Engineering topics
Kurtik, Susan
Publications and source records attributed to Kurtik, Susan.
NASA’s and ESA’s Tracking Networks, A Decade of Strategic Partnership for Solar System Exploration
Planetary missions travel vast distances in the Solar System for valuable scientific exploration. Spacecraft return data to Earth via radio links that suffer power losses inversely proportional to the square of the distance, which forms a tremendous engineering challenge compounded by relatively low onboard transmitter power, typically 20 Watts at X-band (~8 GHz). Deep space missions are enabled only because leading space agencies invested in developing very large communications antennas as well as provided a sophisticated suite of tracking, telemetry and command standard services. NASA’s Deep Space Network and ESA’s ESTRACK network are distributed geographically to provide global coverage and utilize stations ranging in size from 34 meters to 70 meters in diameter. Over time, the expanding number of missions, increased requirements for redundancy during critical events as well as the drive for improved navigation accuracy via long-baseline interferometric techniques, increased the networks’ loading and strongly motivated collaboration between the two agencies. Ten years ago, NASA and ESA established a cross-support agreement in addition to multiple on-going mission-specific agreements to meet this need. This strategic partnership was enabled by the development of international inter-operability technical standards and compatible spectrum usage. Over recent years, many critical events were supported via these agreements and some scientific breakthroughs were enabled. A multi-nation tracking contention period envisioned in the near future will also benefit from this partnership. Due to its success over the last decade, the DSN-ESTRACK partnership is serving as a model for other agencies with deep space communication facilities and similar interest. This paper reviews the benefits and lessons learned from collaborative deep space exploration, especially via communications networks, and discusses the potential implementation of similar NASA agreements with other space agencies.
Communications During Critical Mission Operations: Preparing for InSight's Landing on Mars
Radio communications with deep space missions are often taken for granted due to the impressively successful records since, for decades, the technology and infrastructure have been developed for ground and flight systems to optimize telemetry and commanding. During mission-critical events such as the entry, descent, and landing of a spacecraft on the surface of Mars, the signal's level and frequency dynamics vary significantly and typically exceed the threshold of the budgeted links. The challenge is increased when spacecraft shed antennas with heat shields and other hardware during those risky few minutes. We have in the past successfully received signals on Earth during critical events even ones not intended for ground reception. These included the UHF signal transmitted by Curiosity to Marsorbiting assets. Since NASA's Deep Space Network does not operate in the UHF band, large radio telescopes around the world are utilized. The Australian CSIRO Parkes Radio Telescope supported the Curiosity UHF signal reception and DSN receivers, tools, and expertise were used in the process. In preparation for the InSight mission's landing on Mars in 2016, preparations are underway to support the UHF communications. This paper presents communication scenarios with radio telescopes, and the DSN receiver and tools. It also discusses the usefulness of the real-time information content for better response time by the mission team towards successful mission operations.
Deep Space Network (DSN): Mission Services and Operations Interface for Small Deep Space Missions
No abstract available