Author Topic: Orion to the moon using F9 and F9H  (Read 8600 times)

Offline sevenperforce

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Re: Orion to the moon using F9 and F9H
« Reply #20 on: 03/07/2018 11:47 am »
I doubt those Falcon Heavy on-orbit delivery figures. The official figure is 63,800 kg to orbit - the mass of the stage combined with it's residual propellant should get to be a little more than that; since it would not be pushing against payload gravity losses, still...
It's not a difference in gravity drag (though the enhanced TWR helps), but a difference in mass fraction. The key is to look at Falcon Heavy's performance for very small payloads rather than looking at the largest possible payloads.

FH is advertised at being able to send 3.5 tonnes to Pluto. A Hohmann transfer to Pluto requires an 8.2 km/s burn from low Earth parking orbit. 8.2 km/s at the MVac's 345 s of specific impulse requires a propellant mass fraction of 91.14%. 4 tonnes for the upper stage and 3.5 tonnes of payload means 77.19 tonnes of propellant to perform that 8.2 km/s injection burn toward Pluto.

The Falcon family upper stage carries 107.5 tonnes of propellant, so this means it must burn 30.31 tonnes of propellant to get from staging to LEO with a payload of 3.5 tonnes. That's 1.035 km/s of dV, suggesting a staging velocity of around 6.765 km/s. Now, if the upper stage is not carrying 3.5 tonnes of payload at staging, it will burn slightly less propellant (29.39 tonnes) to achieve the same 1.035 km/s from staging to LEO, leaving it with 78.11 tonnes of propellant in LEO.

And that's without factoring in lower gravity losses (3% higher TWR at staging) and a higher staging velocity (the "payload" of the core booster is 3% lower).

Yes - figure should be closer to, but still less than 70 metric tons all up.
Try at least 80 tonnes. 90+ might be pushing it but a lot depends on the ascent and booster separation profile for Falcon Heavy: how and when it throttles will really change a lot of things.

Offline MATTBLAK

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Re: Orion to the moon using F9 and F9H
« Reply #21 on: 03/07/2018 09:24 pm »
Yes - things would certainly look good for lunar missions, doing 'distributed launch' of the spacecraft and the Earth Departure Stage (EDS). A Falcon 9 could place a 20 ton Lander or Command Module type vehicle into orbit first. A Falcon Heavy places it's upper stage as an EDS into orbit next, where it's only payload is propellant (65-70 tons?) and a docking mechanism. The spacecraft docks with this and the EDS burns for TLI. With a 'long duration kit' modification to the EDS; it could also insert the payload into lunar orbit with another burn. Any residuals could put the stage on lunar escape later or de-orbit it to the lunar surface.
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Offline sevenperforce

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Re: Orion to the moon using F9 and F9H
« Reply #22 on: 03/07/2018 09:33 pm »
Yes - things would certainly look good for lunar missions, doing 'distributed launch' of the spacecraft and the Earth Departure Stage (EDS). A Falcon 9 could place a 20 ton Lander or Command Module type vehicle into orbit first. A Falcon Heavy places it's upper stage as an EDS into orbit next, where it's only payload is propellant (65-70 tons?) and a docking mechanism. The spacecraft docks with this and the EDS burns for TLI. With a 'long duration kit' modification to the EDS; it could also insert the payload into lunar orbit with another burn. Any residuals could put the stage on lunar escape later or de-orbit it to the lunar surface.
Yeah, this is quite a good approach.

Propellant on the EDS is 70-80 tonnes with FH expendable, 60-70 tonnes with side booster recovery, and 30 tonnes with three-core recovery.

Offline redliox

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Re: Orion to the moon using F9 and F9H
« Reply #23 on: 03/08/2018 04:07 am »
Probably doable, at least between two FH launches.  The real showstoppers however would be a mix of Orion's low dv, safety concerns (since FH isn't crew rated), and NASA bureaucratic pride.  A better investment would be to develop a one-way lander that could use FH.  The Orion needs some overhauling, or at least its service module, if you wish it to be invested.

Also, I don't think SpaceX would be interested since it will be creating ITS/BFR which will make both FH obsolete and be capable of moon landings itself.
« Last Edit: 03/08/2018 04:09 am by redliox »
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Offline arezn

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Offline raketa

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Re: Orion to the moon using F9 and F9H
« Reply #25 on: 03/14/2019 12:58 am »
From

https://forum.nasaspaceflight.com/index.php?topic=42363.msg1782831#msg1782831

the delta-Vs they use has GTO is too low and Mars is too high.

