After more than a year of delays, the Antares rocket was rolled out onto its Virginia coast launch pad on Saturday in preparation for the first of two test launches, the first of which is scheduled for April 17.

Should everything go according to plan, the rocket, developed by aerospace firm Orbital Sciences Corp., will work ferrying cargo to the International Space Station (ISS) as part of a $1.9 billion deal with NASA.

To start with, however, Antares will be carrying a mock-up of Orbital's unmanned spacecraft, a simulator built to mimic the actual weight of Cygus, the spacecraft the rocket will carry when testing is over. It's planned that Antares will reach a height of 155 miles to 185 miles during the test flight.

In addition, it will deliver four small satellites into orbit, including three PhoneSats and a nano-satellite called the Dove-1.

If the mission proves a success, the company will launch a demonstration flight of Cygnus to the ISS later this year.

In all, Orbital is committed to conducting eight cargo resupply flights.

This does not, however, mark the first deal between NASA and a private manufacturing company: since the agency's space shuttle program ended in 2011, several companies have moved in to cover the market. SpaceX's Dragon made history as the first commercial vehicle to successfully attach to the International Space Station in May 2012 and has been completing regular resupply missions since.

Other interested parties include Boeing, which is currently at work on a capsule it hopes to launch on an Atlas 5 rocket, as well as Amazon's Jeff Bezo's Biue Origin, which is designing a rocket of its own to launch the Space Vehicle, according to Space.com. And finally, there is Sierra Nevada Space Systems located in Colorado, which is working on a reusable space plane that would ferry astronauts to and from low-Earth orbit.

 
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