LIVE: Proton-M ESA ExoMars I (Trace Gas Orbiter/EDM) - March 14 2016 (09:31 UTC)

[Svetoslav]

ESA has published a video of simulation of the launch:



So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

[eeergo]

ESA has published a video of simulation of the launch:



So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

It isn't something out of the ordinary for Proton-M/Briz-M: most GEO missions have spacecraft separation at T+9-10h.

[Star One]

ESA has published a video of simulation of the launch:



So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

It isn't something out of the ordinary for Proton-M/Briz-M: most GEO missions have spacecraft separation at T+9-10h.

Are the extended missions these days more influenced by launch site location or launcher performance?

[owais.usmani]

ESA has published a video of simulation of the launch:



So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

Proton-M/Briz-M has performed missions in the recent past where the payload separates from Briz-M more than 15 hours after launch.

[eeergo]

ESA has published a video of simulation of the launch:

So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

It isn't something out of the ordinary for Proton-M/Briz-M: most GEO missions have spacecraft separation at T+9-10h.

Are the extended missions these days more influenced by launch site location or launcher performance?

I understand the long mission durations are mostly related to the low thrust of the S5.98 engine, and so require several coast phases for maneuvers that could be compressed into a single burn with a higher thrust system.

[Phillip Clark]

For GEO missions you find profiles with 3, 4 and 5 burns of the Briz-M assembly.   I have always assumed that the number of burns was chosen to minimise the delta-V required by the payload to reach its GEO drift orbit and also get the payload in a deployment orbit (separation orbit from Briz) with an apogee reasonably close to the planned GEO location.

[Svetoslav]

I guess I'm more worried than I should.

Russia has a significant failure rate when it comes to launching lunar/interplanetary missions. The Proton rocket still fails at regular intervals. If the flight profile for ExoMars includes 4 or 5 burns, this adds to the usual risks.

[Sam Ho]

ESA has published a video of simulation of the launch:

So far I haven't seen the trajectory of Briz-M and how many burns are planed. But my goodness, spacecraft separation is scheduled for 10.5 hours after launch! This is a long flight profile, very complicated.

It isn't something out of the ordinary for Proton-M/Briz-M: most GEO missions have spacecraft separation at T+9-10h.

Are the extended missions these days more influenced by launch site location or launcher performance?

I understand the long mission durations are mostly related to the low thrust of the S5.98 engine, and so require several coast phases for maneuvers that could be compressed into a single burn with a higher thrust system.

It's all related.  Baikonur's latitude means that you need an apogee burn and can't do a direct injection to GEO-1500 like Ariane.  That takes mission duration up to at least 4 hours.  The low thrust of the Briz engine means that performance is better by about 1700kg if you break up the perigee burn into multiple burns with a coast phase in an intermediate orbit.  That takes the mission up to the standard 9 hours.  Throw in a supersynchronous insertion to improve performance by another 200kg and you get a 15.5-hour mission (Inmarsat 5).  Briz on-orbit lifetime is limited by batteries.

Source: Proton Mission Planner's Guide.

[baldusi]

This is not a GEO insertion mission. This is an escape mission. Latitude does not really matter, as long as you do the burn on the opposite node of your escape vector. And given Oberth effect, it's more efficient to do it as low as possible.
Since Mars insertion plane is surely below 17deg, I would guess they will have to go to LEO, coast almost half an orbit until it actually is on the opposite node, and then burn to depletion.

[Sam Ho]

This is not a GEO insertion mission. This is an escape mission. Latitude does not really matter, as long as you do the burn on the opposite node of your escape vector. And given Oberth effect, it's more efficient to do it as low as possible.
Since Mars insertion plane is surely below 17deg, I would guess they will have to go to LEO, coast almost half an orbit until it actually is on the opposite node, and then burn to depletion.

Yes, that's a good point.  Most Proton missions are GTO, so the latitude affects performance, and the reference missions I mentioned earlier are for GTO, but that's not relevant to ExoMars.  The Mission Planner's Guide also has reference escape missions, which take about 9 hours for a hyperbolic velocity that gets you to Mars.  The reference missions make two perigee burns to intermediate orbits before the escape burn, and that is because of Oberth effect and the low thrust of the Briz.

[zubenelgenubi]

Re: Proton-launched interplanetary missions
Proton has not been used to launch an interplanetary mission since Mars '96, and before that for the two Fobos craft in 1988.

These flights used Blok-D upper stages.

[Star One]

Re: Proton-launched interplanetary missions
Proton has not been used to launch an interplanetary mission since Mars '96, and before that for the two Fobos craft in 1988.

These flights used Blok-D upper stages.

So this is all untried territory.

[russianhalo117]

Re: Proton-launched interplanetary missions
Proton has not been used to launch an interplanetary mission since Mars '96, and before that for the two Fobos craft in 1988.

These flights used Blok-D upper stages.

So this is all untried territory.

Phobos Grunt was initially planned on Proton-M/Briz-M before it was redesigned to a Navigator bus and Flagman propulsion stage which could not fly on Proton-M

[Star One]

Scientists want to avoid inadvertently sending microbes from Earth to Mars because they could ruin research into ancient Martian history aimed at determining whether the planet ever harbored life of its own.

The Baikonur Cosmodrome did not have facilities capable of such stringent modern “planetary protection” standards, officials said, so the ExoMars team brought extra gear to meet the cleanliness requirement.

