Aethon

Blue Origin Thread (merged)

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dragon.jpg

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6 hours ago, Bill Phil said:

The USAF already tried to develop an SLS. That was the actual acronym...

It was my attempt at an F35 joke..

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"Small deployable satellites" sounds like "we didn't know what to put into an overpowered rocket while the ship is too light"

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I assume it's something a customer could potentially request, but no such thing has ever been done AFAIK.

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7 hours ago, kerbiloid said:

"Small deployable satellites" sounds like "we didn't know what to put into an overpowered rocket while the ship is too light"

In this case it is more like "customer paid for the whole rocket, but only brought half the payload".  I'd hardly call falcon 9 overpowered, although I'd assume that falcon 5 was originally intended for this role (had they developed falcon 5, landing would be like landing a falcon 9 on three engines without the ability to cut two at the last second).  I'd also assume that developing Falcon 5 would have similar costs to Falcon Heavy, which certainly wasn't all that cheap (and have nearly zero savings compared to a reused falcon 9).

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8 hours ago, Streetwind said:

I assume it's something a customer could potentially request, but no such thing has ever been done AFAIK.

There was a secondary on CRS-1.

AFAICT, modern versions of the launch licence for CRS missions no longer authorise the carriage of secondary payloads, but this could change in future.

Edited by Kryten

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5 hours ago, wumpus said:

In this case it is more like "customer paid for the whole rocket, but only brought half the payload".  I'd hardly call falcon 9 overpowered, although I'd assume that falcon 5 was originally intended for this role (had they developed falcon 5, landing would be like landing a falcon 9 on three engines without the ability to cut two at the last second).  I'd also assume that developing Falcon 5 would have similar costs to Falcon Heavy, which certainly wasn't all that cheap (and have nearly zero savings compared to a reused falcon 9).

Is just that the cargo capacity of the dragon advised by SpaceX, like in the picture posted by @tater, is not realistic. Useful things are usually a lot less denser that what dragon will allow in the little space it have. In this dragon it was only 2389kg, and only 1492kg are pressurized. That's less than half the announced payload.


Dragon in theory could have 3300 kg of pressurized cargo in 10m3 and the enhanced cygnus for a similar cargo capacity (3300kg using an Antares, 3500kg  with an AtlasV) has 27m3, that's almost 3 times the space for the same cargo. The unpressurized extra cargo capacity of the Dragon is mostly unused and has never flown to more than half the advised capacity (and that time was because it was used to send the bigelow beam module), but the cygnus has already flown at full capacity. We could also compare with the now retired ATV that had 48m3 for pressurized cargo or the good old Progress, both have the capacity to deliver propellant, and both have flown at full announced capacity. I will admit that I have little knowledge of the HTV, but looks like it also was launched with it theoretical full cargo capacity.

Dragon is a good cargo spacecraft, with it's limitations, but please, stop repeating the over-promising claims of SpaceX

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The purpose of the image I posted was exclusively to show the nose cap visible in the image posted above it a few posts as it fell away after separation.

On 2/20/2017 at 10:30 AM, YNM said:

Can anyone identify what closure this is ? Is it the docking ?

cap_huh.png?dl=0

Also, now they have aluminum foil to close the "back" part of the engine ?

 

21 hours ago, tater said:

dragon.jpg

 

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3 hours ago, kunok said:

Is just that the cargo capacity of the dragon advised by SpaceX, like in the picture posted by @tater, is not realistic. Useful things are usually a lot less denser that what dragon will allow in the little space it have. In this dragon it was only 2389kg, and only 1492kg are pressurized. That's less than half the announced payload.


Dragon in theory could have 3300 kg of pressurized cargo in 10m3 and the enhanced cygnus for a similar cargo capacity (3300kg using an Antares, 3500kg  with an AtlasV) has 27m3, that's almost 3 times the space for the same cargo. The unpressurized extra cargo capacity of the Dragon is mostly unused and has never flown to more than half the advised capacity (and that time was because it was used to send the bigelow beam module), but the cygnus has already flown at full capacity. We could also compare with the now retired ATV that had 48m3 for pressurized cargo or the good old Progress, both have the capacity to deliver propellant, and both have flown at full announced capacity. I will admit that I have little knowledge of the HTV, but looks like it also was launched with it theoretical full cargo capacity.

