C U.S. Launch Vehicles for Small Satellites
This appendix provides the history and development status as of October 1998 for the candidate small satellite mission U.S. launch vehicles discussed in Chapter 5.
The Delta II is provided by Boeing Corporation (formerly McDonnell Douglas Aerospace). The company has provided various versions of the Delta vehicle since 1960 and has increased the payload capacity with each generation. The Delta II series became operational in 1989 and is capable of lifting 1,840 kg to geo-transfer orbit (GTO) in its heaviest configuration.
The Delta II launch vehicle consists of two primary stages with an option for a third. The last digit in the vehicle designation indicates which, if any, third stage is used; a version 7920, for instance, would indicate no third stage (Isakowitz, 1995, p. 230). The first stage main engine is a Rocketdyne RS-27, while the second stage uses the restartable Aerojet AJ10-118K engine; both engines use liquid fuel. The second digit in the vehicle designation indicates the number of solid rocket strap-ons (Hercules graphite epoxy motors—GEMs) the vehicle employs. Delta II 7925 uses nine strap-ons and a third stage, while the Delta II 7320 has three GEMs and no third stage. Models smaller than the 7920 are referred to as Delta II Lite vehicles.
The 7300 series is under contract to the National Aeronautics and Space Administration (NASA) under the agency's Medium Expendable Launch Vehicle (MELV, or Medlite) program. McDonnell Douglas (Boeing) is also looking into an opportunity to build a Delta Lite vehicle smaller than the 7300 series, consisting of two Castor 120 engines sequenced for stages 1 and 2, with an Aerojet AJ10-118K acting as the third stage. The first flight of a Delta Lite vehicle (7420-10) was on February 14, 1998, and carried four Globalstar satellites.
Currently, there are a variety of launch options for the Delta II. As mentioned previously, the Delta II 7925 is a true intermediate-class launch vehicle, capable of lifting 1,840 kg to GTO. However, the Medlite Delta II 7320 is capable of transporting 1,750 kg to a 700 km Sun-synchronous orbit. Even this smaller Delta II is half again as large as the next competitor, the Athena 2. A single Delta II 7320 flight could theoretically be used to boost up to three small Earth observing satellites simultaneously, contingent upon their relative size and orbital requirements.
The International Space Industry Report (1998b) estimates launch costs for the Delta II 7925 and 7320 at approximately $55 million and $35 million, respectively; NASA (1996, p. D-15) estimates the cost for launching on a Delta II 7320 is approximately $42 million for a single payload manifest under its MELV contract. Launch
sites are Vandenburg Air Force Base and Cape Canaveral Air Force Station for Sun-synchronous and lower inclination orbits, respectively.
The Delta II is available with both a 9.5 and 10 ft fairing. The use of the 10 ft fairing reduces mass performance by around 50 kg for the three-stage vehicle and 120 kg for the two-stage launcher.
The Delta launcher has been a workhorse vehicle for both the civil and military space programs. It has the longest launch record of any family of vehicles in the American space program and has proven itself highly reliable. From 1989 through October 1998, the Delta II family had flown 67 times with 65 successes—a 97 percent success rate.
The Pegasus launch vehicle is a commercially designed, all-solid propellant booster which is launched after being released from the belly of a Lockheed L-1011 aircraft. Designed in a cooperative effort between Orbital Sciences Corporation (OSC) and Hercules Aerospace, the launcher is now operated by OSC. The rocket is released from the belly of the aircraft when the plane reaches an altitude of 38,000 ft and a speed of Mach 0.79 (OSC, 1998, p. 2-1). The winged body launcher consists of three booster phases with an option for a fourth.
The use of the air drop technique grants OSC a level of launcher flexibility not enjoyed by ground-based launchers. Ground-based support is minimized, enabling OSC to launch basically from any site with an airstrip; the Pegasus is, in effect, a mobile launch system. In addition, the use of the aircraft allows the Pegasus to use the plane's velocity to gain a wider variety of orbital inclinations than can be obtained by a comparably sized vehicle launched from a similar ground site. In April 1997, the Pegasus successfully placed a Spanish research satellite in orbit, originating the L-1011 flight from the Spanish Canary Islands off the coast of Africa.
