Author Topic: Dragon 2 or Starliner derived dedicated lunar lander?  (Read 21734 times)

Offline sdsds

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #140 on: 03/09/2017 06:25 AM »
Here is my latest Reusable Dragon Horizontal lander

That's a beautiful design! But what allows the MVac to restart successfully after a days-long cold soak during trans-lunar coast? Because ... kerolox doesn't do that?
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Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #141 on: 03/09/2017 09:26 AM »
Here is my latest Reusable Dragon Horizontal lander

That's a beautiful design! But what allows the MVac to restart successfully after a days-long cold soak during trans-lunar coast? Because ... kerolox doesn't do that?
Thanks, off the top of my head would be simple heater blankets and strip heaters powered off the solar arrays. Orientation toward the Sun would help as well and it would need to be tested in a space environment test chamber. I'm always open to suggestions! :)
« Last Edit: 03/09/2017 09:34 AM by Rocket Science »
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Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #142 on: 03/09/2017 09:40 PM »
Here is another Reusable Dragon Horizontal lander simple carbon fiber truss frame with hypergolic drop tanks MMH/N2O4 (red), grey section is a payload drop-pallet. Retractable solar array deployed on upper surface (dark blue), fold-out ladder to surface inside bottom hatch. Four Super Dracos main engines to perform deorbit burn to lunar surface with 8 side Super Dracos performing the flare to land. Leave drop-tanks tank on surface during lift-off with Super Dracos, Four Super Dracos main engines stays attached to rear truss. O2 tanks (light blue), He tanks (green), hypergolic prop (purple) for Dracos and 8 side Super Dracos.

 As before, if you wanted to do suit-ports, they could be on an inner bulkhead and stored there and protected by the outer hatch cover. Open back suit-port cover, climb in, open the outer hatch and unfold the ladder and descend the few steps to the surface...
« Last Edit: 03/13/2017 11:04 PM by Rocket Science »
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Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #143 on: 03/09/2017 10:33 PM »
Suit-ports, hatch open, steps unfolded:
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Offline GWH

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #144 on: 03/10/2017 03:59 AM »
Dragon2 Lander Concept:
Nested in the original SuperDraco mounts are new Vac SuperDracos.  All pressure fed tanks have been removed, utilizing the primary propellant tanks with electric turbo pumps.  Draco engine mounted arrangement is maintained in the conformal pods on the side of the pressure vessel.
4xSuper Draco Vacs, 345s ISP.  Double engine SD packs modified to single engine & actuators added for gimballing at landing + vac nozzle.
Dragon 2 Dry Mass: 6750 kg
-chutes + heatshield: -780 kg
+ turbo pump batteries: 164 kg
+ electric turbo pumps: +40 kg*
- D2 pressurized tanks: -100kg*
- Helium tanks: -20kg*
- nose cone, ascent thermal shield & misc weight savings: -351kg*
+ carbon fiber prop tanks: +300kg**
+ legs and ladder: +200kg*

Total Lunar Lander Dry mass: 5800kg
*Numbers marked as asterisk are guesses and need further research of confirmation, based off 10% prop mass of Dragon 2 for removed tanks.
**Does anyone have any reference info on what I could expect Carbon fibre tanks to weigh?

Total Required Prop Mass for 1000 kg payload: 14000 kg
LLO to Lunar Surface: 8900 kg prop for 1.9 km/s dV
Lunar Surface to LLO: 5100 kg prop for 1.9 km/s dV

At launch a Falcon Heavy could launch into a GTO transfer the D2 Lunar Lander without payload and a full prop load of 15,500 kg for a combined mass of 21,100kg. 
Arriving in LLO the lander would have 7500kg prop remaining with the remaining 6500kg to be transferred in orbit by Orion stack or separate transfer vehicle.

