The amount of fuel saved (and thus weight dropped -- greatly reduces the need to "lift" very heavy spacecraft -- ones with large liquid ox fuel tanks), leads most deep space missions to now rely on one or more gravity assist "manoeuvres" (to adopt the French formulation of that term, as below), to get to the destination(s).
So it is, with ESA's Hera mission to Didymos, an doublet asteroid system. . . "way out there". [And a prior one of our items, on this mission.] Here's the full story:
. . .Hera is on a two-year journey to the Didymos binary asteroid system, where it will analyse the results of humankind’s first asteroid deflection experiment.
The recent deep-space manoeuvre was carefully calculated to line Hera up for a gravity assist in March 2025 that will shorten the travel time to Didymos.
“We are very fortunate that Mars is in the right place at the right time to lend a hand to Hera,” says Pablo Muñoz from ESOC’s Mission Analysis team, who planned Hera’s journey.
“This enabled us to design a trajectory that uses the gravity of Mars to accelerate Hera towards Didymos, offering substantial fuel savings to the mission and allowing Hera to arrive at the asteroids months earlier than would otherwise be possible. . . .”
Hera fired its three orbital control thrusters for 100 minutes, kicking off its first deep-space manoeuvre and changing its velocity by approximately 146 m/s. A second burn on 6 November lasted 13 minutes with the aim of providing an additional boost of around 20 m/s.
Together, these burns have put Hera on a trajectory that will enable a gravity assist at Mars in March 2025. . . .
Onward. Now you know; smiling.
नमस्ते
No comments:
Post a Comment