White Knight 2 - Booster for Orbital Payloads also?

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stephentracey

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I recently read an interview from Burt Rutan, and that got me thinking about the design of White Knight 2.<br />Is it possible that Scaled will design WK2 to allow it in the future to carry a booster rocket for orbital flights, when the market is ready for them 5+ years ?<br />Does anybody have any comment ?<br />Regards<br />steve
 
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mikejz

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take SS2, make it ummanned, or single pilot---add a cyrogenic upper stage, and you have a small orbital launcher.
 
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radarredux

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> <i><font color="yellow">Is it possible that Scaled will design WK2 to allow it in the future to carry a booster rocket for orbital flights</font>/i><br /><br />t/Space (which includes Scaled Composites) includes an air launch, potentially using WhiteKnight2, for the Crew Transfer Vehicle (CXV). AirLaunch recently launched dumby rockets from a Scaled Composite plane and a C-17.</i>
 
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josh_simonson

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Unles WK2 is overdesigned so that it can carry a six-pack of SS2s, it won't be able to orbit anything of significant mass with an air-launch.
 
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rocketman5000

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if you took the wings off, removed the life support and anything that was used for passenger carrying. Strap on some booster hybrid cores I think you would be able to launch a couple of small satelittes. well maybe only one.
 
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shyningnight

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Hmm.. Idle thought...<br />Wonder what Airbus is planning to do with their prototype A380? :)<br /><br />Sucker has the wing lift to carry a fueled Atlas... (OK, perhaps I exaggerate a BIT...).<br /><br />Paul F.
 
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shyningnight

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True enough, the AN-225 would be better...<br />But Burt would have an easier time getting replacement/repair parts for an A380... heh heh..<br /><br />So it has that pesky "how to mount useful cargo" problem...<br />Told you it was an idle thought.<br /><br />Paul F.
 
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nacnud

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Why would Burn need to repair the An225? Just hire it for the day, launch the rocket then let the An225 get back to its normal business.
 
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nibb31

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"Wonder what Airbus is planning to do with their prototype A380? :) "<br /><br />Prototype #1 is to undergo some extreme structural testing, like bending the wings and fuselage. After that, it will be scrapped. #2 is currently flying, but I don't know what the plans are for it, maybe refurb.<br /><br />However, feel free to purchase a production model at retail price in the upcoming months <img src="/images/icons/wink.gif" />
 
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scottb50

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I would be interested to see what you could get into an AN225. <br /><br />The Gemini-Titan II weighed 340,000 pounds to launch two people. <br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>
 
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scottb50

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Very true. I'm sure Spacester could give numbers. I still think it is a lot more than you think.<br /><br />I'll give you two, even three times what Pegasuas can orbit, but thats peanuts if you want commercial uses. <div class="Discussion_UserSignature"> </div>
 
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spacester

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Thanks for the vote of confidence, Scott. I was going to plead ignorance, because I know next to nothing about aircraft, just what I've learned here really, lol. But I see the question is about a good ol' rocket launch so we can prolly figure this out together.<br /><br />To find the mass at 30,000 feet,we need the time of flight to reach 30,000 feet. We should be able to use the Isp and/or mass flow rate to find the fuel consumed if we know that time period. <div class="Discussion_UserSignature"> </div>
 