Since its maiden flight in 1990, OSC has marketed three variations on the Pegasus vehicle. The original Pegasus had three stages—respectively, an Orion 50S, an Orion 50, and an Orion 38. To increase performance and accuracy, OSC later added a fourth stage option, the Hydrazine Auxiliary Propulsion System (HAPS). To date, both flights with HAPS have resulted in less than nominal orbits, with the HAPS stage responsible for one of the anomalous results. OSC also made structural improvements to the first and second stages, enabling them to carry more propellant; it designated the improved vehicle the Pegasus XL, and the original Pegasus was subsequently phased out. The first Pegasus XL/HAPS was launched successfully in the latter half of 1997.
The Pegasus XL is capable of lifting a 225 kg payload to a Sun-synchronous orbit at 700 km altitude. NASA currently contracts with OSC to use the Pegasus vehicle under both the Ultralite Expendable Launch Vehicle Program and the Small Expendable Launch Vehicle Program. The former is for the launch of sub-150 kg payloads as secondary manifests on Pegasus flights; the latter is for a traditional dedicated Pegasus payload designation. Under these contracts, the cost of a Pegasus XL flight is $20 million for the dedicated launch and $8 million for the secondary manifest (NASA, 1996, p. D-15). OSC itself advertises a cost of $12 million to 14 million for an independently contracted launch.
Including all versions of the vehicle, the Pegasus has flown 24 times through October 1998. Of those flights, 19 achieved all launch objectives for a 79 percent total success rate.
The Taurus is also an OSC booster, first developed under a Defense Advanced Research Projects Agency (DARPA) contract for a demonstration launch of a "standard small launch vehicle" (NASA, 1996, p. D-15). The Taurus is a four-stage, all-solid rocket vehicle, which builds on the design of the Pegasus by adding an initial Castor 120 to the configuration and designating it "Stage 0" (minus the winged body that the Pegasus needs for air flight) (NASA, 1996, p. 257). The Taurus is designed to be launched from the ground as a mobile launching platform, capable of assembly and launch once on site in under a day; standard commercial service launches from established ranges.
The first Taurus debuted in 1994 with the successful launch of the Space Test Experiment Program M0/DARPASAT payload. The booster's second flight was in February 1998, when it carried three satellites into orbit.
Current OSC plans are to market a next generation version, the Taurus XL, which uses the same upper stages as the Pegasus XL. OSC intends to offer various versions of an upper stage, including the standard Orion 38 (now used on the Pegasus and Taurus) and the Star 37, which is larger and meant as a growth option. The Taurus XL/Orion 38 will launch 945 kg to Sun-synchronous orbit at 700 km. The Taurus XL/Star 37 will increase performance to the above orbit to around 1,160 kg. OSC plans to launch from Vandenburg Air Force Base for Sun-synchronous missions and from Cape Canaveral for lower inclination orbits. Reliability statistics in this case are not significant, as the Taurus XL has not yet flown, and the standard Taurus has flown only three times, albeit successfully.
OSC cites the cost of a dedicated manifest Taurus launch in the range of $18 million to $22 million. For its Medlite contract, NASA gives a cost of $30 million for the Taurus XL and $35 million for the XL version with an upper stage (Orion 38 or Star 37). The Taurus is available in both a 63 in. diameter fairing and a 92 in. one. The use of the larger fairing reduces mass performance by about 140 kg.
