Updates GOCE Mission News

[Scrooge McDuck]

Ready for launch mail from ESA:

The Russian State Commission has given the go-ahead for GOCE to be launched today at 15:21 CET from the Plesetsk Cosmodrome in northern Russia. GOCE will map Earth’s gravity field with unprecedented accuracy, providing insight into ocean circulation, sea-level change, climate change, volcanism and earthquakes. Read more at:
http://www.esa.int/SPECIALS/GOCE/SEMFIYITYRF_0.html

 

[SiberianTiger]

http://www.esa.int/SPECIALS/GOCE/SEMFIYITYRF_0.html

As GOCE Project Manager, Muzi will have to confirm to the Russian launch authorities whether ESA’s satellite and ground segment are ready.
"Forty minutes before launch, we will confirm that satellite telemetry is as expected and check with the Flight Director at ESOC that the ground segment is ready," Muzi said. "Then, I will flip three 'Red/Green' switches over to 'Green' - that's the final step on the ESA side.".

 

[Scrooge McDuck]

Update after we watched the live broadcast:

Surprizingly, the launch was put on hold 7 seconds before launch. Source of the problem is yet unknown. Probably scrubbed for today.


When available, more news here:

http://www.esa.int/SPECIALS/GOCE/index.html

http://news.bbc.co.uk/2/hi/science/nature/7946480.stm

 

[Woo482]

The problem was definitely the tower not moving back

 

[stjimmy225]

d'oh!

 

[SiberianTiger]

It looks like the problem appeared earlier than 7 seconds before the launch time, while the "official" clock kept ticking. There are no confirmations what happened yet, but there are rumors that one service tower's door did not open.

Hmm, all **** happens when I'm not looking. Over the last year: two satellites put in wrong orbit, a Soyuz ballistic reentry... Every time I wasn't looking.

---------- Post added at 23:24 ---------- Previous post was at 19:51 ----------

Postponed exactly one day till
17.03.2009 at 14 h 21 m 17 s UTC (16.03.2009 17 h 21 m 17 s Moscow Local Time )

---------- Post added at 17:40 ---------- Previous post was Yesterday at 23:24 ----------

There's a lift-off!

---------- Post added at 17:40 ---------- Previous post was at 17:40 ----------

First and 2nd stages performed nominal.

---------- Post added at 17:42 ---------- Previous post was at 17:40 ----------

530 sec, third stage is performing good.

---------- Post added at 17:43 ---------- Previous post was at 17:42 ----------

580 sec MECO, 3rd stage sep

---------- Post added at 18:56 ---------- Previous post was at 17:43 ----------

GOCE Separation confirmed and signal received.

 

[Scrooge McDuck]

Telemetry received, GOCE separation confirmed! Responding well to test commands.

 

[SiberianTiger]

Telemetry received, GOCE separation confirmed! Responding well to test commands.

Good luck GOCE!

 

[Notebook]

More news of GOCE

http://www.esa.int/esaCP/SEMOKLJTYRF_index_0.html

N.

 

[Notebook]

http://www.esa.int/esaCP/SEMZ8TJTYRF_index_0.html

GOCE completes early orbit phase


N.

 

[Pquardzvaark]

Maybe I should read about it a bit more closely, but I hear the GOCE satellite works by detecting small variations on the gravitational attraction from the Earth, correct? And the small thruster is to compensate for air drag in the Earth's atmosphere.

Anyway, doesn't the density of the upper atmosphere change depending on solar activity? So how does GOCE compensate for that without screwing with its other measurements?

Just curious.

 

[tblaxland]

Maybe I should read about it a bit more closely, but I hear the GOCE satellite works by detecting small variations on the gravitational attraction from the Earth, correct? And the small thruster is to compensate for air drag in the Earth's atmosphere.

Anyway, doesn't the density of the upper atmosphere change depending on solar activity? So how does GOCE compensate for that without screwing with its other measurements?

Just curious.

Here's my understanding of it. GOCE contains accelerometers that are spatially distributed on the spacecraft. The spatial distribution means that these accelerometers are experiencing a slightly different gravity field to each other at any one time and combining their results yields the gravity gradient. The effects of atmospheric drag are compensated for by accurate position and velocity measurements using the Satellite-to-Satellite Tracking Instrument (SSTI) mentioned in that article that Notebook linked to.

 

[SiberianTiger]

A video found on youtube:

 

[Notebook]

Nice animation. Wonder what the graph is showing on top right? At 2:20 into the video, there is quite a transient when the 1st stage seperates, then its flat till end.

N.

 

[tblaxland]

Wonder what the graph is showing on top right? At 2:20 into the video, there is quite a transient when the 1st stage seperates, then its flat till end.

Chamber pressure?

 

[SiberianTiger]

Nice animation. Wonder what the graph is showing on top right? At 2:20 into the video, there is quite a transient when the 1st stage seperates, then its flat till end.

N.

This one, in the top left here? It reads "Launch Vehicle's Angles' Deviation": red (1 in row) stands for pitch, green (2 in row) stands for yaw and blue (3 in row) stands for roll. So there was a -6 degrees parasite roll before the 1st stage separation and till the 2nd took up attitude controls.

 

[Notebook]

Yes, thats the one, thanks for the translation. I thought it might be thrust, but there wasn't any transient on the 2nd stage seperation.

Thanks, N.

 

[Notebook]

For anyone who wants to know where GOCE is:-

http://www.esa.int/SPECIALS/GOCE/SEM7IPJTYRF_0.html

N.

 

[Notebook]

http://www.esa.int/esaCP/SEMSZCEH1TF_index_0.html

GOCE's electric ion propulsion engine switched on

N.

 

[Notebook]

http://www.esa.int/esaCP/SEMUKIEH1TF_index_0.html

8 April 2009
GOCE’s highly sensitive gradiometer instrument has been switched on and is producing data. Forming the heart of GOCE, the gradiometer is specifically designed to measure Earth’s gravity field with unprecedented accuracy.

N.