OFMM Development: Atmospheric Vessels

[Bj]

Here a small view on the prototype Skycrane, It is still getting some mesh changes and lacks propulsion, but I can already use it for animation and aerodynamic tests.

Nice mesh

I take it the cargo is in the inside? or hows that working?

Aerodynamic tests? How do you go about doing that?

 

[Columbia42]

I'd prefer to bring all of the parts ourselves. Those parts have been sitting in martian terrain since 2003, so that can't be in mint condition. I think sacrificing a little space is worth it to ensure we will have working rovers.

Good point.

 

[Bloodworth]

A little off topic, here's an idea about the rover:
What if we landed near one of the MER rovers and used it's parts to help us build a small vehicle. It couldn't carry more than one or two people so we would need somethng like a UAV as well but it would save a little mass if we didn't have to bring all of the rover's parts with us.

1) just how big were those rovers? I don't believe they were big enough to use on a people carrying vehicle.

2) Dismantling them for parts would also go against one of our ground ops missions which is to locate such vehicles, asses their condition for historical, scientific and possible conservatory purposes. I could see dismantling one to bring it or parts of it back home for study, but not for parts.

 

[Urwumpe]

I take it the cargo is in the inside? or hows that working?

Yes, below the main structural ring, and maybe even partially inside the ring.

The current idea is, that the heat shield remains attached to the payload after landing, acting as foundation. So, the only thing that happens is that the side panels around the payload open, exposing it and protecting it from any engine blast effects while it is still close, and the payload is winched down until it is about 50m below the Skycrane.

Aerodynamic tests? How do you go about doing that?

Fly it into Mars at different angles, and log as much data as possible...maybe even produce KML files for Google Mars.

The more flight data, the better.

EDIT: And the discussions about the rovers belows to the ground operations, people. And no, the MER rovers remain where they are. You sure wouldn't think about repairing your modern Ferrari with parts from a VW Beetle, why should that be different with the MER rovers?

 

[Salun]

[/QUOTE] EDIT: And the discussions about the rovers belows to the ground operations, people. And no, the MER rovers remain where they are. You sure wouldn't think about repairing your modern Ferrari with parts from a VW Beetle, why should that be different with the MER rovers?[/QUOTE]

Exactly what I had in mind. Though some one mentioned Enshrining them or something?

Mind you I'm against that as well. Why spend all that time in the hostile environment and lugging all that stuff so one can delay the inevitable? Eventually Mars will claim the rovers. I'm thinking rather leaving like a gold plate. Memorializing the Rovers and all those involved.

However I'm thinking a piece of the rover(s) Should be brought back. For research purposes. The long term effects of man made objects on the Martian surface.

Case in point Apollo 12 Getting the camera from Surveyor III

 

[Bj]

Exactly what I had in mind. Though some one mentioned Enshrining them or something?

Mind you I'm against that as well. Why spend all that time in the hostile environment and lugging all that stuff so one can delay the inevitable? Eventually Mars will claim the rovers. I'm thinking rather leaving like a gold plate. Memorializing the Rovers and all those involved.

However I'm thinking a piece of the rover(s) Should be brought back. For research purposes. The long term effects of man made objects on the Martian surface.

Case in point Apollo 12 Getting the camera from Surveyor III

possible I suppose, we need a mesh of a rover, or part of it anyway. The short range exploration crew could go pick it up while out on missions I guess.

 

[Urwumpe]

As suggestion for such small subplots: Why not task two-three people with doing such small subplots in mild secrecy, so people can get a small level of surprise when they actually do the mission?

It is hard to do this with the big mission concept, but the smaller stuff can be done as surprise.

 

[garyw]

As suggestion for such small subplots: Why not task two-three people with doing such small subplots in mild secrecy, so people can get a small level of surprise when they actually do the mission?

It is hard to do this with the big mission concept, but the smaller stuff can be done as surprise.

If I was involved in such things I'd be quite annoyed. Why the need for ANY sort of mission secrecy? Aren't you all supposed to be working together? Aren't you all following a planned mission architecture?

 

[Urwumpe]

If I was involved in such things I'd be quite annoyed. Why the need for ANY sort of mission secrecy? Aren't you all supposed to be working together? Aren't you all following a planned mission architecture?

Yes, but it is a bit more boring if all that the player actually does later is already known and planned. It is a bit like a good pen&paper RPG, while the game master has the plot in his head and all major events and NPCs planned, the players must not know this completely.

So, what missions will happen, and when, should be known in the mission plan in public, but what REALLY happens, which surprises could be waiting along the way, that could be really done secretly. That we visit a rover and do something there is known - how it happens not.

 

[Bj]

I suggest naming the second manned lander "OFSC Doctor Martin Schweiger"...and the first one "OSFC Urwumpe". :lol:

On that note, any estimates for what a 8 man lander would weigh and its dimensions?

First off, do you think the skycrane can be designed big enough to land the mars lander, and if not, can we use an inflatable heat shield on a 45+ tonne lander? Using the skycrane, we can reuse a large portion of that heat shield weight and so on. I am also hoping the skycrane will lower the soon to be 1000 kWe nuclear generator to the Martin surface.

 

[Urwumpe]

On that note, any estimates for what a 8 man lander would weigh and its dimensions?

Depends on how long it should be used and how it should be used. The ISS has a crew of six, but the manned primary structure is pretty small.

