Northrop Grumman [NOC] will perform a system demonstration of a Three-Dimensional Expeditionary Long-Range Radar (3DELRR) prototype in July, according to a company executive.

Northrop Grumman Ground-Based Radar Programs Director Mike Meaney also told reporters recently at a press briefing in Washington that a critical moment in the competition, Milestone B, is expected this calendar year. 3DELRR is the Air Force’s future main air defense radar, designed to detect both aircraft and missiles. 3DELRR will replace the AN/TPS-75 radar, which has been in service since the 1980s.

“Because we’re the original developer of the AN/TPS-75, we worked with them back in the 80s and 90s and clearly understand the mission set and that really enables us to optimize our solution for them,” Meaney said.

The Air Force said in briefing slides presented at a Jan. 24 industry day it expects a source selection announcement by the end of March 2014.

Lockheed Martin [LMT] and Raytheon [RTN] are also gunning for the 3DELRR contract, which Meaney said is valued at $1.3 billion. All three companies were awarded pre-engineering and manufacturing development (EMD) contracts in August worth approximately $35 million. Lockheed Martin spokeswoman Rashi Ratan said in a statement the company unveiled and demonstrated in December 2010 a functioning full-scale system prototype.

Raytheon spokesman Michael Nachshen said Raytheon is on track to meet all contractual obligations in the current pre-EMD phase. Saab Sensis, a subsidiary of Saab, is a subcontractor on Raytheon’s offer. Saab Sensis said in January 2011 it demonstrated the capabilities of its full-scale 3DELRR prototype in a relevant expeditionary environment to military and civilian participants from the Air Force, Marine Corps and the Office of the Secretary of Defense (OSD).

The Air Force said firm fixed-price and/or fixed-price incentive firm contracts are planned for EMD periods. The service said it previously planned to award cost-plus-incentive-fee contracts.