SES-8 - for launch on F9 v1.1 - Dedicated Spacecraft Thread

#40 by deltaV on 24 Nov, 2013 15:45
Quote from: Roy_H on 24 Nov, 2013 14:18
I am not a rocket scientist, and am finding this an interesting education on orbital mechanics. So if I understand correctly, the most cost effective maneuvers for SES-8 from the delivered orbit would be burns directly away from earth at perigee to circularize the orbit, and at apogee in a northern or southern direction to change the plane of orbit. The north/south burns would not be directly north or south, but at some optimal off angle, and they would have to be done when the perigee coincides with crossing the equator. Did I get this right? To take this a little farther, I assume it best to do the plane change first so it is an equatorial orbit, is this done in a single burn?

My comment about thrusting away from the center of the Earth was in answer to AJA's question only. AFAIK geosynchronous missions do not make use of burns directed towards or away from the center of the Earth. Even if such a burn were used for circularization it would have to be done when at geosynchronous altitude, not at perigee.
#41 by Lars_J on 24 Nov, 2013 18:37
Quote from: Roy_H on 24 Nov, 2013 14:18
I am not a rocket scientist, and am finding this an interesting education on orbital mechanics. So if I understand correctly, the most cost effective maneuvers for SES-8 from the delivered orbit would be burns directly away from earth at perigee to circularize the orbit, and at apogee in a northern or southern direction to change the plane of orbit. The north/south burns would not be directly north or south, but at some optimal off angle, and they would have to be done when the perigee coincides with crossing the equator. Did I get this right? To take this a little farther, I assume it best to do the plane change first so it is an equatorial orbit, is this done in a single burn?

No, the most effective way to circulariize any orbit is always to thrust in your orbital direction (if at apogee) or the reverse of that (if at perigee).

It may seem like a silly suggestion, but the simulation game "Kerbal space program" is a *great* about learning basic orbital mechanics. You get to play with orbits, set new orbits, and the game will indicate the most efficient way to thrust to realize that new orbit. It can be surprising and sometimes counter-intuitive.
(EDIT: here is a quick video that shows how KSP can teach you how thrusting in different directions affects your orbit: youtu.be/_aNlR4-1IrM )
#42 by Eer on 24 Nov, 2013 21:59
Quote from: Lars_J on 24 Nov, 2013 18:37
(EDIT: here is a quick video that shows how KSP can teach you how thrusting in different directions affects your orbit: youtu.be/_aNlR4-1IrM )

Thanks, Lars - I found that very helpful ;-)
#43 by Nomadd on 24 Nov, 2013 22:58
You can always change direction in the middle of the burn.
#44 by Avron on 24 Nov, 2013 23:19
Quote from: Nomadd on 24 Nov, 2013 22:58
You can always change direction in the middle of the burn.

The burn itself is made to change direction in terms of orbit.. can you change the space craft orientation in mid burn .. yes.. see Apollo 13.. but why?

ooops my bad.. wrong thread...
#45 by jacqmans on 25 Nov, 2013 15:17
SES-8 SATELLITE LAUNCH ON BOARD SPACEX/FALCON 9 SET FOR NOVEMBER 25

25.11.2013

Cape Canaveral, Florida, November 25th, 2013 – SES S.A. (NYSE Euronext Paris and Luxembourg Stock Exchange: SESG) announces that the launch of the SES-8 satellite is slated for November 25th, 2013. The launch window for the maiden launch of an SES satellite on board Falcon 9 stretches from 17:37 - 18:42 EDT (23:37 - 00:42 CET).

SES-8 has been manufactured by Orbital Sciences Corporation. The satellite features up to 33 Ku-band transponders (36 MHz equivalent). SES-8 will be co-located with NSS-6 at the orbital location of 95 degrees East to provide growth capacity over Asia-Pacific. The spacecraft's high performance beams will support the rapidly growing markets in South Asia and Indo-China, as well as provide expansion capacity for DTH, VSAT and government applications.

In North America, the live broadcast of the launch will be available on the SES-1 satellite at 101 degrees West, 21K, downlink frequency 12120 MHz, vertical polarization, Symbol rate 30.00 MSym/s, FEC 3/4, service ID 1.

In Europe, the broadcast of the launch via ASTRA satellite is available at the orbital position 19.2 degrees East, channel 1.028, downlink frequency 11626,5 MHz, vertical polarization, Symbol rate 22.00 MSym/s, 8PSK, FEC 2/3, service ID 4400, service name SES 8 Launch.

A webcast is available via www.spacex.com/webcast. The video transmission of the launch of SES-8 will begin approximately 30 minutes before liftoff.

To listen to a playback of the press call held on Sunday with Elon Musk, CEO and Chief Designer of SpaceX, and Martin Halliwell, CTO of SES, please dial the following number and access code:

US\Canada: (855) 859-2056
International: (404) 537-3406
Conference ID: 16853657

Please find a press kit on SES-8 here: http://www.ses.com/16395608/spacex-ses-8-launch-kit.
#46 by Lars_J on 25 Nov, 2013 17:14
SES has posted a video on Facebook - SES-8: from concept to reality:

https://www.facebook.com/photo.php?v=10152001440048189
#47 by Joffan on 27 Nov, 2013 00:07
For orbital mechanics students etc, the SES plan to get to GSO from LEO is a bi-elliptic transfer, which will never thrust either towards or away from Earth in principle - all burns are along the path of travel for orbit raising, and across the path for inclination change. Probably the major inclination change by SES-8 will be at apogee of the initial high orbit for efficiency, in conjunction with the perigee-raise (a combined burn to do both tasks).

