Post central for information on CEV IV - Before thread #3 melts down

Ad Astra · 2005-05-03 23:04:39

Let the intellectual 'battle royale' begin!

BWhite · 2005-05-04 08:36:57

Two points:

Does http://exploration.nasa.gov/documents/r … pdf]Boeing favor L1 over LLO? see page 27

Mike Griffin is wary of http://www.spacepolitics.com/archives/0 … commercial fuel providers for the VSE.

Grypd · 2005-05-04 10:29:43

Having studied the popular mechanics "design" and with the likehood that Boeings will be of the more feasible Appollo, Gemini style of capsules I wondered why create such an obvious no goer for people who actually understand what is needed and best for a CEV.

Came to the answer its not people who understand mass and weight limits who will decide. Give you an example. Children have model aeroplanes and of course spaceships but how come they prefer the spaceshuttle to Gemini models. Simple the shuttle looks like what a spacecraft should

GCNRevenger · 2005-05-04 20:19:08

Say, does anybody have any figures for how much delta-V you would need for the TEI and TLI/LOC burn? I would like to calculate if Lockheed's winged CEV fuel tanks are big enough to do what job, to get a better handle on how exactly their contraption is supposed to get there and back.

RobertDyck · 2005-05-05 20:49:45

The "Rocket Monopoly" thread changed to a discussion of CEV, so let's continue here.

The Lockheed Martin design in http://www.popularmechanics.com/science … ml]Popular Mechanics describes the Thermal Protection System (TPS) as SLA-516. I haven't found that but SLA-561 is a silicone based ablative. How do you make a vehicle reusable if the TPS is ablative? If you try to replace the tiles you'll find they melted on. If it isn't reusable, what's the point of a lifting body?

Then there's the Active Thermal Control. That means a coolant that's consumed during heating. Active cooling systems require more mass than ablative systems; they aren't a good idea. Most importantly, why use active cooling at all if the TPS is ablative? Any ablative material will not heat above its melting temperature until it's all gone.

What's the landing system? I don't see any wheels but I do see a couple things labeled Air Bags, and one labeled Float Bags. Are they planning to splash down? That would expose it to salt water, not good for reusablility. Or are they planning a parachute-and-air-bag landing at the salt flats, with float bags for emergency only? Ok, my idea's been stolen already.

Then again, Boeing's web site now shows an image of Shuttle-C with 3 SSME's and 2 OMS pods. Hmmm. Me things they're reading this BLOG.

In case anyone with influence is reading, I feel a winged vehicle shouldn't leave LEO. Keep the lunar vehicle small and light; purpose built for space. Lifting bodies only make sense for reusable vehicles, expendible vehicles should be capsules.

The last point is the inefficient use of volume in Lockheed Martin's vehicle. What's with the aft crew space? Design the lunar module with as much space per astronaut as an Apollo command module, propulsion system aft and mission module fore. Then you don't need a space wasting corridor.