Dragon is a good cargo spacecraft, with it's limitations, but please, stop repeating the over-promising claims of SpaceX

While the Dragon may be volume limited greater than weight limited, it does have one advantage over all of the other craft you mentioned.  It can return cargo to Earth.  Also, it's not "over promised" if the vehicle can actually do what is claimed.  The only reason it hasn't is that NASA has yet to give it a cargo that meets the weight requirements at that volume.

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Reading about ships (not only Dragon) which would return 1-2 t from the orbit, I'm still trying to imagine, 2 tonnes of what they are going to return?
Mostly they deliver fuel, water and food. And equipment to be scrapped later.

Grow crystals? As already known, a crewed station is not the best place for this due to vibration. And I doubt that ISS already is ready to grow several tonnes per year.
A separated uncrewed module would make more sense (as this was planned for Mir-2/ISS). But I've never heard about Dragonlab or Dragonplant for this purpose.

(I have a personal interest, as I'm thinking: whether 500-kg returning VA TKS capsule enough for my KSP manufacturing or not. :0.0: )

Edited by kerbiloid

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10 hours ago, sojourner said:

While the Dragon may be volume limited greater than weight limited, it does have one advantage over all of the other craft you mentioned.  It can return cargo to Earth.  Also, it's not "over promised" if the vehicle can actually do what is claimed.  The only reason it hasn't is that NASA has yet to give it a cargo that meets the weight requirements at that volume.

It is a bit weird to imagine that the cargo needs to be adapted to the transporter, instead of the transporter being developped for a given cargo.

But in the end, Dragon was also developped for manned flight, so there were restrictions on how the cargo version could look like, if they wanted to keep them similar. Maybe in the future, cargo transport will be adapted to Dragons specialities or secondary payloads such as cubesats (which wouldn't be surprising, since there are cubesats that were set out by the ISS), which will add to the efficiency. And in the end, let's not forget that it is mostly about the cost per kg to ISS (and optionnally back).

12 minutes ago, kerbiloid said:

Reading about ships (not only Dragon) which would return 1-2 t from the orbit, I'm still trying to imagine, 2 tonnes of what they are going to return?
Mostly they deliver fuel, water and food. And equipment to be scrapped later.

2 tonnes is a lot, but there are biological experiments being done on ISS, for which it would probably be nice to analyse them down on Earth. But the only other options of cargo return are the small cargo return capsule that Progress can transport or together with the astronauts inside Soyuz, i.e. very limited. So Dragons huge return capability allows for a lot more flexibility for the return of experiments.

Also, as above, we are speaking of the cargo version of a manned space craft, i.e. adding that huge return payload was very cheap in development cost.

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17 minutes ago, Tullius said:

Also, as above, we are speaking of the cargo version of a manned space craft,

Not only manned. The pictured Dragon v1 makes hype also with its ability to return heavy cargo in its capsule, rather than single-use tin cans like ATV, HTV, etc.
So, its capsule weights several tonnes. And these tonnes could be additional cargo.

Edited by kerbiloid

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1 hour ago, kerbiloid said:

Not only manned. The pictured Dragon v1 makes hype also with its ability to return heavy cargo in its capsule, rather than single-use tin cans like ATV, HTV, etc.
So, its capsule weights several tonnes. And these tonnes could be additional cargo.

Problem is not weight but volume. an single use craft can have an larger pressurized volume for its weight. 
Still its not an problem, spacex probably designed dragon after nasa guidelines they could easy have made it higher if they needed and an longer trunk. 
As it is the volume is to low to utilize the maximum weight in normal settings 

The return capacity is important Soyuz has an very limited return capacity in it cramped return module 

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13 hours ago, sojourner said:

While the Dragon may be volume limited greater than weight limited, it does have one advantage over all of the other craft you mentioned.  It can return cargo to Earth.  Also, it's not "over promised" if the vehicle can actually do what is claimed.  The only reason it hasn't is that NASA has yet to give it a cargo that meets the weight requirements at that volume.

NASA is the client, is SpaceX who needs to adapt to the NASA cargo not the other way, more when the dragon was designed to meet NASA's needs. Of course is overpromised, and also an unproven claim. And the capacity to return cargo IIRC wasn't a requisite

2 hours ago, Tullius said:

let's not forget that it is mostly about the cost per kg to ISS

With is also higher that the cygnus.

