Author Topic: Red Dragon Discussion Thread (1)  (Read 559061 times)

Offline adrianwyard

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Re: Red Dragon
« Reply #1120 on: 11/29/2013 08:17 pm »
Sure. The trick is to determine when to stop making modifications and just design a new vehicle. As it is, the spacecraft pictured differs from the basic Red Dragon concept only by separating the heat shield. It also addresses concerns expressed with the basic concept, i.e. backshell heating and landing clearance. It would also place the Super Dracos even further into the wake (minimizing the supersonic retropropulsion risk factor.)

But I'd really like to know if carrying that larger heat shield and/or extensions all the way to Mars actually buys you an increase in landed payload mass. Armchair physics says yes, but reality can be counter-intuitive. (See the description in the Manned Mars Lander thread).

Offline mlindner

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Re: Red Dragon
« Reply #1121 on: 11/29/2013 08:57 pm »
I've thought for a long time that theorizing on what the _vehicle_ looks like before we see what the _rocket_ looks like is a rather futile task and similarly for MCT, theorizing what the _vehicle_ looks like before we know what the _engines_ will be is also another futile task.
LEO is the ocean, not an island (let alone a continent). We create cruise liners to ride the oceans, not artificial islands in the middle of them. We need a physical place, which has physical resources, to make our future out there.

Offline adrianwyard

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Re: Red Dragon
« Reply #1122 on: 11/29/2013 09:14 pm »
We know what these are for the Red Dragon concept: Falcon Heavy (Merlin 1D) , and Dragon with SuperDracos (similar or identical to the abort/landing motors for crewed Dragon.)

Falcon Heavy is predicted to throw ~10 mt to Mars, and allow a Dragon to take ~1 mt of payload to the surface.
The SuperDracos (x8), mounted in the pods in the sidewall are rated ~15K lb each.


Offline beancounter

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Re: Red Dragon
« Reply #1123 on: 12/02/2013 11:44 pm »
We know what these are for the Red Dragon concept: Falcon Heavy (Merlin 1D) , and Dragon with SuperDracos (similar or identical to the abort/landing motors for crewed Dragon.)

Falcon Heavy is predicted to throw ~10 mt to Mars, and allow a Dragon to take ~1 mt of payload to the surface.
The SuperDracos (x8), mounted in the pods in the sidewall are rated ~15K lb each.

Raptor is in the frame now.  I'd expect that to be the engine of choice for any vehicles referenced for Mars missions such as MCT.
Beancounter from DownUnder

Offline go4mars

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Re: Red Dragon
« Reply #1124 on: 12/03/2013 04:06 am »
We know what these are for the Red Dragon concept: Falcon Heavy (Merlin 1D) , and Dragon with SuperDracos (similar or identical to the abort/landing motors for crewed Dragon.)

Falcon Heavy is predicted to throw ~10 mt to Mars, and allow a Dragon to take ~1 mt of payload to the surface.
The SuperDracos (x8), mounted in the pods in the sidewall are rated ~15K lb each.

Raptor is in the frame now.  I'd expect that to be the engine of choice for any vehicles referenced for Mars missions such as MCT.
...   Do you mean essentially a scaled up dragon with 8 raptors instead of 8 superdracos?         Whoa... 
I guess it fits within  Elon's quote about the "spaceship raptor is attached to".  But whoa...

 Sounds more comfortable and practical for the tens of thousands of travellers I suppose. 

Imagine the rocket it will need!!       Whoa...

Go SpaceX!!
« Last Edit: 12/03/2013 04:09 am by go4mars »
Elasmotherium; hurlyburly Doggerlandic Jentilak steeds insouciantly gallop in viridescent taiga, eluding deluginal Burckle's abyssal excavation.

Offline adrianwyard

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Re: Red Dragon
« Reply #1125 on: 12/03/2013 04:28 am »
The value of Red Dragon IMHO has always been how it could demonstrate so much for so little. New larger Mars landers will be more useful and impressive, but here's the argument that appeals to me:

If Falcon Heavy flies by 2015,
And FH performance is as expected - it can throw ~10 mt to Mars, i.e. a Dragon.
And crewed Dragon with Super Dracos is successfully demonstrating powered abort/vertical landings by 2015.

Then as early as 2016, a FH test flight could theoretically send a test Dragon to Mars, and make SpaceX the first private company to place a lander on its surface, and in doing so demonstrate a number of technologies and capabilities, that are in line with the founders' vision.

Placing a 1 tonne payload on Mars is nothing new - the MSL EDL system did that, and is arguably a better solution. But if SpaceX were to do it, even if it was just once, that would be a major milestone in commercial spaceflight history.

