Hubbry Logo
Star (rocket stage)Star (rocket stage)Main
Open search
Star (rocket stage)
Community hub
Star (rocket stage)
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Star (rocket stage)
Star (rocket stage)
Star (rocket stage)
View on Wikipedia
from Wikipedia

The Star is a family of US solid-propellant rocket motors originally developed by Thiokol and used by many space propulsion and launch vehicle stages. They are used almost exclusively as upper stages, often as apogee kick motors. The number designations refer to the approximate diameter of the fuel casing in inches.

Three Star 37 stages, and one Star 48 stage, were launched on solar escape trajectories; fast enough to leave the Sun's orbit and out into interstellar space, where barring the low chance of colliding with debris, they will travel past other stars in the Milky Way galaxy and survive potentially intact for millions of years.

Star 13

[edit]

The Star 13 (TE-M-458) is a solid fuel apogee kick motor.[1][2] It was used on NASA's Anchored Interplanetary Monitoring Platform satellites.[3] Several other versions were developed.[1][4][5][6][7][8][9][2] Star 13D (TE-M-375) was used on the Syncom 1, Star 13A (TE-M-516) on LES 1/2, Aurora (P67-1), Orbiscal (P68-1), Lincoln Calibration Sphere 4, S3-2, Solrad 11A/B, SPX plume generator package, Freja, Meteor and Equator-S, Star 13C (TE-M-345-11/12) on AMSAT P3A and Star 13B (TE-M-763) on AMPTE-CCE payloads.[3]

Thiokol Star 13 family[1][4][5][6][7][8][9][2]
Name Thiokol# Mass (kg) Prop. mass fract. Imp. Burn (s)
Total Empty Spec., Isp (s) Tot. (kgf-sec)
Star 13 TE-M-458 36 5 0.869 273 8,524 22
Star 13A TE-M-516 38 5 0.87 287 9,544 15
Star 13B TE-M-763 47 6 0.87 286 11,807 15
Star 13C TE-M-345-11/12 38 8 0.795 218 8,252
Star 13D TE-M-375 35 6 0.81 223 7,799
Star 13E TE-M-385 31 6 0.822 211 6,438
Star 13F TE-M-444 40 7 0.83 240 9,608

Star 17

[edit]

The Star 17 (TE-M-479) is a solid fuel apogee kick motor, first launched in 1963.[10] It was used for payloads such as Radio Astronomy Explorer, SOLRAD and S3 satellites. The Star 17A (TE-M-521-5) version was used for orbit circularization on Skynet 1, NATO 1, IMP-H and IMP-J satellites.[10][11]

Thiokol Star 17 family[10][11]
Name Thiokol# Mass (kg) Prop. mass fract. Imp. Burn (s) Length (m)
Total Empty Prop. Spec., Isp (s) Tot. (kgf-sec)
Star 17 TE-M-479 79 9 70 0.881 286 20177 18 0.98
Star 17A TE-M-521-5 126 14 112 0.903 287 32556 19 0.98

Star 20 (Altair 3A)

[edit]

The Star 20 (TE-M-640) is a solid fuel apogee kick motor, also known as Altair-3A.[12] It was used as a second stage on an Atlas-E/F vehicle launching Stacksat.[13][14] The TE-M-640 motor is similar to Altair 3 (FW-4S), and both are designated by NASA as Altair IIIA.[15]

Thiokol Star 20 family[12]
Name Thiokol# Mass (kg) Prop. mass fract. Imp.
Total Prop. Spec., Isp (s) Tot. (kNs)
Star 20 Spherical TE-M-251 123 114.8 0.934 234 296.25
Star 20 TE-M-640-1 300.9 273.2 0.908 286.5 771.77
Star 20A TE-M-640-3 314.3 286.0 0.910 291.9 822.48
Star 20B TE-M-640-4 306.7 273.8 0.893 289.1 776.53

Star 24

[edit]

The Star 24 (TE-M-604) is a solid fuel apogee kick motor, first qualified in 1973.[16][17] It burns an 86% solids carboxyl-terminated polybutadiene (CTPB)[broken anchor]-based composite propellant.[16][18] The "24" designation refers to the approximate diameter of the Titanium fuel casing in inches.[16]

Thiokol Star 24 family[16][19][20][21]
Name Thiokol# Mass (kg) Prop. mass fract. Imp. Burn (s) Length (m)
Total Empty Prop. Spec., Isp (s) Tot. (kNs)
Star 24 TE-M-604 218.2 18.33 199.9 0.916 282.9 560.5 29.6 1.03
Star 24A TE-M-604-2 198 19 179 0.903 282 500
Star 24B TE-M-604-3 219 19 200 0.915 283 561.6
Star 24C TE-M-604-4 239.3 19.73 219.5 0.92 282.3 613.9 28.0 1.07

Star 26

[edit]

The Star 26 (Burner 2A or TE-M-442) is an upper stage motor used in Burner II stage of the Sandia Strypi IV vehicle introduced in 1965.[22] The Star 26B (TE-M-442-1) variant was used on the Thor-LV2F Burner-2A launcher.[23] Star 26C (TE-M-442-2) was used on the DOT sounding rocket.[24][25]

Thiokol Star 26 family[22][23][24]
Name Thiokol# Mass (kg) Prop. mass fract. Imp. Burn (s)
Total Empty Spec., Isp (s) Tot. (kN)
Star 26 TE-M-442 268 37 0.86 220 39.10 18
Star 26B TE-M-442-1 261 23 0.91 272 34.63 18
Star 26C TE-M-442-2 264 32 0.88 272 35 17

Star 27

[edit]
Star 27
A Star 27H kick motor for IBEX
Country of originUnited States
Solid-fuel motor

The Star 27 is a solid apogee kick motor, with the 27 representing the approximate diameter of the stage in inches.[26][27] It burns HTPB-based composite propellant with an average erosion rate of 0.0011 inches per second (0.028 mm/s).[28][26]

It as used as a second stage on a version of the Atlas E/F rocket, launching the Solwind and Geosat satellites.[29] When used on the Pegasus air-launch rocket payloads are capable of leaving Earth orbit.[26]

A version of the Star 27, designated the Star 27H,[30] was used in the launch of the IBEX spacecraft.[31] The spacecraft had a mass of 105 kg by itself and together with its Star 27H motor, 462 kg.[31] The Star 27H helped it get to a higher orbit, beyond Earth's magnetosphere.[31]

Thiokol Star-27 family[32][33][34][35][36]
Name Thiokol# Mass (kg) Prop. mass fract. Imp.
Total Empty Spec., Isp (s) Tot. (kgf-sec)
Star 27 TE-M-616 361 27 0.924 288 96986
Star 27A TE-M-616-1 336 27 0.919 288 89684
Star 27B TE-M-616-4 345 28 0.921 288 92296
Star 27C TE-M-616-5 333 28 0.918 288 88555
Star 27D TE-M-616-8 332 26 0.921 288 88668
Star 27E TE-M-616-9 331 26 0.921 287 88301

Star 30

[edit]

The Star 30 (TE-M-700-2) is a solid fuel motor, with the 30 representing the approximate diameter of the stage in inches.[37] Different versions (A, B, C, E and BP) were used as an apogee motor for satellites such as G-STAR, Skynet 4, Koreasat or the HS-376 satellite bus.[37] Star 30E was used by the small ORBEX orbital launcher.[37] A Star 30 booster was also used on the CONTOUR comet probe.[38]

