Could Armadillo type VTOL be used for orbit insertion?

[aphh]

<p>If Armadillo type VTOL launch platform was used to lift the rocket to, say, 100KM altitude for launch, the rocket didn't need to fight the athmosphere and only minimally the gravity to accelerate to orbital velocity and could be launched almost horizontally.</p><p>Would this be viable method for launching small satellites into orbit?&nbsp;</p>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If Armadillo type VTOL launch platform was used to lift the rocket to, say, 100KM altitude for launch, the rocket didn't need to fight the athmosphere and only minimally the gravity to accelerate to orbital velocity and could be launched almost horizontally.Would this be viable method for launching small satellites into orbit?&nbsp; <br />Posted by aphh</DIV><br /><br />How would they attach and launch a rocket from that type of platform? <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If Armadillo type VTOL launch platform was used to lift the rocket to, say, 100KM altitude for launch, the rocket didn't need to fight the athmosphere and only minimally the gravity to accelerate to orbital velocity and could be launched almost horizontally.Would this be viable method for launching small satellites into orbit?&nbsp; <br /> Posted by aphh</DIV></p><p>&nbsp;</p><p>The "VTOL launch platform" would just be a first stage and still would still fight the atmosphere.&nbsp; If you are saying that it goes slowly&nbsp; (hovers up to) to 100km, then it would incurr large gravity losses and be extremely inefficient</p>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How would they attach and launch a rocket from that type of platform? <br /> Posted by BrianSlee</DIV></p><p>I think it would rest on the platform on a launch pad and the launch would occur horizontally, the angle depending on the altitude and desired orbit parameters.&nbsp;</p>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;The "VTOL launch platform" would just be a first stage and still would still fight the atmosphere.&nbsp; If you are saying that it goes slowly&nbsp; (hovers up to) to 100km, then it would incurr large gravity losses and be extremely inefficient <br /> Posted by Cygnus_2112</DIV></p><p>Good point, however, if the operation of this kind of platform of 1st stage was cheap enough to operate, then it might make sense to launch at the altitude of 100KM even if the VTOL vehicle wasn't very efficient from the physics point of view.</p><p>It seems to me the operation of the Armadillo VTOL is far cheaper than building a conventional 1st stage of a rocket. But sure enough the 2nd stage would need to accelerate more, so the savings might not be enough to warrant use of VTOL platform as a launcher.&nbsp;</p>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think it would rest on the platform on a launch pad and the launch would occur horizontally, the angle depending on the altitude and desired orbit parameters.&nbsp; <br />Posted by aphh</DIV><br /><br />A launch rail on top maybe?.&nbsp; Doesn't seem immediately practical.&nbsp; But with good gyroscopic stabilization and dynamic response it might be doable.&nbsp; I think trying to maintain attitude during second stage firing would likely send it into an irrecoverable condition real fast unluss the rocket was in-line with the thrust of the platform which would entail the addition of heat shielding (how much usable payload would go away in this case).&nbsp; Seems easier to use an existing two stage configuration.&nbsp; I also think they need to demonstrate a significantly higher MTBF (Mean Time Before Failure) before attempting something like this. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Good point, however, if the operation of this kind of platform of 1st stage was cheap enough to operate, then it might make sense to launch at the altitude of 100KM even if the VTOL vehicle wasn't very efficient from the physics point of view.&nbsp; <br /> Posted by aphh</DIV></p><p>&nbsp;</p><p>" wasn't very efficient from the physics point of view.&nbsp;"&nbsp; also means more costly </p><p>&nbsp;</p><p>&nbsp;</p>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Seems easier to use an existing two stage configuration..... <br />Posted by BrianSlee</DIV><br /><br />.....than to try and redesign something not designed for that purpose originally. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>A launch rail on top maybe?.&nbsp; Doesn't seem immediately practical.&nbsp; But with good gyroscopic stabilization and dynamic response it might be doable.&nbsp; I think trying to maintain attitude during second stage firing would likely send it into an irrecoverable condition real fast unluss the rocket was in-line with the thrust of the platform which would entail the addition of heat shielding (how much usable payload would go away in this case).&nbsp; Seems easier to use an existing two stage configuration.&nbsp; I also think they need to demonstrate a significantly higher MTBF (Mean Time Before Failure) before attempting something like this. <br /> Posted by BrianSlee</DIV></p><p>I was thinking of dropping the rocket from the platform at the right altitude, but this would quickly negate any velocity gains that the 1st stage platform had achieved.&nbsp;</p>

 

[BrianSlee]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I was thinking of dropping the rocket from the platform at the right altitude, but this would quickly negate any velocity gains that the 1st stage platform had achieved.&nbsp; <br />Posted by aphh</DIV><br /><br />From 100Km up you would have a lot of gains to work with.&nbsp; But again it seems to me that it would be easier to start with something designed for the task and modify that.&nbsp; You also have to&nbsp;carry a lot fuel to get back unless you recover with a chute or via some other mode.&nbsp; I have not seen the technicals so I can't comment on how their stacked configuration&nbsp;would stack up (pun intended) against an already existing&nbsp;booster system that is already recoverable i.e. the shuttle SRBs.&nbsp; So the real question might be How much weight can they carry to 100Km and how much does it cost per trip.&nbsp; Then, can it&nbsp;compete with exisiting capabilities.&nbsp; In this case I would say your closest competitor would be Pegasus which has a relatively high cost per Kg when compared to other launch methods but a relativley low overall cost. <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[aphh]

