Sierra Nevada Cargo System

[Superluminaut]

This is interesting, but I don't get it. Whats the extra thing on dream chaser for?

[Scotius]

By the look of it, it's a service module combined with docking port. As you can see it houses solar panels and probably batteries. Maybe additional tanks for monopropellant too. What puzzles me, this additional module apparently is not reuseable - which means additional cost of replacing it after every flight. Wouldn't it be better to enlarge the orbiter a bit, and house everything in the chassis? Sure, such craft would be heavier, but there would be no lost parts.

[Kryten]

The boxes on the outside are unpressurised cargo. Without something like that service module, SNC are unable to compete for the unpressurised portion of the contract.

[Budgie]

The way that it leaves the solar panels deployed after undocking with the Dreamchaser would make me think it stays on-orbit and future Dreamchaser flights would dock with it. But rewatching the video shows that there is a service module included in the fairing images at the beginning, so so much for that idea.

[xenomorph555]

So they stole the service module from the Hermes shuttle, nice...

[Superluminaut]

The boxes on the outside are unpressurised cargo. Without something like that service module, SNC are unable to compete for the unpressurised portion of the contract.

Hmm, I would think though, pressurized or not, they could just put those boxes inside it. Or must they be accessible from the outside?

Also this is marketed as a way of returning cargo, and the extra module does not land.

[billbobjebkirk]

hmm, these CRS 2 proposals are pretty interesting.I wonder if SNC is hoping to use this to build up to a manned dream chaser? Anyhow, Spiral still refuses to die.

[Superluminaut]

By the look of it, it's a service module combined with docking port. As you can see it houses solar panels and probably batteries. Maybe additional tanks for monopropellant too. What puzzles me, this additional module apparently is not reuseable - which means additional cost of replacing it after every flight. Wouldn't it be better to enlarge the orbiter a bit, and house everything in the chassis? Sure, such craft would be heavier, but there would be no lost parts.

But dream chaser was designed to dock with the ISS, it doesn't need a service module.

[Kryten]

Hmm, I would think though, pressurized or not, they could just put those boxes inside it. Or must they be accessible from the outside?

Anything too big for the Kibo experiment airlock would have to be brought out via EVA, and they are to be avoided if possible. Also cargo items may not be rated to enter the pressurised volume (e.g. anything with hydrazine thrusters) or may be too bulky.

[Superluminaut]

Anything too big for the Kibo experiment airlock would have to be brought out via EVA, and they are to be avoided if possible. Also cargo items may not be rated to enter the pressurised volume (e.g. anything with hydrazine thrusters) or may be too bulky.

If that is the case, then essentially all they have done is built a pod with a space plane attached to it for storage space. Plus the extra gimmick of being able to return materials slightly faster. I don't see how they can possible expect anything to develop out of this.

[magnemoe]

Hmm, I would think though, pressurized or not, they could just put those boxes inside it. Or must they be accessible from the outside?

Also this is marketed as a way of returning cargo, and the extra module does not land.

Unpressurized cargo tend to be put on the outside of ISS, either its equipment or just materials for space testing, dragon do the same for its fairing.

Its handled by the arm and only more complicated stuff require an spacewalk.

But yes putting the docking port there surprises me, more so as it has to be pressurized with a tunnel trough it. I was sure they would put port on top leaving both the trunk and the back of craft for equipment.

[Bill Phil]

The folding winglets might cause problems later on.

[magnemoe]

The folding winglets might cause problems later on.

They have worked pretty well on carrier aircraft in almost 100 years.

I liked the design but not the rear access.

[Superluminaut]

They have worked pretty well on carrier aircraft in almost 100 years.

I liked the design but not the rear access.

They can encounter different problems at hypersonic flight due to the blowtorch effect on every tiny crevice. However the shuttles landing gear housing never had any issue, and spacex is also deploying its landing legs from the heat shield, so it may not be that big a deal.

[Bill Phil]

They have worked pretty well on carrier aircraft in almost 100 years.

I liked the design but not the rear access.

This is space, though. What happens in space, Murphy's Law applies at all times.

Plus, those wings are manually operated. Or were for a long time. As far as I know.

[Albert VDS]

Are there any plans for orbital test of the Dreamchaser? As far as I know it only had 1 drop test and landing.

[magnemoe]

This is space, though. What happens in space, Murphy's Law applies at all times.

Plus, those wings are manually operated. Or were for a long time. As far as I know.

The carrier planes wings might be manually operated as its no reason to automate it, the mechanism don't have to be strong as you will unfold the wings in vacuum and 0g.

[sgt_flyer]

ESA shown interests in Dreamchaser once i think ? but they asked for reduced wings to fit inside Ariane's fairing ?

guess that's SNC's answer for fitting DC inside a fairing.

nevertheless, this could be interesting for softlanding some of the stuff they bring back from ISS - some of those are quite delicate, and needs considerable care for their packaging to survive current Dragon parachute landings. (that, or they bring it back in the Soyuz capsule - which can't bring a lot down)

as for the service module, it can be a good compromise for storing most of the toxic RCS fuels as well as giving a berth for vacuum capable large payloads. after all, if they drop all their remaining toxic RCS fuel before reentry, they won't need to passivate them after landing - which could considerably lower post landing maintenance and reduce turnaround times.

[magnemoe]

ESA shown interests in Dreamchaser once i think ? but they asked for reduced wings to fit inside Ariane's fairing ?

guess that's SNC's answer for fitting DC inside a fairing.

nevertheless, this could be interesting for softlanding some of the stuff they bring back from ISS - some of those are quite delicate, and needs considerable care for their packaging to survive current Dragon parachute landings. (that, or they bring it back in the Soyuz capsule - which can't bring a lot down)

as for the service module, it can be a good compromise for storing most of the toxic RCS fuels as well as giving a berth for vacuum capable large payloads. after all, if they drop all their remaining toxic RCS fuel before reentry, they won't need to passivate them after landing - which could considerably lower post landing maintenance and reduce turnaround times.

Yes, however can they not just vent it during reentry? it will still be present in pipes. Still an trunk for vacuum payload and extra fuel makes sense, you pretty much has to have one interface to upper stage anyway, still the docking port confuses me.

[Nibb31]

It looks like yet another desperate attempt to stick wings on something that doesn't need them.

[Frozen_Heart]

I'm pretty sure that the service module is for unpressurised cargo.

I like the idea of the folding wings. Solves one of their problems of fitting it in a fairing

Then again why are we using wings in space? If it was fully reusable I kind of get it but this just seems like the disadvantages of both worlds.

[monophonic]

I'm pretty sure that the service module is for unpressurised cargo.

I like the idea of the folding wings. Solves one of their problems of fitting it in a fairing

Then again why are we using wings in space? If it was fully reusable I kind of get it but this just seems like the disadvantages of both worlds.

It looks like yet another desperate attempt to stick wings on something that doesn't need them.

I think it goes the other way round, it's yet another attempt to sell something that has wings on it but no market that needs those wings.

[B787_300]

actually there is a reason for the wings. There are some cargos that should not be subjected to high gs upon reentry, and the wings means that it wont plus because it is landing on a known runway they can pull out sensitive cargo immediately, unlike the current dragon capsules which IIRC takes about a week for NASA to get

[Kibble]

Am I the only one thinking:

[Bill Phil]

The carrier planes wings might be manually operated as its no reason to automate it, the mechanism don't have to be strong as you will unfold the wings in vacuum and 0g.

It has to survive launch, though. And it seems very complicated. Especially compared to "letting the winglets poke out of the fairing."