Thiokol Star 30 family[37][39][40][41][42][43]
Name Thiokol# Mass (kg) Prop. mass fract. Imp.
Total Empty Spec., Isp (s) Tot. (kgf-sec)
Star 30 TE-M-700-2 492 28 0.943 293 136455
Star 30A TE-M-700-4 492 28 0.942 295 137095
Star 30B TE-M-700-5 537 32 0.941 293 148816
Star 30C TE-M-700-18 630 39 0.939 287 171002
Star 30E TE-M-700-19 667 45 0.932 291 182216
Star 30BP TE-M-700-20 543 38 0.931 292 148816

Star 31 (Antares 1A)

[edit]

The Star 31 (also known as Antares 1A or X-254) is a solid fuel motor, with the 31 representing the approximate diameter of the stage in inches.[44] It had a thrust of 60.50 kN and a mass of 1225 kg.[44] It was used as a stage on the WASP missile, Scout X, Scout X-1, Blue Scout Junior, Blue Scout I, Blue Scout II, Scout X-1A and RAM B.[44]

Star 37

[edit]
Star 37
Star 37E (TE-M-364-4)
Country of originUnited States
Date1963-present
ManufacturerThiokol
ApplicationUpper stage/Spacecraft propulsion
PredecessorStar 27
SuccessorStar 48
StatusActive
Solid-fuel motor
Configuration
Chamber1
Performance
Thrust, vacuum33.600 kN (7,554 lbf)
Specific impulse, vacuum(161,512 N•s/kg)
Dimensions
Length2.27 m (7.44 ft)
Diameter0.66 m (2.16 ft)
Empty mass113 kg (249 lb)
Used in
Upper stage on Thor and Delta

The Star 37 was first used as the engine for the Thor-Burner upper stage in 1965. The Burner I used the Thiokol FW-4 engine and the Burner II used the Thiokol TE-M-364-2.[45]

The "-37" designation refers to the approximate diameter of the titanium fuel casing in inches; Thiokol had also manufactured other motors such as the Star 40 and Star 48. Internally, Thiokol's designation was TE-M-364 for early versions, TE-M-714 for later ones, and TE-M-783 for a special HTPB model used for FLTSATCOM launches.

Subtypes are given one or more letter suffixes after the diameter number, or a trailing number (i.e., "-2") after the internal designation. Not surprisingly, the "T" prefix stands for Thiokol, and the following letter refers to the company division that developed the rocket motor. In this case, "M" refers to the Magna, UT Division. "E" refers to the Elkton, MD division.

The Star 37FM rocket motor was developed and qualified for use as an apogee kick motor on FLTSATCOM. The motor is a replacement for the Star 37E Delta, which has been discontinued. The Nozzle assembly uses a 3D carbon-carbon throat and a carbon-phenolic exit cone. Maximum propellant weight is 2,350 pounds (1,070 kg), while the motor has been qualified for propellant off-loading to 2,257 pounds (1,024 kg).

A spin-stabilized (Star 37FM) or thrust-vectoring (Star 37FMV) version of Star 37 is used as the final stage of the Minotaur V launch vehicle.[46][47]

The Pioneer 10 & 11, and Voyager 1 & 2 Propulsion Modules used Star 37E motors; each is now on a similar interstellar trajectory to its companion probe, and is set to leave the Solar System (except the Pioneer 11 stage, which is thought to have remained in solar orbit[48]).

Thiokol Star 37 family
Name (Thiokol#) Mass (kg) Prop. mass fract. Prop. Thrust, vac. (kN) Imp. Burn (s) Length (m) Remark
Total Empty Prop. Spec., Isp (s) Tot. (kNs)
Star 37 (TE-M-364-1) 621.2 62.7 558.4 0.899 Solid 43.50 260.0 1584.46 42 0.80
Star 37B (TE-M-364-2) 718.4 64.7 653.7 0.910 Solid ? 291.0 1858.91 ? ?
Star 37C (TE-M-364-18) 1047.5 82.8 964.7 0.921 Solid ? 285.5 2707.19 ? ?
Star 37D (TE-M-364-3) 718.4 64.7 653.7 0.910 Solid ? 266.0 1858.91 ? ?
Star 37E (TE-M-364-4) 1122.7 83.1 1039.6 0.926 Solid ? 283.6 2910.03 ? ? Discontinued
Star 37F (TE-M-364-19) 934.1 67.3 866.8 0.928 Solid ? 286.0 2444.46 ? ? Discontinued
Star 37FM (TE-M-783) 1147.4 81.5 1065.9 0.929 HTPB 47.26 289.8 3051.35 63 1.69 Developed and qualified for use as an apogee kick motor on FLTSATCOM
Star 37G (TE-M-364-11) 1152.4 86.4 1065.9 0.925 Solid ? 289.9 2988.36 ? ?
Star 37N (TE-M-364-14) 622.9 63.5 559.3 0.898 Solid ? 290.0 1590.24 ? ?
Star 37S (TE-M-364-15) 711.4 53.4 658.0 0.925 Solid ? 287.3 1872.43 ? ?
Star 37X (TE-M-714-1) 1150.0 82.8 1067.2 0.928 Solid 51.10 295.6 3047.69 60 ?
Star 37XE (TE-M-714-4) ? ? ? ? Solid ? ? ? ? ?
Star 37XF (TE-M-714-6) 953.2 67.7 885.4 0.929 Solid ? 290.0 2542.03 ? ?
Star 37XF (TE-M-714-8) 882.5 67.1 815.4 0.924 Solid ? 291.1 2342.74 ? ?
Star 37XFP (TE-M-714-17/18) 955.3 71.7 883.6 0.925 HTPB 38.03 290.0 2537.49 67 1.50 Qualified as the orbit insertion motor for Boeing's Global Positioning Satellite (GPS), and as the apogee motor for the RCA SATCOM Ku-Band satellite.
Star 37Y (TE-M-714-2) 1152.1 80.6 1071.4 0.930 Solid ? 297.0 3118.20 ? ?

Star 48

[edit]
Star 48
Star-48B rocket motor
Country of originUnited States
Date1982 - present
ManufacturerThiokol
PredecessorStar 37
Solid-fuel motor
Main article: Star 48

The Star 48 is a type of solid rocket motor developed primarily by Thiokol Propulsion, which was purchased by Orbital ATK in 2001. In 2018, Orbital ATK in turn was acquired by Northrop Grumman.

The "48" designation refers to the approximate diameter of the fuel casing in inches; Thiokol had also manufactured other motors such as the Star 37 and Star 30. Internally, Thiokol's designation was TE-M-711 for early versions, and TE-M-799 for later ones. Subtypes are given one or more letter suffixes after the diameter number, or a trailing number (i.e., "-2") after the internal designation. The "T" prefix stands for Thiokol, and the following letter refers to the company division that developed the rocket motor. In this case, "E" refers to the Elkton, MD division and the "M" stands for motor.

The most common use of the Star 48 was as the final stage of the Delta II launch vehicles. Other launchers such as ULA's Atlas 551 have also incorporated the motor, but with lower frequency. On board the Space Shuttle, the complete stage (motor plus accessories) was referred to as the Payload Assist Module (PAM), as the Shuttle could only take satellites to low Earth orbit. Because geostationary orbit is much more lucrative, the additional stage was needed for the final leg of the journey. On such missions, the stage was spin-stabilized. A turntable, mounted in the shuttle payload bay or atop the previous Delta stage, spun the PAM and payload to approximately 60 rpm prior to release.

Usually after motor burnout and just prior to satellite release the spin is canceled out using a yo-yo de-spin technique.