And the clincher is the upgrades needed to do this are comparatively minor, i.e. deep space navigation and com, perhaps some rad hardening, and stressing the supposed long duration capabilities of the Dragon.
« Last Edit: 12/03/2013 04:32 am by adrianwyard »

Offline beancounter

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Re: Red Dragon
« Reply #1126 on: 12/03/2013 07:01 am »
The value of Red Dragon IMHO has always been how it could demonstrate so much for so little. New larger Mars landers will be more useful and impressive, but here's the argument that appeals to me:

If Falcon Heavy flies by 2015,
And FH performance is as expected - it can throw ~10 mt to Mars, i.e. a Dragon.
And crewed Dragon with Super Dracos is successfully demonstrating powered abort/vertical landings by 2015.

Then as early as 2016, a FH test flight could theoretically send a test Dragon to Mars, and make SpaceX the first private company to place a lander on its surface, and in doing so demonstrate a number of technologies and capabilities, that are in line with the founders' vision.

Placing a 1 tonne payload on Mars is nothing new - the MSL EDL system did that, and is arguably a better solution. But if SpaceX were to do it, even if it was just once, that would be a major milestone in commercial spaceflight history.

And the clincher is the upgrades needed to do this are comparatively minor, i.e. deep space navigation and com, perhaps some rad hardening, and stressing the supposed long duration capabilities of the Dragon.

I wouldn't like to go to Mars in a DragonCrew vehicle.  Too small but that's just me.
Beancounter from DownUnder

Offline guckyfan

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Re: Red Dragon
« Reply #1127 on: 12/03/2013 07:11 am »
I wouldn't like to go to Mars in a DragonCrew vehicle.  Too small but that's just me.

Nobody ever suggested sending people to Mars using Red Dragon. Not even Mars One. They were talking about a  5m version.

http://marsonefans.com/archive/index.php/t-617.html

Offline newpylong

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Re: Red Dragon
« Reply #1128 on: 12/03/2013 02:03 pm »
The value of Red Dragon IMHO has always been how it could demonstrate so much for so little. New larger Mars landers will be more useful and impressive, but here's the argument that appeals to me:

If Falcon Heavy flies by 2015,
And FH performance is as expected - it can throw ~10 mt to Mars, i.e. a Dragon.
And crewed Dragon with Super Dracos is successfully demonstrating powered abort/vertical landings by 2015.

Then as early as 2016, a FH test flight could theoretically send a test Dragon to Mars, and make SpaceX the first private company to place a lander on its surface, and in doing so demonstrate a number of technologies and capabilities, that are in line with the founders' vision.

Placing a 1 tonne payload on Mars is nothing new - the MSL EDL system did that, and is arguably a better solution. But if SpaceX were to do it, even if it was just once, that would be a major milestone in commercial spaceflight history.

And the clincher is the upgrades needed to do this are comparatively minor, i.e. deep space navigation and com, perhaps some rad hardening, and stressing the supposed long duration capabilities of the Dragon.

The margins are too close, they won't bother with the current FH. Loaded Dragon 1 is 10-11 tons, they say FH can TMI 13 tons. Add on all the items required to make sure Dragon can land on Mars successfully you're at or over TMI capability of FH.

They will wait until they can do something meaningful before attempting this.

Offline Zannanza

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Re: Red Dragon
« Reply #1129 on: 12/03/2013 03:17 pm »
Then as early as 2016, a FH test flight could theoretically send a test Dragon to Mars, and make SpaceX the first private company to place a lander on its surface, and in doing so demonstrate a number of technologies and capabilities, that are in line with the founders' vision.
May I ask is the PICA-X heat shield of Dragon designed and expected to survive a high-speed reentry of the Martian atmosphere?

Offline adrianwyard

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Re: Red Dragon
« Reply #1130 on: 12/03/2013 03:39 pm »
May I ask is the PICA-X heat shield of Dragon designed and expected to survive a high-speed reentry of the Martian atmosphere?
That's a key question, and yes it is.

There's a lot of information upthread, and places like http://en.wikipedia.org/wiki/Red_Dragon_(spacecraft)

For those that don't know, Red Dragon EDL was evaluated by NASA Ames who added some insight from MSL. Their concerns were not mass or heatshield, but things like backshell heating, firing the engines while supersonic, and landing leg strength. (Aspects I addressed in my cartoon design above.)
« Last Edit: 12/03/2013 04:19 pm by adrianwyard »

Offline adrianwyard

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Re: Red Dragon
« Reply #1131 on: 12/03/2013 03:47 pm »
The margins are too close, they won't bother with the current FH. Loaded Dragon 1 is 10-11 tons, they say FH can TMI 13 tons. Add on all the items required to make sure Dragon can land on Mars successfully you're at or over TMI capability of FH.

They will wait until they can do something meaningful before attempting this.

Dry mass of stock Dragon is supposed to be ~4.5 tonnes, and web sources say Red Dragon comes in at 6.5+1 for payload.