Orbit Stage dV  old dV  new dV
LEO   3214      0       0
GTO   5090      2270    2500
Mars  6156      4300    3800
Pluto 9236      8200    8200


This has a best fit of dv = 0.734*dv1 + 3264

dv1 = 3180 m/s (TLI)
dv = 0.734*dv1 + 3264 = 5598.1 m/s (total stage delta-V)
ms = 4 t
mp = 107.5 t
ve = 3383.3 m/s
dv = ve*ln(1+mp/(mc+ms))
mc = mp/(exp(dv/ve)-1)-ms = 21.4 t

That is, FH expendable can send 21.4 t to the Moon. Orion mass after separation with two crew is 25.6 t, so the answer is no, it is not possible to send Orion to the Moon using Falcon Heavy. Orion is simply too heavy, thanks to its large 5 m diameter width. Orion mass from link below.

http://www.lpi.usra.edu/meetings/leag2014/presentations/klaus.pdf

1/What about F9H launch Orion.Second stage stay connected with Orion+F9.2(second stage F9)
2/F9 launch Dragon 2
3/Second stage stay connected with Dragon+F9.2
4/Second Dragon+F9.2 dock with Orion Orion+F9.2
5/Astronaut switch to Orion
6/F9.2+Dragon do partial TLI for Orion+F9.2
7/Orion+F9.2 will finish TLI

Offline Tantal

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Re: Orion to the moon using F9 and F9H
« Reply #26 on: 03/18/2019 10:40 am »
Hi everyone,

Let me post my first post here with - maybe a naive - question.

Wouldn't it be the most reasonable to redraw/exchange the second stage of FH with something that can be refuelled on LEO. Lets call it a Moon Taxi Stage. Than also built a tanker which can fly on F9 or FH.

Fly both - Moon Taxi with Orion to LEO, then tank, send it with huge fuel reserve to the Moon.

Of course NASA & consortes do not have any interest in making this happen, SpaceX is concentrated on making brand new BFR. I simply thought that it would cost just a fraction of what SLS does, i.e. R&D 1 bln USD, building Taxi and Tanker another 1 bln and mission cost of around 200 mln. Something in the middle between outdated and bloody expensive SLS and state-of-the art idea of BFR.


Or another version - re-arranging FH first stage to more powerful cross-type set consisting of 5 Falcon boosters. Would it provide, theoretically, enough thrust to cover this 20-25% that FH lacks to match SLS?

« Last Edit: 03/18/2019 11:40 am by Tantal »

Online eric z

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Re: Orion to the moon using F9 and F9H
« Reply #27 on: 03/18/2019 11:39 am »
 Hi Tantal, and welcome to the site. You will find a lot of people here that love putting different stages, engines modules, rockets, fuels, launch sites, etc. etc. into wild and weird combinations; some of which may even be good ideas, or at the least fun to contemplate! ;D

Offline hopalong

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Re: Orion to the moon using F9 and F9H
« Reply #28 on: 03/18/2019 11:45 am »
Hi everyone,

Let me post my first post here with - maybe a naive - question.

Wouldn't it be the most reasonable to redraw/exchange the second stage of FH with something that can be refuelled on LEO. Lets call it a Moon Taxi Stage. Than also built a tanker which can fly on F9 or FH.

Fly both - Moon Taxi with Orion to LEO, then tank, send it with huge fuel reserve to the Moon.

Of course NASA & consortes do not have any interest in making this happen, SpaceX is concentrated on making brand new BFR. I simply thought that it would cost just a fraction of what SLS does, i.e. R&D 1 bln USD, building Taxi and Tanker another 1 bln and mission cost of around 200 mln. Something in the middle between outdated and bloody expensive SLS and state-of-the art idea of BFR.


Or another version - re-arranging FH first stage to more powerful cross-type set consisting of 5 Falcon boosters. Would it provide teoretically, enough thrust to cover this 20-25% that FH lacks to match SLS?

My understanding is that there is a time contrant - e.g. by the end of next year. So there will be no time to develop anything too fancy like a Falcon super heavy, this will be more or less an come as you are party. SpaceX may be able to do something with the 2nd stage, but would they have the time to build and test a stretched 2nd stage and/or a boost stage?


Offline hektor

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Re: Orion to the moon using F9 and F9H
« Reply #29 on: 03/18/2019 11:59 am »
Could FH put you in a highly elliptical orbit, super GTO and then Orion's ESM provides an extra kick to go TLI ?