A non-spinning, thrust-vectoring version is known as the Star 48BV, which had its design based off of the Star 48B.[49] It is available, but much less common. A Star 48BV is the final stage of the Minotaur IV+ launch vehicle.

A Star 48B motor used in the 3rd stage of the New Horizons probe was the first part of the New Horizons mission to reach Jupiter, crossing Pluto's orbit in 2015 at a distance of 200 million kilometers.[50] It is now set to leave the Solar System, traveling on a similar interstellar trajectory to its companion probe for the indefinite future.

In 2013 a Star 48GXV was tested for the Parker Solar Probe mission as the upper stage on an Atlas V 551 vehicle,[51] but the development was canceled, in favor of a Delta IV Heavy / Star 48BV combination. The Star 48GXV boasted a carbon composite casing and nozzle, enabling it to operate at triple the chamber pressure of an ordinary Star 48. It also featured electro-mechanical actuators to gimbal the nozzle, along with digital flight controls.[52]

Star 63

[edit]

The Star 63 is a solid fuel motor, with the 63 representing the approximate diameter of the stage in inches. Different versions exist: Star 63D (used on PAM-D2), Star 63DV and Star 63F.[53][54] It was used to launch payloads from the Space Shuttle, and as stage on the Titan 34D and Delta 7925 rockets.[53][54]

Thiokol Star-63 family[53][54]
Name Thiokol# Mass (kg) Prop. mass fract. Imp. Burn (s)
Total Empty Spec., Isp (s) Tot. (kNs)
Star 63D TU-936 3499.1 248.4 0.929 283.0 9043.23 118
Star 63DV 118
Star 63F TE-M-963 4590.4 325.9 0.929 297.1 12530.64 120

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Star (rocket stage)

View on Grokipedia
from Grokipedia
The Star is a family of motors originally developed by Chemical in the 1960s and now produced by , primarily utilized as upper stages in launch vehicles, apogee kick motors for satellites, and propulsion systems for space missions. These motors employ high-performance propellants such as TP-H-3062 and TP-H-3340, with case materials ranging from to Kevlar-epoxy composites, enabling a wide range of thrust levels from approximately 38 lbf to over 57,000 lbf and total impulses up to 10,000,000 lbf-sec. Over 1,300 successful flights have demonstrated their reliability across more than 70 qualified variants, making them a cornerstone of U.S. space and defense propulsion since the mid-20th century. The development of the Star family began with early models like the STAR 5C in the early 1960s, evolving through qualifications for programs such as Sandia's Strypi IV (STAR 26, 1964) and NASA's International Ultraviolet Explorer (STAR 24C, 1978). Thiokol's innovations in solid propulsion, building on post-World War II advancements in propellant chemistry and motor design, positioned the Star series as versatile building blocks for multi-stage rockets, with ongoing enhancements into the 21st century including composite cases for improved mass fractions up to 0.94. Key milestones include the qualification of larger variants like the STAR 48 in the 1980s for the Payload Assist Module (PAM) on the Space Shuttle, reflecting Thiokol's (later Northrop Grumman's) expertise in scalable, flight-proven technology. Notable applications span scientific, commercial, and military missions, including the propulsion of NASA's (STAR 5D, 1997) and (STAR 8, 2004) landers, as well as upper stages for the Scout (STAR 31, 1979) and Delta II (, multiple GPS and GOES satellites). The B powered the mission to (2006), while the BV served in the (2018) and numerous apogee insertions for communications satellites like Anik and GOES series. Smaller variants, such as the STAR 12GV, have supported tactical systems like the U.S. Navy's , and emerging models like the Oriole (22-inch diameter, qualified 2000) enable sounding rockets and hypersonic testing, with continued use in missions into the 2020s. This broad utility underscores the Star family's enduring role in enabling precise orbital insertions and deep-space trajectories.

Introduction

Background and Naming

The Star family comprises a series of solid-propellant rocket motors originally developed by Thiokol Chemical Corporation, now produced by Northrop Grumman, primarily for use as upper stages and apogee kick motors in space launch vehicles and satellite systems. These motors provide reliable, high-thrust propulsion for post-launch maneuvers, leveraging solid propellant technology to deliver precise velocity increments in vacuum environments. The for the Star motors is straightforward and size-based, with the numerical designation indicating the approximate of the motor casing in inches—for instance, the Star 37 features a casing around 37 inches in . This system allows for easy identification of the motor's scale and intended application within the family, which has evolved over decades to include configurations optimized for various mission profiles. In general, Star motors serve critical roles in insertion, velocity adjustments, and delivery for space missions, enabling satellites and probes to reach their operational orbits after separation from primary launch vehicles. The family encompasses a broad size range, from smaller variants like the 13-inch diameter Star 13 to larger ones such as the 63-inch diameter Star 63, with total impulses varying from thousands of lbf-sec in compact models (e.g., approximately 280 lbf-sec for the Star 3) to millions of lbf-sec in high-performance units (e.g., over 2.8 million lbf-sec for the Star 63F). This versatility supports applications across scientific, commercial, and space endeavors.

Role in Space Missions

The Star family of solid rocket motors has played a pivotal role as upper stages in launch vehicles such as Delta and Titan, providing the necessary thrust for payload deployment into high-energy following separation from lower stages. These motors have also served as apogee and perigee motors for satellites, enabling precise orbit circularization and adjustments after initial insertion, which is essential for long-term operational stability in geosynchronous or other specialized . Additionally, Star motors function as stages for deep probes, delivering the final increments required for escape trajectories beyond Earth's influence. Notable achievements of the Star series include enabling interstellar trajectories for landmark NASA probes, such as and 11, and 2, and , where they provided critical propulsion burns to achieve solar system escape velocities and facilitate extended exploration of the outer planets and beyond. The family has accumulated over 1,300 successful flights across , U.S. military, and commercial missions, demonstrating exceptional reliability in diverse environments from to interplanetary space. For instance, the motors powered the propulsion module for , igniting shortly after separation to boost the probes toward and Saturn encounters. Integration examples highlight the Star family's versatility, including its use in the Payload Assist Module (PAM) systems for Delta-launched satellites, where variants like the provide spin-stabilized boosts to geosynchronous transfer orbits; the Burner upper stages for Thor-derived vehicles, enhancing payload capacity for early reconnaissance missions; and contributions to air-launched programs like and ground-based ones like , supporting constellations and responsive launches. This widespread adoption has significantly improved mission accessibility by offering low-cost, storable solid propulsion solutions that reduce complexity and preparation time for orbit raising and small payload delivery, thereby democratizing space access for scientific and commercial endeavors.

Development History

Origins at Thiokol

The Star family of solid-propellant rocket motors originated at Chemical Corporation during the and , as the company expanded from chemical manufacturing into aerospace propulsion to meet growing demands for reliable upper-stage engines in the early space era. established dedicated facilities, including a major solid-fuel rocket plant in in 1956, to support this shift amid the emphasis on missile and satellite technologies. The development was driven by the need for dependable solid motors following the mixed successes of early programs like , where upper-stage solid propellants proved essential but highlighted reliability challenges in achieving orbital insertion. Key contracts from the U.S. and fueled Thiokol's early efforts, positioning the Star series as a cornerstone for military and civilian space applications. In 1958, the awarded Thiokol one of the three primary contracts for the Minuteman intercontinental ballistic missile's solid-propellant stages, alongside and , accelerating Thiokol's expertise in scalable, high-performance motors. , seeking robust propulsion for sounding rockets and satellite launches post-Vanguard, integrated Thiokol motors into programs like Nike-Tomahawk vehicles developed for atmospheric research. These partnerships emphasized motors that could deliver precise thrust for upper stages, addressing the limitations of liquid-fueled alternatives in terms of storability and simplicity. The first major qualifications of the Star family marked Thiokol's breakthrough in the mid-, with the Star 26 certified in 1964 for use in the Air Force's Thor-Burner upper stage and Sandia's Strypi IV vehicle, enabling controlled orbital insertions for reconnaissance payloads. This was followed by the Star 37's qualification in 1965, also for the Thor-Burner II configuration, which powered multiple Delta and Thor launches to support early deployments. Early innovations included the adoption of composite propellants—combining oxidizer with binders for improved and stability—alongside fiberglass-reinforced cases to reduce weight and costs compared to alternatives. These advancements, demonstrated in tests like the 156-inch fiberglass case motor in the early , laid the foundation for the Star family's versatility in space missions.

