The first decade of the 21st century saw the emergence of very small satellites. Without doubt this development has been made by the miniaturization of electronic components that is also seen in, for instance, computers. Accompanying this trend was an evidently reduced cost in the development and construction of satellites that made them attractive to educational institutions as a learning tool.
The California Polytechnic State University (Cal Poly), in San Luis Obispo, California, and Stanford University took the idea of small satellites for educational purposes one step further by developing the CubeSat concept of small satellites measuring 10 x 10 x 10 cm which, either as a single satellite or as multiple satellites, provided a modern and fun way of teaching science and engineering in a multi-disciplinary environment with the end result being a small orbiting satellite.
To date, 29 CubeSats have been launched, of which 23 were for educational purposes. Another 10 educational CubeSats are scheduled for launch in the foreseeable future, while about 10 are known to be planned. They provide an opportunity to motivate and challenge students’ interest in the fields of space, technology and science. In fact, even if an educational satellite does not reach orbit because the launch vehicle failed, the primary objectives as an educational tool, have already been achieved. Getting the satellite in space and getting it to work there, is merely ‘the icing on the cake’.
CubeSat Specifications
Cal Poly and Stanford University have now become the central focus of an international collaboration of more than 40 universities, high schools, and private firms throughout the world.
Cal Poly also provides the basic standards and specifications for CubeSats, prescribing the outer dimensions, recommended materials and restrictions. Cal Poly also acts as a launch coordinator. In addition Cal Poly organizes conferences and workshops.
The satellites can be constructed as single CubeSats, double CubeSat (10 x 10 x 20 cm), and triple CubeSat (10 x 10 x 30 cm), depending on the payload and mission requirements.
For the deployment of CubeSats, three separate deployment pods have been developed:
- P-POD (Poly-Picosatellite Orbital Deployer), developed by Stanford University and California Polytechnic Institute. It can hold three single CubeSats stacked on top on each other
- T-POD (Tokyo Pico-satellite Orbital Deployer), a Japanese deployer that can hold one single CubeSat
- X-POD (eXperimental Push Out Deployer), a custom, independent separation system that was designed and built at the University of Toronto’s Institute for Aerospace Studies/Space Flight Laboratory for each satellite and may be tailored to satellites of different sizes ranging from a single CubeSat to larger nanosatellites of arbitrary dimensions
An obvious consideration for any satellite project is the cost of such a project. In the author’s opinion, the financial cost of a University based CubeSat project should be relatively low, as most of it, in particular the infrastructure cost and the labor cost, can be absorbed in the on-going study and research programs undertaken by the University. This should limit the financial outlay during the system development, design and construction phases to the purchase of hardware and specialized services that somehow are not included in the on-going study and research programs.
This leaves the launch cost as the largest single item of expenditure. Currently, most CubeSats are being launched on decommissioned Russian rockets. Through companies like Eurokot and Kosmotras, the launch costs are currently about US$40,000 per single cube. However, the range of launch vehicles that will carry CubeSats is gradually increasing in number and recently it was announced that CubeSats can fly on Atlas V launch vehicles. The cost of a single secondary payload on board of an Atlas V has been quoted as $1 to $2 million per slot.
The author, who is a Cost Accountant by profession, proposes to evaluate the cost of a satellite in further detail to a realistic level, using accepted commercial accounting techniques. In doing so, a simplified approach will be taken as the costing is not based on a particular satellite but rather a generic satellite launch.
To offer an example: a professor at a University is being paid, irrespective of whether a satellite project is undertaken or not. His primary role is to educate. As such, the professor’s cost is avoidable for a satellite project and no financial expense should be incurred for the project. Of course, if the professor is engaged only for the satellite project, his cost becomes unavoidable. The same applies for most of the university facilities (buildings, equipment and instruments) which are used in the project — they are there first of all for the purpose of educating. Again, the exception is if equipment etc. is specifically acquired for the satellite project. An identical argument will be made later in this article, for the launch cost
Project Cost Estimate
To develop this cost estimating model we adopt, as a base line, a 10 x 10 x 10 cm CubeSat that carries a camera and a transmission system. The satellite mass is limited to 1 kg and it requires some attitude control. The project will pass through various phases each of which should be costed separately.
