NASA Astronomy Picture of the Day

Nov 19, 2023

Space Station, Solar Prominences, Sun

That's no sunspot. It's the International Space Station (ISS) caught passing in front of the Sun. Sunspots, individually, have a dark central umbra, a lighter surrounding penumbra, and no Dragon capsules attached. By contrast, the ISS is a complex and multi-spired mechanism, one of the largest and most complicated spacecraft ever created by humanity. Also, sunspots circle the Sun, whereas the ISS orbits the Earth. Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes, but getting one's location, timing and equipment just right for a great image is rare. The featured picture combined three images all taken in 2021 from the same location and at nearly the same time. One image overexposed captured the faint prominences seen across the top of the Sun, a second image underexposed captured the complex texture of the Sun's chromosphere, while the third image the hardest to get captured the space station as it shot across the Sun in a fraction of a second. Close inspection of the space station's silhouette even reveals a docked Dragon Crew capsule.

https://apod.nasa.gov/apod/astropix.html?

Lockheed Martin Prepares First 5G.MIL® Payload for Orbit

NOVEMBER 13, 2023

First Regenerative Non-Terrestrial Network 5G Satellite Base Station Completes Final Demo Prior to Space Mission

Lockheed Martin is one step away from showcasing how its 5G.MIL® capability can reach all domains around the world. In its final successful lab demonstration, the company validated that its innovative space payload is set to deliver global advanced communications capabilities from orbit.

During the October demonstration, Lockheed Martin showcased the industry’s first fully regenerative Advanced 5G Non-Terrestrial Network (NTN) Satellite Base Station – developed as a space component of the company’s 5G.MIL Unified Network Solutions Program.

In 2024, in a self-funded mission, the company will launch this payload to orbit bringing 5G’s capabilities to the final frontier to prove its capability to connect the globe.

In a live hardware-in-the-loop lab environment, the Advanced 5G NTN Satellite Base Station performed high-speed data transfers connecting with prototype NTN user equipment, compliant with 3GPP Release 17, an industry standard for improved radio flexibility and low latency. During a simulated satellite orbital pass, the Satellite Base Station, running on space-hardened flight hardware and the user equipment on the ground, successfully connected and transferred data, including live video streaming.

“Space layer capabilities are essential for consistent, secure connectivity and global coverage for 5G communications systems. 5G from space will enable Joint All-Domain Command and Control operations especially in austere environments, remote locations and contested areas,” said Joe Rickers, Lockheed Martin’s vice president for Connectivity, Transport and Access. “Our Satellite Base Station is real, operational hardware and we’re excited for the next step – integrating this powerful payload into our self-funded Tactical Satellite which we’ll launch next year.”

Lockheed Martin’s Advanced Satellite Base Station for 5G, or gNodeB, as it is technically known:

• Includes a full 5G New Radio (NR) Radio Access Network (RAN) stack, RAN Intelligent Controller (RIC) and 5G Stand Alone (SA) Core running on space-qualified flight hardware that will fly on the TacSat.

• Is reprogrammable on orbit using Lockheed Martin’s SmartSat™ software-defined satellite architecture.

• Can be structured with a split architecture placing the Control Unit (CU) on the ground and the Distributed Unit (DU) on the satellite, further enhancing network implementation options.

• Connects to industry-leading prototype NTN user equipment through a space communications channel emulator that introduced doppler and delay parameters consistent with a satellite Low Earth Orbit.

“Space-based communications will provide high-speed backhaul to land, air and sea 5G.MIL Hybrid Base Stations as well as direct access to user equipment running 3GPP NTN standard protocols from orbit,” said Dan Rice, vice president for Lockheed Martin’s 5G.MIL Programs. “Regenerative NTN solutions enable direct, satellite-based secure communications between users in a coverage area – bypassing more vulnerable terrestrial networks when necessary.”

Lockheed Martin’s standards-based approach is compliant with 3GPP Release 17 and was developed in anticipation of pre-Release 18 & 19 regenerative specifications. 5G NTN provides another communications pathway to support ubiquitous, heterogeneous communications across all operational domains in support of customer missions.

Leading up to this successful pre-launch demonstration, Lockheed Martin has developed and integrated the regenerative 5G NTN HBS-Space system over the past 3 years working with key subcontractors:

AccelerComm™ provided an advanced 5G NTN Layer 1 PHY solution, developed to support Lockheed Martin’s system requirements and space flight hardware specifications.

Radisys supplied 5G NTN Layer 2/3 and 5G SA Core software, working with Lockheed Martin to ensure interface implementation enabled seamless integration with L1 and RIC solutions.

