Landing StarShip Horizontally

[llertag86]

Presenting the SpaceX StarShip Starbase: S.S.S.S.

As seen above the basic premise of the idea is to reorient a landed StarShip to the horizontal position

 

Taking a page from the Apollo Venus mission proposal for the 1970's

Logistics aside, what are the advantages of an unflyable StarShip As a base/ Starbase? The StarShip is cited as having appx. 1000M^3 of habitable space internally. However this is above the fuel tanks and only accounting for ~1/3-1/2 of the ship volume. If the tanks were drained, you now have approximately between two and three times the volume. Bear in mind 1000m^3 is about the internal volume of the ISS! For further comparison its roughly ~150/ 300 Apollo LEM’s internal volume.

 

Other Advantages,

1. Once horizontal it could be covered directly by lunar soil or have a thin tarp draped over it and then covered providing radiation protection and protection from micrometeorites.

2. Ease of access, instead of having to use the proposed elevator for going to and from the crew quarters the air locks would now be at ground level, though depending on design may be sideways but still usable.

3. For a moon trip in theory SpaceX could get away with just three vacuum engines allowing more cargo to the lunar surface.

4. Prefabricated base ready on arrival, instead of relying entirely on inflatable structures initially crew will have a nice area to work, sleep and prepare for base expansion whether on the Moon, Mars or wherever.

5. In theory the in development fuel transfer system could be designed to be removable within an airlock bulkhead.

 

Back of the envelope calculations for StarShip

(These are my guesses only, if you have better data please expand upon this idea)

Diameter 9m, height 50m,

Assuming cone is ~5m also containing the forward fuel tank V= Pi(r^2)(h/3)

area of cylinder Pi*(r^2) *H

with draining the tanks

V = Pi(4.5^2)*45m + Pi(4.5^2)(5/3)

V ~= 2970m^3

Obviously it would be significantly less as 9m is the exterior diameter but even with factoring in 20mm of steel for the hull assuming that floor thickness and tank thickness are similar we still have over 2000m^3 of usable space!

 

Next question, how to orient to horizontal?

As the ship is not designed to land horizontally this does pose a challenge but solvable. The benefit of all solid celestial bodies in the solar system that humans have desire to visit have less than one g of surface gravity. On the moon 1/6 and Mars 1/3. In assuming that StarShip has sufficient structurally sound an anchor and winch system could be set up to safely lower the ship without compromising its habitability. There are probably other ways of setting up such a system but in my mind going through the thought experiment you need at least four cables. Two pulling on either side near the top of Starship and two anchors at the base to prevent sliding. Once Starship has tilted sufficiently in the direction you want it to be in you can take away one cable as gravity is now doing the work for you. It will then be a relatively simple matter of lowering Starship to the ground assuming you anchored your winch system sufficiently beforehand. Alternatively depending on the torque that the RCS system can give on the ship it may be able to slow its rotational decent down to a survivable angular speed though I find this unlikely.

 

From Wikipedia, StarShip’s empty mass ~ 120,000kg on the moon that translates to a weight of ~196kN admittedly the forces would be different I will get around to doing proper calculations later but a 45mm (1.75") diameter steel cable would be capable of handling the load. Less would likely be sufficient and admittedly this would eat into cargo mass but considering the advantages it may be a small price to pay compared to shipping a similarly voluminous area for a first outpost. Besides steel is recyclable and the new area we just opened up will need it for dividing into floors, walls etc.

[James Kerman]

Welcome to the forum @llertag86,

I have split and moved your post to it's own thread to discuss the merits of landing Starship horizontally.

[cubinator]

Early Starships will likely be repurposed in such fashion. Elon himself mentioned during his presentation that their steel makes for an excellent building material for astronauts on other planets to weld into whatever is needed. Orienting some horizontally and turning them into habitats sounds like a great idea.

Starship already has some attachment points for cranes built in for transport on Earth - these same attachments could be used on other planets, and one mobile crane could be assembled which could tip many ships. Perhaps if very skilled welders were sent, they could attach many Starships together to form even bigger ba...

....wait.