Phase 1 — Project definition and initiation
This is the phase where the feasibility is studied and a working group is put together. This phase should not incur any financial expenses unless a Workshop is attended. Assuming this is done the cost will involve travel to the workshop and accommodation cost. This is estimated at US$5,000. Documentation and specifications of CubeSats that are required in this phase, are freely available from Cal Poly.
In this phase, equipment will have to be purchased. Remember that cost of labor (students and professor) is avoidable and non existing, as described above. Recently, ISS in Delft, The Netherlands, established the one stop, on-line, CubeSatShop.com facility that sells off-the-shelf components for CubeSat developers. The components to be purchased include. . .
Satellite frame: The ISIS CubeSat structure is a developed as a generic satellite structure based upon the CubeSat standard. The design created by ISIS allows for multiple configurations as to give the nanosatellite developers the freedom to develop their satellite with respect to the basic lay-out of their internal configuration — cost: 2,300 euros.
Attitude control system: A Passive Magnetic Attitude Stabilization System is selected to lock the CubeSat to the Earth Magnetic field like a compass needle — cost: 2,000 euros.
Camera system: A Sanyo VCC-5884E 1/3 in. Color CCD DSP High-Resolution Camera, 540TVL, 1 Lux Sensitivity, 12VDC/24VAC, Automatic Gain Control (ON/OFF), used for security cameras with a mass of 167 grams and size of 68 x 63 x 52 mm — cost: US$170.
Transmission system: CubeSat UHF downlink, VHF uplink full-duplex transceiver, provides telemetry, telecommand & beacon capability in a single board — Cost: 8,500 euros.
Antenna system: The ISIS deployable antenna system contains up to four tape spring antennas of up to 55 cm length, which deploy from the system after orbit insertion — cost: 3,000 euros.
Solar cells: The NanoPower P-series power supplies are designed for small, low-cost satellites with power demands from 1-30W — cost: 2,000 euros.
Miscellaneous minor components
Cost: US$6,270.
This provides an estimated total cost for the construction of the spacecraft of:
Euros {(2,300+2,000+8,500+3,000+2,000) * exchange rate 1,32} + (US$ 170 + 6,270) = US$30,000 (rounded)
Phase 3 — Launch preparation
In this phase the satellite has to be transported to the launch site and placed in the special CubeSat deployer.
The transport of the satellite, along with a team member overseeing installation, is estimated at US$5,000. Obviously this cost is dependent on the location of the university and the launch facility as well as the degree to which the accompanying team member is prepared to make a vacation of the trip (meaning making some contribution to the travel cost).
A typical 3-Unit CubeSat Deployer is available from ISIS CubeSatShop and comes in 1U, 2U, 3U, depending on the number of CubeSats it can contain. The cost of a triple (3U) unit is 25,000 euros.
Assuming this cost is shared with two other CubeSats, this means the cost is 8333 euros per satellite = US$11,000. The total cost for this phase is therefore estimated to be US$16,000.
Phase 4 — Launch cost
It has been suggested that the launch vehicle cost is the highest cost of a CubeSat project. As outlined above, commercial prices range from US$40,000 to US$2 million. In considering these prices, we should, however, remember that they are;
“commercial”, they typically apply to commercial satellites that are placed in orbit to generate a profit to their owners; and
“prices”, which in a commercial environment are only related to the ‘cost’ to the extent that it would be nice to recover all the cost, but with the price ultimately being determined by whatever the customer is prepared to pay.
In the case of educational (i.e., non-commercial) CubeSats, it will be necessary to investigate launch cost in more detail. To get an idea of how this cost is determined Wertz7 has proposed the formula located at the bottom of the previous page.
A further idea of the cost per kg to be applied to a launch can be obtained from the table at the top of the previous page:
From the straight ‘proportion by kg basis’ displayed in the above table, launch cost of an educational CubeSat can be reduced further by the application of the concept of avoidability, as outlined above, a concept that is also referred to as marginal costing.
To explain this further the reader must appreciate that there are many components of the launch vehicle cost that are fixed and will have to be paid for by the owner of the primary payload (for instance a communications’ satellite). These costs are not directly related to the mass of the primary satellite and are fixed for the satellite mass +/- a few hundred kg.
Other components of the launch vehicle are, however, variable with the mass of the payload.
In marginal costing it is argued that the 1 kg CubeSat should only pay for this additional variable cost that is very specific to the additional 1 kg to be launched by the launch vehicle.
It is suggested that this additional cost is only:
the installation of the launch deployment pod on the framework that supports the principal satellite (or some other part of the launch vehicle); and the additional fuel required to lift the additional 1 kg for the satellite + app. 1 kg to represent the launch pod, i.e., 2 kg additional hardware to be lifted.
Without much of an idea of the specific trade and expertise that is required to fit the CubeSat + launch pod to the launch vehicle, the author proposes that the cost of this should be for two workers who take about two hours to complete this task. At an hourly rate of US$100 (a generally accepted tradesman rate), we should be looking at a cost of US$400 for the installation of the CubeSat + launch pod. To round it off, say US$500 to be paid by the CubeSat owner.
In absence of detailed information, it is more difficult to determine the cost of the additional fuel, but perhaps US$100 would be a good ball park figure, making the total estimated cost of placing a CubeSat in orbit a mere US$600. But let us be generous and estimate this phase at US$1000.
Of course, the launch vehicle provider plus/or the commercial satellite-to-be-launched owner may decide to ignore this cost in exchange for goodwill.
Ironically, the above treatment might be less sustainable for launches that have a large number CubeSats in that the cubsesats can no longer be considered as ‘marginal’.
Post Launch Operations
Finally, there is the cost of the operation of the CubeSat once it is launched and is in orbit. Bearing in mind that the prime objective of educational CubeSats is its function as a learning tool, and that such an objective is achieved before the launch takes place, in-orbit operation is a mere bonus. Much like phase 1, this final cost should be completely absorbed in the educational program of the university department that built the satellite or, if appropriate, a department that can make use of scientific data.
Conclusion
This, then, brings the total cost of placing an educational CubeSat in orbit at:
5,000 + 30,000 + 16,000 + 1,000 = US$52,000
The author is, however, the first to admit that he has taken many short cuts and assumptions in his development of an estimate for an educational CubeSat. As such, the above estimate should serve only as a demonstration to university professors and students that an educational CubeSat should be within their reach. It should also demonstrate to major launch vehicle operators that they have a choice between either charging a commercial rate for the launch of an educational CubeSat, or providing it for free and invest in the future by stimulating educational institutions.
While this offer is a clear indication that launches can be inexpensive and will attract people that will happily part with US$8,000 to have a piece of hardware with their name in orbit for as much as three months, this does not seem to be a viable option for educational institutions as the objective of educational CubeSats is the construction of a satellite by students, as a learning tool, and not to fly a small piece of hardware in space.
More Info
For more details of these satellites, refer to:
Heyman, J., A Western Australian CubeSat — Floating An Idea, Tiros Space Information News Bulletin Vol. 32 No. 10 (special), 15 July 2007
For more details regarding these satellites, refer to Tiros Space Information News Bulletin Vol. 34 No. 10
CubeSat (http://CubeSat.atl.calpoly.edu/)
England, J., Atlas V — Auxiliary Payload Overview, presentation CubeSat Summer Workshop 2006
(http://atl.calpoly.edu/~bklofas/SummerWorkshop2006/England-Atlas_V.pdf).
http://cubesat.atl.calpoly.edu/pages/documents.php
http://www.cubesatshop.com
7Wertz, J.R., Responsible Launch Vehicle Cost Model, Paper No. RS2-2004. Second Responsive Space Conference Los Angeles, CA, April 19–22, 2004
Futron, Space Transportation Costs: Trends in Price Per Pound to Orbit 1990-2000, September 6, 2002
http://interorbital.com/TubeSat_1.htm