Artist's concept of retrorocket

A proposed SpaceX mission to Mars, called Red Dragon, would offer NASA data about how the lander’s retrorockets (depicted in this artist’s concept) interact with the planet’s surface.

SpaceX/Flickr

Elon Musk’s path to Mars begins with Red Dragon—but what science will it do?

​Elon Musk is whetting the appetites of Mars scientists. The SpaceX CEO has unveiled a vision for the colonization of Mars that he says will involve hundreds of reusable craft, each carrying somewhere between 100 and 250 colonists or so. Fueled in Earth's orbit with methane and oxygen, they could depart to the Red Planet in armadas during launch windows that naturally occur about once every 26 months, Musk told an audience today at the International Astronautical Congress in Guadalajara, Mexico. By using reusable rockets, spacecraft, and tankers; refueling the Mars landers in orbit; and also producing fuel from available resources on Mars for the return trips, a colonist’s cost for a ticket to Mars could be as little as $100,000, Musk says.

The first missions to carry people to the Red Planet aren’t yet scheduled, but unmanned missions—including ones needed to test critical technologies needed to land massive payloads on Mars’s surface—could commence as soon as early 2018. These so-called Red Dragon missions would adapt the same crewed capsule that SpaceX is developing to help NASA send astronauts to the International Space Station, and place it on top of a Falcon Heavy rocket—whose maiden test flight is scheduled for 2017.

Although the first Red Dragon mission would largely be a technology demonstration, there has been great interest from scientists about what sorts of experiments might piggyback on the mission—or, more likely, on its follow-ons in 2020 and beyond, says James Reuter, a deputy associate administrator in NASA’s Space Technology Mission Directorate at the space agency’s headquarters in Washington, D.C.

The notion of the Red Dragon missions “has generated a lot of interest, but we don’t know a lot yet,” says Jeffrey Johnson, a planetary geologist at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and chair of a NASA Mars analysis committee. For instance, he notes, researchers don’t know the size, weight, or electrical system parameters that the Red Dragon craft would make available. “We can’t do much planning,” he adds, until NASA figures out how the Red Dragon missions would be folded into the space agency’s portfolio of upcoming missions.

Typically, NASA chooses science missions and then purchases rockets to deliver the payloads. Musk has flipped that scenario on its head, saying that he will provide a rocket and a lander, and that the rest will follow. The billionaire hasn’t said how he would pay for Red Dragon missions, although he has indicated that he would use some of his personal fortune for them.

Even without dedicated science instruments, Red Dragon could provide a wealth of scientific data to NASA. The space agency isn’t providing any funding for the mission or hiring extra people to operationally support it. But in exchange for technical support, NASA will get access to flight-test data that could help the agency increase the amount of weight it can safely carry to Mars’s surface,  Reuter says. One of these technologies is supersonic retropropulsion—the use of retrorockets to slow a craft as it blazes into the Red Planet’s upper atmosphere at supersonic speeds. Another is pinpoint landing, the same sort of techniques SpaceX has already used to bring its rockets back from space to Earth. Together, Reuter says, these technologies would let NASA land bigger payloads at Mars. The techniques now available to soft-land a craft on Mars—using large parachutes, airbags, and small retrorockets, among others—can only handle payloads of 1 to 1.5 metric tons, but “human missions will need to carry about 20 times that,” Reuter notes.

Flight-test data gleaned during a Red Dragon mission would be available to NASA at a fraction of the cost and about a decade sooner than NASA could do it, Philip McAlister, director of NASA’s Commercial Spaceflight Development Division in Washington, D.C., told a colloquium last week.

If Musk is ever able to achieve his dreams of sending craft large enough to carry a hundred or more colonists to Mars, the same vehicles would offer scientists the hope of sending experiments much more massive than NASA’s previous payloads—including the 185-kilogram Spirit and Opportunity rovers and their follow-on, the car-sized, nearly 900-kilogram Curiosity rover.