K
keermalec
Guest
No_way, if you want to go straight up and down you only need a delta-v of about 3 km/s get to 100 km altitude (assuming 1.4 Gs of acceleration).<br /><br />But in order to go into orbit you also need orbital velocity wich is around 8 km/s at that altitude.<br /><br />Altogether you need about 10 km/s to go from the ground to orbit.<br /><br />Using the rocket equation:<br /><br />final mass = inital mass * e^(-final velocity/gas exhaust velocity)<br /><br />So for Armadillo's chemical rocket, assuming an ISP of 455s:<br /><br />final mass = inital mass * e^(-10000/(455*9.81))<br /><br />final mass = 0.106 * inital mass<br /><br />That means your final mass can only be 10.6% of your initial mass. Considering that the structure itself in a rocket is 4-10% of its total mass, it is ivery difficult to build a single stage, chemically-propelled rocket that will put a useful payload into orbit.<br /><br />Armadillo's Pixel can therefore probably only be used to lift payloads up but they will then come down again. However, if it is further developed into a two or three stage rocket then it may get payloads into orbit, but will it be reusable?<br /><br />At the moment the most convincing reusable single stage vehicle I have found is SEI's ARTS Horizontal take Off and Landing Vehicle. It uses existing chemical thrusters on a spaceplane design. Using wings allows you to reduce the 3 km/s needed to get into space as one uses air to lift. <br /><br />This reusable spaceplane has the same lift capacity as the space shuttle and SEI estimates its developement cost at "only" 8.8 billion USD... <div class="Discussion_UserSignature"> <p><em>“An error does not become a mistake until you refuse to correct it.” John F. Kennedy</em></p> </div>