The SpaceX expolsion has delayed the Falcon Heavy

SpaceX has said it’s Falcon Heavy, which may be the most powerful rocket on Earth when it comes into service,has been grounded by further delays.The news comes as part of a briefing by Elon Musk and other company executives outlining their plans following the explosion of the Flacon 9.
The company’s Falcon Heavy design had been expected to fly in 2013 when it was first announced, but that date has moved back and it had until yesterday been expected to make its first liftoff later this year. But now "we’ve de-prioritised Falcon Heavy to probably launch in the spring next year, maybe April or so,” Musk told reporters on Monday.
The planned Falcon Heavy is essentially three Falcon 9 first stages bolted together side by side, mustering a total of 27 Merlin rocket engines, with a second stage atop the central core. It is projected to be able to lift 53 tonnes into orbit, more than twice what the biggest operational rocket today – the Delta IV Heavy – can manage.
The Heavy would thus be the most powerful rocket in service if it arrives on time. If there are more years of delays, however, Musk’s heavyweight will perhaps be eclipsed by the upcoming Space Launch System rocket under development by NASA and its old partners on the Space Shuttle programme.
The SLS, comparable in size to a Saturn V moon rocket, will initially be able to lift 70 tonnes to orbit. It is scheduled for a first unmanned test launch in 2018. Eventually enhanced versions of the SLS are planned to be able to haul 130 tonnes, surpassing the Saturn V’s max record of 118 tonnes, perhaps enough to send a manned mission to Mars.