Landing on the red planet is dangerous – NASA engineers describe it as seven minutes of terror when its rovers, most recently Perseverance, arrive.
Since Tianwen-1 was already in orbit around Mars, its entry speed was not quite as fast as that of Perseverance. China’s lander took a little extra terror – nine minutes – to land, the Global Times, a Chinese Communist Party-controlled newspaper, reported on Friday, citing experts. The probe also worked alone, as the signal transmission between Mars and Earth currently takes 17 minutes and 42 seconds.
Spaceships are descending towards Mars at high speed, and the thin atmosphere is insufficient to slow down the journey to the ground. The shock waves of the air compressed by the speed capsule generate extreme heat that must be absorbed or dissipated. A number of Soviet, NASA and European missions have crashed.
Only NASA has reached the surface of Mars intact more than once. The landings of its largest rovers, Curiosity and Perseverance, have relied on parachutes to slow the spaceship, shields to divert heat from atmospheric friction, and intricate systems known as sky cranes. These were basically rocket-propelled jetpacks that carried the rovers under them and lowered them to the surface with cables before safely flying away from the landing zone.
“For our country’s first Mars exploration mission, we had no first-hand data on the environment on Mars, particularly the atmosphere,” said Chen Baichao, a senior designer on the mission, in a comment from The Paper, a Shanghai-based news site ? ˅. “So it was like entering a completely unfamiliar environment, and you can imagine how difficult that is.”
The Global Times reported that the Tianwen-1 probe lowered its elevation from its park orbit before its lander-rover combination separated from the orbiter around 4 p.m. on Friday around 4 p.m. Eastern Time. (It was 4 a.m. on Saturday in China.)
The orbiter then rose and returned to its park orbit about half an hour after it split up to provide relay communications for the landing craft combination, the Chinese space agency told the Global Times. The lander-rover combination orbited Mars for three hours before entering the Martian atmosphere on the way to landing.