The Thor-Burner was an American expendable launch system , a member of the Thor rocket family . It consisted of a Thor missile , with one or two Burner upper stages. It was used between 1965 and 1976 to orbit a number of satellites, most commonly Defense Meteorological Satellite Program (DMSP) weather satellites. Twenty-four were launched, of which two failed. It weighed 51,810 kg and was 24 metres tall.
34-422: There are many Thor-Burner variations, according to the type of upper stages used: The first two flights used a solid fuel MG-18 as second stage ( Thor-LV2D Burner-1 (MG-18) ). After that an Altair rocket stage (same as the third stage of some Vanguard launch vehicles) was used, equipped by Boeing with 3-axis control ( Thor-LV2D Burner-1 (Altair-3) ). These combinations were used for six vehicles. The first
68-506: A B-47 Stratojet . The Bold Orion was tested on 19 October 1959 against the Explorer 6 satellite. The two-stage Bold Orion missile passed within 4 miles (6.4 km) of Explorer 6. From this distance, only a relatively large yield nuclear warhead would likely have destroyed the target. Starting in 1960 the Department of Defense (DoD) started a program called SPIN (SPace INtercept). In 1962,
102-477: A DMSP satellite from Vandenberg's SLC-10W went awry when SECO occurred 5 seconds early. Although the second stage separated and fired properly, the satellite was left in an unusable orbit from which it decayed only one hour after launch. Investigation into the mishap found that the Thor had been loaded an insufficient amount of RJ-1 (a higher grade of kerosene fuel that offered enhanced performance over standard RP-1 ) for
136-474: A large area-to-mass ratio. According to NASA, as of January 1998, 8 of 285 trackable pieces remained in orbit. The last piece of debris, COSPAR 1979-017GX, SATCAT 16564, deorbited 9 May 2004 according to SATCAT . The Solwind test had three important results: In the end, the Solwind ASAT test had few consequences for the planned U.S. space station as station completion (indeed, even the launch of first module)
170-557: A result, the United States anti-satellite weapons development efforts were re-directed to develop systems that did not require the use of nuclear weapons. After the Soviet Union started developing an anti-satellite system, in 1978, U.S. President Jimmy Carter directed the USAF to develop and deploy a new anti-satellite system. In 1978, the USAF started a new program initially designated
204-536: A test against a satellite. The test was delayed to provide notice to the United States Congress . The target was the Solwind P78-1 , an orbiting solar observatory that was launched on 24 February 1979. On 13 September 1985, Maj. Wilbert D. "Doug" Pearson , flying the "Celestial Eagle" F-15A 76-0084 launched an ASM-135 ASAT about 320 kilometres (200 mi) west of Vandenberg Air Force Base and destroyed
238-470: Is similar to Thiokol Star 20 (TE-M-640), and both are designated by NASA as Altair IIIA. This rocketry article is a stub . You can help Misplaced Pages by expanding it . ASM-135 ASAT The ASM-135 ASAT is an air-launched anti-satellite multistage missile that was developed by Ling-Temco-Vought 's LTV Aerospace division. The ASM-135 was carried exclusively by United States Air Force (USAF) F-15 Eagle fighter aircraft . Starting in
272-549: The 48th Fighter-Interceptor Squadron based at Langley Air Force Base in Virginia for the anti-satellite mission. Both squadrons had airframes modified to support the ASM-135 by the time the project was cancelled in 1988. The USAF had planned to deploy an operational force of 112 ASM-135 missiles. The deployment of the ASM-135 was central to a policy debate in the United States over the strategic need for an anti-satellite weapon and
306-576: The US Navy launched Caleb rockets as part of the Satellite Interceptor Program , with the objective of developing an anti-satellite weapon. The United States developed direct ascent anti-satellite weapons. A modified United States Army Nike Zeus missile successfully intercepted an orbiting satellite in May 1963. One missile from this system known as Project MUDFLAP and later as Project 505
340-477: The 910 kilograms (2,000 lb) Solwind P78-1 satellite at closing velocity of 24,000 kilometres per hour (15,000 mph; 6.7 km/s). NASA learned of U.S. Air Force plans for the Solwind ASAT test in July 1985. NASA modeled the effects of the test. This model determined that debris produced would still be in orbit in the 1990s. It would force NASA to enhance debris shielding for its planned space station. Earlier
374-507: The ALMV. The LTV Aerospace design featured a multi-stage missile with an infrared homing kinetic energy warhead . The ASM-135 was designed to be launched from an F-15A in a supersonic zoom climb . The F-15's mission computer and heads-up display were modified to provide steering directions for the pilot. A modified Boeing AGM-69 SRAM missile with a Lockheed Propulsion Company LPC-415 solid propellant two pulse rocket engine
