HomeJust heard from the Flight Dynamics folks here at ESOC, and SOM Andrea Accomazzo dropped by with early news: It appears that Rosetta was just slightly more than 1.1 km from the planned swing-by target! This performance, if confirmed, means that her trajectory was more accurate than predicted. The perigee passage time (= time of closest approach) was less than 0.01 seconds different from the last prediction made before the swing-by. -- Daniel
2 comments | "Swing-by accuracy"
13-11-2009 • 16:57:41
I'm curious to know how much a difference of 1.1km and 0.01 seconds at the swing-by makes to how accurate the asteroid rendezvous will be.
Although I imagine there are many variables, is there a relatively simple way to quantify the tolerances before, say, rocketry would have to be used extravagantly to save the mission?
Answer when you have time!
Enjoying the blog RSS. Thanks.
14-11-2009 • 09:20:23
I asked this question to Trevor Morley here at ESOC. He says:
Neither has any consequence for the Lutetia fly-by next year.
The error in the timing prediction has no consequence at all.
The 1.1-km error will be removed by a so-called 'clean-up' manoeuvre on 23 November. Before the fly-by we knew that for each km error this manoeuvre size would be between 20-40 cm/s depending upon the direction of the error. So the driver for trying to minimise the swingby trajectory error was to minimise the amount of propellant needed for the clean-up. Regards, -- Trevor