Author Topic: SpaceX Falcon Heavy : Arabsat 6A : LC-39A : NET Dec. 2018  (Read 19538 times)

Offline deruch

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #20 on: 02/15/2018 09:02 AM »
Historically, (well over the last 18 months),  how fast can SpaceX manufacture newFirst Stages?

Given that the first F9 block 5 is expected "Real Soon", and that the first few Block5 cores will probably be needed for regular F9 flights, how soon, realistically, will SpaceX have the 3 Block 5 cores (with the special central core) ready  for the next FH launch, (supposedly due in Q2?)

It's not at all required that all 3 cores be "new" Block 5s.  They could do the exact same thing they did for the FH demo mission again.  i.e. Recover those new F9 Block 5 boosters and use them as the side cores for the Block 5 FH.  So, the build order would be Booster, Booster, FH-center.  That, plus 3 upper stages, would let them fly 2 F9 missions and 1 FH (assuming successful recovery of the F9 launches).
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline macpacheco

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #21 on: 02/15/2018 09:51 AM »
Historically, (well over the last 18 months),  how fast can SpaceX manufacture newFirst Stages?

Given that the first F9 block 5 is expected "Real Soon", and that the first few Block5 cores will probably be needed for regular F9 flights, how soon, realistically, will SpaceX have the 3 Block 5 cores (with the special central core) ready  for the next FH launch, (supposedly due in Q2?)
Elon Musk stated FH Block V side boosters can act as or are F9 Block V cores. Just switch the interstage with the nose cone.
So SX only needs to build the Block V center core as long as customer accepts reflights, or stock pile 2 new F9 cores for Arabsat launch then relaunch those as F9 cores. A lot of flexibility.
So manufacturing doesn't look like a problem. Look at how many recent launches have been reflights. Block V reflights should become the norm soon.
Looking for companies doing great things for much more than money

Online LouScheffer

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #22 on: 02/16/2018 12:21 AM »
Performance prediction for Arabsat 6:  If the figures for Mars throw weight are correct, or even close, then FH recoverable can stage at a much higher speed than even F9 expendable, at least 500 m/s more if they press all the performance buttons.  Let's assume the mass is the same as Intelsat at 6700 kg.  Then the question is how conservative/aggressive SpaceX wants to be.

The first FH mission staged at the same speed as Intelsat expendable.  So they could clearly do this again.  The result would be a similar orbit, since the second stage is unchanged:  Add 2550 m/s from LEO, to get 43K x 28.85o, 1729 m/s to go.

More aggressive:  they add +150 m/s to staging, to get  56K x 25o, 1640 m/s to go.

Still more aggressive:  add +300 to staging, to get 78K x 24.5o, 1550 m/s to go.

Almost pull the stops out:  add +450 to staging, to get 90K x 21.82o, 1497 m/s to go.  Clearly reaching diminishing returns here.

My guess is that SpaceX will be more aggressive, but not too much.  Perhaps +225 m/s at staging (2860 m/s), final orbit of 62K x 24o, 1600 m/s to go.



Offline speedevil

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #23 on: 02/16/2018 02:34 AM »
My guess is that SpaceX will be more aggressive, but not too much.  Perhaps +225 m/s at staging (2860 m/s), final orbit of 62K x 24o, 1600 m/s to go.

I assume there is no benefit in any extensively delayed burns?

Online vaporcobra

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #24 on: 02/16/2018 02:51 AM »
My guess is that SpaceX will be more aggressive, but not too much.  Perhaps +225 m/s at staging (2860 m/s), final orbit of 62K x 24o, 1600 m/s to go.

I assume there is no benefit in any extensively delayed burns?

Once in orbit there is, but not until then. Gravity losses are unforgiving...

My curiosity, however, is whether SpaceX will choose to demonstrate another long S2 coast post-separation, maybe even a partial circularization depending on the launch parameters they end up going for. I don't know orbital mechanics well enough to estimate FH performance, so that may just flat out be categorically impossible, but it would sure be of value to the DoD to have two back-to-back successful demonstrations of long coast performance.

Online LouScheffer

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #25 on: 02/16/2018 02:13 PM »
My guess is that SpaceX will be more aggressive, but not too much.  Perhaps +225 m/s at staging (2860 m/s), final orbit of 62K x 24o, 1600 m/s to go.
I assume there is no benefit in any extensively delayed burns?
Once in orbit there is, but not until then. Gravity losses are unforgiving...
My curiosity, however, is whether SpaceX will choose to demonstrate another long S2 coast post-separation, maybe even a partial circularization depending on the launch parameters they end up going for.
This brings up another possibility, now that SpaceX has demonstrated long coast.  They could go into an orbit with a higher perigee.  When MUOS-2 did this they used a 3 burn sequence: (1) into LEO, (2) at equator go to LEO x several thousand km, then wait until rocket gets up to 4000 km (a few hours), then (c) burn to 4000 x GEO.

This can give a very good ride to the spacecraft (I think MUOS only had about 1400 m/s to go) but leaves the second stage stranded forever in the transfer orbit.  Therefore international conventions dictate the perigee be at least 4000 km if this approach is used.  I believe Proton and Sea Launch have also used this strategy, but SpaceX has not (and perhaps could not until they demonstrated long coast).  But now they could if they wanted to do so.

Offline acsawdey

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #26 on: 02/16/2018 02:19 PM »
My guess is that SpaceX will be more aggressive, but not too much.  Perhaps +225 m/s at staging (2860 m/s), final orbit of 62K x 24o, 1600 m/s to go.

I assume there is no benefit in any extensively delayed burns?

Once in orbit there is, but not until then. Gravity losses are unforgiving...