First off, do you think the skycrane can be designed big enough to land the mars lander, and if not, can we use an inflatable heat shield on a 45+ tonne lander? Using the skycrane, we can reuse a large portion of that heat shield weight and so on. I am also hoping the skycrane will lower the soon to be 1000 kWe nuclear generator to the Martin surface.

Yes. I am sure. The current design is maybe a bit large for the available launchers, but I plan with orbital assembly for it, so it can also be FIXED in orbit or on Mars.

The current design goal is landing 45 tons of cargo on Mars. But I need to do some more flight tests to confirm the needed scale. More would maybe be harder to design, since the area and mass of the lander have to get scaled up as well

 

[Bj]

Depends on how long it should be used and how it should be used. The ISS has a crew of six, but the manned primary structure is pretty small.

I am thinking a large part of the consumables and fuel can be stowed outside of the OSHV.

Yes. I am sure. The current design is maybe a bit large for the available launchers, but I plan with orbital assembly for it, so it can also be FIXED in orbit or on Mars.

Excellent

The OSHV should accommodate crew resting bunks, few days of consumables, and area for mission specific tasks.

This is what I'm thinking for this skycrane/lander duo:


I might be a tight-wad but I think 6m^3 for a personal space per person is sufficient. Then something like 100 m^3 for work space is enough. (we have to limit the height though so that the G force on the ceiling is not significantly less than on the floor.

 

[Urwumpe]

Change this a bit - the engines are inside the skycrane, but below the payload, there needs to be a crushable ablative heatshield, that takes the brunt of the punishment.

This way, we can avoid seams in the lower heat shield, and have automatically a stable foundation for the lander.

 

[Bj]

Change this a bit - the engines are inside the skycrane, but below the payload, there needs to be a crushable ablative heatshield, that takes the brunt of the punishment.

This way, we can avoid seams in the lower heat shield, and have automatically a stable foundation for the lander.

I am sorry if this seems to be a silly question, but now looking at your vessel here, which way is down? And where would a OSHV size vessel fit in there? I think that little bar thing going out the middle is the impact absorbing foundation, am I right?

I was thinking this lander would be reusable such that its total engine thrust is capable of lifting whatever payload it is carrying, but it doesnot carry enough fuel to achieve orbit unless it is empty. This way, the lander can go back to the MTV and grab some other cargo. Am I right in saying this?

Edit:

Oh wait, I think I see what your seeing, um here:

This is the OSHV part of that picture, obviously not to scale, but just a general representation of it.



The skycrane I drew was going off the lines like this

except it has a fairing around the payload.

 

[Urwumpe]

Exactly. The engines will be installed in the beams of the top petals. The cylinder in the center is currently just for attaching the actuators of the beams and petals, but could for example be a propellant tank.

The payload is below the center cylinder, slightly contained inside the main structure ring.

 

[fireballs619]

Looking at these pictures, I realized I was picturing the skycrane to be much smaller. Thinking about what it must do, I don't know why. I'm actually sort of confused of its functionality, so correct me if I am wrong. Is this how a standard operation with it would go?

1: It detaches from the stack (or whatever we are calling it now) with its cargo and enters into its own orbit of mars.
2: It will de-orbit to the selected landing site and land, dropping its cargo off.
3: Since it weight has significantly decreased (due to lack of cargo) the remaining fuel will launch it back it orbit, where it will once again dock with the stack.
4: This will repeat as needed.

That's my understanding of it, but please correct me if I am horrendously off the mark.

 

[Urwumpe]

1: It detaches from the stack (or whatever we are calling it now) with its cargo and enters into its own orbit of mars.
2: It will de-orbit to the selected landing site and land, dropping its cargo off.
3: Since it weight has significantly decreased (due to lack of cargo) the remaining fuel will launch it back it orbit, where it will once again dock with the stack.
4: This will repeat as needed.

1) is Wrong, it will be entering Mars orbit with the stack first.

The rest is right. Most of the shape for the Skycrane is reusable heatshield /aerodynamic deceleration, the propellant tanks are rather a small part of it.

 

[Bj]

Exactly. The engines will be installed in the beams of the top petals. The cylinder in the center is currently just for attaching the actuators of the beams and petals, but could for example be a propellant tank.

The payload is below the center cylinder, slightly contained inside the main structure ring.

Ahh I see so like this: (forgive my job drawing)



red = engines
blue = fuel
orange = aerobraking fin things

Left side is closed position, right is opened.


I think we are going to be needing a much larger tank though

calculated using LOX/LCH4 which has 424 kg/m^3

A 5000 kg dry vessel needs 14,000 kg fuel which is 33m^3. Actually maybe that would fit in there, I don't have a very good idea of the dimensions of that so it might still work.

 

[Urwumpe]

Yes, and now turn things upside down. The payload is in the green part.

33m³ is not that much, when the vehicle itself is about 20m large: I calculated with nearly three times as much fuel capacity.

The size of the lander was calculate such, that a 10m payload module can fit into it. Smaller payloads and I can scale it down a bit.

 

[Bj]

Yes, and now turn things upside down. The payload is in the green part.

33m³ is not that much, when the vehicle itself is about 20m large: I calculated with nearly three times as much fuel capacity.

The size of the lander was calculate such, that a 10m payload module can fit into it. Smaller payloads and I can scale it down a bit.

Just curious, do you think multiple landers is a good idea? I would hate to get there and have "we have a problem."

Since these landers will run on methane o2 mix combo, the landers will have to actually land for a while to refuel. But in order for that to happen we would need the insitu fuel converters and h2 and. Power gens down first. Wow, I will have to work on order of landing for these modules.