Discussion Falcon Heavy with Dragon to moon?

[Kyle]

Since (well, actually before it was announced, better then known as the Falcon 9 Heavy) Falcon Heavy was announced, and with the successful flight of COTS-1 with the fact that COTS-2/3 will be launching NET mid-January 2012 to the International Space Station, I was wondering if the two vehicles could be combined for one, short but awesome space flight. I am sure this idea has been discussed before, but I wanted to see if it was possible or have a stand alone discussion of it.

Here's the idea. Place a manned Dragon with a crew of four ontop a Falcon Heavy out of LC40. Modifications are planned at this time to allow Falcon Heavy(s) to launch out of LC40. From a 28.5 degree inclination orbit in a 200km by 200km altitude, the Falcon Heavy can launch 53,000 kg. Obviously, this is more than enough to carry a 6,000 kg Dragon spacecraft into orbit. So, you launch a Falcon Heavy in say, 2017 with a Dragon spacecraft out of KSC for a circumlunar mission. A non-modified Dragon couldn't carry enough fuel or thrust to allow for it to go into orbit around the moon, so a simple flyby would probably be the only option. Re-entry, I don't know the specifics about the heatshield but Musk has stated that his heat shield can apparently 'withstand a high speed re-entry from Mars' (I recall him stating that around 2008 or so, please correct me if I was wrong or misquoted him). Musk may overstate things sometimes, but suppose that's right. What could stop this from happening?

One might argue ''there is no need for a commercial manned mission to the moon, they do not get any commercial value out of it'', but that's not entirely true. You can prove that its possible for a commercial mission to the moon, and you can gamble on its success and say, hey if this can go to the moon, if NASA and its astronauts can go to the moon, why cant you? Paid flights to the moon, one week missions too and back.

Is it possible? Is there enough DV in the FH Upper stage for a TLI? Is Dragon capable of going to the moon, manned? Could there be follow on future modifications that could allow for a orbital lunar mission? Is this what you think is on one of Musk's medium term goals?

I'd love to hear ideas, criticisms, ect.

 

[MaverickSawyer]

If the latest version of the Falcon/Dragon family addon is accurate, you have more than enough dV to make TLI. However, the life support of the addon is a little lacking unless you use the UCGO O2 cargos. The scenario you describe has been done with Orbiter, IIRC.

 

[Kyle]

If the latest version of the Falcon/Dragon family addon is accurate, you have more than enough dV to make TLI. However, the life support of the addon is a little lacking unless you use the UCGO O2 cargos. The scenario you describe has been done with Orbiter, IIRC.

I know, I flew it in orbiter. It worked, other than I was a little steep on re-entry and landed off course (this is of course, due to a flaw I have using MFDs). Orbiter can be inaccurate, well addons can, and it might not take into account the exact specifications of the FH and Dragon, especially given that the FH has never flown yet.

 

[T.Neo]

- It should be at least physically possible, FH should have the dV capability to send Dragon on a translunar trajectory.

- I believe Musk has stated that FH will be human-ratable.

- As FH shares hardware with F9, it should be possible to mount a Dragon onto it.

- It has been stated that the TPS is capable of lunar and Martian reentries. SpaceX's more immediate goal/purpose for this, is likely to be an intention to reuse the TPS (by only having a small amount ablate away on each LEO flight) and have a considerable margin built-in.

- There are many other issues with BEO flight than the TPS alone. The vehicle will need to withstand the different BEO thermal environment. It will need to potentially communicate over longer distances, and have electronics hardened to withstand different conditions. It might need radiation or micrometeoroid shielding for the crew, or a number of other integration of operation issues with various components.

However, the answer to whether Dragon can fly BEO (or has the capability to be upgraded/modified to BEO capability) is best answered not by just insisting that "Dragon is not BEO!!!1!11!11". Currently, only those who have worked on Dragon know its true capabilities.

Musk has supposed a circumlunar Dragon/FH flight.

There are other issues (like ensuring that the capsule geometry can withstand a lunar reentry) for example that have to be dealt with.

But such a mission would be inexorably useful. For these reasons:

1. Demonstrating that what ensures a spacecraft/launcher system can perform BEO human spaceflight has nothing to do with inefficient contract structures or political Porkitude.

2. It would put the nail in the coffin of statements that ""Dragon is not BEO!!!1!11!11", or that special Government Pixiedust is needed to go beyond LEO.

3. Demonstrating the abilities of a system defined by a number of paradigm shifts in the spaceflight industry.

I don't care if you just barely stuff one single person into a Dragon, and launch them on a hohmann halfway to the Moon. Even that would achieve more than NASA's planned remake of Apollo 8. And that's saying a lot.

 

[Codz]

You're acting like just because there isn't an Orion lander now means it can never exist.

 

[Kyle]

I didn't know Musk already had the idea. If that's the case, then there's quite a bit to gain from sending a Dragon to the moon.

 

[Capt_hensley]

T NEO

Do you have to go straight from a 25,000 mph TEO from Mars or Lunar orbit directly to re-entry?

IMO No, you could insert to HEO, orbit a couple times, slow down to 17,500 MPH with decelerating, orbit shrinking, burns to LEO, then re-enter normally. This would reduce the stress commonly found in direct 25,000 mph re-entry, it would increase the survivability of the Dragon, and keep the re-entry to what we know of late, slow LEO re-entry. You just have to pad the expendables in the service module(trunk segment) to enable such a lengthy trip right?