Dragon is a good modular spacecraft, which probably make it worse than any specialized design for any given mission, but very versatile, just not as good like SpaceX marketing claims.

You could see how little I like marketing

Edited by kunok
typos everywhere

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9 minutes ago, kunok said:

You could see how little I like marketing

What? You seem to be trying to tell us how amazingly good SpaceX's marketing department is. :wink:

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Another crowded week, as Progress 66 launched last night for ISS.

Edited by tater

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18 hours ago, kunok said:

Is just that the cargo capacity of the dragon advised by SpaceX, like in the picture posted by @tater, is not realistic. Useful things are usually a lot less denser that what dragon will allow in the little space it have. In this dragon it was only 2389kg, and only 1492kg are pressurized. That's less than half the announced payload.

Dragon is a good cargo spacecraft, with it's limitations, but please, stop repeating the over-promising claims of SpaceX

Dragon is a fairly light payload for spacex.  You may have noticed that the booster returned to land, something that never happens with a full load.  Perhaps my "half a payload" was pretty inaccurate, but spacex certainly had more cargo room for that flight.

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2 hours ago, kunok said:

Dragon is a good modular spacecraft, which probably make it worse than any specialized design for any given mission, but very versatile, just not as good like SpaceX marketing claims.

 

Wasn't Dragon designed to be able to carry both cargo and crew before they decided to leave Dragon as a cargo only and instead develop Dragon v2? I mean, on SpaceX's youtube page some of the first animations regarding crew transport to the ISS are shown with Dragon docking to the ISS without use of canadarm

 

 

Even the description of that video states:

In August 2012, NASA chose SpaceX to complete final modifications necessary to prepare Dragon for crew and return Americans to space. While Dragon is initially being used to transport cargo to the International Space Station, both Dragon and Falcon 9 were designed from the beginning to transport people. The Dragon crew vehicle will feature seats for seven astronauts, the most technically advanced launch escape system ever developed, and advanced environments and controls.

 

Now, if Dragon was designed as cargo craft only I am sure it could have been much more optimized for that purpose.

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Soon (tm)

Would be interesting to know its delta-V budget. As LES test was, iirc 6g x 6s ~= 400 m/s.
According to braeunig.us descriptions, other ships require 300-350 m/s just for orbital operations.
Landing (from 150 m/s vertical speed) would require ~150 * 2 = 300 m/s,

350 + 300 = 400

Edited by kerbiloid

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17 minutes ago, RCgothic said:

Latest I'm hearing is NET 12th March for Echostar 23.

Yes, they had to move it to avoid conflict with the Delta launch on the 8th/9th.

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22 hours ago, monophonic said:

What? You seem to be trying to tell us how amazingly good SpaceX's marketing department is. :wink:

I'm an engineer I suffer the marketing and commercial department overpromising things. ;.; (I don't currently have that kind of job but in the past...)

You develop a sixth sense for this kind of things

20 hours ago, Cuky said:

Wasn't Dragon designed to be able to carry both cargo and crew before they decided to leave Dragon as a cargo only and instead develop Dragon v2? I mean, on SpaceX's youtube page some of the first animations regarding crew transport to the ISS are shown with Dragon docking to the ISS without use of canadarm

Yeah, that's true, they now have a cargo spacecraft that isn't really that modular, but that's not necessarily a problem, I suppose that have common manufacturing processes with the crew version, look at Progress and Soyuz (in the other hand Roscosmos have plans to change the Progress to something non soyuz based because it could be cheaper...).

But that's because the lack of mid/long term technical plans in SpaceX, nothing new.

20 hours ago, Cuky said:

the most technically advanced launch escape system ever developed

And here you can see how they were overclaiming since at least 2012.

21 hours ago, wumpus said:

Dragon is a fairly light payload for spacex.  You may have noticed that the booster returned to land, something that never happens with a full load.  Perhaps my "half a payload" was pretty inaccurate, but spacex certainly had more cargo room for that flight.

The Falcon have extra room, not really the Dragon, and because that they announce they can launch extra secondary payloads capacity so they could claim that the dragon has that cargo capacity. Falcon is pretty overpowered for this cargo.

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Second stage capture to the nadir CBM on Node 2. Dragon is installed at station for 30 days. Hatch opening in a few hours after leak checks

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