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#1732855657940408-461: The MHV separated from the second stage. The infrared sensor was developed by Hughes Research Laboratories . The sensor used a strip detector where four strips of Indium Bismuth were arranged in a cross and four strips were arranged as logarithmic spirals. As the detector was spun, the infrared target's position could be measured as it crossed the strips in the sensor's field of view. The MHV infrared detector
442-561: The Prototype Miniature Air-Launched Segment (PMALS) and Air Force Systems Command 's Space Division established a system program office. The USAF issued a Request for Proposal for the Air-Launched Miniature Vehicle (ALMV). The requirement was for an air-launched missile that could be used against satellites in low Earth orbit. In 1979, the USAF issued a contract to LTV Aerospace to begin work on
476-528: The Solwind P78-1 satellite flying at an altitude of 555 kilometres (345 mi). Prior to the launch, the F-15 — flying at Mach 1.22 — executed a 3.8 g 0 (37 m/s ) zoom climb at an angle of 65 degrees. The ASM-135 ASAT was automatically launched at 11,600 metres (38,100 ft) while the F-15 was flying at Mach 0.934 (992.2 km/h; 616.5 mph). The 14 kilograms (30 lb) MHV collided with
510-555: The U.S. Air Force and NASA had worked together to develop a Scout-launched target vehicle for ASAT experiments. NASA advised the U.S. Air Force on how to conduct the ASAT test to avoid producing long-lived debris. However, congressional restrictions on ASAT tests intervened. In order to complete an ASAT test before an expected Congressional ban took effect (as it did in October 1985), the DoD chose to use
544-461: The data sheet provided by Rocketdyne , however the information contained a typo which led to ground crews loading too little propellant for it. However, the postflight investigation also found that, even if the correct propellant load had been carried, the mission would have still failed because the Thor did not have sufficient performance to loft the DMSP into the required orbit. As the DMSP program evolved,
578-477: The existing Solwind astrophysics satellite as a target. NASA worked with the DoD to monitor the effects of the tests using two orbital debris telescopes and a reentry radar deployed to Alaska. NASA assumed the torn metal would be bright. Surprisingly, the Solwind pieces turned out to appear so dark as to be almost undetectable. Only two pieces were seen. NASA Scientists theorized that the unexpected Solwind darkening
612-616: The last used the X-248 which enabled the Vanguard to launch more massive payload. The X-248 was used as the second stage of some early Thor flights. These vehicles were designated " Thor-Burner ". Altairs were used as the third stage of early Delta rockets . The fourth stage of the Scout-X rocket used the "Altair-1A" stage, powered by a X-248A engine. The Altair 2 (X-258) Thiokol ( Star 25 , TE-M-184-3) solid rocket engine first flew in 1963 and
646-583: The late 1950s, the United States began development of anti-satellite weapons. The first US anti-satellite weapon was the Bold Orion Weapon System 199B (also the High Virgo missile, Weapon System 199C, attempted to conduct an ASAT test but failed to intercept its target; High Virgo's test was a few weeks before Bold Orion's). Like the ASM-135, the Bold Orion missile was air-launched, but in this case from
680-482: The limits of the ban by not engaging a space-borne target. In the same year the deployment of the ASM-135 was estimated to cost $ US5.3 billion up from the original $ US500 million estimate. The USAF scaled back the ASM-135 program by two-thirds in attempt to control costs. The USAF also never strongly supported the program and proposed canceling the program in 1987. In 1988, the Reagan Administration canceled
714-507: The missile towards the target satellite. LTV Aerospace also provided the third stage for the ASM-135 ASAT. This stage was called Miniature Homing Vehicle (MHV) interceptor. Prior to being deployed the second stage was used to spin the MHV up to approximately 30 revolutions per second and point the MHV towards the target. A Honeywell ring laser gyroscope was used for spin rate determination and to obtain an inertial timing reference before
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#1732855657940748-405: The mission. The amount of LOX on Thor boosters was always the same on every launch, but the amount of kerosene could vary depending on the engine, as different LR-79 engines had slightly different performance levels, and so factory acceptance data was used to determine the fuel load needed for a particular unit. The particular engine used in Thor 182 had thus been loaded with kerosene according to
782-526: The potential for anti-satellite weapon arms control with the Soviet Union . Starting in 1983, Congress placed various restrictions on the ASM-135 program, and in December 1985, banned testing the ASM-135 on targets in space. This decision was made only a day after the Air Force sent two target satellites into orbit for its next round of tests. The Air Force continued to test the ASAT system in 1986, but stayed within