Evolution and Modern Use

During the 1980s and 1990s, the Star family saw expanded applications in key U.S. space programs, including the motor integrated into the Payload Assist Module-D (PAM-D) for deploying commercial satellites from missions, such as those on through . Similarly, variants like the Star 63 were employed as upper-stage kick motors in the , supporting payloads through the program's operational peak. These developments coincided with significant corporate restructuring: merged with Morton-Norwich in 1982 to form Morton Thiokol, which spun off its division as Thiokol Corporation in 1989; by 1998, Thiokol rebranded as Cordant Technologies to reflect its diversified propulsion portfolio. Cordant was acquired by in 2000, briefly placing the Star production under aluminum giant oversight. In 2001, (ATK) acquired Thiokol Propulsion from for $685 million, consolidating expertise in solid rocket motors and enabling further integration of Star variants into defense and space applications. ATK merged with Orbital Sciences in 2015 to create Orbital ATK, enhancing capabilities that incorporated Star motors. The acquisition of Orbital ATK by was completed on June 6, 2018, renaming the propulsion unit Northrop Grumman Innovation Systems and positioning the Star family within a broader portfolio of advanced solid systems. Full integration of the acquired assets occurred through a sector reorganization effective January 1, 2020, which absorbed Innovation Systems into the Aeronautics Systems, Defense Systems, Mission Systems, and Space Systems sectors. As of 2025, continues production of motors, notably the 48BV variant used as an optional fourth stage on the launch vehicle, which achieved a successful NROL-174 mission for the in April 2025, demonstrating 100% reliability across recent flights since 2010. To enhance , the company has conducted tests, including for large solid rocket motors like those in the 2024 Solid Motor Annual Rocket Technology Demonstrator (SMART Demo), which streamlines design and production processes applicable to legacy families such as . Emerging adaptations explore -derived technologies for hypersonic applications, leveraging their proven high-thrust performance in rapid-response scenarios. Certain variants, such as the 63, were phased out following the program's decommissioning in 2005, ending its role in heavy-lift military launches after 36 successful missions. Nonetheless, maintains active support for legacy Star missions through sustainment programs, ensuring reliability for stored motors and potential reactivation in government contracts.

Technical Design

Construction and Materials

The Star family of solid rocket motors features a modular construction that allows scalability across a range of sizes, with structural components designed for high pressure containment and thermal protection during operation. Early models, such as the STAR 5C, 5CB, and 5F, utilized steel cases, typically D6AC alloy, for robust pressure vessels in initial developments by Thiokol. Subsequent iterations transitioned to lighter materials for improved performance; for instance, aluminum cases were employed in the STAR 5A and 6B, while titanium alloys like 6Al-4V became standard in smaller to medium variants including the STAR 3, 5D, 8, 13B, 17, 17A, and 24, offering a balance of strength and reduced weight. Later evolutions incorporated advanced composites for further mass efficiency: fiberglass-epoxy in the STAR 20, Kevlar-epoxy in the STAR 31, and graphite-epoxy (e.g., IM7/55A filament-wound) in models like the STAR 4G, 9, 12GV, 15G, 30XL, 48GXV, and related GEM series, enabling significant weight reductions compared to metallic cases while maintaining structural integrity under operational loads. Nozzle designs in the Star family vary between fixed and extendible configurations to accommodate different mission requirements, with many incorporating flexseal mechanisms for thrust vector control in vectorable variants. Fixed nozzles predominate in non-steerable models, featuring carbon-phenolic or graphite exit cones for thermal resistance, as seen in the STAR 20 and Orion 32. Extendible flexseal nozzles, derived from qualified fixed designs, enable deployment and vectoring (e.g., ±4° in the STAR 48BV), utilizing polyisoprene or natural rubber seals with steel shims and actuators for flexibility and sealing. Throats across the family commonly employ carbon-carbon composites, such as 3D or 4D carbon-carbon for high-temperature endurance, or graphite/pyrolytic graphite in earlier or smaller motors like the STAR 17 and 37FM; aft closure systems integrate these nozzles seamlessly with the case for vehicle-level assembly. Ignition systems rely on pyrotechnic pyrogen assemblies, often head-end or forward-mounted for reliable initiation, with redundant designs in models like the STAR 13A/B and consumable aluminum-cased variants in modern iterations; the STAR 27, for example, includes a 0.5 lbm pyrogen charge. Thermal insulation consists of elastomeric liners, primarily formulations—such as silica-filled EPDM in the STAR 30C or aramid-filled EPDM in the GEM 60 and ASAS series—to shield the case from heat and prevent burn-through, with Kevlar-filled options enhancing durability in high-stress environments. These components support modular assembly, facilitating customization and across the family. The Star motors exhibit scalable dimensions to suit diverse applications, with diameters ranging from approximately 3 inches in the smallest variants like the STAR 3 to 63 inches in larger ones such as the STAR 63D, lengths from about 11 inches (e.g., STAR 3) to 150 inches (e.g., STAR 30XL at 144.2 inches), and inert masses spanning less than 1 kg for the smallest models to around 500 kg in extended configurations like the series (e.g., 131 kg inert for STAR 48A).

Propellant and Performance

The Star family of solid rocket motors primarily employs composite solid propellants based on (HTPB) as the binder, combined with (AP) as the oxidizer and aluminum (Al) powder as the additive, with aluminum content typically ranging from 6% to 20% by weight. Earlier variants utilized -based binders or carboxyl-terminated polybutadiene (CTPB), reflecting evolutionary improvements in propellant formulation for enhanced and stability. These high-solids-content formulations, often exceeding 85-89% solids loading, enable efficient in space environments. Propellant grain geometries within the Star family are designed to achieve tailored thrust profiles, commonly featuring finocyl or star-shaped configurations that provide neutral to progressive burning characteristics. These geometries optimize the burning surface area evolution, supporting burn durations from less than 1 second to 120 seconds, depending on mission requirements. The grains are cast to ensure high utilization, approaching 95% efficiency through precise control of regression rates and minimal residue formation. Performance metrics for the Star family include vacuum specific impulses ranging from approximately 190 to 310 seconds, reflecting the propellant's chemical efficiency and expansion ratios optimized for upper-stage applications. Total impulses scale with motor size from about 10³ to 10⁷ N·s, enabling a broad spectrum of increments for orbital insertion and maneuvering. Thrust-to-weight ratios generally fall between 10 and 20, balancing high with structural integrity under operational loads. Burn characteristics emphasize reliability in and zero-gravity conditions, with neutral burns for steady and progressive profiles for rapid impulse delivery in short-duration firings. Qualification involves extensive static fire testing to verify performance under simulated flight environments, contributing to the family's overall success rate of 99.79% across thousands of tests and flights.

