Encyclopedia Astronautica
TIP



znova.jpg
TIP
Credit: APL
American navigation satellite. 6 launches, 1972.09.02 (Triad 1) to 1988.06.16 (Nova 2).

The Transit Improvement Program (TIP) was established in 1969 to test improvements to the Transit Navigation System with the goal of providing a redundant, radiation-hardened satellite that could continue to provide its correct position for over five days without update from the ground. This "drag-free" satellite would use a Disturbance Compensation System (DISCOS) developed at Stanford. Substantial improvements to Transit were demonstrated in the three satellites flown, followed by three production Nova satellites. These evidently were intended to provide ballistic missile submarines with a minimum Transit capability even after a nuclear exchange. However they did not replace the earlier model of Transit satellites, which continued to be launched.

The TIP 150- and 400-MHz transmitters had the output power raised to 3 W at 150 MHz and 5 W at 400 MHz. Each TIP satellite was equipped with a redundant, radiation-hardened, fully programmable minicomputer with 64 KB of memory, a formidable technical accomplishment at the time. To correct for orbital precession over the long life of the Transit satellites, TIP was equipped with a main hydrazine thruster to make orbital corrections as needed to keep the satellite in its polar orbit.

The DISCOS sensor consisted of a mass floating inside a cavity. Small thrusters were automatically fired to keep the floating mass in the middle of the cavity. These thrusters were an innovative pulsed-plasma design developed by Republic Aviation, and used solid Teflon as the fuel. The Teflon was vaporized by an electrical arc, then heated, focused, and expelled by a magnetohydrodynamic bottle. The resulting jet had a specific impulse of 500 seconds, and 1 kg of Teflon, divided between two thrusters, was adequate for ten years of DISCOS operation. Each thruster generated a discrete impulse of 0.38 mN within one second of command.

The TIP satellite also demonstrated a lighter-weight, more accurate oscillator and an improved incremental phase shifter to improve spacecraft timing. A quadrifilar helix antenna of near-ideal configuration was introduced.

In 1977, the Navy awarded a contract to RCA for the production of three Nova spacecraft with the option to build two more. These satellites were nearly identical to the TIP satellites, with minor improvements, including the addition of magnetic damping to DISCOS and a stiffening of the lower boom assembly.

However the basic Transit system had been upgraded in accuracy over the years through improvement of the ground and processing segment and met fleet requirements. Therefore further Nova satellites were not orbited, or only three were needed for the post-strike strategic navigation mission. Instead, six Transits built in the 1960's were orbited two at a time in the late 1980's, and this kept the system in operation until all surface users could convert to GPS and the Transit system was shut down.

AKA: Triad; Nova.
Gross mass: 170 kg (370 lb).
First Launch: 1972.09.02.
Last Launch: 1988.06.16.
Number: 6 .

More... - Chronology...


Associated Countries
See also
  • Scout Solid-fuel, light payload, lower-cost launch vehicle developed by the Air Force and NASA in the late 1950's and used in a variety of configurations over thirty years. Launched from Cape Canaveral, Vandenberg, Wallops Island, and from Italy's equatorial San Marco platform off Kenya. Italy studied but did not develop subsequent upgraded versions. More...

Associated Launch Vehicles
  • Scout American all-solid orbital launch vehicle. Solid-fuel, light payload, lower-cost launch vehicle developed by the Air Force and NASA in the late 1950's and used in a variety of configurations over thirty years. Launched from Cape Canaveral, Vandenberg, Wallops Island, and from Italy's equatorial San Marco platform off Kenya. Italy studied but did not develop subsequent upgraded versions. More...
  • Scout B American all-solid orbital launch vehicle. Four stage vehicle consisting of 1 x Algol 2B + 1 x Castor 2 + 1 x Antares 2 + 1 x FW4S More...
  • Scout B-1 American all-solid orbital launch vehicle. Four stage vehicle consisting of 1 x Algol 2C + 1 x Castor 2 + 1 x Antares 2 + 1 x Star 20 More...
  • Scout D-1 American all-solid orbital launch vehicle. Four stage vehicle consisting of 1 x Algol 3A + 1 x Castor 2 + 1 x Antares 2 + 1 x Star 20 More...
  • Scout G American all-solid orbital launch vehicle. Four stage vehicle consisting of 1 x Algol 3A + 1 x Castor 2 + 1 x Antares 3 + 1 x Star 20 More...