clark · 2005-05-05 20:58:04

http://www.spaceref.com/news/viewsr.htm … ?pid=16509

NASA has initiated the Exploration Systems Architecture Study (ESAS) in an effort to minimize the gap between the final Space Shuttle mission and the maiden flight of an operational Crew Exploration Vehicle (CEV). Attached is the NASA Memorandum signed on April 29, 2005 by Administrator Griffin which initiated the ESAS.
"The National Aeronautics and Space Administration (NASA) has embarked upon a rigorous review of the Crew Exploration Vehicle (CEV) architecture to determine opportunities to minimize the gap between an operational CEV and retirement of the Shuttle in 2010. This assessment is a part of the "Exploration Systems Architecture Study", which was chartered by the NASA Administrator on April 29, 2005. The product of this analysis is anticipated by mid-July 2005.
The Exploration Systems Architecture Study will take place concurrent with the evaluation of offeror proposals received May 2, 2005 in response to NASA CEV Request for Proposal (RFP) issued March 1, 2005 by the Exploration Systems Mission Directorate (ESMD). The RFP contemplated award of up to two competitive contracts with down-select to a single contractor in 2008, based on offerors' responses to a planned letter request for Phase 2 proposals to be issued by the ESMD CEV contracting officer.
To facilitate minimizing the gap, up to two contracts are expected to be awarded prior to completion of the Exploration Systems Architecture Study. Following these awards a "Call for Improvements" (CFI) based on the results of the Exploration Systems Architecture Study will be issued to the selected contractor(s). CFI proposals will be evaluated for a final down-select decision to a single contractor expected in early 2006.
The CEV competitive source selection for offeror proposals received May 2, 2005 is progressing in accordance with the terms of the RFP. The NASA source evaluation board (SEB) is sequestered at the designated secure facility, and is not involved in the Exploration Systems Architecture Study deliberations. Segregation of these activities ensures fair and objective assessments of (1) SEB evaluation of CEV offeror proposals in response to RFP criteria and (2) Exploration Systems Architecture Study gap minimization analyses which may result in a revised CEV architecture."

So NASA reviews the designs, tells the contractors what improvements will be needed to deal with the gap between 2010 and 2014, and based on the better deal, chooses the contractor.

So gentlemen and ladies, which design is better suited to adjust to the gap of CEV and the Shuttle?

Think capabilities!

Looks like the contractors just got their first test as "flexibility" in spiral development! :laugh:

GCNRevenger · 2005-05-05 21:16:20

Say, does everybody see all that stuff behind Lockheed's winged section of the CEV?

Guess which part you won't need for an ISS ferry

Thats probobly the big reason for Lockheed's crazy design... it really IS the OSP jerry-rigged to be a Lunar ferry.

Apparently, the Lockheed people are so parinoid of Columbia-ing, that they have included -two- TPS systems, at least able to reinforce the primary if its damaged, or perhaps even handle reentry seperatly (at least to make it surviveable). The outter ablative shield won't be reuseable, which you are correct isn't a good for reuseability, but neither is the big circular one for a capsule.

What really frightens me is the idea that Lockheed intends to use an active cooling system, which they will probobly have to given the heating in the nose from Translunar velocity... um, to be quite frank, what if the pump mechanism fails? Or the pipes clog? Hello, Lockheed? Are you really just trying to sell OSP and betting that VSE will be canceld come 2008?

Give the crew a little more space then Apollo, especially if you are going to be putting six (even eight) to a flight, but this is silly... the only explanation I have is, Lockheed is betting on some of the crew STAYING in the CEV during the two-week Lunar missions.

SpaceNut · 2005-05-06 10:17:13

Well the CEV is getting a review process to make sure that the least amount of time with no manned space flight capability happens and that what was will be less than the original plan.

NASA Legislative Affairs Memo Regarding the Exploration Systems Architecture Study (ESAS)

The National Aeronautics and Space Administration (NASA) has embarked upon a rigorous review of the Crew Exploration Vehicle (CEV) architecture to determine opportunities to minimize the gap between an operational CEV and retirement of the Shuttle in 2010. This assessment is a part of the "Exploration Systems Architecture Study", which was chartered by the NASA Administrator on April 29, 2005. The product of this analysis is anticipated by mid-July 2005.

Good step to get us to stay in space with manned flights not relying on the soyuz.

The Exploration Systems Architecture Study will take place concurrent with the evaluation of offeror proposals received May 2, 2005 in response to NASA CEV Request for Proposal (RFP) issued March 1, 2005 by the Exploration Systems Mission Directorate (ESMD).

Then all we have is the lockheed propasal?

The RFP contemplated award of up to two competitive contracts with down-select to a single contractor in 2008, based on offerors' responses to a planned letter request for Phase 2 proposals to be issued by the ESMD CEV contracting officer.

Sort of hard to award 2 contracts if only one proposal is recieved?