816-505: The satellites gradually became heavier and more complex. Program planners, aware of this, selected an LR-79 engine which had particularly high performance, but it still turned out to not be enough for the mission. The failure was thus ultimately attributed to poor mission planning. There were twenty six Thor-Burner launches from Vandenberg AFB : DSAP-1 F10 (Stage 2 failed to separate from satellite) DSAP-1 F11 DSAP-3 F1 DSAP-2 F1 DSAP-4A F1 Altair (rocket stage) The Altair
850-476: The target satellite. Four pods at the rear of the MHV contained small attitude control rocket motors. These motors were used to damp off center rotation by the MHV. On 21 December 1982, an F-15A was used to perform the first captive carry ASM-135 test flight from the Air Force Flight Test Center , Edwards AFB , California in the United States. On 20 August 1985 President Reagan authorized
884-431: The target. Direct Proportional Line of Sight guidance used information from the detector to maneuver and null out any line-of-sight change. A Bang-bang control system was used to fire 56 full charge "divert" and lower thrust 8 half charge "end-game" solid rocket motors arranged around the circumference of the MHV. The half charge 8 "end-game" motors were used to perform finer trajectory adjustments just prior to intercepting
918-533: Was a solid-fuel rocket with a fiberglass casing, initially developed for use as the third stage of Vanguard rockets in 1959. It was manufactured by Allegany Ballistics Laboratory (ABL) as the X-248. It was also sometimes called the Burner 1 . The X-248 was one of two third-stage designs used during Project Vanguard . Early launches used a stage developed by the Grand Central Rocket Company , but
952-454: Was available for launch from 1964 until 1967. A nuclear-armed Thor anti-satellite system deployed by the Air Force under Program 437 eventually replaced the Project 505 Nike Zeus in 1967. The Program 437 Thor missile system remained in limited deployment until 1975. One drawback of nuclear-armed anti-satellite weapons was that they could also damage United States reconnaissance satellites. As
986-401: Was cooled by liquid helium from a dewar installed in place of the F-15's gun ammunition drum and from a smaller dewar located in the second stage of the ASM-135. Cryogenic lines from the second stage were retracted prior to the spin up of the MHV. The MHV guidance system solely tracked targets in the field of view of the infrared sensor, but did not determine altitude, attitude, or range to
1020-527: Was due to carbonization of organic compounds in the target satellite; that is, when the kinetic energy of the projectile became heat energy on impact, the plastics inside Solwind vaporized and condensed on the metal pieces as soot. NASA used U.S. Air Force infrared telescopes to show that the pieces were warm with heat absorbed from the Sun. This added weight to the contention that they were dark with soot and not reflective. The pieces decayed quickly from orbit, implying
1054-458: Was launched on 1965-01-18 and the sixth on 1966-03-30. These were early launches of classified DMSP satellites. Two of these launches failed. The Burner 2 used with the Thor-Burner was the first solid fuel upper-stage vehicle used for general space applications that had full control and guidance capability. The first Burner-2 flight was on 1966-09-16. On February 19, 1976, the attempted launch of
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1088-513: Was pushed beyond the mid-1990s. The record-high level of solar activity during the 1989–1991 solar maximum heated and expanded the atmosphere more than anticipated in 1985, accelerating Solwind debris decay. Fifteen ASM-135 ASAT missiles were produced and five missiles were flight tested. The United States Air Force intended to modify 20 F-15A fighters from the 318th Fighter Interceptor Squadron based at McChord Air Force Base in Washington and
1122-651: Was the kick stage motor for Delta D , Scout A , Scout X-4, and Atlas-D OV1 as part of the Orbiting Vehicle satellites. It was retired in 1973. The Altair 3 (FW-4S) solid rocket engine first flew in 1968 and was used on the Atlas-E/F OV1 as part of the OV1 upper stage. It was also used as the second stage of the ASM-135 ASAT anti-satellite missile. It as proposed as the fourth stage for Advanced Scout. The FW-4S motor
1156-570: Was used as the first stage of the ASM-135 ASAT. The LTV Aerospace Altair 3 was used as the second stage of the ASM-135. The Altair 3 used the Thiokol FW-4S solid propellant rocket engine. The Altair 3 stage was also used as the fourth stage for the Scout rocket and had been previously used in both the Bold Orion and Hi-Hoe (Caleb) anti-satellite weapons efforts. The Altair was equipped with hydrazine fueled thrusters that could be used to point
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