Rosetta gets in position to release Phalae
Rosetta has successfully maneuvered into position prior to releasing Philae on November 12 for landing on Comet 67P/C-G.
The thruster burn took place starting at 02:09:55 UTC (03:09:55 CET), ran for 90 seconds and, based on an initial analysis of spacecraft radiometric data, delivered a delta-v – change in speed – of 9.3 cm/sec, as confirmed by the Rosetta Flight Dynamics team. It was the second and final of two ‘deterministic’ (i.e. direction and thrust are prepared in advance) manoeuvres that moved Rosetta onto the planned lander delivery orbit, now at a height of about 30 km, which will be maintained right up until the pre-delivery manoeuvre at two hours before separation at 08:35 UTC (09:35 CET) on the morning of 12 November.
…[T]he next planned orbit-changing manoeuvres will occur on the 12th at (a) 2 hours before separation and (b) about 40 minutes after, in between which Philae will be released. The pre-delivery manoeuvre will shift Rosetta’s trajectory so that the orbiter would be on a path so as to pass over the comet at a distance of 5 km, while the separation will occur at 08:35 UTC on board the spacecraft about 22 km (the confirmation signal will arrive on Earth at 09:03 UTC).
Since Philae is a passive lander, firing no thrusters but simply being thrown gently at the comet by Rosetta, the last two burns are crucial. The first literally puts Rosetta on the same collision course as Philae so that when the lander is released it is on a course to hit the comet. The second takes Rosetta out of that collision course, since no one wants it to hit the comet also.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Rosetta has successfully maneuvered into position prior to releasing Philae on November 12 for landing on Comet 67P/C-G.
The thruster burn took place starting at 02:09:55 UTC (03:09:55 CET), ran for 90 seconds and, based on an initial analysis of spacecraft radiometric data, delivered a delta-v – change in speed – of 9.3 cm/sec, as confirmed by the Rosetta Flight Dynamics team. It was the second and final of two ‘deterministic’ (i.e. direction and thrust are prepared in advance) manoeuvres that moved Rosetta onto the planned lander delivery orbit, now at a height of about 30 km, which will be maintained right up until the pre-delivery manoeuvre at two hours before separation at 08:35 UTC (09:35 CET) on the morning of 12 November.
…[T]he next planned orbit-changing manoeuvres will occur on the 12th at (a) 2 hours before separation and (b) about 40 minutes after, in between which Philae will be released. The pre-delivery manoeuvre will shift Rosetta’s trajectory so that the orbiter would be on a path so as to pass over the comet at a distance of 5 km, while the separation will occur at 08:35 UTC on board the spacecraft about 22 km (the confirmation signal will arrive on Earth at 09:03 UTC).
Since Philae is a passive lander, firing no thrusters but simply being thrown gently at the comet by Rosetta, the last two burns are crucial. The first literally puts Rosetta on the same collision course as Philae so that when the lander is released it is on a course to hit the comet. The second takes Rosetta out of that collision course, since no one wants it to hit the comet also.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
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