SpaceX Falcon Heavy : Arabsat 6A : LC-39A : April 11, 2019 - DISCUSSION

[Celestar]

Placed this in the wrong thread  Why is Space X using a Falcon Heavy to launch such a light payload? I must be missing something as a Falcon 9 can place this into GTO with mass to spare. According to the space X website it can carry enough mass to place 4 of these sats in GTO. It can place 2 of them in Martian orbit! So what is going on? I am very well confused.

There are number of reasons (imho):
You're looking at the expendable figures, and SpaceX apparently isn't willing to expend the booster (or rather: the customer doesn't want to pay to expend the booster). Also Heavy needs a commercial demonstration launch. A Falcon 9 with recovery will probably not make GTO. sub-GTO yes, but GTO-1800 probably not. With Heavy, the SAT can be placed in something like GTO-1500 or better, adding many years of service life.
Plus, having 3 booster landings is going to be bloody awesome.

Celestar

[ranma]

Still the ArabSat is around 6,000 kilos. Using the firgure of 15,000 kilos it could easily place another satellite into GTO as well. Am I wrong about the mass of the ArabSat?

[Celestar]

AFAIK, the maximum payload for a Falcon Heavy with all boosters recovered (side -> LZ[12], center -> ASDS) is somewhat north of 8000kg.

Celestar

[envy887]

Still the ArabSat is around 6,000 kilos. Using the firgure of 15,000 kilos it could easily place another satellite into GTO as well. Am I wrong about the mass of the ArabSat?

That would put Arabsat 6 into a lower orbit, or requires the side boosters to land downrange to increase performance.

Not all GTOs are equal.

[ranma]

Thank You kindly for the information. While I have an interest in Space, my background is aviation. 

[Vettedrmr]

Thank You kindly for the information. While I have an interest in Space, my background is aviation. 

Right there with you!  Learning tons ever since I started reading this forum!

Have a good one,
Mike

[Alexphysics]

Placed this in the wrong thread  Why is Space X using a Falcon Heavy to launch such a light payload? I must be missing something as a Falcon 9 can place this into GTO with mass to spare. According to the space X website it can carry enough mass to place 4 of these sats in GTO. It can place 2 of them in Martian orbit! So what is going on? I am very well confused.

Falcon 9 can place this one to GTO-1800 only in expendable configuration. If you want to reuse the booster, the final orbit will be subsynchronous which means the orbit will be lower and the satellite will have to do much of the work. The numbers you see on the SpaceX website are for expendable FH not reusable. Depending on how you reuse the boosters from FH, you can go from a F9expendable-like performance where FH can only put 8 tons to GTO-1800 or up to 26 metric tons if you expend the whole three boosters, so there are a lot of possibilities there. This one will be able to place Arabsat into a very good GTO and be able to recover all three boosters

[intelati]

Falcon Heavy's 27 Merlins. See the full launch gallery and support NASAspaceflight by subscribing to L2. http://www.nasaspaceflight.com/l2

L2 thread link

Cannot recommend it enough. It's been well worth the $20 for just two months already!

E:Fix Quote

[joncz]

https://twitter.com/TheFavoritist/status/1115972568454975489

Falcon Heavy's 27 Merlins. See the full launch gallery and support NASAspaceflight by subscribing to L2. http://www.nasaspaceflight.com/l2

L2 thread link

It's mind-boggling that they can raise the vehicle to vertical, connect all the GSE, power up and start fueling FH in under 8 hours.

[FutureSpaceTourist]

Fantastic 'photo' 

https://twitter.com/_TomCross_/status/1115991462804692992

A FH launch through those clouds would be something to see!

[e of pi]

Why is there a shamrock on the patch.

It's an old SpaceX tradition dating back to Falcon 1 Flight 4. After three heart-breaking failures and with very little capital sustaining the company, they stuck a shamrock on the patch alongside all the engineering changes made to ensure a successful launch. There's one hiding in every SpaceX patch since to the best of my knowledge. Sometimes they're green, sometimes they're other colors and hidden in background detail.

[FutureSpaceTourist]

Elon thinking about worst case, as usual:

twitter.com/elonmusk/status/1115998728878321672

First flight for Falcon Heavy Block 5 means there is some risk of failure between 5% to 10% imo. Many good design improvements from Falcon Heavy demo, but the changes are unproven.