GCNRevenger · 2005-05-06 10:40:49

No, surely Boeing/et al. have already submitted it... please tell me that Lockheeds' crazy ship isn't the winner by default.

ftlwright · 2005-05-06 11:55:39

No, surely Boeing/et al. have already submitted it... please tell me that Lockheeds' crazy ship isn't the winner by default.

What about the awesomeness of Alt|Space, its like Starfleet!

With everything that's happened in the past few days, Griffin's remarks make a little more sense. Lockheed's option is an over engineered 'shuttle mini'; trying to be all things to all people. I'm guessing Griffin would rather go with the devil he knows *shrug*. I would really like to take a look at LM RFP, is it available?

Things to consider:
1) With the completion of CEV and lunar exploration fully underway, who is most likely to receive the contract for developing a launch vehicle for Mars?
2) There is now only one company manufacturing engines for large payload delivery.
3) For all the whooping and wailing over the CEV program, there is still little evidence that going to the moon is useful.

edit: doggone english language...

RobS · 2005-05-06 14:47:32

GCN asked for delta-vs. Here are some from a defunct Caltech web page:

Earth's surface to low earth orbit: 9.7 km/sec
LEO to escape: 3.2 km/sec (Hohmann to Mars from LEO, 3.8)
Lunar surface to low lunar orbit: 1.6 km/sec
Low lunar orbit to escape: 0.7 km/sec

If you want to stop at L1 on your way to the moon or go to the moon or Earth from L1, the delta-v is something like 0.3 km/sec. I think there are ways to make this even less (lunar gravity assist, for example).

-- RobS

Vir Stellae · 2005-05-06 15:10:21

Oh god that Lockheed design makes me want to barf... :down:

BWhite · 2005-05-06 15:16:40

GCN asked for delta-vs. Here are some from a defunct Caltech web page:
Earth's surface to low earth orbit: 9.7 km/sec
LEO to escape: 3.2 km/sec (Hohmann to Mars from LEO, 3.8)
Lunar surface to low lunar orbit: 1.6 km/sec
Low lunar orbit to escape: 0.7 km/sec
If you want to stop at L1 on your way to the moon or go to the moon or Earth from L1, the delta-v is something like 0.3 km/sec. I think there are ways to make this even less (lunar gravity assist, for example).
-- RobS

Any clue as to the travel time from L1 to Luna or vice versa?

Also, L1 allows access to all of the Moon.

As I recall, all Earth launch inclinations are essentially equal for travel to L1, just as L1 can provide access to any point on the Moon.

GCNRevenger · 2005-05-06 17:55:46

By my calculations, the wing tanks on the Lockheed contraption have about ~700kg of useable propellant for the main LOX/Ethanol engines. Assuming these engiens have about a 260sec Isp, that would come out to a maximum delta-V of:

-Assuming 10MT wet: 185m/s
-Assuming 15MT wet: 121m/s
-Assuming 20MT wet: 90.8m/s

Thats enough for deorbit, but not enough for TEI. Therefore, Lockheed must be intending the propulsion stage to perform the TLI/LOC and TEI burns.

Edit: I think I may have added a zero someplace... those numbers are possibly off. Checking my math.

Update: Oops, there are 1000L per m^3, not 100. That places the LOX/EtOH propellant at just right, all okay. The Propulsion Module looks to hold about 20-24MT of LOX/LH2.

Update: With 24MT of LOX/LH2 @ 451sec, that gives you about 4.0km/sec worth of propellant... Enough for TLI and TEI.

Update: The propulsion stage would weigh too much if it were carrying Methane. That rules out Lockheed's design for long-term Lunar orbit storage.

oberth · 2005-05-06 19:09:18

No, surely Boeing/et al. have already submitted it... please tell me that Lockheeds' crazy ship isn't the winner by default.

