NASA's top scientists claimed to not be able to sleep at night, sweaty palms, stomach aches and pure moments of terror when the $ 993-million Mars Insight approached the high drama final Monday: landing on Mars.
The aim of Mars Insight is to listen to earthquakes and vibrations as a way to uncover the inner mysteries of the Red Planet, how they formed billions of years ago, and by extension, how other rocky planets like Earth formed.
Unmanned spacecraft was launched nearly seven months ago, and was the first NASA aircraft to try to land on planet Earth that was near the planet since Curiosity's flight arrived in 2012.
More than half of 43 attempts to reach Mars with explorers, orbits and probes by space agencies from around the world have failed.
NASA is the only space agency that has made it, and invested in this robotic mission as a way to prepare the first human explorer on the planet in the 2030s.
"We never considered Mars as a matter of course. Mars is difficult, "said Thomas Zurbuchen, NASA's associate administrator for the science mission directorate, on Sunday.
‘Really scary thoughts'
High drama of entry, descent and landing phase begins at 11:47 (1940 GMT) at NASA's Jet Propulsion Laboratory in Pasadena, California, home to mission control for Mars Insight.
A carefully arranged sequence – which has been fully programmed in a spacecraft – lasted for the next few minutes, creating "six and a half minutes of terror."
Accelerating faster than bullets at 19,800 kph, a heat shielded spacecraft faces fearsome friction as it enters the Martian atmosphere.
The heat shield rises to a temperature of around 1 500 Celsius. The radio signal might disappear for a while.
The heat shield was removed, three landing feet spread out, and the parachute popped out.
"We plunged for just a little, which was a really frightening thought for me," said Tom Hoffman, InSight project manager.
But then, the spacecraft's driver started shooting, slowing down the 365 kilogram spacecraft to a speed of only about 8 km per hour when it reached the surface.
Because there is no joystick back on Earth for this spacecraft, and there is no way to intervene if something goes wrong, Hoffman describes his emotions as a mixture.
"I was really comfortable and really nervous at the same time," he said.
"We have done everything we can to make sure we will succeed, but you never know what will happen."
Hoffman, who is the father of a child aged two and four years, added that "it didn't sleep that much," although he said it might be because of his babbling children.
But when the first signal arrived in 2001 GMT, hopefully it showed that the lander set himself down, whole and upright, "I will really let go of my four-year-old mind at that time," he said.
Purpose: 3D Mars map inside
Zurbuchen described InSight as "unique" because waist-high landers contained instruments donated by several European space agencies.
The French National Center, Spatiales (CNES) created the Seismic Experiment for Interior Structure (SEIS) instrument, a key element for sensing earthquakes.
The German Aerospace Center (DLR) provides a self-hammer mole that can immerse 16 feet (five meters) to the surface – farther than the previous instrument – to measure heat flow.
The Centro de Astrobiologia from Spain makes spacecraft wind sensors.
Other important contributions to this project came from the Center for Space Research from the Polish Academy of Sciences and Astronics in Poland, the Swiss Institute of Technology in Switzerland, and Imperial College and Oxford University in England.
Together, these instruments will use physics to study geological processes, said Bruce Banerdt, InSight's principal investigator at NASA's Jet Propulsion Laboratory.
By listening to tremors on Mars, whether from earthquakes or meteor impacts or even volcanic activity, scientists can learn more about their interiors and reveal how planets form.
The aim is to map the inside of Mars in three dimensions, "so we understand the inside of Mars and we have understood the outside of Mars," Banerdt told reporters.
Understanding how Mars was formed can reveal more about the processes that make up the Earth as well.
© Agence France-Presse