Associated Manufacturers and Agencies
  • APL American manufacturer of rockets and spacecraft. Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, Laurel, Maryland, USA. More...
  • USN American agency overseeing development of rockets, spacecraft, and rocket engines. USN Joint Task Force 7, USA. More...
  • RCA American manufacturer of spacecraft. RCA, USA. More...

Associated Programs
  • Transit Spin-stabilized Transit satellites were developed by the US Navy into the first operational navigation satellite system, for use by ballistic missile submarines and surface vessels. Early Transits carried a variety of piggy-back payloads, many still classified. Transit was also known as the Navy Navigation Satellite (NNS). Transit provided continuous navigation satellite service from 1964, initially for Polaris submarines and later for civilian use. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • McDowell, Jonathan, Launch Log, October 1998. Web Address when accessed: here.
  • Danchik, Robert J, "An Overview of Transit Development", John Hopkins APL Technical Digest, Volume 19, Number 1, 1998. Web Address when accessed: here.

Associated Launch Sites
  • Vandenberg Vandenberg Air Force Base is located on the Central Coast of California about 240 km northwest of Los Angeles. It is used for launches of unmanned government and commercial satellites into polar orbit and intercontinental ballistic missile test launches toward the Kwajalein Atoll. More...
  • Vandenberg SLC5 Scout launch complex. Dedicated Scout launch pad, used during the life of that vehicle from 1962 to 1994. More...

TIP Chronology


1972 September 2 - . 17:50 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout B-1. LV Configuration: Scout B-1-F S182C.
  • Triad 1 - . Payload: TIP 1. Mass: 94 kg (207 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. USAF Sat Cat: 6173 . COSPAR: 1972-069A. Apogee: 792 km (492 mi). Perigee: 709 km (440 mi). Inclination: 90.0000 deg. Period: 99.80 min. Summary: Prototype of improved Transit satellite..

1975 October 12 - . 06:39 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout D-1. LV Configuration: Scout D-1 S195C.
  • Triad 2 - . Payload: TIP 2. Mass: 94 kg (207 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. Decay Date: 1991-05-26 . USAF Sat Cat: 8361 . COSPAR: 1975-099A. Apogee: 490 km (300 mi). Perigee: 427 km (265 mi). Inclination: 90.4000 deg. Period: 93.80 min. Summary: Prototype of improved Transit satellite. Tested pulsed plasma engine..

1976 September 1 - . 21:14 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout D-1. LV Configuration: Scout D-1 S197C.
  • TIP 3 - . Payload: Triad 3 (TIP 3). Mass: 94 kg (207 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. Decay Date: 1981-05-30 . USAF Sat Cat: 9403 . COSPAR: 1976-089A. Apogee: 789 km (490 mi). Perigee: 345 km (214 mi). Inclination: 90.3000 deg. Period: 95.90 min. Summary: Prototype of improved Transit satellite. Also tested pulsed plasma engine..

1981 May 15 - . 06:07 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout G. LV Configuration: Scout G-1 S192C.
  • Nova 1 - . Mass: 170 kg (370 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. USAF Sat Cat: 12458 . COSPAR: 1981-044A. Apogee: 1,185 km (736 mi). Perigee: 1,165 km (723 mi). Inclination: 90.2000 deg. Period: 108.90 min. Summary: Improved Transit..

1984 October 12 - . 01:43 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout G. LV Configuration: Scout G-1 S208C.
  • Nova 3 - . Mass: 165 kg (363 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. USAF Sat Cat: 15362 . COSPAR: 1984-110A. Apogee: 1,200 km (700 mi). Perigee: 1,152 km (715 mi). Inclination: 89.9000 deg. Period: 108.90 min. Summary: Improved Transit. Pulsed plasma engine..

1988 June 16 - . 06:54 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC5. LV Family: Scout. Launch Vehicle: Scout G. LV Configuration: Scout G-1 S213C.
  • Nova 2 - . Mass: 174 kg (383 lb). Nation: USA. Agency: USN. Program: Transit. Class: Navigation. Type: Navigation satellite. Spacecraft: TIP. USAF Sat Cat: 19223 . COSPAR: 1988-052A. Apogee: 1,198 km (744 mi). Perigee: 1,154 km (717 mi). Inclination: 90.1000 deg. Period: 108.90 min. Summary: Improved Transit. Pulsed plasma thruster.

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