Broadcasting from the Green Bank Telescope control room, Toney Minter, head of GBT operations, explains what the GBT monitored during the InSight Mars landing Monday. At left, doctoral student Rachel Slank shared a slide and described what the monitors in the control room would show during the landing. S. Stewart photos

Suzanne Stewart
Staff Writer

Five months and 21 days after it was launched from Vandenberg Air Force Base in California, the InSight robot successfully landed on the Elysium Planitia near the equator of Mars.

While NASA was unable to witness the landing, the Green Bank Telescope saw it all and monitored the landing during the “seven minutes of terror” – the time between the final descent and the transmission from the robot.

To celebrate the momentous occasion, the Green Bank Observatory held an InSight Landing Party which included activities, video feed from the GBT control room and a presentation titled “A Look Inside the Red Planet: the InSight Mission,” by Rachel Slank, a doctoral student at the University of Arkansas.

When it came time for the landing, visitors waited eagerly in the science center auditorium where a live feed from the GBT control room was broadcasting on the screen. As they waited, the astronomers and their guests in the control room explained what the GBT would monitor and how it would show up on the screen.

Prior to the landing, Slank explained the process InSight went through during the “seven minutes of terror.”

“There will be a two-minute period where it’s just so hot, the heat shield it has around it won’t be able to send out the radio waves, but for almost the entire seven minutes we should be able to see it,” she said. “We will be able to see it when the parachute opens; we’ll see it slowing down, and we’ll see it land.”

When Slank says “see” she doesn’t mean a video feed of the actual landing. The GBT was able to monitor the radio waves transmitting from InSight and when there was a peak in the waves on the screen, that was the moment the robot landed.

At the time of the landing, InSight was programmed to send a transmission to let NASA know it was in place. It also sent a transmission giving a function status.

“When InSight lands, it’s going to ‘yell’ in tones, ‘Yay, I made it! Yay, I made it!’” Slank said. “I imagine it’s doing a little dance even though I know that’s not possible. Then it’s going to send a stronger signal right after– letting us know how healthy it is, if there’s any damage and if it’s completely functioning.”

In her presentation, Slank gave an overview about the history of Mars and what is known about the planet so far. She then dove into the reason for InSight and what the robot will do during its time on the red planet.

“Why InSight?” Slank said. “We have a ton of stuff that’s happening over there; why do we need a new mission? Well, all of this focused on the surface history. We looked at canyons. We looked at volcanoes and rocks and dirt, but we never really looked at the inside of this happy little guy. We want to know what’s happening below. How it formed; is it still active. Mars is perfect for that because it’s not too big and it’s not too small, so it actually allows the record to be preserved to look at the subsurface.”

InSight stands for the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. While on Mars – for a Martian year, roughly two Earth years – the robot will be searching for answers to questions like how much tectonic activity is occurring and what creates the interior of Mars.

“We’ll get to know more about the crust which is the outer layer; the mantel which is the middle beefy part and the core which we actually don’t even know if it’s liquid or solid,” Slank said. “We have no clue, so hopefully InSight will give us some insight to that.”

InSight is a stationary lander so it will stay motionless while it collects data. It has three instruments which will do all the work.

“It’s going to do a check-up of the planet because everyone needs to go to the doctor,” Slank said. “It’s going to be checking its vital signs. It’s going to be checking its pulse – the seismology; its temperature – heat flow; and its reflexes with precision tracking.”

The seismometer will be able to detect Marsquakes as well as when meteorites strike the planet. It is the first seismometer in 40 years to be used on Mars. The second instrument is called the Heat Flow and Physical Properties Probe which will burrow into the planet and send out heat pulses to monitor the interior’s reaction to heat.

“Once it gets down to its sixteen feet, it’s going to measure how much heat is escaping from the Martian interior,” Slank said. “That will help us figure out how Mars formed, and it can also see if Mars and the interior are warm enough to have pockets of liquid water. In July, we found a subsurface lake at the South Pole of Mars but it is not going to be the same process we’re looking for here. Here, they’re hoping it’s just warm enough somewhere on the surface that a pool of water can exist.”

The third main instrument is the Rotation and Interior Structure Experiment, also known as RISE, which is basically a GPS system.

“There are these two little antennas that are just super fancy GPS,” Slank said. “They’re precisely tracking the location of the lander at all times down to a few centimeters and its main goal is to figure out how much the North Pole wobbles as it orbits around the sun and, with that, it will be able to determine the size of the core, if it’s liquid or a solid and then what the core is composed of, hopefully.”

After her presentation, Slank opened the floor to questions and then joined the astronomers in the GBT control room to witness the landing.

The live feed was also broadcast to the Clay Center in Charleston.