A kerosene-fueled X-33 as a single stage to orbit vehicle.
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From: hallerb on 22 Mar 2010 10:20 On Mar 22, 9:12�am, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > On 3/22/2010 4:07 AM, Pat Flannery wrote: > > > > > > > On 3/21/2010 4:53 PM, Marvin the Martian wrote: > > >> It is apparent you're not acquainted with rocket science. Getting through > >> the "dense lower atmosphere" is no big deal. Von Braun did that with an > >> single stage alcohol fueled rocket 65 years ago. > > >> The problem is getting up to orbital velocity. > > > If you can put the LOX aboard the rocket at altitude, where the humidity > > is very low, you can eliminate the weight and complexity of having to > > put insulation on the outside of the oxidizer tank section, as ice won't > > form on it like it would if it were fueled and launched from the > > surface. Not only does the booster then end up carrying the weight of > > ice still sticking to it during ascent, but the ice that sheds can > > damage the booster due to its mass and impact speed. > > So how much "weight and complexity" is involved with a little bit of > spray-on foam? �And in practical terms how much difference is this going > to make? �I'm sorry, but you're trying to reduce launch costs by > tackling an at best second order effect without dealing with the major > cost drivers. �In any case the tankage on the X-33 is does not have > surfaces exposed to the airflow so this becomes a non-issue. > > And if you're talking an X-33 it has to have a thermal protection system > for reentry anyway. > > And the X-33 could not achieve more than half of orbital velocity on > HYDROGEN so how in the Hell do you expect it to do that with kerosene? > > SSTO, if it can be done at all with chemical fuels, is _barely_ doable.- Hide quoted text - > > - Show quoted text - If you call the airplane a non stage since it basically flies up to release altitude then flies back to base. A SSTO where the only stage is a orbital one is very doable. espically since you dont have to carry ALL the fuel from the launch pad to orbit. with in flight refueling along the way it is a real winner. no loaded bomb launch either:)
From: J. Clarke on 22 Mar 2010 10:54 On 3/22/2010 10:20 AM, hallerb(a)aol.com wrote: > On Mar 22, 9:12�am, "J. Clarke"<jclarke.use...(a)cox.net> wrote: >> On 3/22/2010 4:07 AM, Pat Flannery wrote: >> >> >> >> >> >>> On 3/21/2010 4:53 PM, Marvin the Martian wrote: >> >>>> It is apparent you're not acquainted with rocket science. Getting through >>>> the "dense lower atmosphere" is no big deal. Von Braun did that with an >>>> single stage alcohol fueled rocket 65 years ago. >> >>>> The problem is getting up to orbital velocity. >> >>> If you can put the LOX aboard the rocket at altitude, where the humidity >>> is very low, you can eliminate the weight and complexity of having to >>> put insulation on the outside of the oxidizer tank section, as ice won't >>> form on it like it would if it were fueled and launched from the >>> surface. Not only does the booster then end up carrying the weight of >>> ice still sticking to it during ascent, but the ice that sheds can >>> damage the booster due to its mass and impact speed. >> >> So how much "weight and complexity" is involved with a little bit of >> spray-on foam? �And in practical terms how much difference is this going >> to make? �I'm sorry, but you're trying to reduce launch costs by >> tackling an at best second order effect without dealing with the major >> cost drivers. �In any case the tankage on the X-33 is does not have >> surfaces exposed to the airflow so this becomes a non-issue. >> >> And if you're talking an X-33 it has to have a thermal protection system >> for reentry anyway. >> >> And the X-33 could not achieve more than half of orbital velocity on >> HYDROGEN so how in the Hell do you expect it to do that with kerosene? >> >> SSTO, if it can be done at all with chemical fuels, is _barely_ doable.- Hide quoted text - >> >> - Show quoted text - > > If you call the airplane a non stage since it basically flies up to > release altitude then flies back to base. > > A SSTO where the only stage is a orbital one is very doable. What does that sentence mean? If it is single stage to orbit then there is only one stage and since it achieves orbit it is necessarily "orbital". But your assertion does not convince. You are posting on the Internet. Most people posting on the Internet have opinions. Most of those opinions are ignorant twaddle. So one must take your opinion as ignorant twaddle until you can provide some numbers to go with it. > espically since you dont have to carry ALL the fuel from the launch > pad to orbit. So where do you carry it? Is Spock beaming it into your vehicle with the transporter or something? > with in flight refueling along the way it is a real winner. So how do you refuel it in flight? > no loaded bomb launch either:) So when does the "bomb" get "loaded" and how does that happen? Show me the numbers on your airliner-launched SSTO. All that your airliner brings to the party is a portable launch pad. Its effect on the performance requirements is negligible.
