Request Lunar dragons

[barrygolden]

I have a copy of a Space X Dragon designed to land on the Moon, couple this with the Deep Space Dragon and makes a cool looking addon but it seems to be unfinished. Yes the landing legs work but thats about it not much control in Orbit or landing.

I was thinking about using a Dragon XL with the Falcon 9 landing legs and 8 Draco thrusters around the bottom of the service module and maybe the eight around the crew module to do the last landing burn . It would need an elevator in the middle to get to the surface. When the legs deploy there could be EVA stuff and instruments to be deployed stowed there . No heat shield or nose cap needed. Maybe a big window like the LM lander has to allow a good look at the surface. could be launched on a Falcon Heavy

As for the manned Lunar Dragon would have no legs the same super Dracos for the LOI and TEI burns and a normal Dragon for the landing.. It too use Falcon heavy to lift off and stage 2 for the TLI burn

Just some ideas to look at

 

[francisdrake]

Making a Dragon lunar lander would probably need so much modifications, that in the end not much of a Dragon would be left.
I tried to land the normal Dragon DM2 on Brighton Beach, but had to "top off the tanks" twice during the approach, cheating by modifying the 'current state' scenario file.

And this was only for the landing. You may want to bring the crew back to orbit again. Then this becomes a different vessel. It would need a landing stage capable of landing an over-fuelled Dragon on the surface.

 

[barrygolden]

That why I think a dragon XL might carry enough fuel. there is a lot of talk about a mini Star ship and it would be a lot like a Dragon XL

 

[francisdrake]

I fully agree, it would be an interesting concept to make a Lunar landing architecture based on 'Dragon-derived' vehicles.
Still, the Dragon and the DragonXL are orbital vehicles. They are not built to land and ascend.

On the DragonXL very little data have been published. When I did the DragonXL-addon I made some back-of-the-envelope calculations.
Data see below. The dV is too little to land on the Moon. The main thrusters are firing forward, not downwards.


Modifications might be:

• Add much more fuel, partly as drop-tanks, or integrated in a landing stage, which remains on the Moon.
• Define suitable landing thrusters. Dracos are a bit weak, but SuperDracos are too powerful.
• Add landing legs, an egress hatch, ladder and solar arrays suitable to operate in gravity.
• Add a Lunar capture stage, to minimize the mass of the actual landing vessel.
• ...

 

[barrygolden]

It looks like a Dragon XL would have a service module about the length of 2 normal dragon service module
super dragos for sure with 8 spaced between the landing legs in pairs
the crew transit Dragon would use a normal cabin and the Super Dragos in the bottom with no legs
the lander would use a little different cabin might need a small elevator either in the middle of Service module or
on the outside Surface tools and Instruments could be carried inside the legs of the lander a small lander would be needed to deliver
a rover and larger instruments launched on another Falcon

 

[francisdrake]

I made some calculations for a DragonXL-based Lunar lander. The vessel has a dV of 3.2 km/s, down and up in one piece. It is for 2 astronauts with provisions for 10 days on the Lunar surface. Any heavier payload would need to go separately on a dedicated cargo lander.

Kept the diameter of the DragonXL, but stretched the upper part to make room for the tanks.
This makes the vessel grow considerably in length. The cabin is in the lower part, to make Lunar egress easy. With this design feature resembles the Blue Moon Lunar lander.

Observations:
The SuperDraco thrusters are a bit over-powered for a soft landing, but lack in ISP.
So I gave them the ISP of normal Dracos (3000 m/s) and large nozzle extensions.

Made the oxidizer tank torodial around the central crawl tunnel, which leads up to the docking port.
I think, this tank-shape would be a totally new development.

The spherical fuel tanks might still be optimized. They were few at the beginning, but their number grew with every design iteration.

25 ton launch mass exceeds considerably FalconHeavy's TLI payload of 15.460 kg.
In addition to the 25 ton, a Lunar capture stage is required, that would add another 10 ton.

For those who would like to dig deeper into the numbers, the spreadsheet is in the zip-file.

 

[francisdrake]

Just saw this on X:
The cargo dragon on CRS 33 has an independent fuel tank and two additional Draco thrusters in the trunk to support ISS reboosts.
This may be a first step towards a 'service module' trunk version, which could significantly boost the dV of a Dragon capsule.

 

[barrygolden]

Saw this and might be a good guide for size with an Apollo size SPS

the lander would need to be same size but have Falcon 9 landing legs mounted on it

 

[barrygolden]

any one want to have a go at this prodject

 

[francisdrake]

Made a simple cfg-style lander, called it DragonLL (Lunar Lander). It is basically a DragonXL with torodial fuel tanks stacked on top. It has a start mass of 30 ton. The lander and scenarios are in the attached zip-file. Two scenarios are included, to land on Brighton Beach or Ukert crater. I think the concept is quite different from what Barry had in mind. The problem is not to land, but to launch into orbit again. Every kg that shall go up requires several kg of fuel to go down. You end up with a vehicle much larger than originally anticipated.

 

[barrygolden]

I do like the idea with this it is different from what i was thinking but its a great idea
In my time at space X I did see a concept a little like this but it had the Falcon 9 legs with the tits being able to fold up to be the landing pads and external cargo carried inside the legs so when the legs were down the EVA guys had access to them

Can you do a Falcon heavy launch for this and one in Lunar orbit

 

[barrygolden]

Ok just saw where it is in Lunar Orbit looks way cool

you might think about nav lights on top and eva lights around the lower part
Might need to work on some new Space X EVA suits as well and some place to put cargo

 

[barrygolden]

Hey this is way cool a landing super but then kept moving untill I used scn ed to stop it

I know this is just the early version but looks pretty cool thanks a bunch

 

[francisdrake]

Can you do a Falcon heavy launch for this?

Yes, but that does not bring you to the Moon.

The 30 ton payload exceeds the 'throwing capacity' of a FalconHeavy, even in a fully expendable configuration.
And there is the need to add a ~10 ton cruise stage to capture into Lunar orbit, which would even worsen the situation.

I think, this configuration (all down and up in one piece, using hypergolic fuel) is not a viable option.

In my time at space X I did see a concept a little like this but it had the Falcon 9 legs ...

Would you have pictures or docs of this concept? Maybe the SpaceX guys had better ideas on this.

 

[barrygolden]

No pictures of this it was kept pretty close in house It did have the larger SM but with a Dragon 1 on top

Most of the Lander concepts don' show a transfer stage or space tug

the team USA lander did show one with the lander

 

[barrygolden]

Hey saw this one and might make a good EVA suit

 

[barrygolden]

can you send me a copy of the falcon heavy launch scn

 

[francisdrake]

can you send me a copy of the falcon heavy launch scn

Give me a few days. The launch requires a cradle, which I 'borrowed' from my LEV Lunar lander, but need to make one for the DragonLL with the folded legs.

 

[barrygolden]

thanks the lander does need a few thing like RCS smoke and I might would an upward facing RCS nozzle instead of the nose trusters some EVA lights as well ..

I did like the LEV lander but I think it was hard to control if I remember need to try it again

 

[francisdrake]

I did like the LEV lander but I think it was hard to control

I use the PursuitMFD for landing from orbit. This is quite reliable, and is much better than landing manually.

landing super but then kept moving untill I used scn ed to stop it

Welcome to the Lunar slipping-and-sliding contest!
Orbiter does not support static friction. So even with a slight inclination the vessel slides slowly.

Workarounds:
- Land on Brighton Beach. The landing pads are fully flat.

- Land exactly at the marked spot at the Ukert crater rim. There is a saddle point, and it stands still.
You have to enter 'Ukert' manually as landing target in the PursuitMFD.

- Use the Sleepy Vessels addon.
If your sliding speed is < 1m/s and you hit the brakes, the vessel is forced to 'Landed' status