Author Topic: SNC Dream Chaser DISCUSSION Thread  (Read 658297 times)

Offline Patchouli

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2000 on: 05/01/2018 09:39 PM »


Technically it should be easy, but it probably wouldn't be very useful. With fixed-position wings it can't fit in a fairing, meaning it can't carry the expendable module. Without that, pressurized volume drops by like half and it loses unpressurized capacity entirely, plus the scheduling benefit of being able to do IDS or CBM attachment. With the main launch options all being fully or mostly expendable, it seems difficult for such a craft to compete against the other CRS systems with such a drop in capability. It'd still need at least an AV N32 most likely, judging by the crew variant (less densely packed I assume) needing 2 boosters and 2 RL10s. Cygnus has over two times the pressurized volume, but requires no boosters and only 1 RL10 (~25-30 million dollars savings). And folding wings (even if deployed at liftoff, without a fairing) are likely a hard no for NASA crew missions
They would just go back to the original "fixed winglet" DC without a cargo module, an adapter plus abort engines for crewed flights or even back to the HL-20 adapter with SRMS for abort...
https://forum.nasaspaceflight.com/index.php?topic=29126.20
[/quote]

With New Glenn they probably can use SRMs for abort without any worries about it having an impact on payload.
Since it's stages are 7M wide the bending loads probably would be much less of an issue.
« Last Edit: 05/01/2018 09:41 PM by Patchouli »

Offline john smith 19

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2001 on: 05/07/2018 08:05 AM »
A lot of people seem to be reading this as 'Sierra Nevada' owns the DC launched on the foreign rocket.  I, however, read this more as a 'sales ploy'. 

"So, ESA/JAXA wants its own astronaut launch capability?  Here, buy a couple DCs from us, they'll work on your launcher with just a little fine tuning." 

"Hey Virgin Galactic.  Why spend all that money developing SS-3 in-house when we have a perfectly viable system to put in your hands."
I think you have this backward.

SNC have a part of the CTS II contract.  It would make sense for them to investigate if other LV's can launch it cheaper than the current Atlas V baseline.

Obviously launching to the ISS is a nice reference mission for both Arianespace and (IIRC) Mitsubishi Heavy Industries to add to their portfolio for potential customers.

But AFAIK SNC would be buying those flights on their own. They would be the customer.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline brickmack

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2002 on: 06/03/2018 05:33 AM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

Offline Star One

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2003 on: 06/03/2018 11:47 AM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

You seem to be making a heck of a lot of assumptions here in multiple areas. For a start I very much doubt that Dragon offers a comparable downmass/volume capacity for the simple fact that DC is intending to fulfil its cargo commitments with less flights than Dragon is.

Offline SweetWater

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2004 on: 06/03/2018 12:57 PM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

We don't know how serious the interest in flying experiments on Dream Chaser is from any of these ~150 parties is - just that they have apparently expressed interest.

DragonLab got at least as far as SpaceX manifesting flights http://www.spacex.com/press/2012/12/19/spacex-adds-two-dragonlabtm-missions-manifest The press release is from December of 2008, about 18 months from when Falcon 9 first flew. I don't think they ever released who their customers were or why those flights were canceled.

Don't get me wrong - I'd like to see Dream Chaser succeed, and the interest alone is encouraging for Sierra Nevada. But right now there's just a tweet.

Offline yg1968

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2005 on: 06/03/2018 02:32 PM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

DC will only be using an Atlas V for its first flight. SNC has hinted that Blue Origin could be an option for its other flights to the ISS.

Online gongora

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2006 on: 06/03/2018 05:09 PM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

DC has one possible governmental organization sponsored cargo mission they're talking about.  That's not really much more success than DragonLab.

You seem to be making a heck of a lot of assumptions here in multiple areas. For a start I very much doubt that Dragon offers a comparable downmass/volume capacity for the simple fact that DC is intending to fulfil its cargo commitments with less flights than Dragon is.

