the team is working on it and it's a scenario they've "worked through in the past with other missions".

He says the signal from Perseverance remains strong.

Perseverance's Twitter account adds: "I am healthy and on my way to Mars, but may be too loud for the antennas on Earth while I'm so close. Ground stations are working to match my signal strength so that I can communicate clearly with my team."

We've got less than an hour before Nasa's post-launch news conference, where we'll hear from officials.

Jonathan Amos
Science correspondent, BBC News

Image source, NASA/JPL

A small chunk of Mars is heading home with Perseverance.

The robot is carrying a meteorite that originated on the Red Planet and which, until now, has been lodged in the collection of London's Natural History Museum (NHM).

The rock's known properties will act as a calibration target to benchmark the workings of a rover instrument.

It will give added confidence to any discoveries the robot might make.

This will be particularly important if Perseverance stumbles across something that hints at the presence of past life on the planet - one of the mission's great quests.

"This little rock's got quite a life story," explained Prof Caroline Smith, head of Earth sciences collections at the NHM and a member of the Perseverance science team.

"It formed about 450 million years ago, got blasted off Mars by an asteroid or comet roughly 600,000-700,000 years ago, and then landed on Earth; we don't know precisely when but perhaps 1,000 years ago. And now it's going back to Mars," she told BBC News.

Read the full story here.