That means that NASA won't know whether or not InSight has successfully landed on Mars' surface until after the attempted landing takes place. When it lands 6-1/2 minutes later, it will be travelling a mere 5 miles per hour (8 kph).
"Landing on Mars is hard".
But the US has pulled off seven successful Mars landings in the past four decades.
"The goal of InSight is nothing less than to better understand the birth of the Earth, the birth of the planet we live on, and we're going to do that by going to Mars", Bruce Banerdt, principal investigator of the InSight mission, told CBS News back in May.
When it lands, InSight will have cruised 301,223,981 miles at a top speed of 6,200 mph, while being followed by two cube satellites. InSight will enter the planet's atmosphere at hypersonic speed, and must slow down quickly in order to make a gentle landing. An inquiry completed previous year concluded that onboard computer software errors led to data conflicts, causing the probe to strike Mars at high speed.
An undated handout illustration made available by NASA shows a simulated view of NASA's InSight lander descending towards the surface of Mars on its parachute. The giant NASDAQ screen in New York's Times Square will start broadcasting NASA Television an hour before InSight's scheduled 3 p.m. EST touchdown; so will the National Air and Space Museum's Udvar-Hazy Center in Chantilly, Virginia, and the Denver Museum of Nature and Science. "We have 12 small descent engines grouped around the bottom of the lander that are providing the thrust to slow us down the final kilometer".
The landing will be streamed live on NASA's official YouTube presence.
InSight handed NASA its eighth win.
The InSight mission will also bring several martian "firsts" to interplanetary science, including the first seismometer situated on the surface, to detect and analyze waves created by "marsquakes".
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The entry, descent, and landing phases will each emit a slightly different radio frequency, enabling engineers to track InSight's progress. "The seismometer is what allows us to see deep into the planet, to have insight into the planet, and it uses the seismic waves that are generated by marsquakes". And Tuesday night, the Mars Odyssey orbiter should confirm that the spacecraft's solar arrays have unfurled. Unlike InSight, the MarCO spacecraft keep on going past Mars into space.
The JPL controllers also expect to receive a photo of the probe's surroundings on the flat, smooth Martian plain close to the planet's equator called the Elysium Planitia. Due to a global dust storm, which only recently abated, dust has been redistributed over almost the entire surface of Mars.
The third thing InSight will do is to dig below the planet's surface.
Still, there are no life detectors aboard InSight. The thee-legged, one-armed InSight will operate from the same spot for the next two years.
The $1 billion global effort calls for the robotic geologist to explore Mars' mysterious interior.
The Heat Flow and Physical Properties Probe (HP3) will compliment SEIS, using a self-hammering device to burrow down to a planned five meters below the surface-deeper than any digging on Mars before.
Is Curiosity still on Mars?
Mars has been the graveyard for a multitude of space missions.
It will take two to three months for InSight's robotic arm to set the mission's instruments on the surface. Mars 2020 will also look for water, test oxygen-producing tech, and collect data on weather, wind, radiation, and dust.