Newbie, with opinions on CEV!

[darkenfast]

Good evening! I have just joined and wanted to toss out my thoughts regarding the CEV and possible launcher. Although I am not an engineer (retired U.S. Navy turned playwright), I have been following both the U.S. and Soviet/Russian space programs since the 60's. While I would love to see things like SSTO's, and other exotica, I have come to the conclusion that the approach represented by the ATK shuttle-derived SRB/J-2S and the Apollo-shaped capsule represent the best way forward for the next couple of decades. <br />Some of my reasons:<br />1. Safety. The combination of SRB (1 motor) and J-2 (1 engine) is proven. Add in the escape tower (they DO work, just ask the Russians), and you have as safe a rocket as you will ever see. The "capsule with a heat shield" is also safer. The Russians had casualties early on, mostly from rushed work, but they have also survived some truly hairly situations. I found a report done for ATK on the safety of the proposal and it was impressive (of course, it was biased for them, but still...)<br />2. Suitability for deep-space. Apollo was the only manned spacecraft to ever venture beyond LEO. I believe the CEV can fufill that role well (a common hull in LEO and deep space versions, I presume). The drawing I have of the ATK proposed launcher shows a capsule with a base diameter of 201 inches, which is a considerable increase over the Apollo CM. That drawing may be purely conjectural as regards the CEV, but it seems like a versatile size for a variety of missions. <br />3. Cost. There is no way around the fact that our culture is simply not willing to spend as much as we here would like on something as "frivolous" and "wasteful" as space travel. We (the U.S.) are not the same country as we were in the early 60's. This launcher/CEV approach has got to be the cheapest by far to develop and fly repeatedly. <br />The work and sacrifices that have gone into the Shuttle have not been in vain. We have acquired so much exp

 

[mattblack]

An Apollo shaped CEV, (as long as it holds 6 people) would be an excellent spacecraft. I would suggest that it used 2 or maybe even 4 Gallium-Arsenide high efficiency solar arrays instead of fuel cells and for main propulsion, use LOX/Methane fuelled engines like the RL-10; which is restartable and well-understood. Not to mention that Liquid Methane doesn't boil-off anywhere near as bad as LH2, and takes up far less room. Also, LOX/Methane is about 30% percent more efficient than hypergolics. <br /><br />The Apollo-type re-entry capsule could use a Soyuz-derived docking mechanism for maximum compatibility with ISS and perhaps any future vehicles. For the Service Module, I'd suggest a Block 1 or "short" module with basic RCS, batteries and life support for ISS missions and no big RL-10s for propulsion. The required Delta-Vee could come from the RCS system (6x clusters for ISS flights, 4x clusters for Block 2 "Long Module" on lunar and Mars missions).<br /><br />The Block 2 "long module" with 2x RL-10s could be sized with appropriate total mass to fit within the proposed maximum sized 26 ton capacity of the 5-segment "Single Stick" SRB launcher. <br /><br />NOTE: I propose naming the big-stick launcher "CAESAR". (After all" It would a big "Roman Candle"!!) <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[darkenfast]

Thanks for the replies so far.<br />For Mattblack: I believe there's a proposal for using methane on a four-man lunar lander later on. Would the engines have to be pump-driven (like the RL-10), or could they be pressure fed (like the Apollo, LM, Shuttle OMS)? I'm thinking of reliability. Is that your drawing, and is the MM a "Mission Module" ala the Soyuz Orbital Compartment?<br />For Shuttle Guy: That's exactly the kind of info I was looking for. I already had some fun drawing possible layouts for the interior of a 201" diameter CEV, and hopefully we'll see something soon.<br />Gentlemen, this is exactly what I needed. All the people I hang around with are theater types, and when I try to talk about this, their eyes sort of glaze over. Thanks!

 

[shoogerbrugge]

welcome<br /><br />Although I am a big fan of the capsule based proposal I would caution a little bit of making drawings and specific criteria for the the complete vehicle. A different mission might will require a different vehicle. And its the advantage of a capsule, because they are easy adaptable (as shown by Soyuz)<br /><br />For example, for a CEV to visit the ISS it would need a much different propulsion module then for beyond LEO missions. <br /><br />It might be intresting to look at the 3 compartments seperatly, and also design them seperatly, and assemble them for specific missions to your needs. A bit like LEGO blocks, you have 7 different options and assemble then to make a vehicle mission specific, without loosing the commonality and its advantages.<br /><br />Whatever you mission might be, a capsule based design will have 3 parts, the orbital module, decent module and the propulsion module. A fourth module can always be added, but will involve some more adjustments<br />The decent module can be the same for every mission, because it only needs to be safe harbour during launch and landing. So no difficulty there, one option, 6 man, hull expendable, but much of the electronics should be re-used.<br /><br />The orbital module you might want to design 2 or 3 different versions for that one, because it depends on how long the 6 man crew is supposed to be in orbit, for example if you fly to the ISS, you might want to consider to have less living space and more cargo capacity. But on the otherhand, flying towards the moon, you don't want your crew to cramped. The trick is to design 2 or 3 different orbital modules with the biggest commonality possible, same size, same software, just different lay-out.<br /><br />The propulsion module, now this is tricky, getting the CEV to 400km orbit on the ISS inclination doens't need that much power, compared to reaching escape velocity. So getting commonality on the propulsion module might be difficult, but should at least be the goa

