1. I wonder how hard that would have been to tame and how cost effective it would have been?2. I also wonder will the OSC incident cause a reevaluation of the commercial crew?3. The full size DC can do much of Cygnus's or Dragon's cargo duties if one gets grounded since it has a similar capacity.While the CST-100 has a much smaller cargo capacity then either vehicle.
To expand on Jim's reply -- DC and CST both use docking tunnels, which can't accommodate the large, bulky cargo that the CBM allows.
3. Wrong. CST-100 can carry as much.
Quote from: vt_hokie on 10/28/2014 02:11 amIt was a little late in the game for a propulsion change. Pretty remarkable how DC went from hybrid-palooza to no hybrids at all! I also wonder will the OSC incident cause a reevaluation of the commercial crew?The full size DC can do much of Cygnus's or Dragon's cargo duties if one gets grounded since it has a similar capacity.While the CST-100 has a much smaller cargo capacity then either vehicle.
It was a little late in the game for a propulsion change. Pretty remarkable how DC went from hybrid-palooza to no hybrids at all!
Plus, no CCiCap competitor offered more than 16m³ of volume. Enhanced Cygnus (the 3-segment pressurized module version that would fly from CRS-4 onwards), is 26m³, and the proposed "SuperCygnus" version (with 4 segment pressurized module) would have 33.5m³. Of course either Atlas V 501, Delta IV M+(5,2) or even Falcon 9 v1.1 could fit within existing fairing and with a lot of mass margin. They could take up to 4 tonnes of cargo per trip with that configuration. With that they could cover their CRS1 contract in just five launches. The nice thing of flying Cygnus on Atlas V is that ISS would be fully redundant on crew and cargo but still get a nice level of orders for each system. I guess it would require 3 Cargo Dragon, 1 Crew Dragon, 2 Cygnus and 1 CST-100. That's 4 x Falcon 9 per year and 3 x Atlas V. They could get a nice discount on that. Specially since its contracted through commercial means and thus SpaceX, Orbital and Boeing will fight for the best price.
1. It took some searching but the only cargo mass number I can find for the CST-100 is 2000kg and another that was even less at 2800lbs this is less then the upgraded Cyngus,much less then Dragon, and less then Dream Chaser.In fact by mass this is even less then Progress which carries up to 2350kg.2. The biggest issue by far is it is more volume limited then the other vehicles so it's unlikely all that mass will ever be utilized.The Apollo OML is not exactly an efficient shape for cargo.Of course Boeing could replace the capsule with a cargo carrier like on Cygnus and eliminate this limitation but I find this unlikely without extra $$$$$ on NASA's part.3. vDreamChaser has 16 cubic meters of volume that is mostly cylindrical so in this respect it not only beats the CST-100 it even beats Dragon though the enhanced Cygnus still can carry a lot more.
Quote from: Patchouli on 10/29/2014 10:42 pm1. It took some searching but the only cargo mass number I can find for the CST-100 is 2000kg and another that was even less at 2800lbs this is less then the upgraded Cyngus,much less then Dragon, and less then Dream Chaser.In fact by mass this is even less then Progress which carries up to 2350kg.2. The biggest issue by far is it is more volume limited then the other vehicles so it's unlikely all that mass will ever be utilized.The Apollo OML is not exactly an efficient shape for cargo.Of course Boeing could replace the capsule with a cargo carrier like on Cygnus and eliminate this limitation but I find this unlikely without extra $$$$$ on NASA's part.3. vDreamChaser has 16 cubic meters of volume that is mostly cylindrical so in this respect it not only beats the CST-100 it even beats Dragon though the enhanced Cygnus still can carry a lot more.1. I find 2800kg2. Where are the volume numbers to back up the claim? OML is meaningless. The CST-100 is wider than dragon. I see 16-18 for CST-1003. Most not useable for cargo in the DcAnother offhanded claim debunked.
1. 2800kg for CST? The number I found was less than 1200kg, but it wasn't clear if that was in a cargo optimized configuration or an unmanned crewed capsule.
