July 2020 was a huge month for Mars. Taking advantage of its nearby position in orbit, three missions departed the Earth on a seven-month journey to the red planet. Now those spacecraft -- NASA's Perseverance rover, the Chinese space agency's Tianwen-1 and the United Arab Emirates' Hope -- are arriving at their destination. They're poised to uncover the secrets our celestial neighbor hides within its atmosphere and barren plains and may even reveal relics of ancient life on the planet's surface.
Although all three spacecraft will make it to orbit around Mars this month, NASA's Perseverance (or "Percy") gets to take center stage. It will be the only mission to land on the surface this month, with an expected arrival date of Feb. 18. Perseverance builds on an impressive history of interplanetary exploration, with its sibling rover Curiosity coming up on nine years on Mars, delivering breathtaking photographs and some puzzling data.
That's not to take anything away from the UAE's Hope, or Al Amal, and China's Tianwen-1. Both spacecraft are expected to perform Mars orbital insertion, or MOI, maneuvers within a day of each other on Feb. 9 and Feb. 10, respectively. Hope will remain in orbit and analyze the Martian atmosphere, but Tianwen-1 will attempt something only achieved by two other nations: landing on Mars' unfriendly surface. China is expected to release Tianwen-1's lander and rover duo sometime in May.
Here's a recap of the journey to Mars and what we can expect this month.
Every 26 months, the orbits of Earth and Mars line up in such a way that space agencies can take advantage of something known as a Hohmann transfer orbit.
"We do this kind of transfer orbit in order to use the least fuel," James O'Donoghue, a planetary scientist with Japanese space agency JAXA, told CNET last year. "It's like passing a football to a striker, you've got to aim where they're going to be."
In July 2020, everything lined up perfectly, and the three missions were out of here. Some fast facts:
- Hope launched on July 19, 2020, from Tanegashima Space Center in Japan.
- Tianwen-1 set off on July 22, 2020, from Wenchang Satellite Launch Center on Hainan Island.
- Perseverance departed Earth on July 30, 2020, from the Florida coast.
The cadence of launches means Hope will reach Mars first in February. It's expected to perform its MOI on Feb. 9, slowing down from 75,000 miles per hour to just 11,200. At approximately 7:42 a.m. PT, the bus-length probe will arrive "at" Mars and will begin to transition to the science phase of the mission. The maneuver is totally autonomous, because communication doesn't quite work as quickly as it does here on Earth -- the interplanetary phone call has a more than 13-minute delay, so Hope will be flying on its own from a set of preset instructions.
Tianwen-1's arrival is slightly more mysterious. China's space agency doesn't typically reveal a lot of information about its activities, even for a potentially history-making mission such as this. According to Chinese news service CCTV, it will be the second craft to enter orbit, on Feb. 10.
Three spacecraft, seven months
Although the majority of the science will be performed when the spacecraft reach Mars, scientists and engineers have been testing the capability of their spacecraft on the cruise phase of the mission. The journey itself is a long one -- covering about 300 million miles (~480 million kilometers) -- and each agency has a chance to improve the trajectory of the craft for a perfect arrival. What else has been happening?
- Tianwen-1 took its first "selfie" while traveling through space in September.
- Perseverance has been listening to the sounds of space.
- It's been a little quieter for Hope, but as the orbiter was on its way to Mars, the UAE set its sights a little closer to home, announcing the Rashid mission to the moon.
Last but not least
NASA's Perseverance rover will touch down on Feb. 18. Though NASA's got a good track record of landing on the red planet in the last few decades, there are no guarantees -- Mars is hard.
"Success is never assured," said Allan Chen, engineering lead on the entry, descent and landing phase of the mission, during a NASA press conference on Jan. 27. "That's especially true when we're trying to land the biggest, heaviest and most complicated rover we've ever built to the most dangerous site we've ever attempted to land on."
The space agency expects to have the best footage of landing ever, with a suite of cameras and a microphone ready to capture the entry, descent and landing. It's the first time we'll be able to listen to the sounds of a Martian landing, providing a completely new sensory experience for avid Mars fans. Sadly, there's no way we'll be able to watch live, as such, but NASA will provide coverage of the moment. We've got a comprehensive guide to Mars landing day and what you can expect.
NASA Perseverance rover and Ingenuity helicopter explore the wilds of MarsSee all photos
How to watch NASA's Perseverance landing on Mars
If you're looking to catch Perseverance rover's touchdown on Feb. 18, we've got you covered and you can access the stream right here. And if you're interested in all the other great celestial events and rocket launches, we recommend syncing your calendar with CNET's Space Calendar -- you'll never miss a launch again.