More than a fairing, less than a space capsule, delivering lost of cargo to ISS

[macpacheco]

How could the large cargo capacity of F9R to LEO be used efficiently, for instance to deliver many tons of consumables that are temperature insensitive. Water, oxygen, fuel, bulk materials for a 3d printer. Objects too large for Dragon, but too small to justify a dedicated launch.

The idea is something like a bulk cargo fairing, the 2nd stage would take care of getting close to the ISS. But without the complexity of a dragon spacecraft. No pressurization, little thermal protection.

The additional functions beyond the fairing aerodynamic / basic thermal protection would be provide dividers / attachment points to cargo. Means of organizing lots of items while protecting items from each other with the high g's space launch gets.

Considering ISS is a little higher than 200Km standard LEO orbit, let say F9R could deliver 7 tons to the ISS.

Was there any ideas on how to do it ?

I know the ISS probably don't need it, at least not now. But there will be other more economically active space stations / hotels (otherwise forget about Mars, IMO).

Just food for fought.

A larger space station should have a space hangar that would allow for such a bulk cargo carrier to get inside and then pressurize to make unloading easier. Obviously there would be no down mass capacity on that system, just up mass.

Consider eventually with 3D printing and large payload launches, a Space Station should have some rudimentary local production of parts, perhaps even some machinery to shape metal, produce composite structures.

Any ideas ? Go crazy !

[avollhar]

You forgot the necessity for a propulsion system to rendezvous with the station. This most likely needs a electric system for the on-board computers  which means solar panels. Add an attitude control system and you are quite close to a Dragon.

[nlec]

I think it would require a service module, such as what Orbital attaches to the back of the Cygnus.  The SM could be attached to a non-Shuttle version of the Express Logistics Carrier.  After launch and rendevous, the Canadarm attaches the ELC to the ISS.  Arm detaches the SM and attaches it to an older ELC for deorbit.

http://en.wikipedia.org/wiki/File:ELC_general_layout.jpg

[guckyfan]

It would be possible to build a larger trunk attached to Dragon. Dragon would provide RCS, avionics and the approach capability to the ISS. That attachment could be largely passive and therefore cheap to develop.

It could be a pressure vessel with its own berthing adapter. That way each launch could provide the Dragon crew capacity plus probably a Cygnus mass and volume freight capacity.

Edit: Or it could be a volume for vacuum cargo that would be even much easier to build.

[Todd Martin]

A re-usable space tug kept at ISS would eliminate the need for bulk cargo launchers to worry about that approach capability.     

[douglas100]

Sounds like you're talking about something similar to Parom.

http://www.russianspaceweb.com/parom.html

[Todd Martin]

Thanks Douglas for the link!  The Parom is a great design example of the Space Tug concept; I hope the Russians or another ISS partner builds one.  I think the cost effectiveness of using a dumb, bulk launcher and a re-usable tug depends on flight rate.  You need enough launches of the cheap bulk launches to cover the added cost of the tug.  The upside to such an arrangement would be the mission flexibility a space tug could offer. 

In my opinion, ISS managers should concentrate more on reducing the operational cost.  Lower operational costs make life extensions easier.  Life extensions makes the flight rate problem less of a burden for upgrades like an orbital tug. 

[Zed_Noir]

In theory the original PCM from the first 2 Cygnus CRS flights can fitted inside an extended Dragon trunk. So if you fitted the same CBM hatch as the current dragon then you can carry bring up anything that can pass through that CBM hatch. Obviously you need to flip the vehicle stack around to access the 2 separate cargo compartments. IIRC it's about 27 cubic meters volume in the PCM plus the 10 cubic meter volume in the Dragon that gave you a total of roughly 37 cubic meters of pressurized cargo volume.

Research the PCM fit within the Dragon trunk on one of the Inspiration Mars threads.

[guckyfan]

I think carrying a secondary pressurized structure with Dragon is a preferable option over a dedicated tug for private space stations. A tug might be good if you move much larger mass for in space production later. But then you may give that capability to the upper stage itself.

I assume that a private station will have a much larger turnover of astronauts, part tourists part scientists that go with their experiment. So if every manned launch can carry its supplies along with the astronauts it would be very efficient. Especially if the first stage and the spacecraft is reusable. The secondary structure would not be reusable but very cheap in comparison. You could get 5 or 6 people to the station with their supplies on  a single flight for well below 100 million dollars, maybe as low as 60 or 70 million.