ATHENA (FORMERLY LOCKHEED MARTIN LAUNCH VEHICLE)
The Athena is an entirely commercial effort by Lockheed Martin to provide a family of launchers with incrementally increasing payload capacity. The Athena 1 is a two-stage, all-solid rocket vehicle, using a Castor 120 first stage and an Orbus 21D as the second stage, with an Orbital Adjustment Module carrying the Attitude Control System and avionics package. The next larger version, the Athena 2, made its maiden flight in January 1998 and adds an additional Castor 120 to the configuration. Farther in the future is the Athena 3, for which Lockheed Martin intends to add solid rocket Castor IVA-XL strap-ons to the Athena 2 design. The booster will launch from Vandenburg Air Force Base for polar orbits and from Cape Canaveral for lower inclination destinations. The Athena 1 has a capacity of 200 kg to a Sun-synchronous, 700 km circular orbit, while the Athena 2 can loft 700 kg and the Athena 3 with four strap-ons can loft 2,200 kg to the same orbit. Reliability statistics in this case are not significant, as the Athena 1 has flown only twice. The first flight, in August 1995, carried the GemStar 1 commercial payload but was a failure. The second, in August 1997, successfully placed NASA's Lewis space-craft into orbit. The Athena 2 made its first flight in January 1998, successfully launching the Lunar Prospector.
Recent estimates place the cost of an Athena 1 flight at $16 million, an Athena 2 at $22 million, and an Athena 3 at $30 million to commercial users (ISIR, 1998).
The Conestoga family of launch vehicles is assembled and operated by EER Systems Corporation. The Conestoga fleet is modular in design, with several variations intended to provide incrementally increasing payload capacity. In the Conestoga vehicle designation, the first digit indicates the type of core motor and the second the number of Castor IV strap-ons the version entails, which can be anywhere from two to six. This assemblage is topped by a mid- and upper-stage, designated by the third and fourth digits, respectively (Isakowitz, 1995, p. 220).
To date, only the Conestoga 1620 has been launched—in October 1995—and that flight ended in the destruction of the vehicle and its payload, the METEOR recoverable capsule. EER Systems has higher hopes for the smaller 1229, but without a payload backlog, the vehicle has an uncertain future. The company has designs to market larger versions of its rockets using a more capable core motor, but has not yet moved these into development.
The Conestoga 1229 has the capacity to loft 500 kg to a 185 km circular polar orbit. The larger 1620 can lift around 1,500 kg to the same orbit. However, EER Systems has no agreement in place to cover the use of a launch site capable of servicing these orbits. The company does have a contract to use Wallops Flight Facility for launches between 38° and 66° latitude, and plans to negotiate for the use of the Kodiak site in Alaska to service the higher inclination orbits should interest be shown.
EER Systems Corporation estimates a launch price between $18 million and $20 million for the 1620 (Isakowitz, 1995), and a cost of around $12 million for the smaller 1229 (Bille and Lishock, 1996, p. 9). Reliability estimates in this case are not statistically significant, since the Conestoga has had only one flight, and that launch resulted in the loss of the vehicle and its payload.
ECLIPSE, PACASTRO, KISTLER, AND EAGLE
There are a number of launch vehicles in the design and early development stages that merit consideration for their long-term effect on the small payload launch market and level of competition. If successful, any of the ventures discussed here could prove to be serious competition to the more established market players discussed above. Many of these proposals, especially those that utilize reusable or partially reusable designs would, in principle, have significant cost advantages over their more traditional competitors if they even come close to their stated objectives. Although data are more scarce on these proposed vehicles than on launchers currently in operation, a brief discussion of the stated objectives of each launcher or family of vehicles, in conjunction with their performance goals, will be a useful addition to the dialogue concerning the availability and cost of launchers for small satellites fulfilling Earth observation needs.
Eclipse Express and Astroliner
The Eclipse Express is proposed as a hybrid—part reusable, part expendable launch vehicle. The design calls for a modified F-106 drone to be towed by a Boeing 747 and released. The vehicle will then release at the apogee of its flight an expendable upper stage on which the payload is attached. The drone returns to Earth for the next flight. The initial towing capability demonstration is funded in part by a contract between Kelly Space and Technology and the U.S. Air Force. The launcher is limited in its payload capacity. For a 700 km circular orbit at 90° inclination, Kelly Space and Technology estimates a payload capacity of around 100 kg. However, Kelly's cost goal of $2 million per flight (Bille and Lishock, 1996, p. 9) would make it a competitive player despite its narrower payload capacity.
