spacex founder elon musk has revealed that his company will attempt to recover sections of its rockets using a “giant party balloon”.speaking to his 21 million fans on twitter, musk said the balloon will be used to slow down the rocket’s upper stage, which propels the payload once in space, when it re-enters the earth’s atmosphere after completing its mission. the second phase of the south african-born billionaire’s “crazy” plan involves this upper stage then landing on a “bouncy house” that will be positioned in the pacific ocean, he said. according to techgenyz, the plan has to potential to significantly reduce the “tremendous expenses” of space travel. the cost of sending a single spacex falcon 9 rocket into orbit is around $62m (£43m), engadget reports. the company currently recovers the main boosters of its rockets, but the upper stage is left to either drift in orbit or crash down to the earth’s surface. see related elon musk: spacex to trial mars rocket next yearspacex sends human sperm to the international space stationusing balloons to salvage the upper stage would allow the aerospace firm to re-use the module on future missions. the balloon idea isn’t the only option on spacex’s radar, says space.com. the company has partnered with boeing to develop a parachute system that could be used to slow down rocket modules on re-entry. this system is designed to recover crew modules during future manned missions, the site says. there...