General Question Realistic applications for Orbiter

[Lacanau]

I was thinking about this the other day...

What could be a real world application for orbiter? Could its digital in flight system be ported of to a real vessel? I was thinking that the information that the flight system orbiter provides is only because it is all in a digital environment. But would it even be possible to construct a system that works the same in reality? I did some searching on the forum for an answer but I couldnt find anything I'm pretty unknowledgeable about these things and I was curious. Fell free to shout/scream/yell :lol:

 

[Izack]

No. Orbiter's instruments for the most part get their data directly from the 'universe' by asking the program specific questions like "what is x vessel's distance from y celestial body?" Much of the perfectly accurate information on OrbitMFD is impossible to garner in real life, let alone with flawless precision. Real systems are many times more complex and give much less accurate data. There is no RealityAPI to pull your data from, they must be acquired elsewhere.

 

[Lacanau]

Ok, where abouts can I find out about the kind of flight systems that are used today e.g. Shuttle? By what means does the shuttle get its information? I know that a lot of information is collected and relayed on earth, but I'm curious as to what information the shuttle itself collects and how it does it. I remember they had an electronic sextant for use in the Apollo days, but surely they have invented more... efficient means.

 

[mojoey]

Ok, where abouts can I find out about the kind of flight systems that are used today e.g. Shuttle? By what means does the shuttle get its information? I know that a lot of information is collected and relayed on earth, but I'm curious as to what information the shuttle itself collects and how it does it. I remember they had an electronic sextant for use in the Apollo days, but surely they have invented more... efficient means.

Computers one the ground, they calculate what what is...but with a certain degree of error

 

[astrosammy]

Hmm well, it has star trackers and an inertial navigation system as far as I know. But there are people here who know the shuttle much better...

 

[Spacethingy]

Artlav and co. were discussing making a system that gathered realistic info from Orbiter...

http://orbiter-forum.com/showthread.php?p=293238&postcount=10

There was another thread I vaguely remember, but I could be wrong...

 

[Grover]

Artlav and co. were discussing making a system that gathered realistic info from Orbiter...

http://orbiter-forum.com/showthread.php?p=293238&postcount=10

There was another thread I vaguely remember, but I could be wrong...

NMolson's Roscosmos lunar lander has some realistic navigation simulation coded into it.... i think at least it was that lunar lander...

anyway, that wasnt strictly realistic, since it also had perfect accurracy, the only difference is that it wasonly available in certain areas close to tracking stations

 

[Artlav]

There was another thread I vaguely remember, but I could be wrong...

That would be this one:
http://orbiter-forum.com/showthread.php?t=25188
With stillborn attempt to port eCos to Orbiter environment and synthesise a realistic set of sensors for it to use instead of omniscient API.

And a slightly related follow-up here:
http://orbiter-forum.com/showthread.php?t=25319
With an idea of programming a space probe and controlling it remotely in a blind, graphics-less environment.


The problem is not so much in having omniscient instruments - reducing precision is markedly easier than increasing - but in lack of any coherent effort to make or demand to have for it.

 

[jedidia]

By what means does the shuttle get its information?

a spacecraft on its own gets most information from analyzing and extrapolating gathered data. Gyroscopes for example record acceleration changes around the axes, based on which the vessel calculates its current rotation, or gather data along axes, from which the vessel calculates its current speed. The instruments have to be calibrated rather painstakingly before flight, and measurement faults pile up over time and can only be resolved by a third party observing the vessels movements or by the vessel correcting its data based on measurements against external references, like stars, landmarks or, most popularly, comm signals.

 

[Lacanau]

Thanks guys!

So if some information is gathered/processed on board, what kind of information does the ground station provide that the vessel cannot gather itself? I've read in numerous places that ground controls are essential to any flight and I understand basically why, but would a vessel be able to complete an orbital flight without the aid of a ground station?