Offline Tantal

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Re: Orion to the moon using F9 and F9H
« Reply #30 on: 03/18/2019 12:21 pm »
Hopalong, I do not expect anyone will go that path. None of the sides interested in. I was interested in theoretical possibility, i.e. if anyone estimated those numbers. Could such a set throw 100 T on LEO? If so, than SLS can go to hell.

It would be a probable way of development only if SpaceX was not about an immidiate development of the BFR.

5-booster Falcon Superheavy is an atractive idea also from another point of view: imagine 4 side boosters landing almost unisono close to each other. Pure symphony. :)
« Last Edit: 03/18/2019 12:24 pm by Tantal »

Offline Steven Pietrobon

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Re: Orion to the moon using F9 and F9H
« Reply #31 on: 03/19/2019 08:56 am »
Could FH put you in a highly elliptical orbit, super GTO and then Orion's ESM provides an extra kick to go TLI ?

Yes. Fully fuelled Orion mass with adaptor is 26.357 t. Orion has a 1215 m/s capability with a full propellant load. If we assume that 1215 m/s is used to complete TLI for a Lunar flyby mission, then this reduces the delta-V for the upper stage to 3185-1215 = 1970 m/s. FH expendable has a payload of 32.3 t for this delta-V (I use my own program to calculate this, link below), which leaves 32.3-26.4 = 5.9 t of margin. You could probably do the mission with core expended, since that only reduces LEO payload from 63.8 to 57.4 t.

http://www.sworld.com.au/steven/space/fh.zip
https://space.stackexchange.com/questions/25452/how-much-payload-can-falcon-heavy-reusable-lift

Alternatively, you can fly Orion on Lunar flyby without a full propellant load (I calculate 17,430 kg for Orion and adaptor for this case). Expendable FH has a TLI payload (3185 m/s delta-V) of 21.8 t, so this mission has a 21.8-17.4 = 4.4 t margin. Again, you could probably do this mission with core expended. The lighter payload would also put less stress on the upper stage.
« Last Edit: 03/19/2019 08:58 am by Steven Pietrobon »
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Offline arezn

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Re: Orion to the moon using F9 and F9H
« Reply #32 on: 03/23/2019 09:50 am »
Fully fuelled Orion mass with adaptor is 26.357 t. And Orion can deliver itself and (!!) A 10 t. Element to LOP-G.
But at pesent:
https://www.nasaspaceflight.com/2019/03/administration-proposes-end-eus-exploration-manifest-rewrite/
... The President’s FY 2020 budget request proposes defunding EUS, Block 1B, and related projects like ML-2. The FY 2020 request calls for
!!! all Lunar Gateway payloads previously under consideration to fly “co-manifested” on SLS with Orion in the Block 1B Crew configuration to
!!! now use commercial launch services.

Lunar flights in the FY 2020 proposal, showing the commercial approach to Gateway assembly the Administration favors. SLS launches would be restricted to the Block 1 configuration and

So Orion needs less fuel ...
 and its total mass is ... ?

Offline Proponent

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Re: Orion to the moon using F9 and F9H
« Reply #33 on: 03/23/2019 10:21 am »
Orion has a 1215 m/s capability with a full propellant load.

Source?

Offline TaurusLittrow

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Re: Orion to the moon using F9 and F9H
« Reply #34 on: 03/23/2019 11:12 am »
Could FH put you in a highly elliptical orbit, super GTO and then Orion's ESM provides an extra kick to go TLI ?

Alternatively, you can fly Orion on Lunar flyby without a full propellant load (I calculate 17,430 kg for Orion and adaptor for this case). Expendable FH has a TLI payload (3185 m/s delta-V) of 21.8 t, so this mission has a 21.8-17.4 = 4.4 t margin. Again, you could probably do this mission with core expended. The lighter payload would also put less stress on the upper stage.

Pardon my ignorance, but is there a C3 approximation (eg, C3 of -2, -3, etc.) for a TLI trajectory?

Offline hopalong

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Re: Orion to the moon using F9 and F9H
« Reply #35 on: 03/23/2019 11:18 am »
Could FH put you in a highly elliptical orbit, super GTO and then Orion's ESM provides an extra kick to go TLI ?

Alternatively, you can fly Orion on Lunar flyby without a full propellant load (I calculate 17,430 kg for Orion and adaptor for this case). Expendable FH has a TLI payload (3185 m/s delta-V) of 21.8 t, so this mission has a 21.8-17.4 = 4.4 t margin. Again, you could probably do this mission with core expended. The lighter payload would also put less stress on the upper stage.