Workers hoisted Schiaparelli atop the Trace Gas Orbiter on Feb. 12 and mated the lander to its carrier craft with 27 screws, which connected a separation assembly between the two modules. When the lander deploys from the orbiter Oct. 16, three days before both spacecraft arrive at Mars, springs on the separation apparatus will push Schiaparelli away, according to a description posted on ESA’s website.

Primarily developed and financed by Italy, Schiaparelli could encounter temperatures as high as 3,360 degrees Fahrenheit (1,850 degrees Celsius) during the plunge through the Martian atmosphere.

With Schiaparelli now together with the Trace Gas Orbiter, the combined spacecraft stands more than 3 meters (10 feet) tall.

The next step to ready the spacecraft for launch will be the fueling of the orbiter with its own propellant supply in the coming week. The orbiter’s total propellant load will be about 2.3 metric tons — more than 5,000 pounds — giving the combined spacecraft a mass of 4.3 metric tons — about 9,480 pounds — at the time of liftoff.

http://spaceflightnow.com/2016/02/19/exomars-orbiter-and-lander-mated-for-final-time/

[Stan Black]

http://www.roscosmos.ru/21958/

Roscosmos announces that the Proton-M rocket has been delivered to Baykonur for 14 march launch date.

Briz-M delivered 16th February.
http://www.express-k.kz/news/?ELEMENT_ID=67258

[Svetoslav]

Update:

http://ria.ru/space/20160221/1378245317.html

Roscosmos is seeking insurance for ExoMars mission in case the Proton-M rocket or the Briz-M stage fail during the flight.

[Svetoslav]

Update:

http://www.esa.int/spaceinimages/Images/2016/02/Fuelling_the_Trace_Gas_Orbiter

ExoMars - Trace Gas Orbiter being fueled for launch. Fueling started Feb. 21.

[Svetoslav]

Anatoly Zak has published a great article about the road to launch:

http://russianspaceweb.com/exomars2016-history-2015.html

Meanwhile ESA has posted important information to media:

http://www.esa.int/spaceinimages/Images/2016/02/Save_the_date_ExoMars_2016_launch_event

Online registration for a dedicated media day at ESA’s operations centre, ESOC, in Darmstadt, Germany, will soon be available via esa.int.

Media representatives as well as social media influencers will be eligible to apply for accreditation to attend the launch event. Note that there is no dedicated social media event; those attending with social media accreditation will be accorded the same access to the event and expert interview partners as traditional/online news media (eligibility requirements will be available soon).

Applicants should already bear in mind that the event at ESOC will take place between approximately 07:00 and 22:00 GMT. In addition to launch coverage in the morning, an extensive programme of speakers is being prepared for the afternoon. The final, fourth-stage rocket burn and separation of the spacecraft, including the first acquisition of signal, is expected later in the evening.

The full programme outline and application details will be available next week.

[jacqmans]

ExoMars 2016 Schiaparelli descent sequence (16:9)
 

Overview of Schiaparelli’s entry, descent and landing sequence on Mars, with approximate time, altitude and speed of key events indicated.
 
Schiaparelli is scheduled to separate from TGO on 16 October 2016, three days before arriving at Mars. Twelve hours after separation, the TGO will perform a course correction to avoid entering the atmosphere, and will continue into Mars orbit. Then, on 19 October, Schiaparelli will enter the atmosphere at an altitude of about 121 km and a speed of nearly 21 000 km/h. In the three to four minutes that follow, it will be slowed by the increasing atmospheric drag, with the front shield of the aeroshell bearing the brunt of the heating. This will slowly melt and vaporise, allowing the absorbed heat to be carried away from the rest of the spacecraft. Once the speed has decreased to around 1700 km/h Schiaparelli will be 11 km above the surface and a parachute will be deployed. The parachute canopy will unfurl in less than a second, and, 40 seconds later, allowing for oscillations to die down, the front shield of the aeroshell will be jettisoned. The parachute will slow Schiaparelli to around 250 km/h, and then the back half of the aeroshell, with the parachute attached to it, will also be jettisoned. It will be drawn rapidly away from Schiaparelli, which will now be completely free of the aeroshell that had kept it safe en route to Mars. Schiaparelli will then activate its three hydrazine thrusters to control its speed. Radar will continuously measure the height above the surface. At an altitude of around 2 m, Schiaparelli will briefly hover before cutting its thrusters, leaving it to free fall. The touchdown speed will be a few metres per second, with the impact absorbed by a crushable structure similar to the crumple zone in a car, on the underside of the lander, preventing damage to the rest of the module. The entire entry, descent and landing sequence will be complete in less than six minutes.
 
More about ExoMars: esa.int/exomars

[Svetoslav]

According to Anatoly Zak, the procedures to attach ExoMars to Briz-M start today.

Here is the timeline, according to http://russianspaceweb.com/exomars2016-prelaunch-processing.html :

February 29: The TGO/Schiaparelli stack to be integrated with its Briz-M upper stage.

March 2-3: A payload section to be encapsulated under payload fairing.

March 5: The ExoMars-2016 spacecraft composite to be integrated with its Proton launch vehicle.

March 11: The Proton-M launch vehicle with ExoMars-2016 to roll out to launch pad at Site 200.

March 14, 09:31:42 UTC: ExoMars-2016 liftoff.