Thanks to a thick bank of predawn fog, Catherine Johnson couldn’t see the rocket when it blasted off early Saturday morning at the Vandenberg Air Force Base in California – but she could hear the roar as NASA’s InSight mission set off on its 6½-month journey to Mars.
“It was really impressive,” said Dr. Johnson, a planetary scientist at the University of British Columbia and a member of the mission’s science team. Describing the mood at the launch as a mixture of relief and joy, Dr. Johnson added that “the spacecraft is finally en route to do what we have worked toward for many years.”
But while InSight’s mission is just getting under way, it also marks the last stage in a particularly fruitful period for the U.S. space agency’s Mars program. In the past two decades, multiple, complementary spacecraft tackled different aspects of Mars science.
Unlike the Curiosity rover, which landed on Mars nearly six years ago and is in the process of climbing a mountain in the middle of an ancient crater, InSight is designed to stay in one place after it touches down Nov. 26. Its purpose is to open a new direction in Mars exploration – one that leads straight down as the spacecraft deploys a unique set of instruments to spy on the planet’s interior.
“What we will learn … will help us understand the earliest history of rocky planets, including Earth,” Dr. Johnson said.
It has been a prolonged voyage to the red planet. In 2015, technical problems forced program managers to postpone InSight’s launch for 2½ years. Now, scientists are hoping for smooth sailing to Mars and an uneventful landing a few hundred kilometres north of Curiosity, at a site that Dr. Johnson cheerfully describes as “boring.”
In this case, the point is not to be near geologically interesting terrain, where geologists can find rock outcrops or steep slopes for a rover to explore. Instead, InSight is designed to land on a much safer, Saskatchewan-flat Martian plain where it can lay down a seismometer and quietly listen for “marsquakes” that gently rattle the planet’s foundations. Another instrument will burrow down to a depth of up to 3 metres to measure heat flow through the planet’s interior while a third will measure the magnetic field. The measurements InSight accumulates should enable researchers to map the planet’s internal structure and composition and reconstruct its formation history.
“This type of mission has been recommended by the scientific community for decades,” Dr. Johnson said.
The catch is that InSight cost nearby US$1-billion between NASA and European partners. If it fails, it will likely be more than a decade before NASA is able to undertake a repeat mission.
Opportunities to launch spacecraft to Mars arise, on average, every 27 months as Earth periodically overtakes and passes the red planet, which is about 50 per cent further from the Sun and moves more slowly through its orbit.
For the next opportunity, in 2020, NASA is preparing another rover mission, this time to drill into Martian rock and gather samples. Later on in the decade, a second rover will retrieve the samples so that they can be ferried back to Earth for detailed study. The key question that these two elaborate operations will aim to answer is whether Mars once harboured life in the distant past when the planet was wetter and more hospitable.
But now the growing cost of the two-rover plan has precluded NASA from pursuing other scientific objectives on Mars. For example, last year, the space agency nixed a next generation Mars orbiter that was also supposed to launch in 2020. This threw a wrench into Canada’s plans for developing a radar that would be used on the orbiter to map the distribution of underground ice – a key resource for any future human mission to Mars
Gordon Osinski, a planetary scientist at University of Western Ontario in London, Ont., who led a study of the radar concept for the Canadian Space Agency, said that the best chance for such an instrument ever flying may now hinge on finding another country or even a private company looking to launch a Mars orbiter.
“It’s a big new world out there with a lot of [potential] international partners,” Dr. Osinski said. “Most scientists don’t really care too much who does it, they just want the data.”