T-minus two years to Mars. In a tweet last week, private spaceflight company SpaceX announced its intention to send its Dragon capsule to Mars as soon as 2018. But will the Red Dragon really fly? The timeline has been labelled ambitious, but realistic.
“Everything about Dragon since the beginning has been done with Mars in mind, you can tell from the design,” says Jim Bell of Arizona State University in Tempe, who has worked on several NASA missions to Mars and is working on the planned Mars 2020 rover. “I wouldn’t put anything past these folks.”
The tough part won’t be getting the spacecraft to Mars, but getting it down to the surface. And the company will need some help from NASA. Details are scarce at the moment, but the overall plan has been in motion since at least 2011, says Brian Glass at NASA Ames Research Center in California.
“This is not out of the blue,” he says. “It’s not just boom, two years off the block. This is more like a seven-year effort that culminates with launch in 2018 and goes from there.”
SpaceX’s Falcon 9 rocket first launched in 2010, and its Dragon capsule has been successfully ferrying cargo to the International Space Station since 2012. The trip to Mars will use souped-up versions of both: the Falcon Heavy rocket, which is essentially three stages of the Falcon 9 rocket strapped together, and the Dragon 2 capsule, which will eventually bring astronauts to and from the ISS.
“If the Falcon Heavy stays on schedule and the Dragon 2 stays on schedule, they can make 2018,” says former NASA chief technologist Robert Braun, now at the Georgia Institute of Technology in Atlanta. “If those elements take longer, then 2018 gets harder to do.”
Neither piece of kit has been extensively tested yet. The first Falcon Heavy launch is scheduled for later this year, and Dragon 2 is set to undergo test flights this year and next year.
Given SpaceX’s history of announcing ambitious schedules that then slip, Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics isn’t betting on the timeline.
“You can’t guarantee that the first few launches of this big rocket will be trouble-free,” he says. “I think 2018 is going to be pushing it. I could believe 2019, but I wouldn’t mortgage my house on it.”
Still, he has no doubt that the mission is feasible. “They’ll do it. It’s just a question of when.”
If the Falcon Heavy works to its design specs, then it should have no trouble arriving at Mars.
“The challenges of getting from Earth to Mars orbit are clearly manageable,” says space policy expert John Logsdon of George Washington University, noting that India’s space programme did it on the first try. “I’m very curious how they intend to get from Mars orbit to the surface. That’s the harder part.”
With its thin atmosphere and strong gravity, Mars is a difficult place to land. At 900 kilograms, NASA’s Curiosity rover pushed the mass limit for what parachutes can carry to the surface, and its daring hovercraft landing was described as “seven minutes of terror”.
Dragon 2 will weigh in at about 6400 kilograms, more than seven times heavier. It will be equipped with eight engines that will allow it to hover, which were tested when the capsule was dangling from a crane in January (see photo, above). That’s “key for Mars landing”, SpaceX tweeted.
“I presume he’s going to back it down on its engines,” Logsdon says. “That’s a challenge, obviously.”
Luckily, SpaceX has the most experienced Mars landers in the business on its side: NASA.
“Among the many exciting things we’re doing with American businesses, we’re particularly excited about an upcoming SpaceX project that would build upon a current ‘no-exchange-of-funds’ agreement we have with the company,” wrote NASA deputy administrator Dava Newman in a blog post. “In exchange for Martian entry, descent, and landing data from SpaceX, NASA will offer technical support for the firm’s plan to attempt to land an uncrewed Dragon 2 spacecraft on Mars.”
Some of that support will come in the form of using the Deep Space Network to communicate with the spacecraft while it’s en route to Mars, and advice on planetary protection – shielding anything that might live on Mars from destruction by incoming spacecraft.
“The competition is not, should not be between SpaceX and NASA. It’s between humans and Mars,” McDowell says. “Of course there’s internal rivalry as to who gets there first. But everyone involved is like, if someone has a better idea, great, because this is tough.”
If SpaceX misses the 2018 launch window, it will have to wait until 2020 – which might be long enough to come up with a scientific experiment to send with it. If not 2020, then 2022.
“They just keep trying. That approach is the right approach when it comes to something as challenging as landing on Mars,” Braun says. “More important than 2018, I think today’s announcement is just exciting. There’s a private firm that’s going to go to Mars on their own. That’s unheard of. That’s breaking all kinds of new ground.”