Launch News SpaceX Falcon 9 v1.1 with SES-8, December 3, 2013

[DaveS]

Recorded video of the event:

 

[Thunder Chicken]

Some tweets indicating that they recycled and got the hot fire off a few minutes ago (?).

http://inagist.com/all/403639720938196992/

 

[Kyle]

Hotfire confirmed! Great news.

 

[Thunder Chicken]

Hotfire confirmed! Great news.

Where? That must have been some recycle.

 

[Kyle]

Where? That must have been some recycle.

Chris B - NSF ‏@NASASpaceflight 1h
Good News! SpaceX Falcon 9 v1.1 conducts its Hot Fire for the first time in Florida after an e-vent-ful WDR (pun intended). Article later.

 

[Thunder Chicken]

http://www.nasaspaceflight.com/2013/11/spacex-falcon-9-v1-1-hot-fire-slc-40/

 

[Kyle]

Weather is 80% go for a Monday attempt.

 

[Cosmic Penguin]

A photo of the Falcon 9 being worked at SLC-40 by a crane:

Found at the Facebook page of the mobile crane company, of all places in the world. :hmm:

 

[Kyle]

Livestream announced, which confirms the launch date is set for November 25th.
http://new.livestream.com/spacex/events/2565780

 

[Kyle]

Press kit out!
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=32783.0;attach=558496

---------- Post added 11-24-13 at 08:45 PM ---------- Previous post was 11-23-13 at 11:59 PM ----------

Weather remains 80% go for launch tomorrow, with a 30% go for launch on Tuesday. The first "real" front this fall is coming into Florida as temperatures will be dropping to the upper-30s and low-40s across the state.
http://www.patrick.af.mil/shared/media/document/AFD-070716-028.pdf

My guess is, if they can't go on Monday for whatever reason, they'll try again Tuesday then again on Friday.

Stephen Clark
‏@StephenClark1
#SES8 was mated to Falcon 9 yesterday. Rollout to the pad this evening. Launch from Cape Canaveral at 537 pm EST tomorrow.

 

[Cosmic Penguin]

The rocket is already at the pad 8 hours ago:

 

[Ripley]

Elon Musk tweeted:

Will be toughest mission to date. Requires coast + upper stage restart + going to 80,000 km altitude (~1/4 way to moon).

...Isn't a GEO/GTO around 40.000 km?

[ame="http://en.wikipedia.org/wiki/Geostationary_orbit"]Geostationary orbit - Wikipedia, the free encyclopedia[/ame]
[ame="http://en.wikipedia.org/wiki/Geostationary_transfer_orbit"]Geostationary transfer orbit - Wikipedia, the free encyclopedia[/ame]

 

[Cosmic Penguin]

Elon Musk tweeted:


...Isn' a GEO orbit around 40.000 km?

GEO's altitude is 35786 km. This launch is going to a so called "super-synchronous transfer orbit", in which the apogee is above the GEO altitude. Remember that the higher you go, the less delta-v you need for making plane changes, such that in some cases the delta-v saved for lowering the inclination to 0 is higher than the delta-v needed to lower the apogee to GEO altitude. It make sense if either the launcher cannot go to a lower inclination orbit or that it allows faster drifting to the planned GEO slot. :tiphat:

 

[IronRain]

Remember that the higher you go, the less delta-v you need for making plane changes, such that in some cases the delta-v saved for lowering the inclination to 0 is higher than the delta-v needed to lower the apogee to GEO altitude. It make sense if either the launcher cannot go to a lower inclination orbit or that it allows faster drifting to the planned GEO slot. :tiphat:

Why's that? I know this and I often use this in Orbiter but why is it cheaper then doing a plane change burn in a lower orbit?

:tiphat:

 

[Urwumpe]

Why's that? I know this and I often use this in Orbiter but why is it cheaper then doing a plane change burn in a lower orbit?

Because you are slower. The formula for the DV for a change in inclination is

DV = 2 * Velocity * sin(RInc/2)

Mathematically, this is simply: "how much do I need to add to a vector to rotate it by a set angle?"

The slower you are, the less DV you need.

A bielliptic transfer (=two transfer ellipses), like SpaceX is about to do, is also more effective than a simple Hohmann transfer for GTO missions (even without the plane change), because it makes more use of the Oberth effect. But it requires a few engine restarts, that is why Ariane does not do it usually.

 

[MattBaker]

But it requires a few engine restarts, that is why Ariane does not do it usually.

Yeah, Ariane missions usually don't have such a problem with the inclination. Due to some mysterious reason.:lol:

But the Proton which of course has trouble getting down from 51.6° does this regularly, IIRC.

 

[BruceJohnJennerLawso]

But the Proton which of course has trouble getting down from 51.6° does this regularly, IIRC.

And we wonder why the Russians have such a powerful launcher fleet. :lol:

 

[Urwumpe]

Yes, and instead of engine restarts, the Ariane does a long burn with the cryogen upper stage simply placing the payload into a GTO that brings it more or less fast to its target slot in the Clarke Belt.

Some weeks of drifting into position are common for geostationary satellites anyway.

 

[Cosmic Penguin]

And here's the rocket in vertical position:

 

[Kyle]

GEO's altitude is 35786 km. This launch is going to a so called "super-synchronous transfer orbit", in which the apogee is above the GEO altitude. Remember that the higher you go, the less delta-v you need for making plane changes, such that in some cases the delta-v saved for lowering the inclination to 0 is higher than the delta-v needed to lower the apogee to GEO altitude. It make sense if either the launcher cannot go to a lower inclination orbit or that it allows faster drifting to the planned GEO slot. :tiphat:

And just to double-check, I tried it on Orbiter and it worked. :thumbup: