Author Topic: Are we asking too much of Orion?  (Read 16246 times)

Offline amaturespacecase

  • Member
  • Posts: 40
  • Orlando, FL
  • Liked: 0
  • Likes Given: 0
Are we asking too much of Orion?
« on: 07/14/2008 04:01 AM »
There have certainly been many valid criticisms of Project Constellation. However, most of it seems directed towards Ares I and V(VI?)... with Orion concerns being linked mostly to Ares shortfalls. We have seen Orion's design change again and again to accommodate Ares I's inadequacies, which I believe speaks to the strength and flexibility of the concept. But are we asking Orion to do too much?

Orion will begin by servicing the ISS with crew rotations and supplies. But with an average of only two flights a year, the American ability to accomplish this task will be severely reduced with the retirement of the shuttle. I realize COTS will help augment this role, but it seems like there will be significant design differences between the ISS Orion and the lunar Orion (including heat shield designs and communications ect...). Designing Orion to service the station seems to only further undercut our moon missions with further delays and design costs. If we REALLY want to have a private space sector, why not go all out with COTS to deal with station and design Orion for what it was meant for?

I have faith that Orion will serve us well if we use it correctly. Am I wrong? Thanks in advance.
« Last Edit: 07/14/2008 04:02 AM by amaturespacecase »
NASA's FY 2009 budget request- Ok bend over!

Offline Analyst

  • Senior Member
  • *****
  • Posts: 3337
  • Liked: 1
  • Likes Given: 7
Re: Are we asking too much of Orion?
« Reply #1 on: 07/14/2008 08:38 AM »
You are wrong.

Private sector won't help unless there is money to be made, but there isn't in human spaceflight. A vehicle capable of going to the moon can reach ISS without problems: ISS is not a distraction.

Anyway: ISS and Orion to LEO will be all what's left when all is said and done.

Analyst

Offline William Barton

  • Senior Member
  • *****
  • Posts: 3487
  • Liked: 2
  • Likes Given: 0
Re: Are we asking too much of Orion?
« Reply #2 on: 07/14/2008 10:44 AM »
People tend to use COTS as shorthand for human (ISS-related) spaceflight external to Project Constellation. In that context, "go all out with COTS" is a suggestion NASA simply pay SpaceX to develop a manned Dragon and Orbital to develop Cygnus, with extra budget money to bring it to fruition as quickly as possible. In other words, pay private enterprise to do the ISS jobs w/o NASA design management. I assume Boeing and LM would find this annoying. And, of course, people who think SpaceX is doomed to failure would find the whole notion risible.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32197
  • Cape Canaveral Spaceport
  • Liked: 10845
  • Likes Given: 321
Re: Are we asking too much of Orion?
« Reply #3 on: 07/14/2008 11:18 AM »

there will be significant design differences between the ISS Orion and the lunar Orion (including heat shield designs and communications ect...). Designing Orion to service the station seems to only further undercut our moon missions with further delays and design costs.

There aren't major design differences.  Orion is designed for the lunar mission and but will be used for ISS.   Just like Apollo was used for Slylab

Offline meiza

  • Expert
  • Senior Member
  • *****
  • Posts: 3068
  • Where Be Dragons
  • Liked: 3
  • Likes Given: 3
Re: Are we asking too much of Orion?
« Reply #4 on: 07/14/2008 01:10 PM »
The way COTS has been done, they've selected high-risk solutions that include new launchers, it doesn't look like a very certain thing.

A basic capsule on an EELV (the OSP) could have been chosen years ago and would now be a only few years from an ISS flight. If it was funded. But lunar work is then again different, bigger and somewhat more complicated. I don't have the experience to quickly judge how much an ISS capsule could have helped in building lunar capability.
Then Griffin came in and demolished all that and NASA started building the future on ever bigger solids.

But if the requirements keep fluctuating and the performance of the launchers is so unknown, that will slow down Orion development...

Offline William Barton

  • Senior Member
  • *****
  • Posts: 3487
  • Liked: 2
  • Likes Given: 0
Re: Are we asking too much of Orion?
« Reply #5 on: 07/14/2008 01:28 PM »
I think of COTS an experiment to see if "new blood" can do it cheaper, with faster and better relegated to a forlorn hope. OSP is just one of many workable ideas dropped. Shuttle-C, NLS, etc., etc....

Offline barb.space

  • Member
  • Posts: 9
  • Liked: 0
  • Likes Given: 0
Re: Are we asking too much of Orion?
« Reply #6 on: 07/31/2008 11:32 AM »
With Ares I IOC slipping to 2015 and beyond and the first lunar mission, currently flying in 2020 likely to slip as well, maybe it is time to rethink the “Block 1” Orion being lunar capable.  If the Orion’s initial mission (for 10+ years) is to LEO and ISS one can reduce Orion’s heavy TEI stage to a simple service module.  If one assumes that Orion will fly on a liquid rocket the escape system also be simplified as you no longer are running away from a lit SRB.  The capsule itself can still be common with a future lunar “Block 2” Orion while reducing the near term lift required substantially.  This simplified Orion could fly on a Delta(5,4) or an Atlas(521).  This system simplification is likely to minimize the “gap”, reduce booster/Orion ISS mission cost by a factor of 2 compared to flying the current Orion on a Delta HLV (and more compared to flying Ares I) as well as save over $10B in future Ares I development costs.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32197
  • Cape Canaveral Spaceport
  • Liked: 10845
  • Likes Given: 321
Re: Are we asking too much of Orion?
« Reply #7 on: 07/31/2008 12:13 PM »
If one assumes that Orion will fly on a liquid rocket the escape system also be simplified as you no longer are running away from a lit SRB.

Bad assumption.  The LAS is sized for an upperstage explosion on the ground

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32197
  • Cape Canaveral Spaceport
  • Liked: 10845
  • Likes Given: 321
Re: Are we asking too much of Orion?
« Reply #8 on: 07/31/2008 12:14 PM »
This simplified Orion could fly on a Delta(5,4) or an Atlas(521). 

strap on SRM's are a no-no for LOC/LOM

Offline Analyst

  • Senior Member
  • *****
  • Posts: 3337
  • Liked: 1
  • Likes Given: 7
Re: Are we asking too much of Orion?
« Reply #9 on: 07/31/2008 12:17 PM »
Why two types of service modules: Load the SM tanks only half for LEO and even Ares I will be able to launch Orion.

Analyst

Offline madscientist197

  • Regular
  • Full Member
  • ****
  • Posts: 1014
  • Liked: 2
  • Likes Given: 0
Re: Are we asking too much of Orion?
« Reply #10 on: 08/01/2008 02:22 AM »
If we are going to actually get to the moon we need less of this block 1/2 stuff - everything needs to be lunar capable from the start.
John

Offline Jorge

  • Senior Member
  • *****
  • Posts: 6180
  • Liked: 32
  • Likes Given: 0
Re: Are we asking too much of Orion?
« Reply #11 on: 08/01/2008 03:28 AM »
If we are going to actually get to the moon we need less of this block 1/2 stuff - everything needs to be lunar capable from the start.

Yes, by gum! Even if the upfront costs of building in lunar capability result in program cancellation! Better dead than LEO, or whatever...
JRF

Offline kraisee

  • Expert
  • Senior Member
  • *****
  • Posts: 10481
  • Liked: 405
  • Likes Given: 19
Re: Are we asking too much of Orion?
« Reply #12 on: 08/01/2008 05:16 AM »
The way I understand it, Orion is being designed right now to be Lunar capable from the start.

But to get it onto Ares-I for ISS missions, they are simply planning to fly only two of the four propellant tanks inside the SM.

It's a quick fix.   Easy to accomplish, and safe.   And it will reduce the mass of Orion by about 3-4mT (to about 18-19mT) which will bring it well inside the Ares-I's performance envelope.

But this is not being widely talked about because the EELV teams would cry a very loud and justified "foul" because the Orion would then also be plenty light enough for either the Delta-IV Heavy or Atlas-V 552 to easily fly too.

Ross.
« Last Edit: 08/01/2008 05:18 AM by kraisee »
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline kevin-rf

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8643
  • Overlooking the path Mary's little Lamb took..
  • Liked: 1112
  • Likes Given: 242
Re: Are we asking too much of Orion?
« Reply #13 on: 08/01/2008 03:52 PM »

But to get it onto Ares-I for ISS missions, they are simply planning to fly only two of the four propellant tanks inside the SM.

It's a quick fix.   Easy to accomplish, and safe. 

So you are loosing the redunancy of backup tanks and capability if one of the tanks springs a leak.

I wonder what all this does to the LOM/LOC numbers...

Safer because there are less tanks?

Less safe because you don't have backup fuel in a seperate system to save the crew?
If you're happy and you know it,
It's your med's!

Offline Svetoslav

  • Veteran
  • Full Member
  • ****
  • Posts: 1148
  • Bulgaria
  • Liked: 461
  • Likes Given: 65
Re: Are we asking too much of Orion?
« Reply #14 on: 08/01/2008 04:07 PM »
I think the big question should be: "Are we expecting too much of Orion?"

While most of us agree that the new system will be more fragile and will lack some of the capabilities of the SS, it will have a design that will allow us to go to the Moon. Ares V may not get enough funding but with the design of Orion we may move forward even without it! What do I mean is that in the era of internationalization new ideas may be born. For example Ariane 5+Earth departure stage + Ares 1 + Orion which would make the manned lunar orbital mission. Or one Ariane launch for the lander, one for the stage plus Ares 1 plus the Orion capsule.

There are a lot of pathways even if Obama puts off the heavy part of the system or Ares 5 don't get enough funding.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32197
  • Cape Canaveral Spaceport
  • Liked: 10845
  • Likes Given: 321
Re: Are we asking too much of Orion?
« Reply #15 on: 08/01/2008 04:21 PM »
I think the big question should be: "Are we expecting too much of Orion?"

While most of us agree that the new system will be more fragile

It will be more robust than the shuttle

Offline Svetoslav

  • Veteran
  • Full Member
  • ****
  • Posts: 1148
  • Bulgaria
  • Liked: 461
  • Likes Given: 65
Re: Are we asking too much of Orion?
« Reply #16 on: 08/01/2008 04:24 PM »
With regards to your opinion I'm worried about the thrust oscillation problem and the SRB design.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32197
  • Cape Canaveral Spaceport
  • Liked: 10845
  • Likes Given: 321
Re: Are we asking too much of Orion?
« Reply #17 on: 08/01/2008 04:37 PM »
With regards to your opinion I'm worried about the thrust oscillation problem and the SRB design.

That is a problem with Ares and not Orion

Offline Norm Hartnett

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 2306
  • Liked: 56
  • Likes Given: 2
Re: Are we asking too much of Orion?
« Reply #18 on: 08/01/2008 05:09 PM »
Something I have not seen mentioned so far is Orion’s on orbit loiter time. This is a new US spacecraft capability isn’t it? So far as I know the US has never had a spacecraft capable of remaining on orbit for six months and returning to Earth.
An ISS capable Orion would not need many of the systems needed for lunar missions, thermal, radiation, and high reentry speed shielding, amongst others. In standby mode at the ISS it could draw power from the station, which would be a system not required for lunar ops. The whole LIDS system is questionable for lunar ops too, isn’t it?

“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline kraisee

  • Expert
  • Senior Member
  • *****
  • Posts: 10481
  • Liked: 405
  • Likes Given: 19
Re: Are we asking too much of Orion?
« Reply #19 on: 08/01/2008 05:15 PM »
So you are loosing the redunancy of backup tanks and capability if one of the tanks springs a leak.

I wonder what all this does to the LOM/LOC numbers...

Safer because there are less tanks?

Less safe because you don't have backup fuel in a seperate system to save the crew?

Purely MHO, but for LEO this isn't such a major issue.   The RCS system will still be capable of performing a de-orbit burn in a worst-case scenario to bring the crew safely home should anything fail to work with the main system.

And the redundancy will be there for the Lunar missions - although Orion doesn't have much in the way of 'spare' fuel.   If any of the four tanks went totally off-line the crew is in deep trouble after they've performed the LOI burn.   If they lose any one of the four tanks at that point I don't believe they would have the ability (dV capability) to return to Earth any more.   If they haven't used the LSAM yet, it could make up most of the difference, but if something happened like one tank leaked in Lunar orbit while the crew is still on the surface, they're boned.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Tags: