Northrop Grumman [NOC] has delivered its ESPAStar-D spacecraft bus to L3Harris Technologies [LHX] in Palm Bay, Fla. in preparation for the planned fall 2023 launch of the National Technology Satellite-3 (NTS-3)–one of four Department of the Air Force Vanguard programs to push the technology envelope.

The geosynchronous orbit NTS-3, which the Air Force named a Vanguard in 2019, aims to alleviate interference to satellite position, navigation and timing, including for the U.S. Space Force’s GPS satellites.

Northrop Grumman said that it built ESPAStar-D “to provide affordable, rapid access to space” and said that the bus uses an Evolved Expendable Launch Vehicle Secondary Payload Adapter ring to allow multiple buses to stack on one rocket for missions to geosynchronous, low Earth, and medium Earth orbits.

ESPAStar-D, built in Northrop Grumman’s satellite plant in Gilbert, Ariz., marks the “first time an ESPAStar bus has been built and delivered as a commercially-available commodity,” said Arlen Biersgreen, the NTS-3 program manager with the Air Force Research Laboratory (AFRL) Space Vehicles Directorate at Kirtland AFB, N.M.

The bus contains communications, power, attitude determination and control, and configurations that allow the mounting of payloads.

“NTS-3 is using a unique acquisition model for the ESPAStar line that fully exercises the commercial nature of Northrop Grumman’s product line, in order to provide the bus to another defense contractor for payload integration using standard interfaces,” Biersgreen said in a statement.

AFRL said that it had developed the ESPA ring–“a technology that revolutionized the transport of space experiments, allowing for lower-cost and more frequent ‘rides’ to space, for government and industry users.”

The NTS-3 launch will be the first integrated satellite navigation experiment in more than 45 years, per Biersgreen.

The NTS-3 program’s deputy principal investigator, 2nd Lt. Charles Schramka, said that AFRL Sensors Directorate at Wright-Patterson AFB, Ohio delivered to the program this month the Global Navigation Satellite System Test Architecture (GNSSTA) experimental receiver. A reprogrammable software defined signal receiver, GNSSTA is to allow users to receive legacy GPS signals and advanced signals from NTS-3.

In February last year, L3Harris Technologies said that NTS-3 had passed its preliminary design review about 14 months after the then-Harris Corp. won an $84 million contract to be the prime integrator for NTS-3 (Defense Daily, Feb. 5, 2020). L3Technologies and Harris merged in July 2019.