ExoMars mission, joint project of ESA and Roscosmos, has just entered into its most crucial phase – EDM lander was deployed and we are waiting for successful landing on Mars surface and final confirmation of EDM condition with telemetry data.
After seven months since launching on atop of Proton-M from Baikonur Cosmodrome on March 14, 2016, TGO and EDM finally reached correct distance to Mars to conduct crucial maneuver for whole mission. Today it was planned to deploy EDM (Entry, Descent and Landing Demonstrator Module) from remaining on collision course TGO (Trace Gas Orbiter) and next perform course correction of TGO to avoid collision with Mars. This risky course was necessary to reach necessary position for releasing EDM lander and setting it on correct trajectory to reach 100 km long and 50 km wide landing zone on Meridiani Planum close to Martian equator. Mission Control Center in Korolev already conducted successfully necessary course correction of TGO on July 28, 2016 and two months later on October 3 and October 7, ESA uploaded to series of commands for TGO and EDM to prepare both vehicles for separation and landing.
ESA mission control center in Darmstadt started live broadcast at 14:37 GMT. Basing on data provided Giant Metrewave Radio Telescope (GMRT) radio telescope in Pune, India, ESA specialists were monitoring of separation procedure of TGO and EDM. ESA Flight Director, Michel Denis, took his place on console to personally control whole procedure. Team was waiting to receive final confirmation of separation; previously uploaded commands were executed and now waiting was only thing, which could be done from Earth – TGO and EDM performed separation basing only on string of commands uploaded on October 3 and October 7, 2016. At 14:42 GMT TGO and EDM should be separated, but Mission Control Center in Darmstadt was still waiting for the final confirmation of success. At 14:53 GMT first confirmation was given after interpreting Doppler data provided by GMRT. Still, ESA was waiting with official confirmation to receive and interpret telemetry. Due the fact, that radio signal from TGO reached Earth after 9 minutes 36 seconds, it was known that it would take some time to extract telemetry data and perform analysis. Finally at 15:27 GMT ESA decided to confirm successful separation of vehicles without using telemetry data, basing only on radio signal received from TGO at around 14:54 GMT. It was announced, that separation was correct, but telemetry data have not been received. It was announced, that it will be under further investigation, why telemetry data were not received. Due this fact it is hard to evaluate exact hour of separation moment – probably it was conducted between 14:30 GMT to 14:50 GMT.
Separation of TGO and EDM was set for today, but next phase, landing of EDM will be conducted on 19th October, 2016. It will be hard moment for ESA and Roscosmos – lander will test technologies used for the first time and planned to be utilized during planned under ExoMars program landing of Mars rover in 2020. Any problem at this time would mean necessity of changing seriously project of Mars rover lander and probably additional delay. EDM will slow down using special parachute, which will help in reducing speed from 1650 km/h to only 250 km/h during lasting 6 minutes final descent of EDM. Heat shield will help to survive temperature during passing through Mars atmosphere and three groups of thruster nozzles will help in final stabilization of EDM and reducing speed just before free fall on Mars. TGO after it passed moment of separation will enter under influence of Mars gravitation. It will start its engine to enter into correct Mars orbit to continue flight. Next it will spend on orbit months and uses aero braking (reducing speed using only density of Mars atmosphere without igniting propulsion) and start its mission in 2017.