LIVE: Ariane 5 GS launch - Helios IIB - December 18, 2009

[Chris Bergin]

Moved for live coverage

[WHAP]

Really?  Ariane 5 launching from the equator can't put a 4200 kg mass into a final orbit of 680 km circular?  I'm not buying it.

[Alpha Control]

Whether it coincides with the original in French?

"...sur l'orbite visée."

It needs the equivalent of a Centaur upper stage to raise it's orbit. That must be the missing mass.

And here I was hoping that they were sneaking an ARV demonstrator under the fairing.

[edkyle99]

Really?  Ariane 5 launching from the equator can't put a 4200 kg mass into a final orbit of 680 km circular?  I'm not buying it.

You're right.  G could do 9.5-ish tonnes, plus or minus, to an 800 km sun sync orbit.  GS, with the slightly more powerful solid boosters but heavier EPC, should be able to do a bit less, perhaps 9 tonnes.  Keep in mind too that this EPS does a less than ideal single single-burn ascent profile.

 - Ed Kyle

[sdsds]

It's sad that a clone of the Orbiting Carbon Observatory wasn't available to share the ride with Helios 2B, like PARASOL did with Helios 2A.

[woods170]

Whether it coincides with the original in French?

"La performance demandée au lanceur Ariane GS pour ce vol est de 5 954 kg dont 4 200 kg représentent la masse du satellite HELIOS 2B à séparer sur l'orbite visée."

Not really, a slightly more appropriate translation shoud be:
"The required performance of the Ariane GS launcher for this flight is 5,954 kg of which 4,200 kg represents the mass of the HELIOS 2B satellite at time of separation."

Still, that leaves some 1,700 kg to be accounted for. However, take a good look at the payload-stack image here. Is that an additional small-payload-carrier I see below the satellite adapter? That would at least partially explain the weight difference.

[Mighty-T]

The Ariane 5GS is dramatically overpowered for the launch of Helios. In order to dissipate excess power, it will embark on a de-optimized trajectory and it uses the ASAP platform and MFD ring(s) as additional ballast.

[SIM city]

Has this launch been postponed?
http://www.videocorner.tv/index.htm

[epastel]

Has this launch been postponed?
http://www.videocorner.tv/index.htm

Indeed, it has been postponed.

[Chris Bergin]

Do we have a reason? Rare for Ariane to delay on the day of launch.

[klausd]

During final count-down operations for Flight 193 slated for today, an anomaly occurred in a launcher subsystem.

As a result, Arianespace has decided to replace this part, and thus to postpone the launch for a few days.

The launch vehicle and its HELIOS 2B satellite payload have been placed in stand-by mode and maintained in fully safe conditions.

http://www.arianespace.com/news-press-release/2009/12-09-09-launch-postponed.asp

[Mighty-T]

Reson for the delay is a problem with the Helium pressurization system of the first stage. Launcher needs to return to assembly building to fix it.

[Chris Bergin]

Thanks.

I hope we don't end up with an Endeavour rollover, WISE launch and HELIOS 2B launch all on the same day

[jcm]

The Ariane 5GS is dramatically overpowered for the launch of Helios. In order to dissipate excess power, it will embark on a de-optimized trajectory and it uses the ASAP platform and MFD ring(s) as additional ballast.

OK, thanks. But there are definitely no secondary payloads on the ASAP platform this time? I think that's the first time an ASAP has flown with no piggyback experiments.

[Ben the Space Brit]

Just a thought, if this is a recon/intel bird, shouldn't it be launched into a polar orbit? Do they do that direct from CSG or do they do a plane change burn after reaching an initial equatorial orbit? It might explain the over-powered LV.

[sdsds]

Just a thought, if this is a recon/intel bird, shouldn't it be launched into a polar orbit? Do they do that direct from CSG or do they do a plane change burn after reaching an initial equatorial orbit? It might explain the over-powered LV.

This is covered in the "launch kit" mentioned previously:

The launch kit is available :
http://www.arianespace.com/news-launch-kits/launch-kit.asp

The destination orbit is sun-synchronous polar.  The launcher first climbs vertically for 10 seconds, then rotates towards the North.  I think the trajectory graphic shows it crossing the Gulf of Saint Lawrence before making landfall over Quebec.

[robertross]

The destination orbit is sun-synchronous polar.  The launcher first climbs vertically for 10 seconds, then rotates towards the North.  I think the trajectory graphic shows it crossing the Gulf of Saint Lawrence before making landfall over Quebec.

landfall over Quebec???  ummm, I don't think that sounds quite right.

[sdsds]

The destination orbit is sun-synchronous polar.  The launcher first climbs vertically for 10 seconds, then rotates towards the North.  I think the trajectory graphic shows it crossing the Gulf of Saint Lawrence before making landfall over Quebec.

landfall over Quebec???  ummm, I don't think that sounds quite right.

Sorry, all those big land masses up there look kind of the same to me.  Maybe it crosses over Greenland or something.  Or was "makes landfall" the trouble?  Should I have said, "goes feet dry"?  Or "where the projection of the vehicle's trajectory onto the Earth's surface first crosses from a body of water to a land mass?"

[Art LeBrun]

Actually "rotates towards the north" didn't sound right either. Isn't the English language fun?

[sdsds]

Actually "rotates towards the north" didn't sound right either. Isn't the English language fun?

I won't even try to defend that sentence; I cribbed it directly from the "launch kit" pdf.  Of course we would prefer to say, "pitches north" or possibly "yaws north".  Eh?