Tanks for a 15,500kg prop load are 1xN2O4 2m dia x 2.3m long & 4xMMH 0.87m dia x 2.3m long
An alternative to the cluster tanks would be a 2.1m dia and 3.7m long tank with common bulkhead

Not shown in the model are solar panels & ladder (among many other small details).
« Last Edit: 03/10/2017 04:09 AM by GWH »

Offline Flying Beaver

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #145 on: 03/10/2017 04:46 AM »
Dragon2 Lander Concept:
Nested in the original SuperDraco mounts are new Vac SuperDracos.

Could have a problem with gas expansion damaging the fuel tanks (In a vacuum exhaust gets BIG real quick, see below).

Otherwise brilliant work.

Saw OG-2 Booster Land in person 21/12/2015.

Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #146 on: 03/10/2017 07:53 AM »
Dragon2 Lander Concept:
Nested in the original SuperDraco mounts are new Vac SuperDracos.  All pressure fed tanks have been removed, utilizing the primary propellant tanks with electric turbo pumps.  Draco engine mounted arrangement is maintained in the conformal pods on the side of the pressure vessel.
4xSuper Draco Vacs, 345s ISP.  Double engine SD packs modified to single engine & actuators added for gimballing at landing + vac nozzle.
Dragon 2 Dry Mass: 6750 kg
-chutes + heatshield: -780 kg
+ turbo pump batteries: 164 kg
+ electric turbo pumps: +40 kg*
- D2 pressurized tanks: -100kg*
- Helium tanks: -20kg*
- nose cone, ascent thermal shield & misc weight savings: -351kg*
+ carbon fiber prop tanks: +300kg**
+ legs and ladder: +200kg*

Total Lunar Lander Dry mass: 5800kg
*Numbers marked as asterisk are guesses and need further research of confirmation, based off 10% prop mass of Dragon 2 for removed tanks.
**Does anyone have any reference info on what I could expect Carbon fibre tanks to weigh?

Total Required Prop Mass for 1000 kg payload: 14000 kg
LLO to Lunar Surface: 8900 kg prop for 1.9 km/s dV
Lunar Surface to LLO: 5100 kg prop for 1.9 km/s dV

At launch a Falcon Heavy could launch into a GTO transfer the D2 Lunar Lander without payload and a full prop load of 15,500 kg for a combined mass of 21,100kg. 
Arriving in LLO the lander would have 7500kg prop remaining with the remaining 6500kg to be transferred in orbit by Orion stack or separate transfer vehicle.

Tanks for a 15,500kg prop load are 1xN2O4 2m dia x 2.3m long & 4xMMH 0.87m dia x 2.3m long
An alternative to the cluster tanks would be a 2.1m dia and 3.7m long tank with common bulkhead

Not shown in the model are solar panels & ladder (among many other small details).
Nice work! :) Have you thought about if you lose one or more of the four SD's in flight? How do you abort? That's why I went with eight slightly over-expanded. You may not save all that much weight with carbon fiber tanks so I'm always open either way. You may want to put heat shields in the SD's exhaust plume impingement path or place the tanks above. Do you anticipate any payload to surface? Great modeling BTW! 8)
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Offline GWH

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #147 on: 03/10/2017 12:52 PM »
1000 kg payload is included (meat bags + suits), transfered on orbit during docking.

If operated as a 1 way lander launched by Falcon Heavy expendable cargo to surface would be 2100kg.

With the superdraco thrust 3 engines is plenty but more losses due to gimballing would be incurred if one is lost.

As for impingement of exhaust, I was under the impression that with a very high expansion ratio to achieve the desired isp that this wouldnt be an issue. The F9 pictured is of sea level optomized  engines at altitude. I wil read up more on that. However the engines can be gimballed out to 10 degrees without cosine losses becoming too significant. The 0 degree cant is required to fit in a faring during launch.
« Last Edit: 03/10/2017 12:54 PM by GWH »

Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #148 on: 03/10/2017 01:33 PM »
1000 kg payload is included (meat bags + suits), transfered on orbit during docking.

If operated as a 1 way lander launched by Falcon Heavy expendable cargo to surface would be 2100kg.

With the superdraco thrust 3 engines is plenty but more losses due to gimballing would be incurred if one is lost.