Beyond the Eclipse Express, Kelly Space has plans to market a more capable launch system, the Eclipse Astroliner, whose design is based upon the technological fundamentals proven in the Express program. Kelly Space estimates a payload capacity of approximately 1,590 kg to a 90° circular orbit at 463 km (SpaceDaily, 1998). No cost data were available as of this writing.
The AeroAstro Corporation is in the later development stages for a suborbital launcher, designated PA-X, that is jointly funded with the U.S. Department of Defense. The company intends to build on this vehicle to create three successively larger versions for orbital missions, the R2-10, the R2-150, and the R3-1000. The R2 vehicles are both two-stage, liquid-fueled expendable rockets. The R3 adds a third liquid-fueled stage. AeroAstro cites the proven reliability and greater safety of liquid-fueled rockets, as well as its simple stacked design, as key cost savers. The company currently holds contracts for 10 satellite launches, 3 of which are for KITComm (Australia) and the Swedish Space Corporation.
The R2-10, at a cost of $4 million, is capable only of launching "Bitsy-class" satellites. Its larger sibling, the R2-150, has a payload capacity of 250 kg to 370 km Sun-synchronous orbit. The R3-1000 projected payload capacity to a 705 km Sun-synchronous orbit is 450 kg. AeroAstro cites a cost of $6 million for the R2-150; cost figures for the R3-1000 are not yet available. While precise payload fairing information was not available, AeroAstro advertises the advantages of its wide and tall fairing in reducing the need for deployable structures.
Kistler Aerospace has plans to design and market a two-stage, fully reusable launch system using entirely private funds. The initial system, called the K-1, will utilize three Aerojet/Russian NK-33 LOx/kerosene engines as the first stage and a single NK-33 as the second stage in a stacked design (Kistler, 1999a). Upon separation, the first stage will maneuver to a trajectory back to the launching site, touching down with a parachute-assisted landing. The second stage will follow a similar sequence upon separation from the payload. Kistler's plans call for an inaugural flight after 2000 (Kistler, 1999b).
The K-1 is designed to carry up to 900 kg to low Earth orbit (LEO). Longer term company plans call for a second generation vehicle, the K-2, to come into operation a few years after K-1 with an LEO capacity of around 2,700 kg. Kistler has expressed a desire to build an even larger version, with a 9,000 kg LEO capacity, but these plans are not yet well defined.
E-Aerospace has plans to market a family of launchers based on the solid rocket motors used in the Peacekeeper missile. No further information was available as of this writing.
Bille, M.A., and E. Lishock. Smallsat Launch Options: Choices and Challenges. 1996. Proceedings of 10th Annual American Institute of Aeronautics and Astronautics/Utah State University Conference on Small Satellites.
International Space Industry Report (ISIR). 1998a. July 6 issue. Available online at <http://www.launchspace.com/isir/home.html>.
———. 1998b. Nov. 9 issue. Available online at <http://www.launchspace.com/isir/home.html>.
Isakowitz, S.J., ed. 1995. International Reference Guide to Space Launch Systems, 2nd ed. Washington, D.C.: American Institute of Aeronautics and Astronautics.
Kistler Aerospace Corporation. 1999a. K-1 specifications and performance. Available online at <http://www.kistleraerospace.com/std/specs.html>.
———. 1999b. Kistler Aerospace development schedule. Available online at <http://www.kistleraerospace.com/std/schedule.html>.
National Aeronautics and Space Administration (NASA). 1996. Announcement of Opportunity: Earth System Science Pathfinder Missions. AO-96-MTPE-01. July 19.
Orbital Sciences Corporation (OSC). 1998. Commercial Pegasus user's guide. Available online at <http://www.orbital.com/Prods_n_Servs/Products/LaunchSystems/Pegasus/index.html>.
SpaceDaily. 1998. Kelly Space to demonstrate tow launch. Feb. 28 press release. Available online at <http://www.spacedaily.com>. Space News. 1999. 10(2):1.