[ChrisWilson68]

I assume that a private station will have a much larger turnover of astronauts, part tourists part scientists that go with their experiment. So if every manned launch can carry its supplies along with the astronauts it would be very efficient.

That doesn't follow.  If the requirements for cargo and crew are different enough, it makes more sense to have two different vehicles, each optimized for its purpose.

Most of the cargo won't be the experiments themselves, it will be food water, fuel, etc.

[guckyfan]

I assume that a private station will have a much larger turnover of astronauts, part tourists part scientists that go with their experiment. So if every manned launch can carry its supplies along with the astronauts it would be very efficient.

That doesn't follow.  If the requirements for cargo and crew are different enough, it makes more sense to have two different vehicles, each optimized for its purpose.

No problem. If they really need more cargo they can send an additional dedicated cargo mission. For a cost concious operation sending both cargo and people on one flight should be very attractive. An optimized vehicle for people is not as it does not utilize the full launcher capability until you send 15 or 30 people on one launch.

Most of the cargo won't be the experiments themselves, it will be food water, fuel, etc.

Of course. But one Cygnus sized cargo container should be enough for that assuming ~1 flight per month. If not, for example for spacious experiments an additional cargo flight would be needed. But usually 2 tons per month of supplys for 7 to 10 people should be plenty.

[Jim]

Any ideas ? Go crazy !

You just described Antares/Cygnus.  There is nothing special about a Falcon that makes it anymore different than any other vehicle for this task.

[imspacy]

A re-usable space tug kept at ISS would eliminate the need for bulk cargo launchers to worry about that approach capability.   

A re-used, unmanned 'space tug' would allow cargo to a Space Station at about the $700 per lb/leo of FH (120,000 lbs at $70m)..... a minimal, efficient, low risk approach..
The opposite conceptual approach was the STS Shuttle.. orbiting a 172,000 lb dead weight vehicle to carry a max 60,000 lb payload(at $1.6 billion/launch) ....... for $28,000 per lb payload to LEO .. risking 7 human lives to haul freight.

Note that the simple shrouded payload/tug approach can deliver Space Station modules and equipment.... or deep space vehicle modules/fuel

[AncientU]

Any ideas ? Go crazy !

You just described Antares/Cygnus.  There is nothing special about a Falcon that makes it anymore different than any other vehicle for this task.

F9R?

[Jim]

Any ideas ? Go crazy !

You just described Antares/Cygnus.  There is nothing special about a Falcon that makes it anymore different than any other vehicle for this task.

F9R?

What the launch vehicle does after payload separation has no bearing on the mission.

[AncientU]

Any ideas ? Go crazy !

You just described Antares/Cygnus.  There is nothing special about a Falcon that makes it anymore different than any other vehicle for this task.

F9R?

What the launch vehicle does after payload separation has no bearing on the mission.

The OP discussed bulk cargo operations where cost does have a bearing on the mission.  Antares/Cygnus is a bit pricy for delivering t-shirts and toilet paper. Returning to launch site after separation for another load matters.

[Jim]

The OP discussed bulk cargo operations where cost does have a bearing on the mission.  Antares/Cygnus is a bit pricy for delivering t-shirts and toilet paper. Returning to launch site after separation for another load matters.

F9R costs much less operations have not jelled at this time, hence any trades based on cost are meaningless, hence Antares/Cygnus are just a viable and in some cases, better than others.  It is the typical spacex bias that have many thinking there are no others.

[guckyfan]

Any ideas ? Go crazy !

You just described Antares/Cygnus.  There is nothing special about a Falcon that makes it anymore different than any other vehicle for this task.

If my assumption is right that a private station will have a larger turnover of crew and a flight every month is needed then one Cygnus sized cargo vessel will have a free ride to the station.

Besides Orbitals Antares is as much a non existing rocket for that purpose as Falcon 9R. They don't have the engines. And if they have the engines then let's wait for the cost.

[Jim]

Besides Orbitals Antares is as much a non existing rocket for that purpose as Falcon 9R. They don't have the engines. And if they have the engines then let's wait for the cost.

There is Atlas too, which beats both.

[llanitedave]

Not in cost.