NASA Taps Delta 4 Heavy for Solar Probe Plus Launch


WASHINGTON — NASA has selected the Delta 4 Heavy built by United Launch Alliance to launch its Solar Probe Plus mission in 2018, the agency announced March 18.

That launch, valued at $389 million, will also use a Star-48 upper-stage motor provided by Orbital ATK.

The choice of the Delta 4 Heavy is not surprising: Last year, NASA ruled out the use of the most powerful Atlas 5 because that would have required a new, custom-built upper stage.

NASA relies almost exclusively on the Atlas 5 to launch its scientific satellites, although a Delta 4 Heavy was used to launch the agency’s Orion deep-space capsule on an uncrewed test mission in December. That launch was procured commercially by Orion prime contractor Lockheed Martin Space Systems.