Orbiter Addons
Discussion Orbital Recovery Vehicle
Thread starter T.Neo
T.Neo
SA 2010 Soccermaniac
I have come up with another incredulously useless idea: a vehicle that can fly into orbit atop a booster, grapple an orbiting object- such as a satellite, or space station module, and return it to Earth.
Essentially, a castrated Shuttle- an unmanned shuttle, launched empty on an expendable booster, have a rendezvous capability, and then land conventionally, borrowing basically the entire return phase from STS.
Reusability would be optional but preferred, and less intensive due to the less complex nature of the vehicle. Propulsion system would be based off of something like the Delta K upper stage, and vehicle mass would hopefully be roughly 40 tons, suitable for launch on upper-heavy vehicles such as Falcon 9 heavy + Raptor, Angara A7 or Rus-MT50.
On-orbit power supply would presumably be based on solar panels.
Clueless developer
T.Neo! Will you please stop stealing Chinese satellites!
What are the maximum dimensions of the PLB? This will drive external dimensions of the ORV and drag losses during launch. Thankfully, no heat dumping problems in this vessel...
EDIT: Will it need two RMS or just one? Anyway, lots of lidars will have to be installed, a rendezvous/approach radar, and really smart AI...
EDIT #2: What are cross-range requirements? Have you thought about controlled parachute-assisted return in some freshwater lake to save on landing gear?
I am looking at a comparable PLB size to STS... you raise a very good point about drag losses, I'm also worried about aerodynamic stresses on the wings and tail... to my knowledge, STS needs a special ascent plan to minimise these.
There are no bad waste heat problems here... also no radioactivity problems. All in all, the design actually has to be less complex than STS, as it is an unmanned vehicle...
I don't really see the problem with an automatic rendezvous system, granted there hasn't really been any example of remote RMS work but this can also be done remotely to a limited extent, accounting for factors such as communications lag. The spacecraft could even be programmed to take out many actions automatically, or 'think ahead' of an operator- Mars rovers are already "driven" with pre-programmed commands sent from Earth, with ground operators navigating the planetary terrain beforehand.
Another alternative is to have a manned presence on location, in another spacecraft- presumably a capsule, and/or have an orbital RMS platform which can handle payloads, with the ORV becoming only a return vehicle... it would probably be advantageous to configure the vehicle for both eventualities.
There are things you might need EVA for- like for example, folding up/clipping up large solar arrays or antennas that cannot fit in the bay otherwise.
I'm not sure about the number of RMSes... I like the idea of having two remote manipulators, it was planned for STS anyway, as well as Buran (as far as I can tell).
I'm not really sure about cross-range requirements. She certainly won't need to do any AOA aborts when launching to a polar orbit... I'm not sure what the cross-range requirements are when reentering from a polar orbit... if the crossrange requirements are low enough, the airframe could be quite different from that of STS... for example, it could warrant a return of the nearly-ballistic reentry concept of Faget DC-3 shuttle concept.
STS can ditch survivably... in the right conditions. I wouldn't warrant the potential for LOV or bad TPS damage from a water landing, in addition ground handling would probably be complicated. STS has already proven well the runway landing concept, and gear should not weigh much when compared to the rest of the vehicle.
zerofay32
Depending on the down mass, chute assisted would require a huge chute. Look at the X-38, it would have had a giant parafoil at 687 square meters. If the craft isn't reusable then the landing gear can be one-time use, crushable gear. The point is to bring the payloads back in a stable configuation. Otherwise you'll have to accept the weight penalty of the full landing system.
Reentry is also dependent on max-g limitation of the payload. Spacecraft are fragile creatures. Cross range is a function of available runways, which comes from the geography of the operator country and max payload mass (together with brake design it limits min runway length). You're always looking for a safe divert opportunity, flying anything through a cumulonimbus is not pretty... Selling it to say Malawi or Luxembourg would be tough...
EDIT: zerofay32 - crushable gear may be worth it money-wise!
I can't really see how advantageous crushable gear would be, or even how they would work. There are really two options: One is to have no gear and skid to a halt, the other is to have gear and protect the airframe. The latter would (probably) be smoother on the item being recovered.
If there is enough "stuff" that could be reused, it would make sense to try and recover it, even if there are things that would be replaced or swapped out for another flight.
The size of the country in question is not really a problem, you are aiming for a very small target (a runway) anyway, and weather changes... hopefully. Since this thing isn't manned and is using 'renewable' energy on-orbit, restrictions in terms of time to return are greatly relaxed. And if you are- for some, inexplicable reason- a small country operating this thing, you'd probably just find a landing site overseas, since it'd be launched overseas anyway.
With a crushable landing gear you delete the deceleration systems from the vehicle (ie breaks, wheels, and for the most part standard gas or liquid filled shock absobers). The gear it self can be made from a honeycomb material. Also the gear can "auto deploy" using springs when the doors are opened removing the need for motor driven actions. To save even more use the doors as the lading skids, the gear would basicly pop out and lock in place during final. This also allows for non-runway landing (ie dry lakebeds or Kazakhstan type areas.
I can see a deceleration on wheels or skids as being far gentler as crashing into the ground with only a crushable honeycomb structure to protect you. :shifty:
Landing gear isn't an unknown, it isn't 'space age' technology... it is probably the least risky thing about the whole vehicle. Even then, some sort of spring-loaded device might be a good idea...
T.Neo said:
Or not. Remember: if you have lost so many hydraulic systems that your landing gear can't deploy anymore except by other means, you are also no longer able to control your spacecraft by aerodynamic means, also many other subsystems will fail as well then. For example, all larger valves are typically electro-hydraulically operated.
Better put effort into having a reliable hydraulic system, as such toys for the landing gear. if gravity deployment is no longer an option, you are likely already scheduled for meeting your maker.
Will a tailchase control plane be an option for landing contingencies?