DC can do fewer flights because it has a larger upmass volume, thanks to the expendable pressurized module they're using on the back of DC.

We don't know how serious the interest in flying experiments on Dream Chaser is from any of these ~150 parties is - just that they have apparently expressed interest.

DragonLab got at least as far as SpaceX manifesting flights http://www.spacex.com/press/2012/12/19/spacex-adds-two-dragonlabtm-missions-manifest The press release is from December of 2008, about 18 months from when Falcon 9 first flew. I don't think they ever released who their customers were or why those flights were canceled.

Don't get me wrong - I'd like to see Dream Chaser succeed, and the interest alone is encouraging for Sierra Nevada. But right now there's just a tweet.

There's no private sector interest in flying any of these vehicles at realistic mission prices.  I think you're making a bad assumption about SpaceX ever having customers for DragonLab.  I think they put notional missions on the manifest as advertising for the capability.

Offline rayleighscatter

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2007 on: 06/03/2018 08:46 PM »

There's no private sector interest in flying any of these vehicles at realistic mission prices.

Hit a big nail on the head there. It's no secret that the Russian half of ISS has much less science to do compared to the US half, mostly owing to funding. If there were good commercial demand for space science the Russians would be selling their excess capabilities, and much cheaper than any dedicated launch.

Online deruch

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2008 on: 06/06/2018 07:12 PM »
I gotta wonder though, why is DC apparently having so much more success on this than DragonLab? Dragon already exists and is flying routinely, offers comparable downmass/volume capacity and more unpressurized up capacity, and its probably significantly cheaper since F9 is cheaper than Atlas or Ariane and its trunk is simpler than Dream Chaser's equivalent. Yet SpaceX advertised DragonLab flights for years, and apparently never got any serious interest

I also think one of the big draws is that DC can be landed on a runway in other countries.  So, at least 1 participant country will get to have the vehicle landed in their territory.  That's a much more visible and higher profile demonstration of space activity for local consumption.  Additionally, maybe SNC just came up with a better business model?  IIRC, SpaceX was mainly trying to interest businesses or more individual research orgs.  By going through the UN, maybe SNC has gotten more interest.  The question will be how much money is there in that market?  Will funding be limited to a one-off?  Or will there be enough continuing interest, combined with available funding, to run multiple missions?
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Offline IW1DGG

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2009 on: 06/26/2018 10:17 AM »
DC4EU
I found this interesting presentation available on internet about DC4EU on Ariane-6. It seems that ArianeGroup is seriously working on this.

http://www.essc.esf.org/fileadmin/user_upload/essc/2017-11-23_ESSC_Dream_Chaser_for_European_Utilisation.pdf

did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Online Joseph Peterson

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2010 on: 07/13/2018 10:29 PM »
Article focused on Erin Ozmen.  I didn't notice anything new about Dream Chaser.  That said, I found it to be an interesting read.

https://www.forbes.com/sites/forbesdigitalcovers/2018/07/11/meet-the-unknown-immigrant-billionaire-betting-her-fortune-to-take-on-musk-in-space/
If ZBLAN can't pay for commercial stations, we'll just have to keep looking until we find other products that can combine to support humans earning a living in space.

Offline TripleSeven

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #2011 on: 07/13/2018 10:47 PM »


Hit a big nail on the head there. It's no secret that the Russian half of ISS has much less science to do compared to the US half, mostly owing to funding. If there were good commercial demand for space science the Russians would be selling their excess capabilities, and much cheaper than any dedicated launch.

you are in my view probably correct in that there is not a lot of....non government "commercial demand" for space science.

but I doubt really that even if there were the Russian segment would get the business. 

doing business with the Russians on their part of the space station is 1) very expensive and 2) very complicated in terms of dealing with the Russians.  plus, and this is being kind, the results on the Russian side are very well my words are "less rigorous" than what you get on the US/other side

micro gravity research is the great white whale of space flight...but at some point I predict the science and engineering with catch and harpoon this whale and someone is going to make some serious money with it

it wont be on the Russian side. 

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