Don't worry. Northrop Grumman/Boeing submitted a proposal as well and it looks a lot better (it's a capsule). Lockheed's crazy design won't be selected anyway. Griffin will never allow that.

Commodore · 2005-05-06 19:19:49

No, surely Boeing/et al. have already submitted it... please tell me that Lockheeds' crazy ship isn't the winner by default.
Don't worry. Northrop Grumman/Boeing submitted a proposal as well and it looks a lot better (it's a capsule). Lockheed's crazy design won't be selected anyway. Griffin will never allow that.

....Well?

*Waits for pics*

:;):

oberth · 2005-05-06 19:45:39

Sorry, they didn't release any pics but I read they submitted a proposal (and why should they drop out?).

What I would really like to know is if t/space made a bid...

SpaceNut · 2005-05-06 19:54:57

Ah where was that link again or is it there propaganda pages on there server.
In either case pictures and spec's are only part of what is needed. In the long run who can provide the hardware on time an below cost would be the better place to start. So skip past demonstrator flyoff to the real deal capable of getting us back to orbit in less time.

SpaceNut · 2005-05-06 20:20:07

While the teams of Boeing and of Lockheed are no shuttle size army they do get the job done.
[url=http://www.al.com/business/huntsvilletimes/index.ssf?/base/business/1115371155134860.xml] Boeing, Lockheed hoping review done by year's end
Space critic questions if joint rocket deal actually cuts costs [/url]

Boeing has between 2,300 and 3,000 employees working on its rocket and launch activities, a company spokesman said, while Lockheed Martin reported its launch team includes about 1,300 employees.

Of course the article does also mention the monopoly and its approval process.

clark · 2005-05-06 22:04:51

So this cynic started talking to me...

"Boeing and Lockheed figured it out- they figured that by merging this business, which serves only one customer, and they then could each cut costs in the maintenance of their respective fleets.

Boeing is keeping its more profitable launch systems out of the deal.

This also saves the military, and each company, from having to deal with the threat of an actual down-select (going from two EELV choices, to just one) by Congress. With only one "company" in charge of America's only proven rocket fleet, they both stay alive, and can exert greater pressure when dealing with the government. Afterall, the EELV are a fundamental national security need, at least from the perspective of national leaders.

Oh yeah, the CEV contract is cost-plus."

PurduesUSAFguy · 2005-05-06 22:08:31

I don't understand the logic of making the CEV reusable. Pressure vessel + avionics + heatsheild = CEV. None of these things should be very expensive, making a system robust enough to be reusable to any significant extent will add more cost and complexity to the system then it is worth. It will be the shuttle all over again.

I think the key to making the CEV work as a system is to make the most capable, cheapest generic earth rentry vehicle as possible for rentry after lunar or martian mission as well as some sort of common landing bus for the moon and Mars. With those two things as building blocks throw in a 150 tonne to LEO class heavy lifter and inflatibles for both inspace and surface use.

I have hope that with the growing threat from China and the fledgling alt space start ups we might actually end up with a usefull system. We just really need to bail on the ISS.

GCNRevenger · 2005-05-06 22:37:11

Lockheed and Boeing really wern't in competition for USAF contracts so much... Boeing's Delta-IV Medium is inferior to Atlas-V for small/medium stuff, but the Delta-IV HLV is the only game in town for heavy items.

CEV being cost-plus is a concern though... if it turns into another "$18Bn OSP" then Griffin ought to fire um' both and have only in-house engineers design the thing.

Lockheed's CEV is way, way overcomplicated... two kinds of heat shield systems, escape pod functionality, active cooling, secondary docking/mission module, heavy-duty fuel cell AND solar power, among other things.

It only really makes sense if two things happen:
1: VSE is killed in 2008 and we go back to ISS-status-quo, so Lockheed will have their OSP closer at hand then Boeing/et al.
2: If VSE crews will be spending extended (>week) times in the vehicle, where you'd need extra space and consumeables storage.

