Author Topic: Just an idea about alternative CEV  (Read 16819 times)

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Just an idea about alternative CEV
« on: 10/18/2009 07:18 PM »
Hi,
it is some time that I have something like this in mind and I would like to have the opinion of someone else.
I am not an expert on the matter, but surfing and reading documents it seems to me that something like that has never been proposed (am I correct?) - Lookheed CEV was similar but had the Lifting Body on top.
The idea is simple:
it is almost shared that capsules are the best/safe way to come back from space.
Ok, but we need only the capsule to do that.
Why do not we leave/crash all the rest?
I try to attach a sketch I made (please do not laugh too much about the quality...)
Do you think it could work? we need a smaller LSAM/MLAS to escape as the part we have to save (only the capsule) is smaller...

To resume, let say something like ATV (but a but smaller) with a 90deg tilted capsule on top.

What do you think about? is that reasonable? could fit on ARES-1?

Thanks
« Last Edit: 10/18/2009 07:46 PM by IW1DGG »
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline Idol Revolver

  • Full Member
  • *
  • Posts: 153
  • Liked: 0
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #1 on: 10/18/2009 07:51 PM »
Are you suggesting the crew live in the service module or in the capsule? And why would you have the capsule at right angles like that when you could have it attached by the base? (this also protects the heatshield)

EDIT: I'm not sure what you are suggesting that is so revolutionary. Dumping the service module before re-entry? That happens anyway, with Orion, Apollo, Soyuz and just about every other spacecraft I can think of.
« Last Edit: 10/18/2009 07:59 PM by Idol Revolver »

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #2 on: 10/18/2009 08:00 PM »
Hi!

The crew is in the capsule during launch and reentry.
Then in orbit they can use both service module and capsule (to have more space available), but what comes back to earth is the capsule only.

It is tilted 90deg to avoid the hole for the tunnel to go in the service/hab module in the heat shield.. (maybe it is technically feasible, but would you fly on that?)

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

Offline Idol Revolver

  • Full Member
  • *
  • Posts: 153
  • Liked: 0
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #3 on: 10/18/2009 08:07 PM »
Right, I see what you are getting at now. Unfortunately, the Russians had the same idea (minimise re-entry mass) with soyuz, but they used a re-entry capsule, a service module, and a hab module. Similar to your idea, but still no living in the service module.

Online Jorge

  • Senior Member
  • *****
  • Posts: 6180
  • Liked: 32
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #4 on: 10/18/2009 08:12 PM »
Hi!

The crew is in the capsule during launch and reentry.
Then in orbit they can use both service module and capsule (to have more space available), but what comes back to earth is the capsule only.

It is tilted 90deg to avoid the hole for the tunnel to go in the service/hab module in the heat shield.. (maybe it is technically feasible, but would you fly on that?)



There are many capsule designs (Gemini/MOL, TKS) that had hatches through the heat shield. The shuttle has hatches through the heat shield (landing gear, ET umbilicals).

I would fly on a spacecraft with hatches through the heat shield. I would not fly on a spacecraft mounted sideways on the launch vehicle.
JRF

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #5 on: 10/18/2009 08:15 PM »
Hi again,
I see, but they have the capsule in the middle, so in order to escape from the launch pad they need more powerful escape system, right?
What I was thinking is that if the capsule is on top you have just to extract it from the launch pad in case of need and no extra modules, so less weight...
Am I correct?
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline Idol Revolver

  • Full Member
  • *
  • Posts: 153
  • Liked: 0
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #6 on: 10/18/2009 08:42 PM »
Hi again,
I see, but they have the capsule in the middle, so in order to escape from the launch pad they need more powerful escape system, right?
What I was thinking is that if the capsule is on top you have just to extract it from the launch pad in case of need and no extra modules, so less weight...
Am I correct?

Yes... but that happens anyway. There is no need for the service module during an abort, so it is not "taken along for the ride"
And how are you proposing keeping that capsule balanced on its rim with 3g pressing down on it?

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #7 on: 10/18/2009 08:56 PM »
Well, sorry but I think that while writing I made some confusion between service module and orbital module.
Looking here http://www.russianspaceweb.com/soyuz.html
I understand that during a launch abort they pull away the capsule and the orbital module.

If the capsule is on top you can leave on the pad the obital module with the service module.

How to keep the capsule balanced on its rim with the 3g I cannot answer sorry, maybe this can already be a show stopper...

Anyway if making holes is the heatshield is considered safe enough (I did not know the TKS design) we can also go that way.
Question, is if safe enough also in case of velocities of a moon reentry?

Thanks
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 Jorge

  • Senior Member
  • *****
  • Posts: 6180
  • Liked: 32
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #8 on: 10/18/2009 09:02 PM »
Well, sorry but I think that while writing I made some confusion between service module and orbital module.
Looking here http://www.russianspaceweb.com/soyuz.html
I understand that during a launch abort they pull away the capsule and the orbital module.

If the capsule is on top you can leave on the pad the obital module with the service module.

How is that applicable to CEV? It doesn't have an orbital module in the first place.

Quote
How to keep the capsule balanced on its rim with the 3g I cannot answer sorry, maybe this can already be a show stopper...

Yes, it is a show stopper.

Quote
Anyway if making holes is the heatshield is considered safe enough (I did not know the TKS design) we can also go that way.

There is no need for that with CEV; there is nothing in the service module the crew needs to access.

Quote
Question, is if safe enough also in case of velocities of a moon reentry?

Yes.
JRF

Offline Idol Revolver

  • Full Member
  • *
  • Posts: 153
  • Liked: 0
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #9 on: 10/18/2009 09:09 PM »
Quote
Anyway if making holes is the heatshield is considered safe enough (I did not know the TKS design) we can also go that way.
There is no need for that with CEV; there is nothing in the service module the crew needs to access.
No, he is suggesting the service module be expanded into a sort of living area, so the capsule does not have to be as big.  Like Soyuz, except the service module and orbital module would be merged. Not obvious from his post, since the service module in the picture would be far too small. Which leads back to the pad abort comment, i.e. the orbital module does not have to be aborted too, as it is incorporated into the SM, under the re-entry module
« Last Edit: 10/18/2009 09:12 PM by Idol Revolver »

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #10 on: 10/18/2009 09:28 PM »
Yes, Idol Revolver you understood perfectly, sorry I was not so clear in my previous posts..
For instance is an Apollo like capsule big enough for 4-6 people if we move all what is not needed for launch and reentry in a orbital module?
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline alexterrell

  • Full Member
  • ****
  • Posts: 1634
  • Germany
  • Liked: 89
  • Likes Given: 67
Re: Just an idea about alternative CEV
« Reply #11 on: 10/19/2009 08:15 AM »
The issue is that Orion has the "Hab Space" in the capsule, and the service module is just that.

The idea learnt from Sozuz is to minimise the mass of the re-entry module. So how big does it need to be to sit four people for a few hours? Answer: A lot smaller than Orion.

The concept also allows you to vary the size of the hab module and service module. So for ISS transit, the hab module might be a toilet and baggage hold only. For a multi-month trip it might be a Bigelow inflatable.

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #12 on: 10/19/2009 08:28 AM »
Exactly alexterrell, you got my point.
I have updated my sketch to make it more clear. (I hope)
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #13 on: 10/19/2009 10:27 AM »
Hi again,
I found some nice pictures from Jaxa in another thread and with some editing I tried to better explain my idea...

Now, I will need some structural expert to see if could work or not..
If I have time I will try to figure out a possible mass budget
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline medgar

  • Member
  • Posts: 2
  • Liked: 0
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #14 on: 10/19/2009 11:09 AM »
I also like the idea of putting the re-entry capsule ahead of the orbital module (OM) to minimise the mass to abort.

Two additional ideas in this vein are:

#1. Put the OM behind the SM and have the Capsule and SM do an Apollo style dockng with the OM once in orbit (like Apollo did with the Lander).  The problem with this approach with Ares I is that the SM must do a burn to complete the orbital injection.

#2. Have the capsule use a corona style capsule (t/space), with the OM behind followed by the SM. For docking the vehicle could have a docking port on the SM and go in sideways do dock with the ISS. With this approach the capsule could contain its abort engines and fuel like (t/space), with the fuel potentially used for other purposes if an abort is not required.

http://www.astronautix.com/craft/cxv.htm

regards Malcolm

Offline JayP

  • Member
  • Full Member
  • ****
  • Posts: 788
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #15 on: 10/19/2009 11:55 AM »
The designers of the MOL did a big study on alternate ideas for this problem (transposition and docking, inflatable tunnel, EVA, ect.). They picked the tunnel with a hatch in the heatsheild and even did a full scale, un-manned, orbital test which worked fine. Making it work for lunar return velocities is just a matter of design details.

The other thing is that Orion is assent mass limited, not reentry, so this doesn't really help all that much.

It's a good idea though.

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 7140
  • A spaceflight fan
  • London, UK
  • Liked: 662
  • Likes Given: 771
Re: Just an idea about alternative CEV
« Reply #16 on: 10/19/2009 12:08 PM »
Another way to handle this (and to have the capsule mounted TPS-to-OM, which reduced the chance of MMOD damage) is to use an inflatable transfer tunnel connecting the capsule's egress hatch to a hatch on the OM.  This also leaves the nose hatch available for docking with other vehicles.

In space, the tunnel inflates (Bigelow's experience shows that the resulting hull is as stiff as metal).  The crew can thus go from capsule to OM in shirtsleeves.  Before de-orbit, the hatches are sealed and the connecting tunnel jettisoned.  They it is a completely conventional capsule deorbit, re-entry and recovery.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline William Barton

  • Senior Member
  • *****
  • Posts: 3487
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #17 on: 10/19/2009 12:27 PM »
The Soviet VA capsule validated the heatshield hatch concept about as much as it reasonably needs to be (I have no idea how many times it was flown unmanned, but several). I have no idea if Excaliber Almaz' plan to modernize and refly the existing VA capsules is goofy or not, but I understand they bought the old capsules, so maybe someday we'll actually see somebody ride one (not holding my breath, of course). JAXA's current plan is to have their capsule ride atop the modified HTV (OM equivalent), then have the reentry capsule turned on rails, avoiding both heatshield hatch and transposition and docking issues. I'd be happy to go for a ride in a capsule with a heatshield hatch, even if it wasn't a proven concept.

I do think the orbital module CEV was a pretty good idea. The extra risks (for heatshield hatch or transposition and docking) are balanced by the gains. You could, for example, add redundant life support and flight systems (e.g. a backup OMS) to the OM, allowing the CEV to act as its own lifeboat. For two launch LOR architectures (such as proposed for SD-HLV sidemount), where Orion and Altair go to LLO separately, this could be a valuable feature.

Offline IW1DGG

  • Full Member
  • *
  • Posts: 112
  • Liked: 2
  • Likes Given: 0
Re: Just an idea about alternative CEV
« Reply #18 on: 10/19/2009 02:57 PM »
I tried to make a rough mass budget using data found around on the net.
What do you think about, is this reasonable?
Could be of any help for ARES-1?
did you know that MPLMs, Node 2&3, Columbus Structure, ATV pressurised section and Cupola (50 % of the ISS) have been built in Torino?....

Offline alexterrell

  • Full Member
  • ****
  • Posts: 1634
  • Germany
  • Liked: 89
  • Likes Given: 67
Re: Just an idea about alternative CEV
« Reply #19 on: 10/19/2009 08:49 PM »

The other thing is that Orion is assent mass limited, not reentry, so this doesn't really help all that much.

It's a good idea though.
Only if it goes up on a Ares 1 rocket. If Ares 1 goes ahead, then NASA should probably scrap Orion and create a mini Re-entry capsule and a mini Service Module for ISS only.

Note also that a heavier capsule needs a heavier heat shield, so the disposable hab module concept helps with ascent mass as well.

Tags: CEV