Updates Orion (MPCV) Updates and Discussion
- Thread starter apollo13
- Start date
What's so funny? :dry:
If you intend to reuse your capsule, you will also have to refurbish it.
STS had a very fragile TPS that isn't intrinsic to spaceplanes.
Obviously any TPS on a capsule would have to be handled with care, even if it didn't need the same intensive maintainance the Shuttle TPS did (SpaceX claims that the PICA-X heatshield on Dragon is good for multiple LEO flights).
And it isn't impossible to design a LES for a spaceplane, for example a 'pusher' LES could be a good option, that has also been explored for capsule designs.
Capsules have some advantages, but the advantages of a spaceplane are more intrinsic to the actual concept of a spaceplane than the advantages of a capsule are to the concept of a capsule.
If you intend to reuse your capsule, you will also have to refurbish it.
STS had a very fragile TPS that isn't intrinsic to spaceplanes.
Obviously any TPS on a capsule would have to be handled with care, even if it didn't need the same intensive maintainance the Shuttle TPS did (SpaceX claims that the PICA-X heatshield on Dragon is good for multiple LEO flights).
And it isn't impossible to design a LES for a spaceplane, for example a 'pusher' LES could be a good option, that has also been explored for capsule designs.
Capsules have some advantages, but the advantages of a spaceplane are more intrinsic to the actual concept of a spaceplane than the advantages of a capsule are to the concept of a capsule.
Last edited:
Nah. Not a "toilet". A "waste collection system compartment" :lol:
DanM
Поехали!
I also read that it is supposed to be like a camping toilet. I'm not sure what that means, but I don't think it's a hole in the ground. :rofl:
I was wrong regarding the window of Dragon by the way. It actually has got three windows (not just one) and can have 4 windows optionally. But 10 m³ volume sounds a little less for 7 persons. The MPCV has as twice as much I think. Well, they need space to install the waste collection system compartment I guess :lol:
Dragon is intended initially for flights to and from the space station, ergo it doesn't need much internal space. This is one thing that makes MPCV overkill for ISS missions.
For long duration flights, you obviously want to have a seperate module for extra living space. It's advantageous if it isn't part of the capsule, because you don't need to slap a TPS on it for reentry.
This is what Soyuz currently does, which allows it to have a larger internal volume than the Apollo CSM, while having less mass.
For long duration flights, you obviously want to have a seperate module for extra living space. It's advantageous if it isn't part of the capsule, because you don't need to slap a TPS on it for reentry.
This is what Soyuz currently does, which allows it to have a larger internal volume than the Apollo CSM, while having less mass.
So Dragon can't do everything which the MPCV can do: offer more space. Only the capability to be operated BEO doesn't help.
The MPCV is not supposed to become an ISS transfer vehicle. The capability to dock with the ISS is a backup option, which very likely might never be used. By the time the MPCV might be ready to fly, the ISS will be on its final few years supported by SpaceX, Russia, Japan and Europe.
Soyuz has less mass because it hasn't got a service propulsion system to decelerate into lunar orbit and accelerate back to earth. And its orbital module offers less space than the Apollo Command Module. The reentry module offeres even less. Only both modules combined offer more space, but they are still more cramped individually.
If one talks about long duration missions, the current Soyuz-TMA is not a comfortable option either.
The MPCV + its SM will weigh 10 tons less than the Apollo CSM, whilst offering more volume, which is twice as much as Dragon offers.
If I were to chose a vehicle to fly with, I still would prefer to fly with three other persons on a vehicle that has got twice as much volume than another vehicle in which I would have to fly with 6 other persons.
Plus I will have the opportunity "to go on toilet" :lol:
An apple is not a pear
C3PO
Addon Developer
- Joined
- Feb 11, 2008
- Messages
- 2,604
- Reaction score
- 31
- Points
- 63
I'd choose the Soyuz, mainly because it's got a working launch system. :thumbup:
My selection scenario of course is based on an existing LV for the MPCV
Otherwise I would chose Dragon over Soyuz
Last edited:
C3PO
Addon Developer
- Joined
- Feb 11, 2008
- Messages
- 2,604
- Reaction score
- 31
- Points
- 63
Dragon still doesn't have a working escape system. But when it's finished, I'd probably choose the Dragon too.
We still have to see the finished craft, and plans have a habit of changing when you try to implement them.
Fingers crossed.
We still have to see the finished craft, and plans have a habit of changing when you try to implement them.
Fingers crossed.
Elon Musk said that Dragon is ready for manned flights except the launch escape system. But SpaceX already has got 75 million USD for developing the launch escape system. He said there is nothing which has to be changed on Dragon. And once they will service the ISS they want to go public with their stuff finally. I can't wait to see high res images and videos of the interior of Dragon. I am curious how the controls and displays will look like, and all the other interior stuff of course.
C3PO
Addon Developer
- Joined
- Feb 11, 2008
- Messages
- 2,604
- Reaction score
- 31
- Points
- 63
As far as I know the only things that need to be physically changed are the docking port, and the addition of seats, controllers, and instrumentation.
Dragon and F9 would also have to be certified for manned flights, but they ought to have all the technical requirements for that built into them already.
Is that the cost of developing a LES? Where did you get that figure?
EDIT:
At least the outcome of changing plans is better within SpaceX than it is within NASA... :shifty:
Yes. Basically interior equipment which is required for manned flights. And maybe the mounting for the LES. But Dragon itself will stay as it is Musk says.
Yes. They claim that Dragon and Falcon would already fulfill all NASA requirements, except the LES of course.
What surprises me is how slow Dragon actually does splash down. Okay it's still empty. But it looks just as Elon Musk claims: Dragon is supposed to offer a nice ride...
http://www.spacex.com/updates.php
It's supposed to work once, and work well. In normal operation it's also supposed to detach when you don't need it anymore.
I don't think I've heard of any cases of a LES failing to detach the capsule in an emergency, or detach itself in normal operation. In that case, it could be said to be a pretty safe spacecraft system.
That said... every different system is a different system, Soyuz is by far the most used, Mercury and Apollo notsomuch.
Well there you go.
Yes, but it can be used at any time during ascent (as they claim), which is new I think. The Apollo LES couldn't be used at any time, less than ever the abort modes of the Shuttle.
It had abort modes instead, as mentioned...
RTLS, TAL etc.
But RTLS was not possible during early ascent. That's where something like Dragon (but also the MPCV) will be a lot safer actually. The Shuttle was not the optimal choice anyway if one talks about safety.
Yes, but that's the difference to SpaceX's LES. It will be available all the time. I think a LES abort is more powerful.
Urwumpe
Not funny anymore
- Joined
- Feb 6, 2008
- Messages
- 38,965
- Reaction score
- 3,937
- Points
- 203
- Location
- Wolfsburg
- Preferred Pronouns
- Sire
Ah, time for fact checking. Can't we have a "Orbiter-Forum-Facts" homepage? :lol:
Wrong. Lets calculate: The Apollo CM had just 6.17 m³ internal volume for three astronauts. But still weights 5,800 kg gross.
The Soyuz TMA Reentry Module/CA has an internal volume of just 3.5 m³, but already weights just 2950 kg. Notice something by the ratio?
The Soyuz TMA orbital module/BO weights 1350 kg and has 5 m³ internal volume. Together 4300 kg and 8.5 m³
Also, the Apollo CM is also very cramped inside, the internal volume of it is not one large free space, even when you fold the center seat away.
Even if you include that the heat shield of the Apollo CM has to be stronger - the fact that it simply lands much more mass and thus needs everything to be heavier makes the difference. The Soyuz doesn't even land the reentry guidance system, this is discarded with the PAO.
So, please research first before you make your claims.
Wrong. Lets calculate: The Apollo CM had just 6.17 m³ internal volume for three astronauts. But still weights 5,800 kg gross.
The Soyuz TMA Reentry Module/CA has an internal volume of just 3.5 m³, but already weights just 2950 kg. Notice something by the ratio?
The Soyuz TMA orbital module/BO weights 1350 kg and has 5 m³ internal volume. Together 4300 kg and 8.5 m³
Also, the Apollo CM is also very cramped inside, the internal volume of it is not one large free space, even when you fold the center seat away.
Even if you include that the heat shield of the Apollo CM has to be stronger - the fact that it simply lands much more mass and thus needs everything to be heavier makes the difference. The Soyuz doesn't even land the reentry guidance system, this is discarded with the PAO.
So, please research first before you make your claims.
Last edited:
