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Space Products: Frequently Asked Questions

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1. Which solar cell types are available?

A: Spectrolab is currently producing NeXt Triple Junction (XTJ) and Ultra Triple Junction (UTJ) solar cells in high volume. The other types listed under Products can be produced if ordered in large quantities, and depending on various business considerations. Spectrolab no longer produces silicon solar cells.

2. What’s a CIC?

A: This an assembly comprised of the Solar Cell + Interconnects + Coverglass + Bypass Diode and is approximately 160 microns thick. The coverglass (typically 75 microns) protects the cell from cosmic radiation. The interconnects allow for series connection of the CICs. The rearside-mounted silicon bypass diode protects the cell in the case where a series string of CICs is partially shadowed and a CIC is forced into reverse bias.

3. Are there standard sizes for the solar cells and CICs? How much power do they provide?

A: Spectrolab is currently producing the following standard solar cell and CIC sizes: 26.62 cm2 (3.95x6.89) and 29.85 cm2 (4.33x7.63). Both of these cell sizes provide approximately 1W at 2.3V per CIC (BOL, AM0, 28°C). Please see the product data sheets to determine all of the performance parameters and mass.

4. What is the lead time for these products?

A: Lead times for solar cells and CICs are highly dependent on quantity and the level of our current commitments. Typically an order for 5,000 cells or CICs can be delivered in 6 months. Solar panels, not including the period for qualification if desired, is typically 9-12 months for the first shipset, depending on amount of total power per shipset.

5. How much do these products cost?

A: Our standard UTJ CICs ordered in quantities providing a combined total of 5 KW (5000 Watts) or more cost approximately $250/W (BOL, AM0, 28°C). Customized designs may cost significantly more. Solar panels, not including the insulated substrate which is assumed to be customer furnished, providing a total of 5 KW (BOL, AM0, 28°C) cost approximately $400/W, depending on specific customer technical and configuration requirements. For higher power requirements, the cost per watt is typically less, and for less power the cost per watt is typically more. In addition to the cost for the hardware itself, there’s the cost of non-recurring engineering design, reports and analyses, qualification program, and flight hardware testing. These costs correspond to specific customer requirements as provided to us in a Specification and Statement of Work. If you would like to submit an RFP for solar cells, CICs, or panels (with accompanying specification and statement of work), please contact us by clicking here. If you wish to purchase a small quantity of CICs, please see How do I Place an Order, below.

6. What are BOL and EOL?

A: Beginning-of-Life (BOL) means the product’s performance is calculated before exposure to the space environment. BOL values are measured at 28°C, under the AM0 spectrum (solar irradiance spectrum in space), and assuming solar flux of 135mW/cm2. End-of-Life (EOL) is the design point for the end of the mission. For example, if the spacecraft is required to provide power for 15 years in geosynchronous orbit, then the power needed at BOL - to eventually meet the EOL requirement - would be calculated based on the radiation degradation anticipated over the course of the 15 years having been subjected to the radiation fluence for that orbit (solar cell radiation degradation properties can found on the product data sheets) and at the anticipated operating temperature.

7. Are UTJ CICs operating in orbit?

A: There are currently more than 175kW of UTJ product in orbit today with many more UTJ-powered satellites scheduled to be launched in the next couple of years.

8. Are space cells different from terrestrial cells?

A: Although the underlying structure is similar between the two products, there are differences to optimize performance in their respective environments. Please see the Terrestrial FAQs for more information.

9. Can space solar cells be exported outside the U.S?

A: UTJ solar cells, CICs and panels are generally classified by the U.S. Department of Commerce under the EAR and can be exported to many countries outside the U.S. Depending on the country, export licenses may be required. Additionally there are a limited number of countries and entities to which export is denied. Spectrolab does not accept orders for small quantities outside the U.S. (except for Canada), as the related export costs are not cost-effective on small purchase orders.

10. Can I order samples? Do you offer reject or surplus product?

A: Please see How do I Order UTJ CICs, below. Spectrolab does not offer reject or surplus product for sale. You can also order TASC cells for non-space applications by clicking here.

11. How do I integrate the CICs into my system?

A: You can either weld or solder the CICs (using the interconnects) into series strings (adding voltage) and then wiring the strings in parallel (adding current). You can bond the solar cell strings to your insulated substrate using an RTV-type adhesive.