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

[envy887]

Elon thinking about worst case, as usual:

https://twitter.com/elonmusk/status/1115998728878321672

First flight for Falcon Heavy Block 5 means there is some risk of failure between 5% to 10% imo. Many good design improvements from Falcon Heavy demo, but the changes are unproven.

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

It's the second flight of FH ever, the customer surely understands that there is a higher than normal risk of failure. I'm sure the insurance they paid for reflects that risk. 5-10% is actually better than Proton and only a few percentage points higher than the average orbital LV.

[Norm38]

https://twitter.com/nextspaceflight/status/1115987063608881152

Close-up of the payload fairing for the #Arabsat6A mission. Note the additional heat shielding. #FalconHeavy #SpaceX

Why does the fairing nose need extra heat shielding?  Are they punching extra hard through MaxQ?

[cebri]

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

It's the second flight of FH ever, the customer surely understands that there is a higher than normal risk of failure. I'm sure the insurance they paid for reflects that risk. 5-10% is actually better than Proton and only a few percentage points higher than the average orbital LV.

Elon also said the Heavy Demo Flight had a 50/50 chance. Shotwell made publicly clear that they wouldn't launch if the odds were that bad. I do not believe for a second that they would launch if they though there was a 10% of the rocket failing. Imagine if it fails on the pad, you lose the rocket, the pad (commercial crew pad btw) and you risk not only grounding the FH but also the F9.

[birdman]

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

It's the second flight of FH ever, the customer surely understands that there is a higher than normal risk of failure. I'm sure the insurance they paid for reflects that risk. 5-10% is actually better than Proton and only a few percentage points higher than the average orbital LV.

Elon also said the Heavy Demo Flight had a 50/50 chance. Shotwell made publicly clear that they wouldn't launch if the odds were that bad. I do not believe for a second that they would launch if they though there was a 10% of the rocket failing. Imagine if it fails on the pad, you lose the rocket, the pad (commercial crew pad btw) and you risk not only grounding the FH but also the F9.

I don't think the failure risk is 10%, but it's better to overestimate it than underestimate it. I'm sure the customer is already very well aware of the numerous risks and failure points and doesn't really care about what Elon tweets out, but for the general public, saying that high of a number is good either way, if it soars then the number doesn't matter but if it does fail then it was at least somewhat expected, whereas if they say that it has very low odds of failure, which it may well have, but when it does fail it hurts even more and makes them seem like liars even if they were telling the truth.

[cebri]

Ok, so if you're a SpaceX customer - would you accept a 5% to 10% risk of launch failure ?!

I guess Elon being pessimistic, but an amaxing thing to say about a commercial launch. Gwynne might be getting an urgent customer call ...

It's the second flight of FH ever, the customer surely understands that there is a higher than normal risk of failure. I'm sure the insurance they paid for reflects that risk. 5-10% is actually better than Proton and only a few percentage points higher than the average orbital LV.

Elon also said the Heavy Demo Flight had a 50/50 chance. Shotwell made publicly clear that they wouldn't launch if the odds were that bad. I do not believe for a second that they would launch if they though there was a 10% of the rocket failing. Imagine if it fails on the pad, you lose the rocket, the pad (commercial crew pad btw) and you risk not only grounding the FH but also the F9.

I don't think the failure risk is 10%, but it's better to overestimate it than underestimate it. I'm sure the customer is already very well aware of the numerous risks and failure points and doesn't really care about what Elon tweets out, but for the general public, saying that high of a number is good either way, if it soars then the number doesn't matter but if it does fail then it was at least somewhat expected, whereas if they say that it has very low odds of failure, which it may well have, but when it does fail it hurts even more and makes them seem like liars even if they were telling the truth.

Also, I think Elon knows the general public likes stuff blowing up. So increasing the chances of failing may increase the hype a bit. 

[Lar]

Elon thinking about worst case, as usual:

https://twitter.com/elonmusk/status/1115998728878321672

First flight for Falcon Heavy Block 5 means there is some risk of failure between 5% to 10% imo. Many good design improvements from Falcon Heavy demo, but the changes are unproven.

Elon lowballs. This is conservative (therefore good) but it gives the less clued media and axgrinders... fodder.

[northenarc]

  Has all development of propellant cross feed been completely abandoned for Falcon Heavy?

[Lars-J]

  Has all development of propellant cross feed been completely abandoned for Falcon Heavy?

Yes. There are no immediate payloads that would need it. And with Starship/SuperHeavy in the pipeline, there is even less need.