RobertDyck · 2005-05-06 22:40:44

Boeing did have a web site with pictures just a couple days ago. They've taken it down. It was http://www.boeing.com/defense-space/spa … .html]here. Now I can only link this picture

And right after I posted that they're reading this message board. I think this is further confirmation that Boeing reads this.
However a separate web site (not Boeing) has a copy of Boeing's images http://www.projectconstellation.us/arti … =NA==]here.

::Edit:: Notice neither the Boeing nor Lockheed Martin bids have a lunar lander. The NASA spec said they had to be able to enter lunar orbit by a certain date, so that's all they provide.

clark · 2005-05-07 09:56:53

One-eyed man tells me Lockheed is in a better position with CEV design.

But do any of you know why?

RobertDyck · 2005-05-07 10:30:01

I found a Northrop Grumman web page about CEV http://www.capitolsource.northropgrumma … .html]here. Does this look like Soyuz or what? Service module, Crew module, and between is something not labeled but looks like a Descent capsule. Thruster quads appear to be an Apollo service module pattern rather than Soyuz pattern. It doesn't have solar arrays, but it's shown encapsulated in a fairing with Launch escape tower; solar panels might be enclosed somewhere not shown. This is the only design so far without solar arrays.

New Mars Forums

Announcement

#1 2005-05-03 23:04:39

Re: Post central for information on CEV IV - Before thread #3 melts down

#2 2005-05-04 08:36:57

Re: Post central for information on CEV IV - Before thread #3 melts down

#3 2005-05-04 10:29:43

Re: Post central for information on CEV IV - Before thread #3 melts down

#4 2005-05-04 20:19:08

Re: Post central for information on CEV IV - Before thread #3 melts down

#5 2005-05-05 20:49:45

Re: Post central for information on CEV IV - Before thread #3 melts down

#6 2005-05-05 20:58:04

Re: Post central for information on CEV IV - Before thread #3 melts down

#7 2005-05-05 21:16:20

Re: Post central for information on CEV IV - Before thread #3 melts down

#8 2005-05-06 10:17:13

Re: Post central for information on CEV IV - Before thread #3 melts down

#9 2005-05-06 10:40:49

Re: Post central for information on CEV IV - Before thread #3 melts down

#10 2005-05-06 11:55:39

Re: Post central for information on CEV IV - Before thread #3 melts down

#11 2005-05-06 14:47:32

Re: Post central for information on CEV IV - Before thread #3 melts down

#12 2005-05-06 15:10:21

Re: Post central for information on CEV IV - Before thread #3 melts down

#13 2005-05-06 15:16:40

Re: Post central for information on CEV IV - Before thread #3 melts down

#14 2005-05-06 17:55:46

Re: Post central for information on CEV IV - Before thread #3 melts down

#15 2005-05-06 19:09:18

Re: Post central for information on CEV IV - Before thread #3 melts down

#16 2005-05-06 19:19:49

Re: Post central for information on CEV IV - Before thread #3 melts down

#17 2005-05-06 19:45:39

Re: Post central for information on CEV IV - Before thread #3 melts down

#18 2005-05-06 19:54:57

Re: Post central for information on CEV IV - Before thread #3 melts down

#19 2005-05-06 20:20:07

Re: Post central for information on CEV IV - Before thread #3 melts down

#20 2005-05-06 22:04:51

Re: Post central for information on CEV IV - Before thread #3 melts down

#21 2005-05-06 22:08:31

Re: Post central for information on CEV IV - Before thread #3 melts down

#22 2005-05-06 22:37:11

Re: Post central for information on CEV IV - Before thread #3 melts down

#23 2005-05-06 22:40:44

Re: Post central for information on CEV IV - Before thread #3 melts down

#24 2005-05-07 09:56:53

Re: Post central for information on CEV IV - Before thread #3 melts down

#25 2005-05-07 10:30:01

Re: Post central for information on CEV IV - Before thread #3 melts down

Board footer