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spacester

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Um OK I’m rusty on this calc . . .<br /><br />For Titan 3A-1<br />Isp = 250 sec at sea level, Isp = 302 s vacuum<br />Thrust = 238590 kgf<br /><br />IIRC we simply divide thrust by Isp to get the fuel mass consumed per second. We need to pick an effective Isp between vacuum and sea level, I’ll use 275 sec<br /><br />238590 / 275 = 867.6 kg<br />Multiply by 60 seconds of flight:<br />867.6 * 60 = 52056 kg fuel consumed in 1 minute<br /><br />We should be able to use the start mass and final mass and burn time to get the effective Isp:<br />(116573 – 5443) / 147 = 756 kg fuel per second<br />238590 / 756 = 315 sec<br />Which is higher then the two extremes, so that’s weird . . . .<br /><br />Oh there’s a parallel booster, 3B-1; I get 246077 / 275 * 60 = 53690 kg<br /><br />Total fuel consumed: 52000 + 53700 = ~ 106000 kg = 106 tonne<br /><br />Total launch mass is listed as 156540 kg, so we’re looking at dropping off a booster of 1/3 the mass, if I understand the scenario here.<br /><br />The Titan has the kinetic energy of ~ 1000 ft/sec (‘specific velocity’) and the potential energy of 30,000 ft, while the dropped-off booster only has the potential energy. <br /><br />I get 0.30 km/s delta-v equivalent for the potential energy, and the 1000 ft/s = 0.3048 km/sec. Well that’s interesting, they happen to be almost equal, there’s prolly a reason for that I’m not seeing yet.<br /><br />So anyway, the dropped off booster has about ½ has much energy as the Titan at altitude, but 1/3 the mass.<br /><br />BUT the gravity losses are going to be much higher for the dropped off booster because it’s going to take it a lot longer to get to orbit without that starting velocity. That’s maybe, wild guess, 1.0 km/s more of a burden to bear. So in a sense, the dropped off booster has “negative energy” compared to the Titan: 0.3 – 1.0 = -0.7 km/s versus 0.3 + 0.3 = 0.6 km/s<br /><br />I’m not sure what the conclusion here is, but there are some n <div class="Discussion_UserSignature"> </div>
 
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scottb50

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A rough comparison from Orbital:<br /><br />Pegasus: 23,130 kg vehicle weight, 450kg payload to 400km @28.5 degrees.<br /><br />Taurus: 70,000 kg vehicle weight, 1259 kg payload to 400km @28.5 degrees. <br /><br />It appears to me that to match the payload of the taurus, with an air launched vehicle would take pretty close to the same amount of propellant, if you figure the structural weights to be similar. <div class="Discussion_UserSignature"> </div>
 
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CalliArcale

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Yeah; air-launch really doesn't get you enough to make it worthwhile -- if you look just at things like fuel consumption. However, there is something really big that it does buy you. You don't need a launchpad. The infrastructure for Pegasus is very simple compared to Taurus, and of course you can light the rocket at absolutely any latitude you want. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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radarredux

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> <i><font color="yellow">You don't need a launchpad.</font>/i><br /><br />And those pesky range fees.</i>
 
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shyningnight

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Not to mention "Ranges" that say; "Oh, did we say you could use the range? Well... we changed out mind... have your stuff off the pad ASAP, another customer will be here on the 12th".<br /><br />Paul F.
 
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j05h

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>I would be interested to see what you could get into an AN225. <br /><br />One proposal I've seen was to drop a fully-fueled Proton from the AN225. I'm not kidding. Hypergolic fuels and all that. <br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>One proposal I've seen was to drop a fully-fueled Proton from the AN225. I'm not kidding. Hypergolic fuels and all that. <p><hr /></p></p></blockquote><br /><br />*jaw drops*<br /><br />Can a "Mriya" really haul that much mass????<br /><br />WOW!!!!<br /><br />That's a pretty wild concept. Can you imagine watching that thing go? Would it be a piggyback deal? An-225 was specifically built to carry external payloads piggyback, so that might be doable, although it would take some very skilled pilots. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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nacnud

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Can't be right, the Proton weights 700 tonnes at launch the An-225 can lift 250 tonnes.<br /><br />The Soyuz weights 300 tonnes at launch, that might be more possible, but still... <img src="/images/icons/crazy.gif" />
 
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shoogerbrugge

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utter bollocks, <br /><br />The payload of an An-225 is about 250 tonnes. But if you want to go to 30.000 feet, you might want to restrict yourself to 230.000kg for safe measures. Now that is not even close to the fully fuelled Proton<br /><br /><br />The only idea including the An-225 is the MAKS. More information here <br /><br /><br />the MAKS was supposed to be carried as a piggyback. Although other proposals involving the An-124 would have an fly-back booster dropped from the cargo hold. The payload of the An-124 is 120 tonnes, although they are testing a 150 tonnes version as we speak<br />
 
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CalliArcale

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Well, that sounds a bit more plausible. <img src="/images/icons/wink.gif" /> Thanks. I'll go pick my jaw up now.... <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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publiusr

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Branson just needs to get that second unassembled AN-225 and use it. When not a first stage, it would be used for cargo no C-5 could touch.<br /><br />But Branson is easily distracted by bright shiny objects, so he wants Rutan to build a VLA--when he has no experience at all in building heavy lift aircraft.<br /><br />No getting away from heavy lift people--one way or the other.
 
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