Variants

Star 13

The Star 13 represents the smallest variant in the Star family of solid-propellant rocket motors, originally developed by Chemical Corporation for precise, low-thrust applications in early missions requiring fine adjustments. With a of 13 inches (0.33 m) and a length of approximately 60 inches (1.52 m), it was designed to provide controlled velocity increments for small payloads, enabling apogee raising and attitude control in resource-constrained environments. Key specifications include a mass ranging from 22 to 35 kg of , delivering a total impulse between 6,438 and 11,807 kgf·s and a (Isp) of 211 to 287 seconds. Average thrust levels fall in the range of approximately 3 to 5 kN, with burn times varying from 15 to 22 seconds depending on the configuration, making it suitable for micro-adjustments without excessive structural demands on the host . The motor's total spans 31 to 47 kg across variants, balancing with minimal added for lightweight satellites. The Star 13 encompasses several sub-variants, designated 13A through 13F, each optimized for specific mission profiles such as orbit insertion, inclination changes, or retrofiring. For instance, the 13A (TE-M-516) features a stretched case for enhanced capacity, while the 13B (TE-M-763) incorporates a titanium alloy case for improved strength-to-weight ratio and was qualified in 1983. The 13D (TE-M-375) prioritized reliability for early geosynchronous attempts, and later iterations like 13E and 13F focused on higher impulse efficiency through refined designs. These adaptations allowed the motor to serve as an (AKM) or perigee kick motor (PKM) in elliptical transfer orbits. Notable applications include its debut flight in 1963 as the apogee motor for Syncom 1, NASA's pioneering , where it successfully demonstrated solid-propellant orbit circularization despite the mission's ultimate communications failure due to other factors. In 1966, a Star 13A variant propelled Explorer 33 into as part of the Anchored Interplanetary Monitoring Platform program, enabling despite partial mission anomalies from performance. The motor's final major use came in 1992 aboard Sweden's Freja scientific satellite, where a Star 13A raised the apogee to 1,756 km for auroral and , marking its role in international collaborations. A distinctive feature of the Star 13 is its lightweight case construction, often using filament-wound composites or to minimize mass for small payloads, which contributed to its efficiency in low-thrust scenarios. Though retired from production by the late 1990s following the acquisition of Thiokol's propulsion assets by , the Star 13 left a legacy in enabling precise maneuvers for over two decades of missions, influencing subsequent small-motor designs for propulsion.

Star 17

The Star 17 is a compact motor developed by Chemical Corporation as part of the early Star family, featuring a of 17.4 inches (0.44 m) and a length of approximately 27 inches (0.69 m). It utilizes a case and TP-H-3062 , an 86% solids-loaded carboxy-terminated (CTPB) formulation that represented an early advancement in polybutadiene-based composites for improved performance and stability in vacuum environments. The motor's design emphasized reliability for apogee maneuvers, with a of 70 kg (153.5 lbm) and an 8-point star grain configuration to achieve consistent burn characteristics. Key performance specifications for the Star 17 include a total impulse of 20,200 kgf⋅s (44,500 lbf⋅s), an effective of 286 s, maximum of 12.3 kN (2,775 lbf), average of 11 kN (2,460 lbf), and a time of 18 seconds. The nozzle incorporates a carbon insert and silica-phenolic exit cone with an of 53:1 to optimize operation. A variant, the Star 17A (TE-M-521-5), extends the length to 38.6 inches (0.98 m) with added straight section for integration, increasing total mass to 126 kg (277 lbm) and mass to 112 kg (247.5 lbm), while delivering a higher total impulse of 32,556 kgf⋅s (71,800 lbf⋅s), of 287 s, maximum of 17.3 kN (3,900 lbf), and time of 19 seconds.
ParameterStar 17Star 17A
Diameter (in/cm)17.4 / 44.217.5 / 44.5
Length (in/cm)27.1 / 68.838.6 / 98.0
Total Mass (kg/lbm)79 / 174.3126 / 277
Propellant Mass (kg/lbm)70 / 153.5112 / 247.5
Total Impulse (kgf⋅s / lbf⋅s)20,200 / 44,50032,556 / 71,800
(s)286287
Average Thrust (kN / lbf)11 / 2,46017 / 3,800 (approx.)
Burn Time (s)1819
The Star 17 family saw its first flight in 1963 aboard an Atlas LV-3A/Agena D launch vehicle, marking an early application in low-thrust orbital insertion tasks. It gained prominence as an for the Explorer-A (RAE-A, Explorer 38) , launched on July 4, 1969, via , where it provided the delta-v for placement to enable low-frequency radio observations. The Star 17A variant supported circularization for missions including Skynet 1 in November 1969, a British , demonstrating its role in early GEO insertions despite the challenges of limited capacity. Production remained limited to around 15 units, as rapid advancements in larger Star variants like the Star 20 quickly rendered the 17 obsolete for most subsequent programs by the early .

Star 20

The Star 20 is a family of small motors developed by Chemical Corporation, with the Altair-3A designation applied to certain configurations used in upper-stage roles. These motors feature a filament-wound fiberglass-epoxy composite case and were designed for high mass fractions, typically around 0.91-0.93, enabling efficient performance in space environments. Key specifications for the Star 20 include a of 20 inches (0.51 m) and a of approximately 82 inches (2.08 m) in baseline configurations, though variants exhibit some dimensional variations. mass ranges from 100-150 kg, delivering total impulses between 296 and 822 kN·s, with specific impulses of 234-292 seconds and average thrusts of about 5-7 kN. Multiple configurations exist within the family, such as the TE-M-251 (Star 20 Spherical) with a total mass of 123 kg and the TE-M-640-3 (Star 20A) at 314 kg, featuring burn times of 40-80 seconds tailored to mission requirements. In applications, the Star 20 served as a second-stage motor on refurbished Atlas E/F launch vehicles from the through the , providing velocity increments for small payloads. It was notably employed in the 1990 Atlas E/F launch of the Stacksat experiment, a stack of three microsatellites (POGS, SSR, and TEX) for technology demonstrations in . Additionally, under the Altair-3A designation, it supported missions and suborbital tests, leveraging its modular design for rapid integration. A distinctive aspect of the 20 lineage is its evolution from the series, incorporating advancements in composite casing and propellant formulations that bridged early solid-propellant designs with performance characteristics approaching hybrid systems in and controllability. This adaptability made it suitable for both orbital insertion and suborbital trajectories, with configurations qualified for flight as early as the .

