Scientists also determined in recent weeks that Curiosity was on course to hit the Martian atmosphere about 13 miles east of the optimal “entry point.” Last weekend, they conducted a routine trajectory correction — a “burn,” in pop-science parlance. The operation was a success, but imperfect. The spacecraft’s new trajectory will send it into the Martian atmosphere at a point roughly 3,000 feet from where scientists had planned after the correction.
However, Curiosity’s landing target is an ellipse of land 12 miles wide, allowing for considerable wiggle room. What’s more, the craft has been equipped with a self-correcting navigation system called “guided entry” — thrusters that can correct miles’ worth of error in trajectory.
Adam Steltzner, a leader of the JPL team overseeing the spacecraft’s landing, said an error of just 3,000 feet could easily be “flown out” — absorbed by the sophisticated navigation system. Scientists have two other opportunities for corrective “burns,” but said it was unlikely they would use them.
“We are doing everything we can to make sure that we are going to the right place,” said Tomas Martin-Mur, the mission’s navigation team chief. “I am confident that we will get there and get there safely.”
Also Thursday, scientists revealed that Curiosity already has delivered results, even before it lands.
Curiosity’s instruments are expected to yield a new understanding of Mars’ history and environment. The mission’s impact doesn’t end there, however. Curiosity is also expected to pave the way for future Mars missions, including the first human exploration. President Obama has set a goal of sending an astronaut to Mars by the 2030s.
That would be no small matter. Rather than the three days it took to reach the moon, an astronaut would endure a nine-month trip there and then another one to get home. Scientists are still trying to understand how they might guard against radiation astronauts would encounter. It’s a critical issue. Carrying a proper radiation shield would be both vital and burdensome.