I don't see SpaceX coming up with the cash to do this on their own just to prove they can, but by perhaps 2018 they may have teamed with someone who'd like to try to get 1 tonne to Mars.
« Last Edit: 12/03/2013 03:56 pm by adrianwyard »

Offline Garrett

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Re: Red Dragon
« Reply #1132 on: 12/03/2013 03:55 pm »
The margins are too close, they won't bother with the current FH. Loaded Dragon 1 is 10-11 tons, they say FH can TMI 13 tons. Add on all the items required to make sure Dragon can land on Mars successfully you're at or over TMI capability of FH.

They will wait until they can do something meaningful before attempting this.
That loaded Dragon figure includes several tonnes of cargo I believe. Even half a tonne of cargo to Mars would be extremely useful.
What's not meaningful about a powered landing of a capsule on the Martian surface? Imagine all the science that could be done with only a couple of hundred kilograms of cargo: radiation measurements and atmospheric measurements for example.
Add to that the data and experience associated with Martian orbit insertion, entry and landing; Earth-Mars communication; survivability of electronics and other equipment.
- "Nothing shocks me. I'm a scientist." - Indiana Jones

Offline adrianwyard

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Re: Red Dragon
« Reply #1133 on: 12/03/2013 04:00 pm »
Yes, 10-11 tonnes total mass would be right if you factor in a max payload of 6 tonnes on Dragon 1.0.

So there's  up to 6 tonnes to spend on the crewed Dragon upgrades and payload. (And by 'crewed' I mean a Dragon with Super Draco descent engines, not a crew  ;) )
« Last Edit: 12/03/2013 04:06 pm by adrianwyard »

Offline guckyfan

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Re: Red Dragon
« Reply #1134 on: 12/03/2013 04:05 pm »
Yes, 10-11 tonnes total mass would be right if you factor in a max payload of 6 tonnes on Dragon 1.0.

So there's  up to 6 tonnes to spend on the crewed Dragon upgrades and payload.

Seems enough to send an additional medium size orbiter along.


Offline adrianwyard

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Re: Red Dragon
« Reply #1135 on: 12/03/2013 04:09 pm »
Yes, 10-11 tonnes total mass would be right if you factor in a max payload of 6 tonnes on Dragon 1.0.

So there's  up to 6 tonnes to spend on the crewed Dragon upgrades and payload.

Seems enough to send an additional medium size orbiter along.

Or... that launch mass margin could be spent by using the Falcon Heavy in reusable mode (assuming that works) and therefore reducing launch costs.

Offline baldusi

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Re: Red Dragon
« Reply #1136 on: 12/03/2013 04:13 pm »
I don't see SpaceX coming up with the cash to do this on their own just to prove they can, but by perhaps 2018 they may have teamed with someone who'd like to try to get 1 tonne to Mars.
The Red Dragon paper talked about a cost-cap of 500M including launch. This is the customized dragon, the FH launcher and the drill and instruments development. I doubt it would include DSN and researcher's time.

Offline Chris Bergin

Re: Red Dragon
« Reply #1137 on: 12/03/2013 06:10 pm »
Wow, big thread. Certainly need to look at a Thread 2 for this at some point.

So tie up your conversations and when that point arrives I'll create the second thread.
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Offline newpylong

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Re: Red Dragon
« Reply #1138 on: 12/03/2013 06:48 pm »

The margins are too close, they won't bother with the current FH. Loaded Dragon 1 is 10-11 tons, they say FH can TMI 13 tons. Add on all the items required to make sure Dragon can land on Mars successfully you're at or over TMI capability of FH.

They will wait until they can do something meaningful before attempting this.

Dry mass of stock Dragon is supposed to be ~4.5 tonnes, and web sources say Red Dragon comes in at 6.5+1 for payload.

I don't see SpaceX coming up with the cash to do this on their own just to prove they can, but by perhaps 2018 they may have teamed with someone who'd like to try to get 1 tonne to Mars.

What web sources? It's just an idea... There was a good paper done by Ames a few years ago, a lot has changed since then.

They aren't just going to send a stock Dragon on it's way. The only thing capable of sustaining the journey and EDL is the TPS material. That is just the heat shield itself. You still have the back shell, as well as all of the other pressure vessel supports. Add on the legs, the rad hardening. More batteries. The tonnage adds up. Remember the LEM? They had to pull the seats out to save a few lbs.

It would be very tight.
« Last Edit: 12/03/2013 06:49 pm by newpylong »

Offline guckyfan

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Re: Red Dragon
« Reply #1139 on: 12/03/2013 07:02 pm »
It will be the the manned Dragon without full ECLSS. That will be capable of landing through the earth atmosphere. It will have landing legs that support the landing in earth gravity. It has a pressure cabin, so what backshell? Why additional batteries? It may need better, not bigger solar panels if even that. So except the com equipment for interplanetary distances what else would add weight?

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