Pardon my ignorance, but is there a C3 approximation (eg, C3 of -2, -3, etc.) for a TLI trajectory?

Have a look here -

https://descanso.jpl.nasa.gov/monograph/series12/LunarTraj--05Chapter4TransferstoLowLunarOrbits.pdf

Table 4-1 covers it  :)


Offline TaurusLittrow

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Re: Orion to the moon using F9 and F9H
« Reply #36 on: 03/23/2019 12:12 pm »
Could FH put you in a highly elliptical orbit, super GTO and then Orion's ESM provides an extra kick to go TLI ?

Alternatively, you can fly Orion on Lunar flyby without a full propellant load (I calculate 17,430 kg for Orion and adaptor for this case). Expendable FH has a TLI payload (3185 m/s delta-V) of 21.8 t, so this mission has a 21.8-17.4 = 4.4 t margin. Again, you could probably do this mission with core expended. The lighter payload would also put less stress on the upper stage.

Pardon my ignorance, but is there a C3 approximation (eg, C3 of -2, -3, etc.) for a TLI trajectory?

Have a look here -

https://descanso.jpl.nasa.gov/monograph/series12/LunarTraj--05Chapter4TransferstoLowLunarOrbits.pdf

Table 4-1 covers it  :)

Thanks for the reference. ;-)

Assuming C3 = -1 for a lunar flyby, a fully expendable FH has an estimated payload of 15.8 mT based on the Silverbird Astronautics performance calculator (http://www.silverbirdastronautics.com). A similar payload (15.3 mT) is given by NASA's performance calculator (https://elvperf.ksc.nasa.gov/Pages/Query.aspx).

Of course, payload varies according to the input parameters.

However, I don't see how the FH can boost an unfueled Orion/ESM with a mass of 17.5 mT on a circumlunar flight.

Or maybe I'm missing something.




Offline M129K

Re: Orion to the moon using F9 and F9H
« Reply #37 on: 03/23/2019 01:31 pm »
Considering the big discrepancy between what we can infer from SpaceX' figures on their website and what is listed on NASA's performance calculator I think that, whatever it is that Falcon Heavy can actually launch to TLI, it's probably going to be too close to be a safe bet for such a mission. For Orion on FH, dual launching seems to be the way to go in the coming years.

As far as dual launching is concerned, could docking in a highly elliptical orbit be a possibility? Doing this would mean the least amount of wasted payload per launch, with the initial Orion launch already getting quite a kick towards TLI from FH. A 54 tonne stack consisting of Orion and an equally heavy EDS with about 25 tonnes of fuel and a Ve of 3380 m/s would have approx. 2.1 km/s of delta V, which might be enough for TLI if the staging orbit is high enough, and would eliminate the need for a new hydrolox-powered upper stage with many of the costly ground infrastructure changes that it would require. A 8000x200 km staging orbit should do it. Increased mission complexity might be prohibitive though.


Offline Proponent

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Re: Orion to the moon using F9 and F9H
« Reply #38 on: 03/23/2019 05:03 pm »
I don't see how the FH can boost an unfueled Orion/ESM with a mass of 17.5 mT on a circumlunar flight.

True, although FH likely has the delta-V to put a fully fueled Orion/ESM into a highly elliptical orbit from which it can inject itself into a free-return lunar trajectory (if that's what you mean by "circumlunar").  Delta-V isn't the only consideration, of course.

Online Slarty1080

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Re: Orion to the moon using F9 and F9H
« Reply #39 on: 03/23/2019 07:20 pm »
Is it  possible?
Technically yes. But the reason to send Orion around the moon is to justify SLS. If you remove SLS from the mission, there is no reason for Orion to go around the moon.

I feel like my head will explode after reading that. It reminds me of the saying about modern aircraft flying themselves but still needing to carry a pilot and a dog. Why carry a pilot if the aircraft can fly itself? To feed the dog of course. But why carry the dog? To bite the pilot if he ever touches the controls.

Getting back to Falcon. My favoured option would be a cost plus Government contract for SpaceX to build a Falcon Exploration Upper Stage (FEUS). This would consist of stretched Falcon Heavy methane fueled upper stage with a vacuum raptor engine capable of taking Orion around the Moon.

Considering the difficulty of the contract there would be no penalty for not delivering on time, but a serious penalty would be incurred if the new Falcon Super Heavy provided more thrust than SLS block 1.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

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