Keysight supported 3GPP standards-based development testing of Lockheed Martin’s regenerative 5G NTN base station via their 5G NTN user equipment simulation (UeSIM) product suite.

The Advanced 5G Satellite Base Station is the lynch pin in Lockheed Martin’s vision to provide global 5G connectivity. For the past three years, the company has been investing in, developing and demonstrating fixed, relocatable, mobile and now, space variants, of its Hybrid Base Stations.

“These tools are a major part of our 21st Century Security vision to always keep our customers ahead of ready,” Rice added.

https://www.lockheedmartin.com/en-us/news/features/2023/lockheed-martin-prepares-first-5g-mil–payload-for-orbit.html

NASA’s Deep Space Optical Comm Demo Sends, Receives First Data

Nov 16, 2023

NASA’s Deep Space Optical Communications (DSOC) experiment has beamed a near-infrared laser encoded with test data fromnearly 10 million miles (16 million kilometers) away – about 40 times farther than the Moon is from Earth – to the Hale Telescope at Caltech’s Palomar Observatory in San Diego County, California. This is the farthest-ever demonstration of optical communications.

Riding aboard the recently launched Psyche spacecraft, DSOC is configured to send high-bandwidth test data to Earth during its two-year technology demonstration as Psyche travels to the main asteroid belt between Mars and Jupiter. NASA’s Jet Propulsion Laboratory in Southern California manages both DSOC and Psyche.

The tech demo achieved “first light” in the early hours of Nov. 14 after its flight laser transceiver – a cutting-edge instrument aboard Psyche capable of sending and receiving near-infrared signals – locked onto a powerful uplink laser beacon transmitted from the Optical Communications Telescope Laboratory at JPL’s Table Mountain Facility near Wrightwood, California. The uplink beacon helped the transceiver aim its downlink laser back to Palomar (which is 100 miles, or 130 kilometers, south of Table Mountain) while automated systems on the transceiver and ground stations fine-tuned its pointing.

“Achieving first light is one of many critical DSOC milestones in the coming months, paving the way toward higher-data-rate communications capable of sending scientific information, high-definition imagery, and streaming video in support of humanity’s next giant leap: sending humans to Mars,” said Trudy Kortes, director of Technology Demonstrations at NASA Headquarters in Washington.

Test data also was sent simultaneously via the uplink and downlink lasers, a procedure known as “closing the link” that is a primary objective for the experiment. While the technology demonstration isn’t transmitting Psyche mission data, it works closely with the Psyche mission-support team to ensure DSOC operations don’t interfere with those of the spacecraft.

“Tuesday morning’stest was the first to fully incorporate the ground assets and flight transceiver, requiring the DSOC and Psyche operations teams to work in tandem,” said Meera Srinivasan, operations lead for DSOC at JPL. “It was a formidable challenge, and we have a lot more work to do, but for a short time, we were able to transmit, receive, and decode some data.”

Before this achievement, the project needed to check the boxes on several other milestones, from removing the protective cover for the flight laser transceiver to powering up the instrument. Meanwhile, the Psyche spacecraft is carrying out its own checkouts, including powering up its propulsion systems and testing instruments that will be used to study the asteroid Psyche when it arrives there in 2028.

With successful first light, the DSOC team will now work on refining the systems that control the pointing of the downlink laser aboard the transceiver. Once achieved, the project can begin its demonstration of maintaining high-bandwidth data transmission from the transceiver to Palomar at various distances from Earth. This data takes the form of bits (the smallest units of data a computer can process) encoded in the laser’s photons – quantum particles of light. After a special superconducting high-efficiency detector array detects the photons, new signal-processing techniques are used to extract the data from the single photons that arrive at the Hale Telescope.

The DSOC experiment aims to demonstrate data transmission rates 10 to 100 times greater than the state-of-the-art radio frequency systems used by spacecraft today. Both radio and near-infrared laser communications utilize electromagnetic waves to transmit data, but near-infrared light packs the data into significantly tighter waves, enabling ground stations to receive more data. This will help future human and robotic exploration missions and support higher-resolution science instruments.

“Optical communication is a boon for scientists and researchers who always want more from their space missions, and will enable human exploration of deep space,” said Dr. Jason Mitchell, director of the Advanced Communications and Navigation Technologies Division within NASA’s Space Communications and Navigation (SCaN) program. “More data means more discoveries.”

While optical communication has been demonstrated in low Earth orbit and out to the Moon, DSOC is the first test in deep space. Like using a laser pointer to track a moving dime from a mile away, aiming a laser beam over millions of miles requires extremely precise “pointing.”

https://www.nasa.gov/missions/psyche-mission/nasas-deep-space-optical-comm-demo-sends-receives-first-data/