 

[mrmorris]

<font color="yellow">"Whatever you mission might be, a capsule based design <b>will have 3 parts</b>, the orbital module, decent module and the propulsion module. "</font><br /><br />No -- that is incorrect. The Apollo missions to service Skylab had only two modules, as did Mercury. Gemini had three modules, but only two fell into the classes you describe. The only module you absolutely *must* have is a crew module that can act as a re-entry vehicle. It is <b>very unlikely</b> that a capsule-based re-entry vehicle will contain sufficient propulsion for orbital maneuvering and a de-orbit burn, so a propulsion module is essentially a given. However, an orbital module is not a requirement by any means for LEO missions.

 

[spayss]

Welcome aboard.<br /><br /> "The fact that the possible CEV looks externally like an Apollo is very misleading"<br /><br /> True. Let's just hope that it's not 'more complicated' than Apollo. My first car was a WW2 Jeep Willy and it rode like magic carpet. At 16 my brother and I could take it into the barn, strip it apart and have it back on the road the next day. These days I had to check a manual the first time I changed the oil filter on our new truck.

 

[darkenfast]

I believe the requirements are indeed for: three people and cargo for the ISS, four people for a lunar expidition, and six to transfer to a Mars-bound spacecraft. The Service Module seems to have less propulsive capability at the moment than Apollo; however, in the lunar scenario, the new equivalent of the old S-IVB will also slow the vehicle into lunar orbit.

 

[vt_hokie]

There's already a model of Lockheed Martin's proposed "CEV"!<br /><br />http://www.fantastic-plastic.com/Lockheed-MartinCEVPage.htm<br /><br />It's really a lot like the wingless version of Russia's "Kliper". That's the design I'm hoping to see chosen.

 

[shuttle_rtf]

>That's the design I'm hoping to see chosen.<<br /><br />Me too. If that model comes out in a wood design, I'll be after one!

 

[soccerguy789]

I like both of the major CEV proposals, but I personally would like to see leckhhed take the contract. Everyone will probably be on my case right now because it is "suposedly" more complex than the capsule, so, I will make my reasoning very clear. and.....<br /><br />It has nothing to do with the reentry vehicle!<br /><br />While I do love lifting bodies, and Lockheeds design, my main reason is for thier architecture. if you read the two architecture studies back to back, you'll get what I'm talking about. Beoing plans to put WAY more into orbit to do the same job. I don't know if there is good reason for this, but I would assume some people who are smarter than I am have run the numbers. Beoing's reference moon mission launches 200 tons to orbit. lockheed is 120-140, or a heavy lifter and single stick SRB. Also, one thing tacking tons of weight onto beoing's plan is a single stage reusable lunar lander. sounds like a great idea, until you see that they don't intend to reuse it. ever. Lockheed on the other hand, saves tons of weight by making a disposable two stage lander, that can be made reusable and single stage once an ISRU plant coms online. I have to go with lockheed.

 

[darkenfast]

This is my third attempt at replying (cable company strikes again!), so I'm going to keep this short! In the event of a hairy re-entry, such as the Soviet/Russian program has experienced (ballistic re-entry, second stage failure, Propulsion Module not separating(!)), I would prefer to be in the capsule. In the event of an exploding vehicle while still under aerodynamic loads (like Challenger), I would rather be in a capsule than a lifting body. I simply think that the cone-shaped capsule is stronger and safer under a variety of conditions, that it can be flying sooner, and represents a better value for money. I'm not up to speed on the lunar proposals of Boeing and Lockheed, but the difference in mass for the two is interesting. <br />Thanks for the replies!

 

[mattblack]

**NOTE: Payload tonnage ratings at this point are estimates.<br /><br />Boeing proposes using a CEV as a Command Module and a seperate Lunar Surface Access Module (LSAM) to take a crew of 4 to the lunar surface. The maximum independant stay for the LSAM would be 14 days, but the first mission would likely be 4-to-7 days for initial expeditionary missions. <br /><br />The inline cargo launcher would launch first with an 110-ton payload, consisting of a 35-ton LSAM and 75-ton Earth Departure Stage (equivalent to the Saturn V SIVB) and the Single-Stick "CAESAR" crew launcher would send up the 25 ton CEV to rendezvous and dock with the LSAM and EDS. The EDS sends them on TLI and then is jettisoned. the coast to the Moon occurs and then hours before arrival, the crew of 4 transfers to the LSAM then makes a direct landing on the Moon. The unmanned CEV burns into lunar orbit and awaits the crew like a space station, able to operate quite well by itself. <br /><br />After a stay of 4-to-14 days, the LSAM returns the crew to the waiting CEV. And like Apollo, the LSAM is jettisoned and the CEV returns to Earth. If it landed on desert or a freshwater lake, the CEV could probably be refurbished. <br /><br />In future, for longer duration lunar missions, a second cargo LSAM with dedicated Habitation Module could be pre-deployed. Without the need to ascend, the cargo LSAM would take to the lunar surface equpment and supplies, instead of ascent fuel. This would allow a crew to stay for more than 6 months. This is clearly far superior to Apollo and all parties want the LSAM to use LOX/Methane propellants. Why? Relatively high efficiency compared to hypergolics (like Apollo) and low long-term "boiloff" compared to LH2 meaning you could land larger payloads and this configuration would lend itself well to future ISRU for Mars missions. <br /><br />For instance, an LSAM could become a Mars MSAM by adding an aeroshell. The bonus of aerobraking would mean an MSAM would need less fuel than for a l <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[mattblack]