This is just your excuse for botching that Mun landing, isn't it? 

I jest.  You make great points.

[Ultimate Steve]

If they do add those methalox thrusters for flipping when landing on Earth, if they are if the right power and placement then it should work on the moon. Would have to be like a lot of thrust though

[Wjolcz]

On 10/6/2019 at 6:46 AM, Ultimate Steve said:

If they do add those methalox thrusters for flipping when landing on Earth, if they are if the right power and placement then it should work on the moon. Would have to be like a lot of thrust though

Doing something like this sounds scary, unless you have a lot of Starships landed nearby ready to be used to return when something goes wrong. And there's a high probability such manouvre would go wrong.

If I had to do this I would either build a crane or do it the stone age style: build a ramp out of regolith, tip it onto the ramp and then remove regolith under it until it's horizontal on ground level. Edit: it would probably take a long time but it's a relatively easy thing to do. Basically, reverse this:

Edit 2: alternatively, you could use excess steel to built some sort of structure/scaffolding, weld it directly to the hull and then lower it down doing basically the same thing minus the need for regolith hills.

Edited October 7, 2019 by Wjolcz

[kerbiloid]

1. Dig a funnel.

2. (Optional) Cover it with teflon.

3. Land the Starship wherever you wish inside the funnel either vertically. or horizontally. Just keep the nose radially out.

4. Let it slip down.

???????

10. Profit!!!

Now you have a reusable funnel for any landing and vertical launching.

P.S.
Airbags for soft falling are appreciated, but not required.

Edited October 6, 2019 by kerbiloid

[Rus-Evo]

I think a spacecraft designed for vertical load bearing may need massive reengineering to take horizontal loads.

CANCEL THE ABOVE I didnt read OP adequately.  Sorry

Edited October 7, 2019 by Rus-Evo

[RCgothic]

How much thrust do the hot gas thrusters have? If the combined translational thrust is over 200kN then a 120kN Starship would be able to hover horizontally on the moon and presumably touch down in that orientation.

[Xd the great]

18 minutes ago, RCgothic said:

How much thrust do the hot gas thrusters have? If the combined translational thrust is over 200kN then a 120kN Starship would be able to hover horizontally on the moon and presumably touch down in that orientation.

Pretty sure hot gas thrusters do not have that much thrust.

If landing and tipping over, tip velocity is about 12m/s, or 40km/h. Car crash?

[Technical Ben]

butwhy.gif?

[Wjolcz]

6 minutes ago, Technical Ben said:

butwhy.gif?

To turn it into a base.

But then how hard is it to design a Bigelow-like base modules, put them on Starship and then lower them down to the surface vs tipping the whole thing?

[Xd the great]

4 minutes ago, Wjolcz said:

To turn it into a base.

But then how hard is it to design a Bigelow-like base modules, put them on Starship and then lower them down to the surface vs tipping the whole thing?

Or taking a cargo starship apart for building houses.

I don't want to live in a fuel tank.

[kerbiloid]

5 minutes ago, Xd the great said:

I don't want to live in a fuel tank.

You currently live in an _oxygen oxidizer tank without envelope. Problems?

5 minutes ago, Xd the great said:

Or taking a cargo starship apart for building houses.

Lego Starship.

Edited October 7, 2019 by kerbiloid

[Wjolcz]

8 minutes ago, Xd the great said:

Or taking a cargo starship apart for building houses.

I don't want to live in a fuel tank.

Afaik methane and oxygen aren't toxic so all that would have to be done is to evacuate the tanks and they would be fine to live in.

3 minutes ago, kerbiloid said:

You currently live in an _oxygen oxidizer tank without envelope. Problems?

Pretty much this. There's almost no methane but it's not like it's super toxic.

Brb need to do some research on methane toxicity.

Edit: it's not toxic as long as you have enough oxygen to breathe.

Edited October 7, 2019 by Wjolcz

[RCgothic]

2 minutes ago, Xd the great said:

Pretty sure hot gas thrusters do not have that much thrust.

If landing and tipping over, tip velocity is about 12m/s, or 40km/h. Car crash?