<p>They now sell the base vehicle for 500K (1 unit). They have calculated that the stack of six units would be enough to lift payload of one person to 100KM.</p><p>That would make the 1st stage roughly 3 million vehicle plus modifications required to launch or drop the 2nd stage. </p>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>They now sell the base vehicle for 500K (1 unit). They have calculated that the stack of six units would be enough to lift payload of one person to 100KM.That would make the 1st stage roughly 3 million vehicle plus modifications required to launch or drop the 2nd stage. <br />Posted by aphh</DIV><br /><br />Ok so that equates to lifting 100 kilos to an altitude of 100Km which results in a delta-v savings of app 1450m/s of the 10Km/s requirement for LEO insertion(there will be some savings for drag reduction at that height but this is a ROM).&nbsp; Given an ISP&nbsp;462(I believe this represents current state of the art for bi-propelent configurations)&nbsp;would result in 15.71 Kilos to LEO.&nbsp; Now subtract motors, airframe, etc....for the second stage. </p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Ok so that equates to lifting 100 kilos to an altitude of 100Km which results in a delta-v savings of app 1450m/s of the 10Km/s requirement for LEO insertion(there will be some savings for drag reduction at that height but this is a ROM).&nbsp; Given an ISP&nbsp;462(I believe this represents current state of the art for bi-propelent configurations)&nbsp;would result in 15.71 Kilos to LEO.&nbsp; Now subtract motors, airframe, etc....for the second stage. <br /> Posted by BrianSlee</DIV></p><p>Thanks for the numbers. Looks like a conclusion can be made, it's not going to be enough in that configuration.&nbsp;</p>

 

[soyuztma]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If Armadillo type VTOL launch platform was used to lift the rocket to, say, 100KM altitude for launch, the rocket didn't need to fight the athmosphere and only minimally the gravity to accelerate to orbital velocity and could be launched almost horizontally.</p><p>Would this be viable method for launching small satellites into orbit?</DIV></p><p>That is Carmack's current plan for reaching orbit. He is planning to put a methane/LOX module on top of a stack of modules. The stack of modules will only go up and down, the methane module will deliver all horizontal velocity.</p><p>This blog post gives the advantages and disadvantages of this approach: http://selenianboondocks.blogspot.com/2008/06/orbital-access-methodologies-part-iii.html</p><p>There's also a book about a fictional company which uses this approach to get to orbit; "The Rocket Company" http://www.hobbyspace.com/AAdmin/archive/SpecialTopics/RocketCom/titlePage.html</p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If Armadillo type VTOL launch platform was used to lift the rocket to, say, 100KM altitude for launch, the rocket didn't need to fight the athmosphere and only minimally the gravity to accelerate to orbital velocity and could be launched almost horizontally.Would this be viable method for launching small satellites into orbit?&nbsp; <br />Posted by aphh</DIV></p><p>All that I see, from the point of view of a launch vehicle, in the Armadillo VTOL is an extraordinarily inefficient first stage.&nbsp; If you want to gain altitude and some velocity you would be better off with a jet aircraft.&nbsp; With an airbreather like a jet you have the advantage of much higher Isp than what you get with a rocket, precisely&nbsp; because you do not have to carry the oxidizer with you.&nbsp; That is the basis of the Pegasus system.&nbsp; But also recognize that with available aircraft, you will not be able to handle heavy payloads.&nbsp; For small satellites,&nbsp; 1000 lb or less,&nbsp;you only need book a Pegasus flight.</p><p>http://www.orbital.com/NewsInfo/Publications/Pegasus_fact.pdf</p> <div class="Discussion_UserSignature"> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>All that I see, from the point of view of a launch vehicle, in the Armadillo VTOL is an extraordinarily inefficient first stage.&nbsp; If you want to gain altitude and some velocity you would be better off with a jet aircraft.&nbsp; With an airbreather like a jet you have the advantage of much higher Isp than what you get with a rocket, precisely&nbsp; because you do not have to carry the oxidizer with you.&nbsp; That is the basis of the Pegasus system.&nbsp; But also recognize that with available aircraft, you will not be able to handle heavy payloads.&nbsp; For small satellites,&nbsp; 1000 lb or less,&nbsp;you only need book a Pegasus flight.http://www.orbital.com/NewsInfo/Publications/Pegasus_fact.pdf <br /> Posted by DrRocket</DIV></p><p>I finally had the time to look at the Pegasus system, and it looks impressive indeed. I bet they have a lot of business.&nbsp;</p>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I finally had the time to look at the Pegasus system, and it looks impressive indeed. I bet they have a lot of business.&nbsp; <br /> Posted by aphh</DIV></p><p>&nbsp;</p><p>Not really, there isn't that much of a demand due to the costs </p>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I finally had the time to look at the Pegasus system, and it looks impressive indeed. I bet they have a lot of business.&nbsp; <br />Posted by aphh</DIV></p><p>Not really.&nbsp; It never has been a high volume business.&nbsp;&nbsp; In fact it never met original business projections and some careers went down the tubes because of that.</p> <div class="Discussion_UserSignature"> </div>