Star 24

The Star 24 is a solid-propellant developed by , qualified in 1973 as a mid-sized option for circularization and transfer maneuvers in the mid-1970s. It marked an early adoption of carboxyl-terminated polybutadiene (CTPB) propellant, specifically the TP-H-3062 formulation with 86% solids loading, which provided higher compared to prior polybutadiene-based binders and improved performance for geosynchronous missions. This innovation enhanced while maintaining compatibility with spin-stabilized upper stages, addressing the growing demand for reliable propulsion in Department of Defense (DoD) and scientific programs. Key specifications for the Star 24 include a of 24 inches (0.61 m), an overall of approximately 42 inches (1.07 m), and a mass ranging from 200 to 220 kg depending on configuration. The motor delivers a total impulse of 560 to 614 kN·s, with a of 282 to 283 seconds and average around 20 kN, enabling efficient delta-v additions for payloads up to several hundred kilograms. Burn times are typically 28 to 30 seconds, supporting precise insertion into high-energy orbits without excessive structural demands on the host vehicle.
ParameterValue (Standard)Value (Star 24C Variant)
Total Mass (kg)218239
Propellant Mass (kg)200220
Empty Mass (kg)1819
Total Impulse (kN·s)560614
Specific Impulse (s)283282
Average Thrust (kN)2022
Burn Time (s)3028
The Star 24 features two primary variants: the standard model and the Star 24C, a modified version with an elongated cylindrical section, increased loading, and a larger throat for higher performance. The Star 24C, qualified for NASA's International Explorer (IUE) mission, shortens the effective burn profile while boosting energy output, with masses between 198 and 239 kg across configurations. In applications, the Star 24 supported various DoD satellites, including the UK's Skynet II communications satellite as its primary apogee motor, and facilitated orbit transfers for scientific missions like the IUE launched in 1978 on a Delta vehicle. It also powered the Pioneer Venus orbiter's propulsion needs during its 1978 deployment, demonstrating reliability in interplanetary environments. These uses highlighted its role in transitioning from earlier Atlas-derived motors to more versatile systems, serving as a developmental bridge toward larger Star variants employed in air-launched vehicles like Pegasus precursors. A unique aspect of the Star 24 is its optional case construction, which offers superior resistance for long-term storage and exposure to humid launch environments, unlike cases in smaller siblings. This design choice, combined with a carbon-phenolic exit cone, ensured over 100% success in flights through the , influencing subsequent mid-sized solid motors for dual-use applications.

Star 26

The Star 26, designated TE-M-442 by , is a motor developed as an upper stage for early space applications, with a of 26 inches (66 cm) and a nominal of 33 inches (84 cm). It features a mass of approximately 230-238 kg using the TP-H-3114 formulation, delivering a total impulse of 138,500-142,760 lbf-s (equivalent to about 616-635 kN-s), a of 271-273 seconds, and an average of 7,500-7,800 lbf (33-35 kN) over a burn time of 16.8-17.8 seconds. Qualified in 1964, the motor was initially constructed with a D6AC case, emphasizing reliability for short-burn boost phases in sounding and target missions. Variants of the Star 26 include the baseline Star 26 and lightweight iterations Star 26B (TE-M-442-1, qualified 1970) and Star 26C (TE-M-442-2), which incorporate cases for reduced mass (total inert mass around 30-40 kg, yielding overall motor masses of 261-268 kg) and enhanced performance in high-spin environments up to 400 rpm. These later models maintain similar performance envelopes but offer a of 0.86 and expansion ratios of 16.7:1 to 17.8:1, supporting adaptability for upper-stage roles without significant redesign. The -cased variants achieved at least 14 flights collectively, demonstrating the motor's evolution from steel-based prototypes to optimized configurations for dynamic mission profiles. In applications, the Star 26 served as the upper stage for the ' Strypi IV vehicle in the , providing precise velocity increments for re-entry and target testing. It also powered the Burner 2A stage in the , enabling suborbital and orbital insertions for experiments during the late and early 1970s. Additionally, the Star 26C variant was employed in the U.S. Army's Designated Optical Tracker (DOT) sounding rockets, which utilized a configuration of two Recruit boosters, a Castor first stage, and the Star 26C for atmospheric research and tracking demonstrations. These roles highlighted the motor's versatility in short-duration, high-thrust scenarios for both developmental and operational programs.

Star 27

The Star 27 is a solid-propellant rocket motor developed by Thiokol (now Northrop Grumman) as an apogee kick stage, primarily utilized in satellite missions and launch vehicle upper stages from the late 1970s through the 2000s. It features a nominal diameter of 27 inches and lengths ranging from 48 to 102 inches, depending on configuration, with propellant masses between 300 and 500 kg. The motor delivers a total impulse of 88,000 to 97,000 kgf·s, a specific impulse of 287 to 288 seconds in vacuum, and an average thrust of approximately 20 kN. Key variants include the baseline Star 27 (designation TE-M-616, qualified in 1975) and the Star 27H (TE-M-1157, qualified in 2007), with total masses of 331 to 361 kg and burn times of 30 to 50 seconds. The Star 27H incorporates an HTPB-based (TP-H-3340) for enhanced performance, achieving a longer burn duration of about 46 seconds and a higher expansion ratio of 81.7:1 compared to the baseline's 48.8:1. In applications, the Star 27 served as the upper stage for Atlas E/F launches, including the satellite in 1979 and Geosat in 1985, providing final orbital insertion. It also functioned as a kick motor for the launch vehicle and powered apogee maneuvers for satellites such as the Communications Technology Satellite (CTS) in 1976, GOES weather series, and NASA's (IBEX) mission in 2008 using the Star 27H variant. These uses highlight its role in achieving geosynchronous or high-altitude orbits for scientific and commercial payloads. A distinctive feature of the Star 27 is its standard use of forged titanium cases (6Al-4V alloy), which offer high strength-to-weight ratios and corrosion resistance for reliable performance in space environments. The design emphasizes high reliability, with over 300 successful flights across the broader STAR family, and supports extended burns for geostationary transfer orbit (GTO) insertions in commercial satellites. Propellant formulations like TP-H-313S enable tailored performance, including options for partial offloading to match mission delta-v requirements.

Star 30

The Star 30 is a family of motors developed by (now part of Northrop Grumman Innovation Systems) specifically for apogee kick applications in geosynchronous Earth orbit (GEO) satellite missions, with initial deployments beginning in the mid-1980s. These motors provided the critical velocity increment needed to circularize transfer orbits into operational GEO slots for commercial and satellites. Optimized for reliability in vacuum environments, the Star 30 variants emphasized lightweight construction and precise burn profiles to minimize mass while delivering sufficient delta-V for payloads up to several thousand kilograms. Key specifications for the Star 30 include a of 30 inches (0.76 m), lengths ranging from 59 to 110 inches (1.50 to 2.79 m) across variants, mass of 500-800 kg, total impulse between 136 and 182 thousand kgf-s (1.33-1.78 MN-s), of 287-295 seconds, and average of approximately 25 kN. These parameters enabled efficient orbital insertion for GEO transfers, with the motors using hydroxyl-terminated polybutadiene (HTPB)-based solid s for consistent performance.
VariantPropellant Mass (kg)Length (in)Total Impulse (thousand kgf-s)Isp (s)Avg. Thrust (kN)Burn Time (s)
Star 30BP50559.314929526.655
Star 30C59158.817028932.552
Star 30E63166.318529335.252
The primary variants—Star 30BP, 30C, and 30E—differ in case length, design, and loading to accommodate varying mission requirements, with total masses from 492 to 667 kg and burn durations of 50-60 seconds. The Star 30BP incorporates a filament-wound case and 89%-solids HTPB , enabling higher delta-V through reduced inert mass and improved compared to earlier iterations. Similarly, the 30C and 30E variants feature graphite-epoxy composite cases with carbon-phenolic exit cones for enhanced thermal protection during short, high- burns. In applications, the Star 30 served as the apogee motor for the G-STAR , launched in 1985 aboard a Delta vehicle to enable North American coverage. It was also integral to the British Skynet 4 military satellite series, deployed via Ariane rockets from the late 1980s through the 1990s for secure global communications. A notable non-GEO use occurred with NASA's CONTOUR comet probe in 2002, where the Star 30BP provided a 1,922 m/s delta-V for interplanetary injection following launch on a Delta II; however, contact was lost post-burn, rendering the mission a failure. These deployments highlighted the motor's role in commercial GEO transfers, where its design prioritized cost-effective, high-reliability performance for satellite operators.