Why can't this theory work?, AFAIK it can. Dragons launch abort propellant could be expended as retro fuel right? There should be plenty of deltaV for re-entry using this method.

 

[MaverickSawyer]

IIRC, the abort propellant is also the RCS propellant. The reasoning is, If you abort, you won't need the RCS, and if you don't abort, You don't have wasted mass on a LAS that still fires in order to b e ejected. They also plan to later do propulsive landings with the LA engines, which would make keeping the engines onboard a reasonable mass expense.

 

[N_Molson]

IMO No, you could insert to HEO, orbit a couple times, slow down to 17,500 MPH with decelerating, orbit shrinking, burns to LEO, then re-enter normally. This would reduce the stress commonly found in direct 25,000 mph re-entry, it would increase the survivability of the Dragon, and keep the re-entry to what we know of late, slow LEO re-entry.

Extreme waste of fuel. That kind of strategy could be interesting with ion or plasma thrusters, but with chemical propulsion, it would dramatically increase the size of the launcher.

 

[T.Neo]

You're acting like just because there isn't an Orion lander now means it can never exist.

Sorry, but an Orion-derived lander is complete and utter fiction. At the moment, no more likely to exist than a Dragon-derived lander.

There are no plans for it, there is no funding for it, and it would be a very large development campaign if it were to become reality.

What on Orion are you going to turn into a lander? The capsule TPS and RCS are not needed. The main engine cannot deep throttle. You will need provisions for landing (such as legs/supports) and provisions for egress, surface operations and mounting cargo. All of these things do not exist.

You might be able to make an ascent stage derived from the Orion SM, but many of these problems still exist, and you still need to design a whole new descent stage.

The closest thing to an Orion associated lunar lander that has existed in reality, is the Altair LSAM. But that was cancelled with Constellation and I believe was even de-funded while Constellation was going on. And would obviously cost a lot to develop into real flight hardware.

I am sorry, but all you are stuck with is pretty much a multibillion Apollo 8 remake.

And if you compare, let's say, this mission, with $500 million to modify Dragon for BEO flight, $175 million for a Falcon 9 flight, and $85 million for a Dragon (40% cost growth over quoted figures), it would cost only $760 million to perform this mission. Which is at least similar to the hardware cost alone of an SLS/Orion flight.

Of course, you would likely want to fly an unmanned test flight beforehand, which would mean an extra Falcon Heavy and an extra Dragon. But it would be no difference in the case of Orion/SLS- you would likely fly an unmanned flight first, and you would have to spend those hardware costs too.

Why can't this theory work?, AFAIK it can. Dragons launch abort propellant could be expended as retro fuel right? There should be plenty of deltaV for re-entry using this method.

In addition to concerns raised by others about propellant expenditure (Dragon may have some 300-400m/s of dV, but you would want to conserve as much as possible for things like mid-course corrections), you would also have to deal with increased demand for supplys from the crew (things like food can't be stored in the trunk), as well as repeated reentry cycles on the TPS (which it might not like) and also repeated transits through the van Allen belt (which apparently is something to avoid).

 

[Urwumpe]

TNeo: small correction, there is a NASA design path that would permit a lunar lander. But it isn't Orion.

[ame="http://en.wikipedia.org/wiki/Space_Exploration_Vehicle"]Space Exploration Vehicle - Wikipedia, the free encyclopedia[/ame]

 

[T.Neo]

TNeo: small correction, there is a NASA design path that would permit a lunar lander. But it isn't Orion.

Ah yes... it would probably be a far more logical choice to derive a lunar lander from, but would still likely need a good deal of development to turn into an actual lander.

It would probably take a good deal of money to develop the SEV alone to flight status as well.

 

[Urwumpe]

Ah yes... it would probably be a far more logical choice to derive a lunar lander from, but would still likely need a good deal of development to turn into an actual lander.

It would probably take a good deal of money to develop the SEV alone to flight status as well.

Sure, we are talking about spaceflight here. But the general concept of it is pretty good. Since the basic SEV hull would be pretty versatile, maybe it could be a smart idea to permit license production of it, when finally developed.

 

[T.Neo]

But the general concept of it is pretty good. Since the basic SEV hull would be pretty versatile, maybe it could be a smart idea to permit license production of it, when finally developed.

Interesting possibility, but (as far as I know) SEV is not funded to a serious degree. The fault of SLS and Orion, again... :dry:

 

[Urwumpe]

Interesting possibility, but (as far as I know) SEV is not funded to a serious degree. The fault of SLS and Orion, again... :dry:

Yes, micromanagement by incompetent people has always doomed things.

 

[MaverickSawyer]

The main engine cannot deep throttle.
...
The closest thing to an Orion associated lunar lander that has existed in reality, is the Altair LSAM. But that was cancelled with Constellation and I believe was even de-funded while Constellation was going on.
...

The main engine for the descent stage of Altair was designed to throttle to as low as 5% thrust. My dad did some of the brazing work on the Lunar Engine Test Bed a few years back, which demonstrated the 5% throttle capability. The tech was never developed beyond that.

 

[Kyle]

Thanks for the input guys!