Can I take your number? <a href=" http://www.rumahgps.com/how-much-does-stendra-cost-per-pill.pdf ">stendra ed drug</a> The challenge for Manougian was to devise a solution so that all the propellent in the first stage was exhausted before the second stage ignited and separated. &ldquo;I remember waking up in the middle of the night,&rdquo; Manougian says. &ldquo;Josette asked what the hell was going on and I said I&rsquo;ve figured it out: I needed to place a battery in between the two rockets. And as long as the first stage is not generating any acceleration &mdash; because it&rsquo;s run out of propellent &mdash; it will slow down for a fraction of a second, forcing the second stage to ignite. It was so simple.&rdquo; The difference between a single-stage rocket and a two-stage rocket was vast. As Manougian puts it: it went from &ldquo;kids doing these interesting things to a viable rocket which wasn&rsquo;t a toy.&rdquo;