 

[Sky Captain]

It would be interesting to know if it is possible to make completely independent from groung control spaceraft navigation system. Suppose at some point in the future spacecraft like Delta Glider becomes as common as business jets. Could a navigation system that allow them to reach precise orbit, dock with space station and come back to land at some base be developed that allow to do it without relying on extensive ground control stations?

 

[Lacanau]

It would be interesting to know if it is possible to make completely independent from groung control spaceraft navigation system. Suppose at some point in the future spacecraft like Delta Glider becomes as common as business jets. Could a navigation system that allow them to reach precise orbit, dock with space station and come back to land at some base be developed that allow to do it without relying on extensive ground control stations?

Well I imagine orbit definition would be easy to do on board. I imagine a camera with a field of view wide enough to capture the circumference of the earth, then have a computer analyze the image monitor for changes(altitude)? or to control the orientation of a rangefinder to point exactly "down"? I'm just throwing ideas out there

I read something just the other day that said the phones we use today are 1000s of times more powerful than the apollos entire flight computer :lol:
Youd think wed be exploring the galaxy by now.

 

[Grover]

there is a simple way to reduce the accurracy of your measurements: give them a refresh rate of about 0.1Hz one update per ten seconds (for as long as you are within range of a tracking station), then add a multiplier, giving an error of +/- a certain percentage, that can be randomly generated every time the value refreshes, and is based on distance to the tracking station (so being directly above the station may give a range of error of +/- 1%, but being at the edge of its effective rande could give a range of +/- 5%

 

[streb2001]

Spacecraft in LEO could use GPS surely?

 

[Lacanau]

Spacecraft in LEO could use GPS surely?

Thats a good question, I think theres something about angles with the satellites at those altitudes, but I dont know for sure.

 

[Monroe]

Ok maybe I can get some interest here: I would like to add HIL (Hardware In the Loop) support to Orbiter. To simulate real missions and guidance systems.
To start with I use the Ardupilot which has an IMU and autopilot with GPS location. There is a standard radio control system used for manual input and a mission planner that does all the autonomous autopilot control.

This mission planner has been interfaced with X-Plane, FlightGear and Microsoft FS simulator programs.

This all works fine for terrestrial in atmosphere work but It lacks the space support the Orbiter has and we would like to simulate our real missions with this hardware and software in the loop.

What is it that these simulators have that is not in Orbiter that would alow these kinds of simulations? How much difficulty would be involved in adding this functionality to Orbiter?

Can it be done?

Monroe
Team Prometheus

 

[Arrowstar]

Thats a good question, I think theres something about angles with the satellites at those altitudes, but I dont know for sure.

Spacecraft in LEO can and do use GPS (and other GNSS) for their navigation solutions. It only takes fairly minor and well-understood changes to the receiver hardware/software to get this to work. The largest change, as far as I'm aware, is that the receiver must account for the high relative velocity between the GPS vehicle and the satellite. But as I said, doing so is not impossible by any means.

 

[tl8]

Spacecraft in LEO can and do use GPS (and other GNSS) for their navigation solutions. It only takes fairly minor and well-understood changes to the receiver hardware/software to get this to work. The largest change, as far as I'm aware, is that the receiver must account for the high relative velocity between the GPS vehicle and the satellite. But as I said, doing so is not impossible by any means.

It also needs to be a military spec receiver. This is beacuse there are speed and hieght restrants to civilian ones so they can't be used in missiles by terrorists.

 

[Monroe]

Spacecraft in LEO have no trouble using GPS as long as the COCOM limits are removed (65,000ft and/or 1000kts) and there are two ways around that buy and pay for a GPS without limits that takes some extra paperwork and $3000 total ($2000 for the GPS $1000 for the permit) or build your own receiver.

There may be some issues depending on how high your LEO is but a GPS would work fine on the ISS. Now after that you would have to go to Astral Navigation and I don't know any simulator that does that. But it surely is possible.

For our needs GPS and LEO would be good enough (for now)

Monroe

 

[Lacanau]

So what other intrustments would a vessel otherwise need to become completely independant of a ground stataion? Is it even possible to consider a vessel completely self contained?