Tag: laser communications

Engineers set new laser communications record to asteroid probe Psyche

9:16 am

Psyche-Earth laser communications record
Click for original graphic.

As part of a continuing test program, engineers have set a new long distance laser communications record, exceeding 290 million miles, by successfully using a laser to send communicate with the asteroid probe Psyche from Earth.

The graph to the right, not to scale, shows the orbital configuation of the laser record. It appears however that little actual data was sent in this last test. It merely demonstrated that a link could be established. An actual data transfer record by laser occurred in June.

On June 24, when Psyche was about 240 million miles (390 million kilometers) from Earth — more than 2½ times the distance between our planet and the Sun — the project achieved a sustained downlink data rate of 6.25 megabits per second, with a maximum rate of 8.3 megabits per second. While this rate is significantly lower than the experiment’s maximum, it is far higher than what a radio frequency communications system using comparable power can achieve over that distance.

The high data rates promised by laser communications will significantly improve deep space operations. Most especially, the ability to get data back in much larger packets more quickly will reduce the antenna bottleneck on Earth that limits the number of missions as well as the data can be returned daily. More missions will be able to fly, and scientists and engineers will get their results faster.

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Laser communication tests with Psyche have now included a cat video

9:06 am

Following up on the first tests in mid-November, engineers on December 11, 2023 downloaded a 15-second cat video from the asteroid probe Psyche at a distance of 19 million miles, demonstrating fast download speeds 10 to 100 times faster than the best radio transmissions.

The demo transmitted the 15-second test video via a cutting-edge instrument called a flight laser transceiver. The video signal took 101 seconds to reach Earth, sent at the system’s maximum bit rate of 267 megabits per second (Mbps). Capable of sending and receiving near-infrared signals, the instrument beamed an encoded near-infrared laser to the Hale Telescope at Caltech’s Palomar Observatory in San Diego County, California, where it was downloaded. Each frame from the looping video was then sent “live” to NASA’s Jet Propulsion Laboratory in Southern California, where the video was played in real time.

I have embedded that video below. More details about the information in that video can be found here.
» Read more

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NASA laser communication experiment succeeds in sending data from beyond Moon

9:12 am

A NASA laser communication experiment on the asteroid probe Psyche succeeded on November 14, 2023 in sending data to and from the spacecraft as it traveled away from Earth.

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 experiment seeks to demonstrate the advantages of optical communications, which if successful could have data speeds ten to a hundred times faster than standard high band radio communications. While the technology has been demonstrated as far away as the Moon, this is the first successful test from deep space, a key advance that suggests the technology is becoming mature enough to use on planetary missions.

If so, it could largely replace or at least supplement the various radio-antenna networks on Earth, such as NASA’s Deep Space Network, with smaller and more efficient communication links.

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In an engineering test, LADEE successfully used a laser to beam information back from the Moon this past weekend.

8:25 am

In an engineering test, LADEE successfully used a laser to beam information back from the Moon this past weekend.

Lasers could enhance space communications and lead to radical changes in spacecraft design. Today’s spacecraft communicate with radio, but radiofrequency wavelengths are so long that they require large dishes to capture the signals. Laser wavelengths are 10,000 times shorter than radio, the upshot being that a spacecraft could deliver much more data then even the best modern radio system. For scale, NASA says that the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft that’s carrying this laser experiment would take 639 hours to download an average-length HD movie using ordinary S-band communications. LLCD could download the film in less than eight minutes.

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NASA announces awards for three technology demonstration space missions

2:47 pm

NASA has announced three awards for technology demonstration space missions, all set to fly within four years. More details here.

The three missions are:

  • A solar sail demonstration mission, flying a sail 38 by 38 meter sail.
  • A demonstration of in-space laser/optical communications technologies.
  • The use of a high-precision atomic clock in space.

I especially like the solar sail mission because of its long range possibilities, though the other technologies would probably be put to practical use more quickly.

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