SpaceX FH: STP-2 : LC-39A : June 25, 2019 - DISCUSSION

[Chris Bergin]

Thread title fixed. Silly me!

[grythumn]

OK! A revival of this topic.
I'm trying to sort out the facts, few as they are.
The STP-2 mission, hopefully in 2015, will involve a Falcon Heavy attempting to launch a....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

[Moe Grills]

OK! A revival of this topic.
I'm trying to sort out the facts, few as they are.
The STP-2 mission, hopefully in 2015, will involve a Falcon Heavy attempting to launch a....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

As you've confirmed, few details available.

But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy. I assume he's planning two FH test flights at least; one of them STP-2.
Surely people from all over the world, and from this forum
would have flooded his email box with similar suggestions?
   The Falcon Heavy is more than capable of doing the job.

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
     I think I stirred up an hornet's nest with that one.

[Lar]

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
     I think I stirred up an hornet's nest with that one.

I'm not sure that Elon cares a lot what the skeptics think, unless they have launch contracts or some other decision making authority that impacts him. My view is that SpaceX have their roadmap mapped out a ways, subject to change, and don't think they have a lot to prove now, except to themselves about the things they want to refine.

[Skyrocket]

It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
     I think I stirred up an hornet's nest with that one.

You must be joking. What could be the reason to bump a military contract, which serves as a door-opener for the EELV-class business, for a publicity stunt?

[Lars_J]

Yep, at this point they need more commercial and government payloads launched rather than stunts.

There's only going to be one FH demo where they have the leeway to test out as many features of the LV as possible - presumably they do not want to waste it on a risky BLEO Dragon stunt.

[Moe Grills]

Yep, at this point they need more commercial and government payloads launched rather than stunts.

There's only going to be one FH demo where they have the leeway to test out as many features of the LV as possible - presumably they do not want to waste it on a risky BLEO Dragon stunt.

There's nothing wrong with your asssertion,....to a point.
Commercial launches will pad Elon's bank account. Nothing wrong with that.
But he knows, I know, you know that serious, commercial, human crew
missions to either the Moon or Mars will drain bank accounts of billions, not
pad them.
There's no doubt that Mr. Musk designed and is building Falcon Heavy
boosters for commercial purposes; but his greater agenda with the development of the FH is and was to send humans to the Moon and Mars;
a big financial drain.

OK! I'm starting to drift off topic. So to draw back, suffice to say that whether 2013, 0r 2015, the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.

[Kabloona]

the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.

It's not unusual at all. Launch vehicles don't insure payloads. If the payload wants insurance, they purchase it themselves.

US gov't payloads are self-insured, which means the gov't doesn't bother to purchase insurance. If the payloads are lost, the gov't can choose to build another one. Both primary payloads here fall in that category.

Pegasus and Taurus carried payloads "built and paid for by others" on their first flights. It's common for a first flight to carry an "expendable" payload for a discounted price. The payload gets a cheap ride in exchange for the risk they take by being first in line.

What *is* unusual is the complexity of the mission with 2 primaries and multiple secondary payloads.

[arachnitect]

the first Falcon test-flight is most unusual
in that it risks payloads built and paid for by others. Lack of insurance
must be an issue addressed here.

It's not unusual at all. Launch vehicles don't insure payloads. If the payload wants insurance, they purchase it themselves.

US gov't payloads are self-insured, which means the gov't doesn't bother to purchase insurance. If the payloads are lost, the gov't can choose to build another one. Both primary payloads here fall in that category.

Pegasus and Taurus carried payloads "built and paid for by others" on their first flights. It's common for a first flight to carry an "expendable" payload for a discounted price. The payload gets a cheap ride in exchange for the risk they take by being first in line.

What *is* unusual is the complexity of the mission with 2 primaries and multiple secondary payloads.

STP-2 isn't the first Falcon Heavy.

[ClaytonBirchenough]

OK! A revival of this topic.
I'm trying to sort out the facts, few as they are.
The STP-2 mission, hopefully in 2015, will involve a Falcon Heavy attempting to launch a....?

Read the PDF in the first post; it has a lot of details.

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

As you've confirmed, few details available.

But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy. I assume he's planning two FH test flights at least; one of them STP-2.
Surely people from all over the world, and from this forum
would have flooded his email box with similar suggestions?
   The Falcon Heavy is more than capable of doing the job.

There are a lot of skeptics out there who believe that SpaceX is not up to the task of sending spacecraft and crew to the Moon. They are much more
skeptical about his Mars ambitions. One Falcon Heavy test-flight with an unmanned Dragon to the Moon would silence many critics. It might not be bad if he "bumps" the Cosmic-2, DSX and cubesat payloads off that mission for just that agenda.
     I think I stirred up an hornet's nest with that one.

MANY Cubesats as a ballast? Seems like a cheap way to offer some quality space!

[Skyrocket]

COSMIC-2, DSX, between 2 and 6 auxiliary (unnamed, max 181 kg each)  payloads, up to 8 P-PODs carrying a TBD number of cubesats, and ballast.

http://www.spacex.com/press.php?page=20121205

-R C

One of the (up to) 6 auxiliary payloads is GPIM (Green Propellant Infusion Mission).

The NASA video shows it as part of the STP-2 stack:

[Jason1701]

Great video, I think it's the first animation of the actual Falcon Heavy design.

[jongoff]

But regarding the other matter; (I repeat this) It's most mysterious why Elon Musk hasn't decided to mount a fullsize/full-weight mockup of the Dragon (with basic radio transmitters) and send it on a free-return trajectory around the Moon using a test-launch Falcon Heavy.

Simple. In spite of his sometimes bombastic manner, Elon's actually trying to not piss off those in Congress who already hate SpaceX anymore than he already has to. He's already fighting a huge battle with the Shelby's of the world to keep them from completely cutting Commercial Crew, and he doesn't need to provide them any more reason to hate and actively oppose SpaceX at the moment. This is also probably a big part of why SpaceX hasn't been supportive of Inspiration Mars, BTW. It's "bad enough" for SpaceX that us commercial people are constantly pointing out how Falcon Heavy might make SLS obsolete--the last thing he wants to do is to make it look like SpaceX is trying to make that argument too. You may not get this impression from following his Twitter feed, but Elon's actually quite capable of keeping his mouth shut and not intentionally antagonizing people in Congress who could screw his company (he's a better man than I in that regard).

Plus as others mentioned, flying paying payloads from customers that helps on-ramp them into the EELV program instead of a non-paying stunt is all the more reason not to do it.

~Jon

[newpylong]

Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.

[ClaytonBirchenough]

Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.

Hmmm... I seem to remember the Falcon Heavy being able to throw more to TLI than 10 mt...

[jongoff]

Considering the FH is estimated to be only good for 10 metric tons to TLI and the fully loaded Dragon is also 10 mt he might have a hard time doing that. They would look pretty bad sending the Dragon on a heliocentric or elliptical orbit because the US ran out of fuel before the full burn.

Hmmm... I seem to remember the Falcon Heavy being able to throw more to TLI than 10 mt...

I think it's a little more than 10mT to TLI, but it's much more amazing at getting big stuff to LEO than shoving big stuff up the hill beyond LEO. Someone pointed out recently that Atlas V Heavy, if it flew, would have a greater TLI payload than Falcon Heavy using the currently planned upper stage. I'm a huge SpaceX fan, but ULA's Centaur upper stage is still my favorite for BEO missions (though an ACES stage would obviously win if it ever flies).

~Jon

[QuantumG]

For either vehicle you get better performance using a third stage to do the TLI burn. Something like a Blok DM, which has a propellant mass fraction of 85% using LOX/RP-1, launched on a Falcon Heavy could throw 15 tons to TLI. Probably something like 20 tons using LOX/LH2.

Whether Dragon with some extra tankage, could throw itself to TLI, depends on what isp you think the Draco thruster has on-orbit, the mass of the Dragon, and a bunch of other stuff no-one knows.

[spectre9]

The Inspiration Mars paper gives a good wrap of the FH BEO capabilities.

IIRC they concluded 10mt to whatever C3 they calculated for their Mars flyby trajectory was a good guess.

[ClaytonBirchenough]

A while back on the Falcon Heavy Master Update thread someone poster:

Has SpaceX said (or has anyone surmised) what payload mass Falcon Heavy can push through TLI?

Wikipedia lists 16,000 kg through TLI, but as far as I can tell there is no basis for this figure.

16MT is what you get from mass fraction calculations using 53MT starting at LEO, a 350 ISP engine and adding the DV for TLI. Basicly thats the best. For a 450 ISP you get ~21MT TLI. Direct assent increase performance only slightly, enough to acomodate for whatever is being used as a TLI stage's dry weight.

Wikipedia did say 16,000 kg through TLI and it seems to be removed now.

[Rabidpanda]

In order to get 16MT you would need an additional stage.  What would Falcon Heavy's TLI performance be with just it's standard upper stage? 10MT doesn't seem like a bad guess.