EDIT to fix link... which was working at preview, some BB sofware is just too smart for its own good, grumble...
(thanks kevin)
#48 by Robotbeat on 03 Dec, 2013 22:24
Spacecraft status?
EDIT: Looks good!
Quote from: jongoff on 03 Dec, 2013 22:24
Peter B. de Selding ‏@pbdes 12s

SES has acquired spacecraft and it is in good health.
#49 by Joffan on 03 Dec, 2013 23:36
Do we know when the next burn of SES-8 will occur? Tomorrow morning?
#50 by jacqmans on 04 Dec, 2013 08:35
LAUNCH SUCCESS FOR SES-8 SATELLITE ON BOARD SPACEX/FALCON 9

03.12.2013

55th SES satellite to serve Asia

Cape Canaveral, Florida, December 03rd, 2013 – SES S.A. (NYSE Euronext Paris and Luxembourg Stock Exchange: SESG) announces that the SES-8 satellite was successfully launched into space at 17:41 EST (23:41 CET) from the Kennedy Space Center at Cape Canaveral. A Falcon 9 booster operated by SpaceX successfully injected the SES-8 satellite into geostationary transfer orbit, 31 minutes after lift-off, in what was SES’s maiden use of a SpaceX/Falcon 9 rocket. SES has three more SpaceX/Falcon 9 boosters under contract.

SES-8 was manufactured by Orbital Sciences Corporation. The satellite features up to 33 Ku-band transponders (36 MHz equivalent). SES-8 is authorized by The Netherlands and will be co-located with NSS-6 at the orbital location of 95 degrees East to provide growth capacity over Asia-Pacific. The spacecraft’s high performance beams will support the rapidly growing markets in South Asia and Indo-China, as well as provide expansion capacity for DTH, VSAT and government applications.

Romain Bausch, President and CEO of SES, stated: “SES’s maiden launch on board a Falcon 9 rocket is yet another example of our company’s spirit of innovation and advancement of the commercial space industry. We congratulate the SpaceX team for the success of a challenging launch campaign and our longstanding supplier Orbital for innovating with us in exploring new paths to orbit while delivering a brand-new, state-of-the-art satellite for Asia. Our customers are looking forward to the new capacity, and we are delighted that SES, in collaboration with SpaceX and Orbital, is all set to deliver following today’s successful launch. Through the co-location with NSS-6 at 95 degrees East, SES-8 will not only provide incremental high performance capacity, notably for DTH services, it will also create greater reliability and additional security for customers. The SES-8 satellite will significantly contribute to SES’s growing presence in Asia-Pacific.”

“Today’s successful insertion of the SES-8 satellite marks SpaceX’s first geo-synchronous transfer mission and confirms the Falcon 9 launch vehicle lives up to the industry’s highest performance standards,” said Elon Musk, CEO and Chief Designer of SpaceX. “As always, SpaceX remains committed to delivering the safest, most reliable launch vehicles on the market today. We appreciate SES’s early confidence in SpaceX and look forward to launching additional SES satellites in the years to come.”

Note to Editors:

The next SES launch is slated for early next year, when an European Ariane 5 vehicle will orbit the ASTRA 5B satellite from Kourou, French Guyana.
#51 by corrodedNut on 04 Dec, 2013 15:49
Quote from: Joffan on 03 Dec, 2013 23:36
Do we know when the next burn of SES-8 will occur? Tomorrow morning?

Bump. So five burns over the next two weeks, does anyone have anything more specific?
#52 by corrodedNut on 05 Dec, 2013 13:52
Has this been posted yet? The photos are the same as those previously released, but the narration provides some details:
#53 by Chris Bergin on 08 Dec, 2013 03:57
And now watching the satellite:
http://www.nasaspaceflight.com/2013/12/ses-8-success-trajectory-future-spacex-possibilities/
#54 by Zannanza on 11 Dec, 2013 06:01
as per heavens-above.com information, SES-8 orbit has been changed to 35819 x 79805 km, inclination decreased to 1.2°

source
http://www.heavens-above.com/SatInfo.aspx?satid=39460&lat=0&lng=0&loc=Unspecified&alt=0&tz=CET&cul=en-GB
#55 by Jarnis on 13 Dec, 2013 09:30
..and

Orbit 35,681 x 45,298 km, 0.5°

Almost there.

http://www.heavens-above.com/orbit.aspx?satid=39460&lat=0&lng=0&loc=Unspecified&alt=0&tz=CET&cul=en-GB

Shows the sat fairly close to the planned area over Asia.
#56 by Zannanza on 21 Dec, 2013 05:32
35753X35795 km, 0.0960°, probably already settled in its final orbit
#57 by corrodedNut on 03 Feb, 2014 13:58
Open for business:

http://www.spaceflightnow.com/falcon9/007/140203ses8/#.Uu-uCj1dV8E