PASADENA, Calif. – It all comes down to this.
After a nearly seven-month deep-space journey covering more than 300 million miles (483 million kilometers), NASA's InSight lander is set to touch down on Mars today (Nov. 26) just before 3 pm. EST (2000 GMT). You can watch the action live here at Space.com courtesy of NASA, starting at 2 PM. EST (1900 GMT).
More than half of all Mars missions have failed to arrive safely at the Red Planet over the years, so InSight team is anxious about today's events. [NASA’s InSight Mars Lander: Full Coverage]
"I am completely excited and completely nervous, all at the same time," said Tom Hoffman yesterday (Nov. 25) during a news conference at NASA's Jet Propulsion Laboratory (JPL).
"Everything we've done to date makes us feel comfortable and confident we're going to land on Mars," added Hoffman, who's based at JPL. "But everything has to go perfectly, and Mars could always throw us a curveball."
Hoffman also said that he's been having trouble sleeping over the past few days, but nerves are not the only reason; his young grandkids are visiting for Thanksgiving, and they've been boisterous.
InSight will roll into the Martian atmosphere today at about 12,800 mph (19,800 km / h). Atmospheric drag will dissipate about 90 percent of the lander's considerable kinetic energy, but that will not be enough; InSight will slow itself further with the help of a supersonic parachute and then thrusters.
If all goes according to plan, the lander will drop softly on the red dirt of a flat, boring equatorial plain called Elysium Planitia at about 8 mph (8 km / h) – slightly faster than walking speed. And touchdown will happen and mere 6.5 minutes after InSight gets its first taste of Mars air.
But the tension will not abate right after landing. The InSight team will not know that stationary spacecraft's solar panels have been deployed until 8:35 pm. EST (0135 GMT) at the earliest, when NASA's Mars Odyssey Orbiter will be in position to relay home to Earth confirmation of that milestone event.
The $ 850 million InSight Mars lander mission – whose name is short for "Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport" – launched on May 5 atop a Atlas V racket from Vandenberg Air Force Base in California. This was a first: all previous NASA interplanetary missions had been launched from Florida's Space Coast.
The lander is outfitted with two major science instruments – a burrowing heat probe and a trio of incredibly sensitive seismometers. This equipment will help mission scientists map the Martian interior in unprecedented detail over the next two Earth years, revealing key insights about the formation and evolution of rocky planets, NASA officials said.
The mission team will also use InSight's communications gear to measure the wobble of Mars' axial tilt. Such information will shed light on the size and nature of the planet's core.
This focus on the Martian interior explains why the mission team chose such a boring landing site: Cliffs, craters, ancient river delta and other landscape features would serve only to complicate a safe touchdown.
And do not expect a flurry of data just after landing today: InSight's science work will not begin in earnest for several months. It will take that long for the team to get ready to deploy the seismometer suite and heat probe, both of which InSight must place on the Martian surface with its robotic arm, and then calibrate the instruments.
"InSight is a slow-motion mission," said InSight chief investigator Bruce Banerdt, also of JPL, during the yesterday's news conference.
The lander launched with two briefcase-sized spacecraft called Marco-A and Marco-B, which aimed to prove that cubesats can explore interplanetary space. The two free-flying probes have succeeded in this task, but they have one more job ahead of them: they will try to beam home data from InSight during landing, landing and landing today. A failure on this relay front will not be disastrous, however; other NASA craft, such as Odyssey and the Mars Reconnaissance Orbiter, will perform this work as well.
InSight was originally supposed to launch in March 2016, but mission team members detected a leak in the vacuum chamber surrounding the seismometers in late 2015. The leak was fixed but not in time to meet that liftoff window. (Earth and Mars align favorably for planet missions just once every 26 months, so InSight had to wait a while before finally getting off the ground.)
Visit Space.com today for full coverage of the InSight landing on Mars.
Mike Wall's book about the search for alien life, "Out There"(Grand Central Publishing, 2018; illustrated by Karl Tate) is out now. Follow him on Twitter @michaeldwall. Follow us @Spacedotcom or Facebook. Originally published on Space.com.