EXOMARS 2016 ATTEMPTED LANDING ON MARS FAILS.
Posted on 10/20/2016
This article is based on extracts from Space.com’s article entitled European Spacecraft Reaches Mars Orbit, But Lander’s Date Uncertain. It was published by Mike Wall on October 19, 2016 at 3:00 PM ET. Our comments are in blue fonts.
ExoMars 2016's lander, called Schiaparelli, hit the Martian atmosphere as expected at 10:42 a.m. EDT (1442 GMT); however, mission team members are still waiting for a signal to confirm that the craft survived its touchdown six minutes later. Schiaparelli's signal came in loud and clear as the lander streaked through the Martian atmosphere but stopped shortly before the lander was scheduled to hit the ground, said Paolo Ferri, head of ESA's mission operations department.
"It's clear that these are not good signs, but we will need more information, and that's what's going to happen tonight," Ferri said. "I'm quite confident that tomorrow morning we will know" what happened, he added.
But by the next day there was still no signal. Worse, BBC News reported that it was apparent that the parachute was jettisoned too early (when the lander was too high). If the mechanism that triggered the jettison was linked not just to radar, but also to outside air presssure then instead of releasing the parachute at 1.2 km it might have deployed so high that there might not have been enough rocket fuel to finish the landing successfully. All this would imply higher than advertised Martian air pressure.
Figure 1 - Planned ending to the landing for ESA.
Schiaparelli and TGO launched together in March, lifting off atop a Russian Proton rocket from Baikonur Cosmodrome in Kazakhstan. The two spacecraft represent the first phase of the two-part ExoMars program, which is led by ESA with Russia's space agency, Roscosmos, as chief partner. The second phase of ExoMars will launch a life-hunting rover in 2020, if all goes according to plan. Europe is spending 1.3 billion euros ($1.43 billion at current exchange rates) on the ExoMars program, ESA officials have said.
Schiaparelli and TGO traveled together until Sunday (Oct. 16), when they separated ahead of their divergent Mars arrivals. Schiaparelli reached the Red Planet first, hitting the thin Martian atmosphere at the blistering speed of 13,050 mph (21,000 km/h). Mission team members tracked the lander's progress this far, but they weren't able follow it all the way down to the surface.
"Initial signals [from Schiaparelli] were received via the Giant Metrewave Radio Telescope (GMRT) as Schiaparelli descended to the surface of Mars, but no signal indicating touchdown yet," ESA officials wrote in a blog post this morning, referring to an array of dishes near Pune, India.
This graphic (shown above in Figure 1) provides an overview of Schiaparelli's planned Oct. 19, 2016, entry, descent and landing sequence on Mars, with the approximate time, altitude and speed of key events indicated.
The ExoMars 2016 lander is powered by nonrechargeable batteries that should die in just a few days, ESA officials have said. The data Schiaparelli gathers would therefore be limited. The lander does feature a meteorological station to measure temperature, wind speed, humidity and other weather conditions on the Martian surface. Schiaparelli also was programmed to do some science work during its brief descent through the planet's atmosphere — for example, measuring air density, pressure and temperature from an altitude of 81 miles (130 km) down to the planet's surface, ESA officials said.
So, it seems like what was lost was exactly what was needed to prove (or disprove) our argument that air density and pressure on Mars are higher than NASA asserts. However, perhaps we might still hear about some pressure data that was measured before the apparent crash.