Star 31

The Star 31 is a solid-propellant rocket motor developed by (now ), featuring a nominal diameter of 31 inches (0.79 m). It served dual roles in both civilian launch vehicles and military systems, with the early variant designated 1A (also known as X-254). This motor provided upper-stage propulsion for small orbital insertions, emphasizing lightweight construction for enhanced performance in constrained environments. The 1A variant, qualified in the early , had a total of 1,225 kg, including approximately 931 kg of , a of about 3.38 m, and a time of 39 seconds. It delivered a of 60.5 kN and a of 256 seconds in , enabling reliable third-stage performance for lightweight vehicles. The standard 31, evolved in the late 1970s as the III (TE-M-762), featured improved specifications including a of 30.1 inches, of 113 inches, total of 1,393 kg (with 1,286 kg using TP-H-3340), average of 82.3 kN (18,500 lbf), of 293.5 seconds (effective), total impulse of 3,740 kN·s, and time of 45 seconds. Both variants utilized filament-wound cases, with the later incorporating a Kevlar-epoxy composite for reduced weight and higher structural efficiency compared to earlier designs. In launch vehicle applications, the Star 31 powered upper stages for the Scout family during the and 1970s, including the Scout X and Scout X-1 configurations for missions. The 1A variant supported early Scout X flights starting in 1960, while the Antares III served as the third stage for later Scout vehicles, such as the 1979 MAGSAT satellite launch, achieving 17 successful flights with 100% reliability. Military adaptations included the Blue Scout series, where the Antares 1A functioned as the third stage in vehicles like Blue Scout I, II, and Junior for U.S. target and reentry vehicle testing from the early . Additionally, the Antares 1A propelled the WASP (West Air Solid ) anti-satellite missile system, a ground-launched interceptor developed for potential orbital target engagement in the . These military roles highlighted the motor's versatility in rapid-response scenarios, contrasting with its more limited civilian applications confined primarily to Scout orbital insertions. The Star 31's design prioritized simplicity and storability, making it suitable for both space access and defense needs, though production emphasized military target vehicles over broader commercial use.

Star 37

The Star 37 is a versatile family of solid-propellant rocket motors, nominally 37 inches (94 cm) in diameter, developed by Thiokol Chemical Corporation (later Orbital ATK and Northrop Grumman) for upper-stage applications in launch vehicles and spacecraft propulsion modules. First flown in 1965 as the propulsion for the Thor-Burner II upper stage, it provided reliable performance for orbital insertion and trajectory adjustments, with lengths ranging from 66 to 130 inches (168-330 cm), propellant masses of 600-1,200 kg, vacuum specific impulses of 260-297 seconds, average thrusts of 33.6-51.1 kN, and total impulses up to approximately 3,060 kN·s. Its design emphasized high mass fractions (around 0.92) and adaptability, enabling it to support a wide range of missions from Earth orbit to deep space. Key variants include the Star 37FM, qualified in 1984 for roles with a case, fixed , mass of about 1,066 kg, burn time of 63 seconds, and total impulse of 3,053 kN·s; the Star 37FMV, featuring a vectorable flexseal (±4°) for three-axis control in upper stages, with similar performance but enhanced maneuverability; the Star 37XFP, optimized for extended performance in orbit insertion using an enhanced formulation and fixed contoured , delivering a total impulse of 2,537 kN·s over 66 seconds with a mass of 884 kg; and the Star 37GV, incorporating a lightweight graphite-epoxy composite case for high-performance geostationary transfer orbits, demonstrated in 1998 with a burn time of 49 seconds and total impulse of 2,823 kN·s. These variants typically feature front-end ignition, composite (carbon-carbon throats with carbon-phenolic exits), and between 622 and 1,152 kg, allowing customization for specific mission delta-V requirements. The Star 37 saw extensive use in launch vehicles starting from its debut, powering upper stages for scientific and military payloads, including the Burner II configuration for suborbital and orbital tests. It played a pivotal role in historic deep- exploration, serving as the third stage (Star 37E variant) for and 11 launches in 1972 and 1973, providing the velocity increment for Jupiter flybys and eventual escape from the solar system. Similarly, in 1977, Star 37 motors in the and 2 propulsion modules enabled their hyperbolic trajectories to the outer planets and beyond the , marking the first human artifacts to achieve . These applications highlighted the motor's unique capability with flexseal nozzles in later variants for precise attitude control during burns, ensuring reliable escape velocities exceeding 16 km/s relative to .

Star 48

The is a family of motors developed by Chemical Corporation (now part of Northrop Grumman Innovation Systems) for use as upper stages in space launch vehicles, primarily for insertion and high-energy interplanetary trajectories. With a nominal of 48 inches (1.22 m), it features a lightweight spherical case designed to withstand high pressures while minimizing mass, enabling efficient performance in vacuum environments. The motor's propellant is typically a (HTPB)-based formulation with high solids loading, providing reliable ignition and controlled burn characteristics. Key specifications for the Star 48 include a propellant mass ranging from approximately 2,000 to 2,430 kg (4,431 to 5,357 lbf), depending on the configuration and offloading for mission-specific velocity requirements. Total impulse varies from 5,650 to 7,000 kN·s across variants, with vacuum specific impulse (Isp) around 286–294 seconds and average thrust of 65–70 kN (14,600–15,700 lbf). Burn time is typically 84–87 seconds, and the overall length ranges from 80 to 148 inches (2.03 to 3.76 m) to accommodate short- or long-nozzle options for optimized expansion in space. Gross mass, including inert components, is 2,000–3,000 kg, with the high propellant mass fraction (over 0.94) contributing to its efficiency for payload deployment.
VariantLength (in)Propellant Mass (kg)Total Impulse (kN·s)Isp (s)Average Thrust (kN)Notes
Star 48A (Short)80~~6,800283Early configuration for increased ; short .
Star 48A (Long)88–94.8~~6,950290Extended for higher impulse; used in PAM integrations.
Star 48B (Short)72~~5,680288For Space Shuttle PAM-S; offloadable .
Star 48B (Long)80–94.8~~5,800294Standard for Delta II PAM-D; spin-stabilized option.
Star 48BV81.7~~5,800294Features thrust vector control via flexseal ; for precision maneuvers.
The has been integral to the Payload Assist Module-D (PAM-D) system, first flown in 1982 on Delta 3920/PAM-D missions and later on deployments, enabling the transfer of satellites to geosynchronous orbits with its spin-stabilized design for attitude control during coast and burn phases. Over 100 flights have utilized the , including more than 50 on Delta II vehicles through the program's retirement in 2018, demonstrating its reliability for commercial and scientific payloads. A notable application was the 2006 mission to , where the Star 48B provided the final solid-rocket boost after launch, achieving an escape velocity of 16.26 km/s (36,000 mph) and enabling the spacecraft's interstellar trajectory. In more recent operations, the Star 48BV serves as the fourth stage in the + launch vehicle, enhancing performance by about 200 kg for low-Earth or elliptical orbits in small satellite missions, with an average burn time of 85.2 seconds and total mass of 2,171 kg. Its titanium construction and vectorable options continue to support viable configurations for cost-effective small launches as of 2025.