As for impingement of exhaust, I was under the impression that with a very high expansion ratio to achieve the desired isp that this wouldnt be an issue. The F9 pictured is of sea level optomized  engines at altitude. I wil read up more on that. However the engines can be gimballed out to 10 degrees without cosine losses becoming too significant. The 0 degree cant is required to fit in a faring during launch.
There was some discussion in the AMOS-6 failure thread about the difference in tank material weight IIRC... I believe it was a post by HMXHMX, Don't forget your RCS... I guess you will be going with the Dracos... Wish I could model mine in your program, nice, keep at it! :)
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Offline GWH

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #149 on: 03/10/2017 01:43 PM »
The intent is that the dracos are in identical locations as D2 capsule (conformal pods between engines) modeling those would take some more effort. Some should definitely be added to the underside of the tanks however for improved attitude control and translational (strafe) movements.
Program is Autodesk Fusion 360. Free trial, subscription service.
« Last Edit: 03/10/2017 01:45 PM by GWH »

Offline clongton

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #150 on: 03/10/2017 07:04 PM »
The intent is that the dracos are in identical locations as D2 capsule

Each location is a pair of SDs, do the single nozzles service both engines?
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Offline GWH

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #151 on: 03/10/2017 07:40 PM »
The intent is that the dracos are in identical locations as D2 capsule

Each location is a pair of SDs, do the single nozzles service both engines?

No, single superdraco at each location only where they were previously paired.  I don't think the lander needs 3-4Gs acceleration.
The draco clusters for RCS would be maintained.
« Last Edit: 03/10/2017 07:51 PM by GWH »

Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #152 on: 03/10/2017 10:50 PM »
Whenever I think of the vertical lander the lower half of the LK-3 comes to mind for inspiration...
http://www.succedeoggi.it/wordpress/wp-content/uploads/2016/02/cosmonauti2.jpg
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Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #153 on: 03/12/2017 08:17 PM »
Here is my vertical lander with toroidal drop-tanks like Briz-M for descent and landing burn (red). Toroidal tanks on upper stage for ascent burn. He (green) 8 Super Dracos, Dracos prop (purple) Oxygen (blue), payload (grey). Electrical power from two retractable solar arrays and batteries. WIP...
« Last Edit: 03/13/2017 10:04 PM by Rocket Science »
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Offline oldAtlas_Eguy

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #154 on: 03/13/2017 07:59 PM »
SpaceX has all the hardware pieces for a store-able prop Lander like the LM. It is a matter of the integrated vehicle design and software implementation to make it viable.

Meaning there is no long duration development program required to accomplish. A one way cargo mission using a Red Dragon design is possible (we believe it has > 2.5km delta V required to reach the Lunar surface). It would probably leave off the heat shield decreasing the dry weight and increasing the RD's design's delta V. So SpaceX has designs on the board right now capable of reaching the Lunar surface that can deliver multiple metric tons of cargo/payload. So now if that cargo payload was prop a series of two missions one a prop delivery to the surface. Includes the hardware to reach to another lander to refuel it. Possibly landed by a previous cargo landing such as a rover that has empty tanks that can move between the prop source and prop load destination. And the other a manned flight with a very small portion of the normal Dragon as living space (large enough for two people) that is then refueled on the surface that RD becomes a reusable LDRL (Lunar Dragon Reusable Lander) going back and forth between a Lunar orbit and the surface. Requiring 2 to 3 FH flights 1 to 2 that delivers all the prop for the descent and a LDT (Lunar Dragon Tanker) with prop for the ascent.