A raptor engine has approximately 2000kN.

We're looking for 1/10th that, so agree that even several thrusters together aren't likely to be sufficient.

Tipping would require half as much thrust, but would probably utilise half as many thrusters so no net benefit.

[Guest]

I’ve seen a few people proposing ways to use starship as a permanent base once at its destination but this concept seems to overlook one of the main purposes of starship. It’s intended to be reusable. This is how SpaceX intends to open up space, by dropping launch costs via reusability but there are also logistical bottlenecks that come into play which require a lot of Starships for a Mars city to become a reality. As an end of life use for Starship materials, sure send them to Mars and use them as a resource but taking them out of commission before they have flown to their potential is counterproductive and wasteful. 

Id imagine we are probably talking decades of useful service life with these things.

[Nothalogh]

1 hour ago, Xd the great said:

I don't want to live in a fuel tank.

A fuel tank and a hab module are structurally indistinguishable

[sevenperforce]

4 hours ago, Xd the great said:

Pretty sure hot gas thrusters do not have that much thrust.

If landing and tipping over, tip velocity is about 12m/s, or 40km/h. Car crash?

At 10 metric tonnes of thrust each you would need 8-10 of them mounted on the dorsal aspect of Starship to do a dual-thrust-axis landing.

[Technical Ben]

4 hours ago, Wjolcz said:

To turn it into a base.

But then how hard is it to design a Bigelow-like base modules, put them on Starship and then lower them down to the surface vs tipping the whole thing?

If a "base" it would be permanent, in which case no specialist hardware needed inbuilt to the craft. You would just use a cargo delivery to give you a crain/inflated/rope drop system, OR dig a hole/build up regolith vertical, and not horizontal (use the top for solar, lower for living quarters).

[kerbiloid]

This

Spoiler

should be the very first module of any serious base.

(After the forest cabin for its crew).

No this - no base, only a tourist camp.

P.S.
As well, it can dig for samples.

P.P.S.
This

Spoiler

should be the very first construction.
Protecting the technics from radiation and meteoroids.

Then an aluminium tent on top, to protect from sun.

Edited October 7, 2019 by kerbiloid

[sevenperforce]

Elon says the notional lunar landing mission would involve propellant fill in elliptical Earth orbit, followed by departure, lunar EDL, and SSTO from the lunar surface to Earth entry interface. You need 2.74 km/s from the lunar surface to Earth entry, so let's say 2.94 km/s to allow for course correction and landing props. If this is a crewed mission we will say 30 tonnes payload off the moon, so dry mass is 150 tonnes for Starship and crew cabin. By the rocket equation, liftoff mass will be 432 tonnes. However, Starship needs to be able to deliver up to 100 tonnes of cargo, so let's add 70 tonnes of flatpacked something-or-other during descent. Touchdown mass is roughly 500 tonnes even.

To get one gee of acceleration, you'd need fifty ten-tonne hot-gas thrusters, which is clearly prohibitive. However, the moon is not so tough a mistress. To hover, you need only nine and a half ten-tonne thrusters (accounting for 15% cosine losses). The Vacuum Raptors could be used to decelerate to a hover 50 meters above the surface, at which point the hot-gas thrusters would ignite for a gentle touchdown. You probably want a solid dozen for good measure. 

If you are going to set down on a dual thrust axis, you need more because you'll be needing much more creative differential throttling to maintain attitude.

[llertag86]

There are a lot of good points made, I was originally thinking about this being done to one of the two cargo craft that would be sent ahead to Mars 2 years in advance. However, since SpaceX is looking to take advantage of NASA funding for moon missions I applied the idea for a moon base.

In principal I believe humans prefer living in long flat structures rather than tall cramped structures, Plus it’s a whole lot easier to cover with dirt for radiation protection like this.

Than like this

Sure you could seal in a StarShip like above, but building the printer to enclose the 50m tall StarShip seems ridiculous for initial mass constraints for both the Moon and Mars.