Quote from: arachnitect on 10/30/2014 01:46 am1. 2800kg for CST? The number I found was less than 1200kg, but it wasn't clear if that was in a cargo optimized configuration or an unmanned crewed capsule.http://www.airspacemag.com/space/taxi-to-the-space-station-261647/?no-ist
Couldn't you make vast changes in the CST-100 upmass by changing the configuration of the Atlas 5 it's launching on? They don't need to use the commercial crew configuration for cargo.
Quote from: Jim on 10/30/2014 01:59 amQuote from: arachnitect on 10/30/2014 01:46 am1. 2800kg for CST? The number I found was less than 1200kg, but it wasn't clear if that was in a cargo optimized configuration or an unmanned crewed capsule.http://www.airspacemag.com/space/taxi-to-the-space-station-261647/?no-istThey're using the cursed imperial system. 2800lbs = ~1270kg.Quote from: gongora on 10/30/2014 01:55 amCouldn't you make vast changes in the CST-100 upmass by changing the configuration of the Atlas 5 it's launching on? They don't need to use the commercial crew configuration for cargo.They're already at a 422 which is pretty capable. They can probably fly more efficient trajectory without people on board. No LAS maybe? Can add another solid motor, but beyond that they start getting into the Centaur structural limits.
Its intended payload capacity is a mere 2,800 pounds,
Another offhanded claim debunked.
Quote from: arachnitect on 10/30/2014 02:06 amQuote from: Jim on 10/30/2014 01:59 amQuote from: arachnitect on 10/30/2014 01:46 am1. 2800kg for CST? The number I found was less than 1200kg, but it wasn't clear if that was in a cargo optimized configuration or an unmanned crewed capsule.http://www.airspacemag.com/space/taxi-to-the-space-station-261647/?no-istThey're using the cursed imperial system. 2800lbs = ~1270kg.Quote from: gongora on 10/30/2014 01:55 amCouldn't you make vast changes in the CST-100 upmass by changing the configuration of the Atlas 5 it's launching on? They don't need to use the commercial crew configuration for cargo.They're already at a 422 which is pretty capable. They can probably fly more efficient trajectory without people on board. No LAS maybe? Can add another solid motor, but beyond that they start getting into the Centaur structural limits.Would it not be possible to encapsulate the CST-100 cargo variant within the 5m fairing? CST at 4.56m should just barely fit.
Or flying Cygnus on Atlas.Point is, none of the crew vehicles can do what Cygnus does.
From the SpaceNews article by Dan Leone:QuoteGerstenmaier also disagreed with the members of the source evaluation board about the importance of some planned Dream Chaser features. For example, Gerstenmaier gave less weight to Dream Chaser’s ability to land on runways than did the evaluation board, and was more troubled than the board over some of the remaining technical hurdles in SNC’s proposal.This hints at the possibility the evaluation board might have come to a preliminary conclusion with recommendations of awards, which might then have been over-ridden by Gerstenmaier. That's speculation, but if it did play out that way the over-ride would look ugly in the court of public opinion, regardless of Gerstenmaier's actual reasons for it.
Gerstenmaier also disagreed with the members of the source evaluation board about the importance of some planned Dream Chaser features. For example, Gerstenmaier gave less weight to Dream Chaser’s ability to land on runways than did the evaluation board, and was more troubled than the board over some of the remaining technical hurdles in SNC’s proposal.
Source selection decisions (SSD) made by the Source Selection Authority must be a comparative assessment of proposals based upon the evaluation criteria in the solicitation and represent the independent judgment of the SSA. The SEB helps the SSA make the selection by identifying significant discriminators in each of the proposals resulting from its evaluation and explaining the significance of those discriminators. The SEB performs its duties without comparing proposals. It is the responsibility of the SSA to compare proposals using the findings made by the SEB. The SSA exercises independent judgment when determining how these discriminators factor into the selection decision. Since the findings of the SEB are part of the record, the SSA should return the evaluation to the SEB for its further consideration if the SSA believes the SEB’s findings are flawed.
Most of the CRS cargo can fit through docking tunnels
As to DC - I would only caution you to be careful quoting numbers from a system that didn't make it as mature as CDR.
If the SSA (Gerst) felt the SEB's evaluation was incomplete or flawed, then he would have (or should have) returned to the SEB for clarification or reconsideration--and that would be part of the record.