New hardware/tech not existing required:
- Storable prop transfer (at Lunar surface should be trivial) (possibly storable prop transfer in Lunar Orbit)
- Lunar rover large enough to carry prop tanks to shuttle between landers

This then becomes an infrastructure that enables full support for a Lunar Base at the cost of
- ~$500M per manned mission (includes the up to 3 FH flights of 2 carrying prop and a one way LDT)
- ~$180M per one way cargo to surface carrying ~4mt of cargo
- ~$250M per one way habitat delivery (this requires some new hardware designs that does not use a LD basic design modification but uses elements from it)

At a budget of $3B/yr could do:
- 4 manned missions (continuous occupancy of 4 persons on surface at 6 month durrations)
- 1 habitat expansion delivery or major cargo ~10mt of non-pressurized cargo (like a large manned enclosed rover that can do a sealed dock on the surface with the Lunar Dragons and habitats).
- 4 pressurized supplies delivery ~3mt of supplies

This is a fully functioning and growing Lunar Base Program for the current SLS/Orion $3B budget.
Other commercial providers could be a part of this as well for close to the same costs (Starliner, New Glenn, Vulcan/ACES/[Horizontal Lunar Lander], etc).

Edit Added:
An additional note is that an an additional $1B  for a total budget of $4B a Lunar Orbit station can be supported as well.
- 2 X ~$180M/4 crew single flight to Station (with more of these could reduce the total cost of reaching the Lunar surface)
- 3 X ~$130M pressurized cargo delivery to station
- 1 X ~$220M station hardware expansion (includes the cost of the station expansion hardware (~$120M)
« Last Edit: 03/13/2017 08:19 PM by oldAtlas_Eguy »

Offline Space Ghost 1962

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #155 on: 03/13/2017 08:52 PM »
OK. Please look at OP of this thread. The focus is very narrow. Lets keep to it.

Yes it might enable more. Fine. But that isn't this thread. This thread is about doing something ... hard.

It's a hard, disciplined thing to take a CC vehicle, which we don't know much about (highly granular specs), and turn it into a dedicated lunar lander, in a few years (and I mean it) that could be used by a planned EM 1/2 mission (perhaps other/later). You get something around a billion or so to do this with. That's the challenge.

It does not need to be reusable. LM and LK certainly weren't. You get a bonus for a reusable lander or a plan leading to such. You can't burden dissimilar vehicles with co-integration, that's a no-no.

Here's the simplest expendable system - a Dragon for up, a Dragon for down, outfitted/integrated differently. Both require props/and engine enhancement. Requires precision landing. Requires LLO/direct descent props/pallet/stage (please note that Falcon 9/H had an optional third stage as PAM-D). You can mission plan it if you like. You'll find you'll need about 2k/sec delta-v addition for contingencies, which you can get in a variety of ways.

Like some of the additions this thread has come up with. Drop tanks - inside trunk, outside trunk, on capsule. Be careful you don't want to shade the PV panels. Or have plume impingement. The possibility of using electric pumps in place of pressurized tanks to a)lower tank mass, b) increase thrust/iSP, and c)reduce/reuse consumable pressurant. However, what would be the development time to make that as reliable as a pressurized escape system?

I've let things go a bit wider on this thread so you can gain involvement and promote some. Don't go too far.

The hard part here is coloring within the outline. Think small and tight. Can this be done in a few years at all?

If so, can it be done better? Can it lead to something ... where an aggressive follow-on program might develop its ambitions ...
« Last Edit: 03/13/2017 11:51 PM by Space Ghost 1962 »

Offline oldAtlas_Eguy

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #156 on: 03/13/2017 09:48 PM »
OK. Please look at OP of this thread. The focus is very narrow. Lets keep to it.

Yes it might enable more. Fine. But that isn't this thread. This thread is about doing something ... hard.

It's a hard, disciplined thing to take a CC vehicle, which we don't know much about (highly granular specs), and turn it into a dedicated lunar lander, in a few years (and I mean it) that could be used by a planned EM 1/2 mission (perhaps other/later). You get something around a billion or so to do this with. That's the challenge.

It does not need to be reusable. LM and LK certainly weren't. You get a bonus for a reusable lander or a plan leading to such. You can't burden dissimilar vehicles with co-integration, that's a no-no.

Here's the simplest expendable system - a Dragon for up, a Dragon for down, outfitted/integrated differently. Both require props/and engine enhancement. Requires precision landing. Requires LLO/direct descent props/pallet/stage (please note that Falcon 9/H had an optional third stage as PAM-D). You can mission plan it if you like. You'll find you'll need about 2k/sec delta-v addition for contingencies, which you can get in a variety of ways.