From: Pat Flannery on 22 Mar 2010 14:53 On 3/22/2010 5:12 AM, J. Clarke wrote: > And the X-33 could not achieve more than half of orbital velocity on > HYDROGEN so how in the Hell do you expect it to do that with kerosene? X-33 was never designed to achieve orbital velocity, any more than DC-X was; both were subscale proof-of-concept vehicles to try out engine, aerodynamic, structure, and landing concepts. If NASA and hadn't gotten so fixated on SSTO as a Shuttle replacement, They could have built the Lockheed Starclipper concept, which would have been a major step forward from the Shuttle as it eliminated the need for the SRB's: http://www.astronautix.com/lvs/staipper.htm They maybe even could have redesigned the VentureStar into a version with drop tanks, as it owed a lot of its basic aerodynamics to Starclipper, as well as the use of the (then classified) Starclipper's linear plug-nozzle engine. Any performance shortfall generated by having to switch to a aluminum-lithium LH2 tank from the composite one could have been more than redressed by adding drop tanks to the design. The advantages of high altitude fueling and launch for a Shuttle type vehicle to avoid ice buildup on tankage using any sort of cryogenic propellants go clean back to the Air Force/DARPA ALSV concept that Dwayne Day is following the history of in The Space Review: http://www.thespacereview.com/article/1569/1 http://www.thespacereview.com/article/1580/1 http://www.thespacereview.com/article/1591/1 Fluorine-deuterium? Oh, that will be cheap to use as fuel. ;-) Pat
From: hallerb on 22 Mar 2010 12:01 On Mar 22, 10:54�am, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > On 3/22/2010 10:20 AM, hall...(a)aol.com wrote: > > > > > > > On Mar 22, 9:12 am, "J. Clarke"<jclarke.use...(a)cox.net> �wrote: > >> On 3/22/2010 4:07 AM, Pat Flannery wrote: > > >>> On 3/21/2010 4:53 PM, Marvin the Martian wrote: > > >>>> It is apparent you're not acquainted with rocket science. Getting through > >>>> the "dense lower atmosphere" is no big deal. Von Braun did that with an > >>>> single stage alcohol fueled rocket 65 years ago. > > >>>> The problem is getting up to orbital velocity. > > >>> If you can put the LOX aboard the rocket at altitude, where the humidity > >>> is very low, you can eliminate the weight and complexity of having to > >>> put insulation on the outside of the oxidizer tank section, as ice won't > >>> form on it like it would if it were fueled and launched from the > >>> surface. Not only does the booster then end up carrying the weight of > >>> ice still sticking to it during ascent, but the ice that sheds can > >>> damage the booster due to its mass and impact speed. > > >> So how much "weight and complexity" is involved with a little bit of > >> spray-on foam? And in practical terms how much difference is this going > >> to make? I'm sorry, but you're trying to reduce launch costs by > >> tackling an at best second order effect without dealing with the major > >> cost drivers. In any case the tankage on the X-33 is does not have > >> surfaces exposed to the airflow so this becomes a non-issue. > > >> And if you're talking an X-33 it has to have a thermal protection system > >> for reentry anyway. > > >> And the X-33 could not achieve more than half of orbital velocity on > >> HYDROGEN so how in the Hell do you expect it to do that with kerosene? > > >> SSTO, if it can be done at all with chemical fuels, is _barely_ doable..- Hide quoted text - > > >> - Show quoted text - > > > If you call the airplane a non stage since it basically flies up to > > release altitude then flies back to base. > > > A SSTO where the only stage is a orbital one is very doable. > > What does that sentence mean? �If it is single stage to orbit then there > is only one stage and since it achieves orbit it is necessarily "orbital".. > > But your assertion does not convince. �You are posting on the Internet. > � Most people posting on the Internet have opinions. �Most of those > opinions are ignorant twaddle. �So one must take your opinion as > ignorant twaddle until you can provide some numbers to go with it. > > > espically since you dont have to carry ALL the fuel from the launch > > pad to orbit. > > So where do you carry it? �Is Spock beaming it into your vehicle with > the transporter or something? > > > with in flight refueling along the way it is a real winner. > > So how do you refuel it in flight? > > > no loaded bomb launch either:) > > So when does the "bomb" get "loaded" and how does that happen? > > Show me the numbers on your airliner-launched SSTO. �All that your > airliner brings to the party is a portable launch pad. �Its effect on > the performance requirements is negligible.- Hide quoted text - > > - Show quoted text - Lets make it SIMPLE for you.... A large airliner with little fuel takes off, low fuel level keeps take off weight down:) with multiple in flight refuels, done every day in the military:) gets the vehicle to near release altitude. at this point the airliner sets off its afterburners and releases the actual rocket stage, which achieves orbit. the airliner flies back to base 100s if not a 1000 miles away. a fully fuled rocket sitting on the pad is basically a loaded bomb. a airliner launched rocket stage can use ejection seats for the airliners crew, and a capsule safety pod for the rocket stage crew. think out of the box, the box isnt your friend..............
From: Pat Flannery on 22 Mar 2010 15:07
On 3/22/2010 6:54 AM, J. Clarke wrote: > But your assertion does not convince. You are posting on the Internet. > Most people posting on the Internet have opinions. Most of those > opinions are ignorant twaddle. So one must take your opinion as ignorant > twaddle until you can provide some numbers to go with it. Yeah...but you are posting on the internet also, and I'm not seeing any numbers so far. :-D Pat |