SpaceX Signs Launch Agreements with Asia Broadcast Satellite and Satmex

[baldusi]

That was a part of my question. What alternate GTO profile (than the 185km x 36576km) can you do, that allows more payload, minimizes the Belt passages, and keeps the sat alight as long as possible?
May be you can optimize the GTO for solar exposure. Or go through where the Belt is less "dense" in harmful particles.

[Robotbeat]

Ah, the launch manifest keeps growing and growing and yet the launch rate stays the same.  Not sure how this'll work out.

No one thinks the launch rate will stay the same indefinitely.

(Either it increases or it drops to zero...)

[agman25]

Same deal as AEHF but intended this time.

[Comga]

That was a part of my question. What alternate GTO profile (than the 185km x 36576km) can you do, that allows more payload, minimizes the Belt passages, and keeps the sat alight as long as possible?
May be you can optimize the GTO for solar exposure. Or go through where the Belt is less "dense" in harmful particles.

You can't optimize for solar exposure other than to maximize the apogee, which they are doing anyways.   I guess they could pick an argument of perigee that puts the orbital axis along the Sun vector to shade the perigee, where the velocity is highest and the shadowed time is minimum. 

The GTO process drives the inclination to zero, unless you do something extraordinary like looping around the moon, so that wouldn't be modified.

The only other adjustable parameter would be to launch near one or the other solstice, and they're not going to wait several months for that trivial gain.

edited to remove specious sentence

[ugordan]

http://www.latimes.com/business/la-fi-satellite-contract-20120314,0,1776487.story

"At launch time, the 702SP will weigh just under 4,000 pounds, as opposed to 13,000 pounds for the larger satellite."

[Galactic Penguin SST]

http://www.latimes.com/business/la-fi-satellite-contract-20120314,0,1776487.story

"At launch time, the 702SP will weigh just under 4,000 pounds, as opposed to 13,000 pounds for the larger satellite."

Wow! That's light enough to send one of them to a standard GTO with a Delta II. Wonder if this technology would change the launcher market by favoring smaller launchers?

[douglas100]

Wow! That's light enough to send one of them to a standard GTO with a Delta II. Wonder if this technology would change the launcher market by favoring smaller launchers?

It might, but not right away of course. As well as the spectacular missions like Dawn and Hayabusa, electric propulsion has been slowly, almost stealthily, changing the way some aspects of spaceflight are done. I think it shows great promise.

Edit: should also have mentioned SMART 1 which started its flight to the Moon from GTO.

[ugordan]

Don't forget Deep Space 1.

[douglas100]

Yeah, the pioneer.

[Jim]

http://www.latimes.com/business/la-fi-satellite-contract-20120314,0,1776487.story

"At launch time, the 702SP will weigh just under 4,000 pounds, as opposed to 13,000 pounds for the larger satellite."

A 13,000 pound spacecraft placed in GTO, usually weighs around 6,500 lbs on station in GSO.
So the real comparison that is needed is the EOL weight for both types of spacecraft.

[kevin-rf]

Well, the older 702MP's weighed between 3,500 kg to 3,800 kg once they reached GSO. (from Boeing, http://www.boeing.com/defense-space/space/bss/factsheets/702/intelsat/intelsat.html ). But the telling thing is 702SP (http://www.boeing.com/defense-space/space/bss/factsheets/702/702SP.html) is 3-8 KW, while the deployed 702MP's are 11.8 kw

Assuming (and this is a stretch) that the 702SP is really a 702MP without the traditional fuel and plumbing and a smaller solar array I could see them weighing a little less than a 702MP when they arrive on station.

[baldusi]

4000lbs are about 1820kg. That's a lot smaller, and at GTO.

[oldAtlas_Eguy]

If the &02SP is 1000kg lighter than the 702MP putting thier weight at ~ 2.5-2.8t then two would fit (weight wise) on a F9 Block II with a GTO capability of just less than 6t. You would need a few hundred kg for the dual sat structure.

Question: will two 702SP fit volume wise in a F9 faring?

[agman25]

More on the 702...

Boeing Adds Its Smallest 702 Satellite

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/asd/2012/03/14/06.xml&headline=Boeing%20Adds%20Its%20Smallest%20702%20Satellite

[ugordan]

Question: will two 702SP fit volume wise in a F9 faring?

From the AvWeek article:

"With the 702SP, Boeing is offering a van-sized spacecraft—15 ft. high and 7 ft. wide—that weighs 4,000 lb. at launch."

So they should be able to fit inside.

[baldusi]

Question: will two 702SP fit volume wise in a F9 faring?

From the AvWeek article:

"With the 702SP, Boeing is offering a van-sized spacecraft—15 ft. high and 7 ft. wide—that weighs 4,000 lb. at launch."

So they should be able to fit inside.

Would that fit them side by side or one on top of the other? Both ways should do it. But on top requires more hardware. Side by Side might have more separation risk (interference, plume impigment, etc.)

[Robotbeat]

Question: will two 702SP fit volume wise in a F9 faring?

From the AvWeek article:

"With the 702SP, Boeing is offering a van-sized spacecraft—15 ft. high and 7 ft. wide—that weighs 4,000 lb. at launch."

So they should be able to fit inside.

Would that fit them side by side or one on top of the other? Both ways should do it. But on top requires more hardware. Side by Side might have more separation risk (interference, plume impigment, etc.)

Regarding plume impingement... remember we're talking about satellites that only have very low-thrust electric propulsion (using Xenon, a noble gas).

[McDew]

Question: will two 702SP fit volume wise in a F9 faring?

From the AvWeek article:

"With the 702SP, Boeing is offering a van-sized spacecraft—15 ft. high and 7 ft. wide—that weighs 4,000 lb. at launch."

So they should be able to fit inside.

Would that fit them side by side or one on top of the other? Both ways should do it. But on top requires more hardware. Side by Side might have more separation risk (interference, plume impigment, etc.)

The spacecraft are stacked one on top of the other.  Just like the Russians.  Only need an additional adapter between the two spacecraft.

[Jim]

The spacecraft are stacked one on top of the other.  Just like the Russians.  Only need an additional adapter between the two spacecraft.

Not this spacecraft design. 
a.  It makes an additional panel of one spacecraft unusable for payload systems.
b.  It makes the same spacecraft heavier since it has to support the other spacecraft

[McDew]

The spacecraft are stacked one on top of the other.  Just like the Russians.  Only need an additional adapter between the two spacecraft.

Not this spacecraft design. 
a.  It makes an additional panel of one spacecraft unusable for payload systems.
b.  It makes the same spacecraft heavier since it has to support the other spacecraft

Trust me...it is what it is.  Two different customers for the top and bottom spacecraft.
a. Yes
b. Yes