Like some of the additions this thread has come up with. Drop tanks - inside trunk, outside trunk, on capsule. Be careful you don't want to shade the PV panels. Or have plume impingement. The possibility of using electric pumps in place of pressurized tanks to a)lower tank mass, b) increase thrust/iSP, and c)reduce/reuse consumable pressurant. However, what would be the development time to make that as reliable as a pressurized escape system?

I've let things go a bit wider on this thread so you can gain involvement and promote some. Don't go too far.

The hard part here is coloring withing the outline. Think small and tight. Can this be done in a few years at all?

If so, can it be done better? Can it lead to something ... where an aggressive follow-on program might develop its ambitions ...
Ok my opinion can a Crewed LF be done in a few years? 2 maybe. 3 definitely.

The 2 depends on no slips to FH or CC development programs. Something that cannot be taken for granted.

SpaceX has shown to be very sprightly when it comes to sophisticated software development accomplishing in months (3-9) what it takes others a few years. Adapting and modifying hardware designs is a similar thing 1/2 to 1/4 the time as others. But if the government is involved the time advantages seem to disappear. With this flight as long as there is no government strings attached other than FAA approval, the schedule is a definite achievable in 3 years or less. If it was a government paid for mission I would not expect a flight before 2020. It is not any different in actual hardware or software it is all that extra paperwork and approvals through the various steps that slow things down.

Offline Rocket Science

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #157 on: 03/14/2017 01:33 PM »
Thinking a bit more about my horizontal vs vertical lander, IMO the horizontal lander will be able to deliver a larger payload to the surface such as a Bigelow Lunar Hab...
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Offline Space Ghost 1962

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Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #158 on: 03/29/2017 07:31 PM »
Lunar juggling via uncrasher stage

With the above mentioned, very likely an almost stock Dragon 2, and an enhanced Starliner, could either/both be turned into a dedicated lander, possibly even reusable.

But it would require a long lived in space propulsion system of considerable capability.

Could such a stage be possible in 1-3 years? My read on advanced in space propulsion suggests that ULA/ACES is 5+ years at best for this, and SX/BO have nothing on the board for this "distraction". Anyone ... else?

Could this be possible with Blok DM? Stage lifetime?

add:

Could this be the simplest lander concept? Something that puts the entire burden of propulsion shortfall on a propulsive stage?

So, how this would work is: stage initiates aggressive PDI to suborbital velocity trajectory, within a few miles of surface does braking burn to bring props usage to within lander's capabilities for mission, undocks lander,  lander brakes to confirm engine operation otherwise redocks, stage does high-g ascent burn to recover orbital velocity and enter parking orbit.

A "lunar Uber?" Possibly more than one for redundancy?
« Last Edit: 03/29/2017 07:45 PM by Space Ghost 1962 »

Offline GWH

Re: Dragon 2 or Starliner derived dedicated lunar lander?
« Reply #159 on: 03/31/2017 01:32 PM »
Could this be the simplest lander concept? Something that puts the entire burden of propulsion shortfall on a propulsive stage?

Ahem.

Why place all the dV requirements for ascent/descent on the lander, and in doing so drive up the requirements on the lander significantly when an upper stage can do the work here?   A Xeus-Centaur is at least partly off the shelf, IVF is scheduled to be demo'd in 2018.  Investment in that area would have a much greater return IMO then trying to make a capsule perform a 2-way trip. 

Xeus-ACES might be 5+ off, but Xeus-Centaur could be much sooner.

Gets the Lunar Dragon concept at least to the point where with moderate increases in ISP (canted, partially expanded nozzles) and a large increase in prop meet the ascent requirements.

...., and SX/BO have nothing on the board for this "distraction".

Blue does have something on the board, bould be a fit:
http://spacenews.com/bezos-and-blue-origin-reportedly-pitch-amazon-like-delivery-for-the-moon/
« Last Edit: 03/31/2017 02:53 PM by GWH »

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