My curiosity, however, is whether SpaceX will choose to demonstrate another long S2 coast post-separation, maybe even a partial circularization depending on the launch parameters they end up going for. I don't know orbital mechanics well enough to estimate FH performance, so that may just flat out be categorically impossible, but it would sure be of value to the DoD to have two back-to-back successful demonstrations of long coast performance.

Would another option be to do a GTO burn, then long coast and a third burn at apogee that just gets rid of as much inclination as possible? This leaves the 2nd stage in a low inclination GTO orbit that ought to decay reasonably quickly, and decreases the amount of delta-v remaining.

Online vaporcobra

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #27 on: 02/16/2018 08:49 PM »
This brings up another possibility, now that SpaceX has demonstrated long coast.  They could go into an orbit with a higher perigee.  When MUOS-2 did this they used a 3 burn sequence: (1) into LEO, (2) at equator go to LEO x several thousand km, then wait until rocket gets up to 4000 km (a few hours), then (c) burn to 4000 x GEO.

This can give a very good ride to the spacecraft (I think MUOS only had about 1400 m/s to go) but leaves the second stage stranded forever in the transfer orbit.  Therefore international conventions dictate the perigee be at least 4000 km if this approach is used.  I believe Proton and Sea Launch have also used this strategy, but SpaceX has not (and perhaps could not until they demonstrated long coast).  But now they could if they wanted to do so.

Would another option be to do a GTO burn, then long coast and a third burn at apogee that just gets rid of as much inclination as possible? This leaves the 2nd stage in a low inclination GTO orbit that ought to decay reasonably quickly, and decreases the amount of delta-v remaining.

I think these are both viable options for possible in-orbit activities. It really all depends on the customer, they may quite reasonably be uncertain about trusting their satellite to SpaceX's second-ever extended coast with a real payload. I expect Arabsat to go with a more conservative mission plan, but I don't know the company well enough to judge if they're more SES than NASA LSP, so to speak.
« Last Edit: 02/16/2018 08:49 PM by vaporcobra »

Online jon.amos

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #28 on: 02/17/2018 05:07 PM »
The satellite has arrived from Denver to Sunnyvale.
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Offline FutureSpaceTourist

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #29 on: 02/20/2018 04:23 PM »
Quote
The @Arabsat 6A sat, following Hella Sat 4/SaudiGeosat-1, has arrived at @LockheedMartin's Sunnyvale, Calif site for final testing. Both scheduled for launch in 2018: 6A with @SpaceX, Hella Sat 4/SaudiGeosat-1 w/ @Arianespace

https://twitter.com/pbdes/status/965999810624008192

Offline jacqmans

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Re: SpaceX Falcon Heavy : Arabsat 6A : 2018
« Reply #30 on: 02/21/2018 06:45 AM »
News Release Issued: Feb 20, 2018 (12:09pm EST)

Lockheed Martin Completes Assembly on Arabsat's Newest Communications Satellite

Arabsat-6A Satellite Begins Rigorous Battery of Tests in Preparation for its Delivery to Launch Site Later This Year


DENVER, Feb. 20, 2018 /PRNewswire/ -- A new, high-capacity communications satellite that will deliver TV, internet and mobile phone services to the Middle East, Africa and Europe is one step closer to launch. Lockheed Martin (NYSE: LMT) has completed assembly on the Arabsat-6A satellite, which was recently shipped to its Sunnyvale, California facility to begin a comprehensive series of tests to ensure the satellite is ready for operations in orbit.

"This new satellite will strengthen our existing fleet that offers millions of people mobile and landline communications service across the region," said Khalid Balkheyour, CEO of Arabsat. "We look forward to completing and launching this state-of-the-art new satellite to offer even greater internet, television and radio services to our customers."

Arabsat-6A is part of the two-satellite Arabsat-6G program for Arabsat and is the second of Lockheed Martin's modernized LM 2100 series satellites to complete assembly. The other satellite in the Arabsat 6G program, Hellas Sat 4/SaudiGeoSat-1, recently completed assembly and was also shipped to Sunnyvale in November of 2017 for testing.

"Arabsat-6A and its companion satellite, Hellas Sat 4/SaudiGeoSat-1 are the most advanced commercial communications satellites we've ever built," said Lisa Callahan, vice president and general manager of Commercial Civil Space for Lockheed Martin. "The modernized LM 2100 that these satellites are built on is packed with new innovations, including solar arrays that are 30 percent lighter and 50 percent more powerful, upgraded flight software and more efficient propulsion capabilities resulting in longer maneuver life. Those improvements will deliver greater precision, performance and value in orbit."

During the trip from Denver to Sunnyvale, Arabsat-6A was housed in a "mobile cleanroom," which keeps the satellite secure and in pristine condition, free of virtually any specks of dust and contaminants that could damage its precision electronics.

In California, the satellite will undergo multiple tests to ensure it is fit for flight. The satellite will be blasted with sound, exposed to extreme heat and cold, and subjected to a total vacuum to simulate what it will endure during its launch and operations in space. The testing will be completed and the satellite ready for delivery to the launch site by the end of the year.

Lockheed Martin is building five modernized LM 2100 satellites for a host of missions and customers around the globe.

•For additional information, visit our website: http://www.lockheedmartin.com/commercialspace.

•For more photos of Arabsat-6A, please click here:

https://www.flickr.com/photos/lockheedmartin/albums/72157683974478692

Online gongora

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Re: SpaceX Falcon Heavy : Arabsat 6A : LC-39A : NET Dec. 2018
« Reply #31 on: 06/01/2018 05:55 PM »
[Space News] Arabsat Falcon Heavy mission slated for December-January timeframe
Quote
The Riyadh, Saudi Arabia-based satellite operator told SpaceNews by email that the launch window for Arabsat 6A is between December and January.

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