5.4.3: US Motors in the 1960s

In the mid 1960s the first geostationary satellites were launched. Syncom 1, the first satellite to try and reach synchronous altitude, used a small Thiokol motor, but Syncom 2 and 3 used a motor developed by JPL and Thiokol's comsat apogee motor business languished for some time as it concentrated on other rockets. JPL also provided apogee motors for Early Bird (the first Intelsat) and the ATS technology development satellites. ATS 5, which flew in 1969, was the last satellite to carry a JPL motor, the swansong of JPL's involvement in space propulsion. From now on, JPL would concentrate on its planetary exploration expertise.

Aerojet moved in to fill the vacuum. The Sacramento company, which of course was originally a von Karman offshoot, provided the SVM (Space Vehicle Motor) series of comsat apogee motors, SVM-1 of 1966 to SVM-7 in the late 1970s. SVM-1 powered the Intelsat II satellites in the 1960s, SVM-2 was aboard Intelsat III, SVM-4 was the Intelsat IV motor, and SVM-5 was used in the SMS and GOES weather satellites. SVM-6 was on the first two NATO 3 satellites, and SVM-7 was apogee motor for the initial Satcom birds from RCA/East Windsor, the ancestors of today's Lockheed Martin A2100s.

Another successful apogee motor of the 1970s was UTC's FW5, a scaled down version of their Altair-class FW4 upper stage. The FW5 was the apogee motor for Hughes's HS-333, the first real production series comsat which pioneered the Anik, Westar and Marisat series.

By this time, in the late 1970s, Thiokol was ready with a new line of products which would lead to a dominant presence in the US market. Thiokol had provided small kick motors in the Star series for scientific satellites throughout the 1960s and 1970s. In 1968 the Star 17 was used as apogee motor for the Radio Astronomy Explorer, and in 1969-70 the same motor went to geostationary orbit in the Royal Air Force's Skynet I and NATO's first satellite, NATO IIA. But the Star 17 was too small for most comsats. 1976 saw the first flight of the Star 27, as apogee motor for Canada's Communications Technology Satellite. Star 27 took over from Aerojet's SVM as kick motor for the later GOES weather satellites and NATO 3 comsats, and made 11 flights as kick motor for the Block I GPS navigation satellites.

Star 27 was Thiokol's first comsat apogee motor to see wide use, but its success was eclipsed by the Star 30 which came on line in 1980 to power the Hughes HS-376 and the RCA advanced Satcom satellites. Unlike the other motors I've talked about, Star 30 has been used exclusively as an apogee motor for geostationary comsats, and it's now made over 80 flights.

As payloads get larger and rockets more powerful, the motors move upward in the vehicle. The Star 37 has been replaced as a third stage by the Star 48 PAM-D, but in turn replaced the Star 27 as an apogee motor, first for the FLTSATCOM Navy comsat and more recently for the GPS Block II satellites and Loral's Intelsat-5 class comsats. The Star 48, in turn, has seen some use as a kick motor, for Magellan's Venus orbit insertion and Ulysses' solar orbit kick stage.