Donald Cornwell plenary talk: NASA's Optical Communications Program: 2015 and Beyond

Summary

Don Cornwell, with program responsibility at NASA for the Optical Communications program, discusses significant breakthroughs in laser communication technology. He highlights the need for more bandwidth to transmit vast amounts of data from space, using the example of a 30 cm resolution map of Mars. Cornwell explains that current radio frequency (RF) systems are insufficient for the task, which would take up to 9 years to transmit, compared to 9 weeks using optical communications. He details the successful Lunar Laser Communication Demonstration (LLCD) mission, which set records for download and upload speeds from the Moon. The presentation also covers the technological challenges, such as maintaining a precise beam from the Moon to Earth, and the solutions developed, including an inertial reference system to compensate for spacecraft vibrations. Cornwell outlines NASA's ongoing efforts in optical communications, including plans for deep space optical communications, near Earth missions, and the Laser Communications Relay Demonstration (LCRD), which aims to provide high-speed data transmission from geostationary satellites. He emphasizes the importance of creating a complete product package, including software, hardware, systems integration, commercialization, ground networks, and standards and procedures, to cross the 'chasm' and make optical communications a pragmatic choice for future space missions.

Takeaways

• 🚀 NASA's Optical Communications program has achieved significant breakthroughs in the last few years, exciting both NASA management and the global community.
• 🌌 The need for more bandwidth is driving NASA towards laser communications, as current radio frequency (RF) systems are insufficient for the vast amounts of data generated by space instruments.
• 📈 A 30 cm resolution Google map of the entire Martian surface would take up to 9 years to transmit with current RF systems, compared to 9 weeks with optical communications.
• 🏆 The Lunar Laser Communications Demonstration (LLCD) mission, which operated from the Moon in 2013, was a success and was nominated for the Collier Trophy in 2014.
• 📡 LLCD set records for download speeds from the Moon at 600 megabits per second and upload speeds to the Moon at 20 megabits per second, enabling HD video transmission.
• 🔬 The success of LLCD has paved the way for future optical communications missions, including deep space and near-Earth projects.
• 🌟 NASA is planning a Deep Space Optical Communications project to build a terminal for a mission to Mars, which will require more powerful lasers and a larger receiver due to increased distance.
• 📲 The OPALS mission on the International Space Station demonstrated 50 megabits per second from low Earth orbit to the ground, showcasing the potential for near-Earth optical communications.
• 🔗 NASA's Laser Communications Relay Demonstration (LCRD) is scheduled for launch in 2018, aiming to provide a user rate of one to two gigabits per second for near-Earth communications.
• 🛰️ The Mars 2020 Rover is being considered for a small optical communications terminal that could provide an order of magnitude improvement in data transmission rates compared to RF systems.
• 📚 Efforts are underway to integrate optical communications systems into existing networks, with considerations for standards, procedures, and providing a complete solution for pragmatist users.

Q & A

What is the main responsibility of Don Cornwell at NASA?

Don Cornwell has the program responsibility at NASA headquarters for the Optical Communications program.

Why is NASA interested in free-space laser communications?

NASA is interested in free-space laser communications because it provides more bandwidth, which is necessary to bring back more data from space instruments.

What was the significance of the LLCD mission?

The Lunar Laser Communication Demonstration (LLCD) mission was significant because it demonstrated the viability of laser communications for space, achieving high data rates from the Moon to Earth.

How long would it take to transmit a 30 cm resolution Google map of the entire Martian surface using the current best RF system?

It would take up to 9 years to transmit a 30 cm resolution Google map of the entire Martian surface using the current best RF system.

What was the data rate demonstrated by the LLCD mission?

The LLCD mission demonstrated a data rate of 600 megabits per second for download speeds from the Moon and 20 megabits per second for upload speeds to the Moon.

What is the main challenge of laser communication from the Moon to Earth?

The main challenge of laser communication from the Moon to Earth is accurately hitting a 6 km target from a distance of 400,000 km away.

How does optical communication provide higher performance compared to RF?

Optical communication provides higher performance because it uses light waves with frequencies that are 15,000 times shorter than RF, allowing more data to be imparted onto the beam and enabling more concentrated energy delivery at a distance.

What is the purpose of the system developed by MIT Lincoln Laboratory to compensate for the spacecraft's vibrations?

The system measures the platform jitter caused by vibrations from the spacecraft and compensates for it, ensuring that the laser beam remains stable and accurately targeted.

What is the role of the modem module in the spacecraft?

The modem module, which is about the size of a bread box, includes the lasers and the laser system for communication, as well as the encoding electronics for the optical communication system.

What is NASA's next step in the field of optical communications after the LLCD mission?

NASA's next step is the development of deep space optical communications, with a project led by NASA JPL to build a terminal for a mission to Mars.

What is the expected data rate for the deep space optical communication terminal planned for the Mars mission?

The expected data rate for the deep space optical communication terminal planned for the Mars mission is about 250 megabits per second.