ExoMars launch scheduled for 09:31 GMT (10:31 CET)
esa.int
esa.int
http://www.esa.int/Our_Activities/Space_Science/ExoMars/ExoM...
Half of the recent Proton losses have been from third stage failures (worked here), the other half of the Briz-M upper stage (still needs to do a few more burns).
• 2014, 935-45: Third stage failure
• 2013, 935-43: First stage failure
• 2012, 935-34: Briz-M failure
• 2012, 935-31: Briz-M failure
• 2011, 935-21: Briz-M failure
• 2010, 535-37: Blok-D failure
3/6 in the Proton-M+Briz-M configuration, 3/7 total, for this decade. There were also two failed Rokot launches involving a different Briz configuration (Briz-KM).
Really? Why is so much money spent, seemingly on just that goal? It seems such a waste to search for life on Mars when it's so unlikely. Sure finding signs of past life would be a great discovery, but it seems unlikely after the number of missions that have gone already. Surely there are better goals for a mission.
If you're really searching for tiny signs of life in a nook or layer of dirt, wouldn't you have to send 100s of thousands of probes, not just one additional lander?
Rant ends. Sorry.
[1] http://www.esa.int/Our_Activities/Space_Science/ExoMars/What...
The first relevant thing is indeed the orbital position of Mars in relation to Earth. For simple Hohmann transfers, launch windows to Mars open every 26 months or so, and they last several days. In this case, ExoMars launch could have been delayed until March 25 had any issues prevented the launch today.
The second timescale has to do with Earth's rotation. Even though most interplanetary spacecraft, including the ExoMars probe, are launched into a temporary parking orbit before injection to transplanetary trajectory, that orbit needs to have the right shape and inclination to make the injection burn feasible from the fuel economy point of view. Orbital plane changes are particularly expensive. Thus, the daily launch window may only last a minute or so when the launch site intersects the plane of the ecliptic.
There is a short video of the launch on ESA's youtube channel but the quality is horrible.