Another view of the Boeing LSAM & CEV stack. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[mattblack]

Mars mission version. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[darkenfast]

Thanks, Mattblack! The images haven't been approved yet, and I'm getting cross-eyed, so I'll look at this tomorrow. Sounds very interesting!

 

[mattblack]

You're right, shuttle_guy. But the suspense is killing some of us and we're merely working on what we can go with for now. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[soccerguy789]

I still think you should look at the architecture. I like capsules because, they can be integrated into new vehicles, like that Mars Accent vehicle you posted the picture of,(although I also like lifting bodies) Lockheed's architecture, regardless of thier CEV, is way more efficient.

 

[darkenfast]

Soccerguy, is there a good place to get an overview of the Lockheed proposal?<br />Thanks in advance.

 

[kane007]

May I be of assistance?<br /><br />Try Locheed Martin<br /><br /><i><font color="yellow">"keep it simple, stupid!"</font></i>/safety_wrapper>

 

[john_316]

Information on the Boeing and Lockmart designs I have found over the net using various search engines such as Yahoo and Google.<br /><br />I preferr the Capsule for beyond LEO operations but preferr the Lifting body over the capsule for LEO and ISS operations as we have 3 pallets that will become obsolete when the shuttle retires as they will never fly again or be permanately docked to the ISS..<br /><br />So in honestly go for the gold... An X-38 type vehicle could accomidate 201 inches or what have you but for a 15 meter fairing I believe the improved capsule will win out.<br /><br />Now as for service modules I do support some ideas as in different block configurations. 1 for LEO and ISS, 1 for Moon and 1 for Mars. But I honestly think the Mars CM and SM should be an entirely different vehicle all together..<br /><br />Ok there you got my 2 cents worth..<br />

 

[darkenfast]

What about using the CEV launcher to lift logistics and pieces to the ISS, ala Progress? A cargo container on the front (with docking mechanism), and a service module back end. I'll bet it would come cheaper than a Shuttle flight (and I think we must be prepared for the Shuttle not lasting till it's projected retirement date).<br />Actually, I just remembered, isn't a cargo version in the proposed CEV launcher proposal? I believe it has a better lift capability than the shuttle. <br />I think I might agree with you, that if flights to the ISS were the only mission, a lifting/winged body might be better. Please, see my post on the "resuable capsule" thread for some of my meandering thoughts on capsules. <br />G'night!

 

[barrykirk]

I saw the announcements or at least some preliminary stuff this morning about 2018 to the moon.<br /><br />But it seemed to be saying that the crew would launch from a standard rocket from KSC.<br /><br />What happened to...<br /><br />http://www.transformspace.com/index.cfm?fuseaction=projects.view&workid=CCD3097A-96B6-175C-97F15F270F2B83AA<br /><br />The CXV.....<br /><br />If there is one new technology they really need to introduce it's the one of air dropping the orbital launch vehicle. <br /><br />Once that is done, that techology can be gradually improved.<br /><br />Remember that it is difficult to get a Vertical Launch Rocket of any configuration to have even a 5% payload mass fraction.<br /><br />That's cause rockets have a very poor ISP... Even the SSME is only 455 seconds in vacuum.<br /><br />Jet engines do so much better. It just makes so much sense to use them for the first part of the trip where they can be used.

 

[nacnud]

True, the CXV is going to be for space station (ISS and/or other) and tourist flights. Its benifit to NASA would be to enable NASA to concentrate on VSE rather than ISS operations, but only if it can prove itself on its own merrits. I don't know if NASA is going to be able to fund it fully even if NASA might one day be a customer.

 

[darkenfast]

Regarding the weight deliverable to the ISS by a cargo version of the CEV, doesn't the deletion of the Launch Escape System (about 10,000lbs), help some? I believe it's carried until shortly after second stage ignition.

 

[barrykirk]

The reason that it's unproven technology is that nobody has done it yet. It's a chicken and egg problem. In fact airdrops have been done.<br /><br />X1, X-15, Spaceship 1 come to mind. Nobody has airdropped with the rotation and parachute method before.<br /><br />Once it's in use and working, the sizes can be scaled up.<br /><br />IMHO