Small-Satellite Costs David A. Bearden ighly capable small satellites are small systems would become more preva- others used size. Even scarcer than good commonplace today, but this was- lent than the larger systems built during the descriptions of small satellites, however, n’t always the case. It wasn’t until previous 30 years. were guidelines for cost estimation of small- Hthe late 1980s that modern small But exactly which spacecraft fell into the satellite projects. Clearly, a more useful def- satellites came on the scene. This new new category? A precise description of inition of small space systems was needed. breed of low-profile, low-cost space system small satellites, or “lightsats,” as they were By the 1990s, because of increased in- was built by maximizing the use of existing also called, was lacking in the space litera- terest in small satellites for military, com- components and off-the-shelf technology ture of the day. The terms meant different mercial, and academic research applica- and minimizing developmental efforts. At things to different people. Some estab- tions, the Air Force Space and Missile the time, many thought that because of lished a mass threshold (e.g., 500 kilo- Systems Center (SMC) and the National their functional and operational character- grams) to indicate when a satellite was Reconnaissance Office (NRO) asked The istics and their low acquisition costs, these small; others used cost as a criterion; still Aerospace Corporation for information about Crosslink Winter 2000/2001 • 33 1000 specifically tailored to small-satellite pro- grams. To meet this need, Aerospace even- tually developed the Small Satellite Cost Model, a small-satellite trade-study soft- 100 ware tool that captures cost, performance, and risk information within a single frame- work. Before looking at the development of Aerospace’s trade-study tool, though, it DOD large satellites 10 will be valuable to backtrack to the late Modern DOD small satellites Spacecraft bus cost bus Spacecraft 1980s and review just exactly how small- (FY97 dollars in millions) Traditional DOD small satellites spacecraft programs had been perceived. Streamlined Development 1 0 200 400 600 800 1000 1200 1400 1600 Activities Spacecraft bus dry mass (kilograms) In the 1980s, the DOD Advanced Research Projects Agency and the United States Air Dollars-per-kilogram comparison of DOD large satellites (500 dollars per kilogram), modern small satellites (100 dollars per kilogram), and traditional small satellites (150 dollars per kilogram). Data Force Space Test Program served as the pri- points for these three categories cluster differently, and regression analysis shows that each set of mary sources of funding for small satellites, points determines a different cost-estimating relationship.This information confirms the need for a new which typically were used for technology model using contemporary small satellites as its basis. experiments. The Space Test Program co- capabilities and costs of such systems. In re- satellites offer for rapid incorporation of new ordinated experimental payload flights for sponse, Aerospace commissioned a study to technologies? Could they help reduce the the Army, Navy, Air Force, and other gov- compare cost and performance characteris- long development cycle for military space ernment agencies. Reduced development tics of small satellites with those of larger, programs? Were small satellites really eco- complexity and required launch-vehicle traditional systems. Of specific interest was nomical for operational applications, such as size enabled affordable, frequent access to the ability to examine tradeoffs between navigation and communication? space for research applications. Relatively cost and risk to allow assessment of how tra- These questions led to a series of studies low acquisition costs and short develop- ditional risk-management philosophies on technical and economic issues involved ment schedules also allowed university lab- might be affected by the adoption of small- in designing, manufacturing, and operating oratories to participate, providing individ- satellite designs. small satellites. The studies found that ex- ual researchers access to space—a privilege Estimating costs for small systems isting spacecraft cost models, developed previously reserved only for well-funded raised many questions. What parameters during the previous 30 years to support the government organizations. drove the cost of small satellites? Were tra- National Aeronautics and Space Adminis- Small satellites were procured under a ditional parameters known to drive the cost tration (NASA) and the Department of De- specifically defined “low cost” philosophy. of large systems still applicable? How did fense (DOD), were of limited utility because They were smaller in size and were built small systems compare with large ones? of fundamental differences in technical with maximum use of existing hardware. A Did small-satellite acquisition philoso- characteristics and acquisition and develop- smaller business base (i.e., a reduced num- phies, which prompted reductions in levels ment philosophies between small-satellite ber of participating contractors) was in- of oversight, independent reviews, and pa- and traditional-satellite programs. volved in the development process, and it perwork, enable a reduction in cost-per-unit This finding prompted NASA and DOD was perceived that small satellites repre- capability? What advantages might small to seek cost-analysis methods and models sented a niche market relative to the more prevalent large systems. Mission timelines 10000 from approval to launch were on the order of 24 to 48 months, with an on-orbit life of 6 to 18 months. Launch costs, either for an 1000 existing dedicated small launcher or for a secondary payload on a large launcher, re- mained high, but developments such as the 100 Pegasus air-launched vehicle and new small launchers (such as Taurus and Athena) offered promise of lowering these Total satellite cost Total 10 Traditional NASA missions costs. Additionally, small-satellite flight (FY98 dollars in millions) NASA faster-better-cheaper missions and ground systems typically used the most mature hardware and software avail- 1 able to minimize technology-development 0 1000 2000 3000 4000 5000 6000 7000 and flight-certification costs. Satellite launch mass (kilograms) Emerging advances in microelectronics, This graph compares the dollars-per-kilogram ratio for traditional NASA missions (900 dollars per kilo- software, and lightweight components en- gram) with the ratio as noted in NASA’s faster-better-cheaper missions (120 dollars per kilogram). It’s abled system-level downsizing. Spacecraft clear that the different sets of data points determine markedly different cost-estimating regimes. often cost more than $200 thousand per 34 • Crosslink Winter 2000/2001 1000 800 600 400 200 Cost model estimate/actual cost (percent) 0 MACSAT Microsat LOSAT-X ALEXIS STEP 0 STEP 1 HETERADCAL SAMPEX Clementine NEAR Satellite A cost-percentage comparison that makes use of an older model and the up- the actual cost, and for RADCAL, with a percentage of 801%, the older dated dollars-per-kilogram relationships shown in previous graphs to estimate model’s estimated cost was nine times the actual cost. Because the esti- modern small-satellite costs. Each bar’s height represents the percentage dif- mates far outweighed the real cost in many cases, the chart illustrates the ference between a satellite’s estimated cost and its actual cost. Thus for inadequacy of a traditional cost model for modern small satellites. Clementine, with a percentage of 109%, the older model’s estimate was twice kilogram and could reach $1 million per money, small-spacecraft programs came to space. The development of a broad array of kilogram with delivery-to-space costs in- be perceived as fast-paced, streamlined de- expendable launch vehicles provided in- cluded. With miniaturization, every kilo- velopment activities. Dedicated project creased access to orbit for many different gram saved in the spacecraft bus or instru- leaders with small teams were given full kinds of payloads. Satellite programs at- ments represented a possible saving of up technical and budgetary responsibility with tempted to incorporate advanced technol- to five kilograms in launch, onboard goals tailored around what could be done ogy and demonstrate that fast development propulsion, and attitude-control systems inexpensively on a short schedule. Fixed- cycles, low acquisition costs, and small mass. Reduced power demands from mi- price contracts became the norm, and re- flexible project teams could produce highly croelectronics, instruments, and sensors quirement changes (and associated budget- useful smaller spacecraft. This different could produce similar payoffs. For inter- ary adjustments) were held to a minimum. paradigm opened up new classes of space planetary missions, reduced mass had the The Next Decade applications, notably in Earth science, capability to produce indirect cost savings With the advent of the 1990s came a move- commercial mobile-communications, and through shorter transit times and mission ment toward realizing routine access to remote-sensing arenas. duration. All this downsizing eliminated the need for large facilities and costly equipment such as high bays, clean-room Cost vs. Pointing Accuracy areas, test facilities, and special handling y = 1.67 + 12.98 x –0.5 equipment and containers. 32.00 16 data points Cost vs. Satellite Dry Mass Engineering