StarShip could be approximated as a 1 room apartment 10 stories tall (rounding up for story= 5m)

However if horizontal it then would be 2 maybe 3 stories of ~45m long hallway, or think of a modified submarine outline which I believe gives more living space for astronauts to stretch out in plus no need for an elevator or the problems that come with it.

[sevenperforce]

49 minutes ago, llertag86 said:

Sure you could seal in a StarShip like above, but building the printer to enclose the 50m tall StarShip seems ridiculous for initial mass constraints for both the Moon and Mars.

StarShip could be approximated as a 1 room apartment 10 stories tall (rounding up for story= 5m)

However if horizontal it then would be 2 maybe 3 stories of ~45m long hallway, or think of a modified submarine outline which I believe gives more living space for astronauts to stretch out in plus no need for an elevator or the problems that come with it.

Elevators are not needed, as humans are extremely strong for their weight on both the moon and Mars. Even if someone was ill they could be readily carried up or down a ladder by a fellow crew member with just one arm.

A powdered-regolith laser sintering printer for building structural blocks would be one of the very first machines to have up and running past life support considerations.

The need for a flat floor does tend to complicate things, as it cuts the usable volume considerably. Plus, laying Starship on its side would mean all the elements in the upper cabin which are ordinarily intended for a single axial orientation would be 90 degrees off. Not an issue for a cargo Starship, of course, but it's still a consideration.

I consider it more likely that an end-of-life Starship would be converted into a series of habs by slicing it into sections horizontally. You have three different bulkheads which will provide nice domed roofs, after all. Then the nose-cone crew section can simply be "planted" into the ground as one of several hab structures.

[kerbiloid]

Spoiler

1 hour ago, llertag86 said:

The Martian collectors hold the Martian non-payers in such cells until they agree to co-operate.

 

[llertag86]

3 hours ago, sevenperforce said:

Elevators are not needed, as humans are extremely strong for their weight on both the moon and Mars. Even if someone was ill they could be readily carried up or down a ladder by a fellow crew member with just one arm.

The need for a flat floor does tend to complicate things, as it cuts the usable volume considerably. Plus, laying Starship on its side would mean all the elements in the upper cabin which are ordinarily intended for a single axial orientation would be 90 degrees off. Not an issue for a cargo Starship, of course, but it's still a consideration.

I consider it more likely that an end-of-life Starship would be converted into a series of habs by slicing it into sections horizontally. You have three different bulkheads which will provide nice domed roofs, after all. Then the nose-cone crew section can simply be "planted" into the ground as one of several hab structures.

I realize my assumption on the elevators was made hastialy, I saw this render and assumed it as fact, now thinking about it ladder rungs seem reasonable for the exterior on the leeward side of starship since they shouldn't affect aerodynamics too much, still it would be a long climb with having to hook yourself to every other rung to not fall off though that may be just an in-flight consideration. That or electromagnetic grippers / boots which would be cool.

As far as when, how and where to decommission a starship has alot of variables, as they are currently iterating the design I find it conceivable to use an older model as a base proving the concept that it can land and maintain its integrity for long periods of time. I would think even the Mk1 could get to the moon, though I agree its questionable economics without the data on the cost to use as a display piece, recycle or use for training purposes. This is just a discussion on its feasability after all.

I agree useable volume is in interesting concept and one that is not always easy to understand from picturing it in the mind. Vertically I agree you will get the most useable volume so long as you have tall ceilings however as consequence  astronauts now have to keep track of items on a 4-5m tall circular wall, usable space but not always easialy used with placing objects above ones head. Internal surface area is also important, 10, 9 dimaeter disks are less surface area to work with than even two floors going going through a horizontaly oriented starship as now its easier to mount things to the 'wall' without worry at least for the lower half. 

As far as cutting up a starship for base building, we would either need a crane or orient it horizontaly in order to move said pieces, when we ahave that capability we would in principal also be able to orient the whole ship on its side. I see it as time vs effort problem, also considering variables such as air lock positions connecting to expanding base, radiation protection etc. I'm just not convinced its worth the effort to cut it up vs just putting it horizontal at least for an initial base. Once you have some infrastructure sure, it makes sense, basicaly recycling steel.