proposal for a partly reusable ,SD CEV+payload delivery

[spacefire]

First of all, let me say that I don't agree with the decision to make the CEV a capsule, nor to use shuttle components for the 'next generation' launchers. But, as this is what the powers appear to have decided, based on the document kindly provided to us by Shuttle_RTF, I'd like to propose a delivery method for the CEV or payloads which, while using components of the STS, would at least be reusable to a greater extent. Please note that the drawing illustates the concept and the configuration, and its not meant to have any technical merits. I am awaiting your comments and certaily your criticsm. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[najab]

I don't get what's happening at the tail end of the booster vehicle? Is it really going to be that narrow? Where do the SSME's go?

 

[spacefire]

The tail-end is an SRB stick. The SSMEs will be somewhere on the wing, you can see the black nozzles.<br />The take-off will be vertical, shuttle like, with the SRB and the SSMEs operating together. Landing of the first stage will be horizontal. <br />Note that the SRB stick is fairly short, as its purpose is to aid during liftoff and initial ascent and acceleration, while the wings will aid later on, as the trajectory starts to flatten. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[najab]

So does the ET wrap around the SRB, like a hotdog and bun? (and yes, certain ruder analogies spring to mind >evil emoticon<)

 

[spacefire]

hehe, hotdog and bun...as I said in the previous post the SRB will be fairly short, this vehicle is smaller than the shuttle and the SRB is there just for the initial boost. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[najab]

You do realise that the thrust of a SRB is directly proportional to it's length. A short (single segment?) SRB would have <b>much</b> less thrust than a 'normal' one.

 

[spacefire]

it's OK, it wouldn't need that much. The entire second stage+payload+engines on the first stage+extra structure wouldn't weigh nearly as much as the Orbiter! the idea is to scale down components in size and weight to make reusability possible. <br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[lunatio_gordin]

why not switch your SSMEs and SRB locations?

 

[spacefire]

didn't feel too comfortable with the SRBs on the wings.<br />you want the engine with the most thrust aligned with the axis of the vehicle. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

yes but if there were two SRBs and one misfired...<br />also I don't see the need for two SRBs, just about one half should do.<br />Even the ET could keep its structure, including the crappy foam, if it were held inside an external frame to which the wings attached. <br />The first stage would not get up to orbital velocities. During reentry-correct me if i'm wrong-the G-forces and heating on the now largely empty structure would not be as great due to the large volume and small weight.<br /><br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[propforce]

Interesting. So is your first stage capable of flying back to the launch site? <br /><br />I assume so because you put wings on your first stage. But then you'll need to add landing gears and turbofan engines. <div class="Discussion_UserSignature"> </div>

 

[lunatio_gordin]

that's what "LDG gear" stands for <img src="/images/icons/tongue.gif" />

 

[spacefire]

no turbofans needed. I envision a gliding RTLS. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>that's what "LDG gear" stands for <p><hr /></p></p></blockquote><br /><br />My apology. I am used to working on vehicle without "legs" <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[spacefire]

S_G, a version with 2 SRBs and the SSMEs clustered udner the ET would indeed be much more powerful, but also heavier-which might preclude a RTLS option with a horizontal landing. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>no turbofans needed. I envision a gliding RTLS. <p><hr /></p></p></blockquote><br /><br />Do you have enough propellant to go once around the earth? <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>that's what "LDG gear" stands for <p><hr /></p></p></blockquote><br /><br />What size & brand of tires do you have in mind ? <div class="Discussion_UserSignature"> </div>

 

[spacefire]

I don't know how far downrange the first stage will get. As I said when I first posted, this is just an idea for an alternative to the boring proposals from NASA,using some systems from the STS, but in a scaled down, and reusable(at least the first stage), version. If I had some time, I'd like to compute the delta V for each stage and then see if the configuration as presented is feasible. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

<font color="yellow">What size & brand of tires do you have in mind ?</font><br /><br />50 inch Michelyear.<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

how come? have you studied the problem? I doubt it, so I don't think you are able to prove that my design can't work,since what I outlined is barely a concept sketch. This is the problem with engineers today- they say NO WAY from the outset instead of saying WE'll MAKE IT.<br />Maybe the problem with this country's space program is the lack of German scientists in need of absolvance for their prior inventions.<br />But, Shuttle_guy,<br />I bow to your superior experience and I'd love to hear why you believe this is such a bad idea. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[najab]

><i>I doubt it, so I don't think you are able to prove that my design can't work,since what I outlined is barely a concept sketch.</i><p>I think the fact that shuttle_guy has taken the time to comment on your design in three prior posts before pronouncing it unworkable indicates that he <b>has</b> given it some though.<p>><i>his is the problem with engineers today- they say NO WAY from the outset instead of saying WE'll MAKE IT. </i><p>And the problem with the public today is that they think they are better engineers than the engineers. I have no formal engineering training and can see that your idea is unworkable as presented - never mind shuttle_guy who has been working in this field for his entire career.<p>><i>Maybe the problem with this country's space program is...</i><p>No, the real problem is that the space program has to try to meet the expectations of a bunch of ignoramuses who think they know how to "do" space better than the people who really know how to get it done.</p></p></p></p></p>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>how come? have you studied the problem? I doubt it, so I don't think you are able to prove that my design can't work,since what I outlined is barely a concept sketch. This is the problem with engineers today- they say NO WAY from the outset instead of saying WE'll MAKE IT. <br />Maybe the problem with this country's space program is the lack of German scientists in need of absolvance for their prior inventions. <br /><p><hr /></p></p></blockquote><br /><img src="/images/icons/laugh.gif" /> Oh ... out of mouth of young calf...<img src="/images/icons/laugh.gif" /><br /><br />Now look here, young man. Take a similar launch system, say the current Shuttle STS, and tell me what is the down range distance of the SRBs? Now, multiply that distance by two for your concept (this highly sophisticated technique known as a WAG) and see what that down range distance is? Now figure out how much propellant do you need to "fly" this back to launch site? <br /><br />Are you high enough and fast enough to just "glide" back? Will you be supersonic or subsonic in your glide mode? How would you know? Is your wing big enough for a "glide" back? How big will your first stage need to be? What size wing? Landing gears? Will it have big enough of propellant tanks? BTW, what kind of fuel are you gonna put in your gas tank? RP-1? Jet-A? JP-8? H2? How would you go about to decide? How can you possibly calculate your delta-vee if you don't know any of these answers?<br /><br />Now why use SRB if you don't plan to drop them off along the way? What is the advantage of SRB if you have a reusable 1st stage? How would you know a SRB along with 2 SSMEs will give you enough thrust to take off? <br /><br />You see, young grasshopper. Long before you were born, Shuttle_Guy has been doing this kinda stuff. He was being helpful and try to enourage your imagination along the way. Let's say why don't you pay him some due repect?<br /><br />BTW, what is you majo <div class="Discussion_UserSignature"> </div>

 

[spacefire]

well actually the real problem is lack of commitment. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

oh propforce...it's always been easier to criticize others rather than make something of your own.<br />Energywise-I have determined my design is viable. It can put the 4people CEV in LEO.<br />the RTLS option means either to come back or fly around the Earth, as already stated, and, like you said, it depends on the energy state of the first stage after separation. <br />One nice idea would be to have the first stage (it has wings, remmeber) skip around the Earth's atmosphere like a flat rock on a pond, until it completes one 'orbit' and gets back to the launch site. <br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[tap_sa]

<font color="yellow">" how much propellant do you need to "fly" this back to launch site? "</font><br /><br />Since most launches will occur eastward over a sea, may I propose this environmentally friendly first stage sail-back method.