Star 63

The Star 63 is the largest variant in the Star family of solid-propellant rocket motors, developed by Thiokol (now part of Northrop Grumman) with a nominal diameter of 63 inches (1.60 meters). It features a Kevlar-epoxy composite case, transitioning to graphite-epoxy in later units, and uses TP-H-1202 hydroxyl-terminated polybutadiene (HTPB) propellant. Designed primarily for upper-stage perigee kick applications, it provides high total impulse for geosynchronous transfer orbit (GTO) insertions, enabling payloads ranging from 1,400 to 2,080 kilograms depending on configuration. Key specifications include a length of approximately 1.78 to 2.71 meters across variants, propellant mass of 3,250 to 4,265 kilograms, and unfueled mass of 248 to 431 kilograms. The motor delivers a vacuum specific impulse of 283 to 297 seconds, average thrust of 85 to 105 kilonewtons, burn time of 107 to 120 seconds, and total impulse of 9,043 to 12,530 kilonewton-seconds. These parameters establish its role in heavy-lift missions, with a propellant mass fraction of about 0.83 to 0.93, optimizing efficiency for orbital maneuvers. The primary variants are the Star 63D (also designated TU-936 or TE-M-936) and Star 63F (TE-M-963-2 or TE-M-716). The 63D, with a gross mass of 3,499 kilograms and shorter length of 70 inches (1.78 meters), was optimized for adjustable loads to support GTO payloads of 1,397 to 2,081 kilograms at a increment of 2.44 kilometers per second. The 63F, at 4,590 kilograms gross mass and longer 106.7 inches (2.71 meters), offers higher performance with a up to 297 seconds and was tailored for extended burn profiles. A specialized Star 63DV variant incorporated a flexseal vectoring for up to 5 degrees of thrust direction control. In applications, the Star 63 served as an upper stage for the from the 1980s through the early 2000s, providing final orbital insertion for classified and commercial payloads. It was integrated into the Payload Assist Module-D2 (PAM-D2) for missions, deploying defense communication up to 1,880 kilograms into GTO, with flights spanning the 1980s to 2005. On the Delta 7925, it acted as a perigee motor for enhanced GTO capability, supporting missions like those for the Spacebus series. Overall, it functioned as a reliable perigee kick stage for GTO transfers across these platforms, accumulating over 100 flights with a perfect success record in verified operations. Unique to the Star 63 is its scale as the heaviest in the family, with the static test of an 8-year-old 63D unit demonstrating the durability of the under aged conditions, validating long-term storability for mission assurance. Following the retirement of the program in 2005, operational use of the Star 63 ceased for major U.S. launches, though its solid-propellant design allows extended storage for potential reactivation in niche applications.

References

  1. https://www.northropgrumman.com/wp-content/uploads/NG-Propulsion-Products-Catalog.pdf
  2. https://ntrs.nasa.gov/api/citations/19820002238/downloads/19820002238.pdf
  3. https://arc.aiaa.org/doi/10.2514/6.1995-3129
  4. https://ntrs.nasa.gov/api/citations/19810001583/downloads/19810001583.pdf
  5. https://findingaids.hagley.org/repositories/3/resources/1120
  6. https://issuu.com/utah10/docs/uhq_volume75_2007_number1/s/10239216
  7. https://www.nasa.gov/wp-content/uploads/2023/03/sp-4401.pdf
  8. https://apps.dtic.mil/sti/tr/pdf/ADA406104.pdf
  9. https://apps.dtic.mil/sti/tr/pdf/AD0500267.pdf
  10. https://space.skyrocket.de/doc_stage/pam-d.htm
  11. https://www.deseret.com/1998/5/5/19378291/thiokol-is-now-cordant-technologies/
  12. https://www.marketwatch.com/story/alliant-buys-alcoas-propulsion-unit-for-685-mil
  13. https://www.deseret.com/2001/1/31/19566860/alliant-to-buy-thiokol-for-685-million/
  14. https://investor.northropgrumman.com/news-releases/news-release-details/northrop-grumman-announces-organization-and-leadership-changes-1
  15. https://news.northropgrumman.com/news-releases/news-release-details/northrop-grummans-minotaur-iv-rocket-successfully-launches-national-security-payload-national-reconnaissance-office
  16. https://www.northropgrumman.com/what-we-do/advanced-weapons/hypersonics
  17. https://www.northropgrumman.com/who-we-are/the-facts/solid-rocket-motors-propulsion
  18. https://core.ac.uk/download/pdf/32552938.pdf
  19. http://ui.adsabs.harvard.edu/abs/1992jpnt.confRU...H/abstract
  20. https://ntrs.nasa.gov/citations/20080025653
  21. https://forum.nasaspaceflight.com/index.php?topic=33084.0
  22. https://www.sciencedirect.com/science/article/pii/S1000936121003319
  23. https://ntrs.nasa.gov/api/citations/19680010362/downloads/19680010362.pdf
  24. http://www.astronautix.com/s/star13.html
  25. http://www.astronautix.com/s/star13b.html
  26. https://space.skyrocket.de/doc_eng/star-13.htm
  27. https://planet4589.org/jcm/pubs/space/papers/1997/kick.pdf
  28. https://planet4589.org/space/book/lv/engines/motorlist/star13.html
  29. http://www.svengrahn.pp.se/histind/Swefirst/Satellitedetails/Freja/FrejaFacts.htm
  30. https://ntrs.nasa.gov/api/citations/19680011628/downloads/19680011628.pdf
  31. http://www.astronautix.com/s/star17a.html
  32. http://www.astronautix.com/s/star17.html
  33. http://www.astronautix.com/a/altair3a.html
  34. https://space.skyrocket.de/doc_eng/star-20.htm
  35. http://www.astronautix.com/s/star20spherical.html
  36. https://www.thespacereview.com/article/2104/1
  37. https://space.skyrocket.de/doc_sdat/stacksat.htm
  38. https://ntrs.nasa.gov/api/citations/20160008023/downloads/20160008023.pdf
  39. http://www.astronautix.com/s/star24c.html
  40. https://adb.moonsociety.org/04/03/09/01/thiokol.html
  41. http://www.astronautix.com/s/star24.html
  42. https://space.skyrocket.de/doc_eng/star-24.htm
  43. http://www.astronautix.com/b/burner2a.html
  44. https://www.designation-systems.net/dusrm/app4/castor.html
  45. https://apps.dtic.mil/sti/tr/pdf/AD0764359.pdf
  46. https://www.atlasmissilesilo.com/Documents/AZ-D-O-999-99-ZZ-00005_Atlas_E_F_LaunchVehicle_UnsungWorkhorse.pdf
  47. https://www.planet4589.org/space/book/lv/engines/kick/USMOTORSINTHE1960S.html
  48. https://space.skyrocket.de/doc_sdat/gstar-1.htm
  49. https://space.skyrocket.de/doc_sdat/skynet-4.htm
  50. https://science.nasa.gov/mission/contour/
  51. http://www.astronautix.com/a/antares1a.html
  52. http://www.astronautix.com/w/wasp.html
  53. http://www.astronautix.com/s/star37.html
  54. https://space.skyrocket.de/doc_eng/star-37.htm
  55. https://space.skyrocket.de/doc_sdat/pioneer-1011.htm
  56. http://www.astronautix.com/s/star48.html
  57. https://www.northropgrumman.com/wp-content/uploads/Minotaur-IV-VI-User-Guide.pdf
  58. https://science.nasa.gov/mission/new-horizons/
  59. http://www.astronautix.com/s/star63.html
  60. http://www.astronautix.com/s/star63d.html
  61. http://www.astronautix.com/s/star63f.html
  62. http://www.astronautix.com/d/delta7925.html
  63. https://sma.nasa.gov/LaunchVehicle/assets/delta-7925.pdf
Add your contribution
Related Hubs
User Avatar
No comments yet.