From a vigil-like feeling in mission control as project scientists sat glued silently to their computers to raptous clapping, back-slapping, cheering and applause was all that could be heard when the first successful signal came through that the Trace Gas Orbiter had successfully entered Mars’ atmosphere.  

But, the jury is still out on the success of the ExoMars Lander - scientists are busily analyzing the data which is being sent back to Earth.

Paulo Ferri, head of the Mission Operations Department at ESA, told those who had stayed on to watch the announcement that there would be no news on the Lander's success or death until early Thursday morning. 

Even if the lander doesn’t go to plan, valuable scientific lessons will be learnt for future missions, Jorge Vago, ExoMars Project Scientist said in Darmstadt. In the coming hours though, scientists will have a better idea of the craft’s success. 

Just before, excitement turned to nervousness at the European Space Agency in Darmstadt as the European-Russian Lander Schiaparelli lost signal with Mission Control after entering the Mars atmosphere. 

"All is not lost," Andreas Accomazzo, head of the solar planetary mission division at ESA, said immediately after the announcement from Mission Control that the initial Lander signal was undetectable when the craft entered the atmosphere of the Red Planet. 

"We have to wait for an hour or so, so we can analyze the data" Accomazzo told silent onlookers gathered to watch. "It is only in the last part that we have lost signal. We are waiting for data from the Pune radio telescope. This is an experimental setup, so of course, we could never try it in an environment like this. We cannot [draw] conclusions, we should wait for the Mars express data. Pune as well might find something in the data they have recorded. It’s a very weak signal in this ocean of noise. We shouldnt jump to conclusions."

Nerves and excitement abound. This is the climax of a seven-month 496-million-kilometer (308-million-mile) trip to Mars.

Just minutes before the lander descended into the planet's atmosphere, everything seemed to be going well. Mission control received confirmation that the braking in preparation for the landing had begun. And there was a strong and clear signal from the Giant Meter Wave Radio Telescope in Pune, India, that the Schiaparelli demonstrator module had woken up and was on course to land around 1600 UTC.

Schiaparelli along with the Trace Gas Orbiter (TGO), is a joint project of the European Space Agency and Russia's Roscosmos. Their target destination is the Meridiani Planum in the Martian highlands. 

ESA dispatched the experimental paddling pool-sized probe in March to explore the planet's atmosphere and search for signs of life.

"Everything has to function to millisecond precision," ExoMars project scientist Jorge Vago said ahead of the planned landing. "And our options for intervening are precisely zero."

Data transmitted from the Red Planet takes around 10 minutes to reach Earth. This signal delay means a computer will control the landing maneuver for the 600-kilogram (1,322-pound) machine. Should anything go wrong, the craft will be a pile of scrap metal embedded in the surface of Earth's neighbor before scientists are aware of its fate.

Since space travel began, only seven missions have successfully landed probes on Mars.

And, only time will tell the fate of ESA's ExoMars mission. The joint mission with Roscosmos is Europe's first attempt at reaching Earth's neighbor after a failed bid 13 years ago to place the first non-US rover on the Red Planet. 

And here are some interesting facts about Mars: