Historical mass, power, schedule, and cost growth for NASA science instruments
In the early stages of NASA instrument development, science instruments are typically the most nascent part of any NASA mission development. As the building of spacecraft become less challenging for a mature industry, NASA's continual need to push the cutting edge of science requires the revolutionary and evolutionary development of instruments to meet science requirements. Instruments then face substantial issues that can result in significant increases in mass, power, cost, and schedule. Although previous studies have identified such issues, there are few industry standard reserve/contingency design and programmatic guidelines for instruments. This paper compares historical mass, power, cost, and schedule growth to industry reserve guidelines while offering potential recommendations to minimize instrument mass, power, cost, and schedule growth for future missions.
Instrument first, spacecraft second (IFSS): A new paradigm in space mission development
An analysis was conducted to determine potential benefits of initiating instrument development prior to full mission development for NASA Earth Science missions. A cost and schedule analysis was conducted for representative Tier 2 and Tier 3 Earth Science Decadal Survey missions to quantify the benefits. The results indicate that the savings resulting from such an approach is on the order of $2B, making more funding available for future missions, while providing a less volatile and more manageable mission portfolio.
Integrated two-beam antenna array featuring dual-circular polarization
A concept of an integrated antenna array featuring two independent beams and dual circular polarization has been described. The antenna array consists of two radiating elements which are excited at two orthogonally placed feeding ports with the use of four appropriately connected 3-dB/90° directional couplers. Therefore, such an array generates two symmetrically located beams having right-handed circular polarization (RHCP) and identical two beams having left-handed circular polarization (LHCP). The presented concept has been verified by the design and measurements of an antenna array operating at 2.4 GHz frequency range.