# Tag Info

8

All I could find was here which led to a variety of articles which explain the technology in depth. Not that Wikipedia is always reliable, however it stated that: The satellites will employ optical inter-satellite links and phased array beam-forming and digital processing technologies in the Ku and Ka bands, according to documents filed with the U.S. ...

7

The problem is the plasma is VERY bright. I can't find all the numbers easily but let's find a ballpark figure cobbling some available data together. A reentry capsule of $m=3$ tons (like Soyuz). Blackout of $t=4$ minutes (like Gemini 2). Initial blackout velocity $v_0 = 7$ km/s, final $v_1 = 4$ km/s (like the shuttle) The produced plasma is created using ...

6

The European Data Relay System has recently begun testing. It's for getting data from Earth orbiting satellites down to the ground quickly, without waiting for the satellite to pass over a base station. Claimed data rate: "Up to 1800 Mbit/s" and "At least 50 TBytes/day". (Note: I don't see how these two figures equate.) Here is the first big test: an image ...

5

It looks like the answer is probably no. The paper from the 2015 talk seems to refer to this as "a recent NASA JPL study", and notes that it would need a similar terminal on an orbiter. It looks like this was a paper study to see whether it would be possible, rather than a specific planned experiment. A similar talk (slides) by Cornwell in 2017 ...

5

As it happens, reentry temperatures peak at approximately the same temperature in kelvins as reentry speed in m/s, so assuming roughly 8 km/s, 8000 K is the figure to work from. This diagram from Ohio State shows that roughly half the emitted black-body radiation at 8000 K is in the UV spectrum: Nearly all of that is in the near and middle UV range (200-...

5

The lunar mission which tested optical communication was LADEE. The ISS program you're thinking of is OPALS. Both tests succeeded, but neither was meant for ongoing operation. LADEE intentionally impacted the moon, and the US orbital segment of ISS currently uses S and Ku band radio communication through TDRSS. The next proposed study on laser ...

4

In case of optical communication we don't deal with electromagnetic waves that are collected in an antenna at a ridiculously low power level, are amplified by many orders of magnitude and then need to be correlated with a known signal shape to extract meaningful information from the abundant noise. In optical links (here: infrared light at 1500 nm) each and ...

3

Probably the first and only ground to space optical communications experiment with an object on the lunar surface was a laser communication line with Lunokhod-2. "Эта же наземная аппаратура была использована для эксперимента по исследованию возможности передачи информации методом время-импульсной модуляции по оптическому каналу связи Алма-Ата - "...

3

Yes, the optical link being discussed is a laser--here's an article (behind a paywall, but the abstract mentions that the technology is laser technology) that discusses the exact satellite link you're talking about: http://ieeexplore.ieee.org/document/5475229/ Lasers do not have to be optical light. They can be anything from infra-red to X-rays, though X-...

3

Not really amateur, but CubeSats for sure. AeroCube 7 / OCSD would have already tested it, but had attitude control problems. Should relaunch in a few months. One can find plenty of detailed publications too. ArgoMoon will be one of the next. Testing it from beyond Moon orbit, but not much is known yet. Edit 2018-12-08: AeroCube-7B successfully ...

3

There was one that I can find, a beacon that used infrared light to communicate at a rate or 400 bits/second, on AO-40, which was a technology demonstration mission by AMSAT. Wikipedia doesn't include any amateur missions. It is proposed to use laser based communication for satellites beyond Earth's orbit, such as the ...

2

ILLUMA-T will work with the LCRD flight segment payload on Space Test Program Satellite-6 (STPSat-6); see page 4 of this document from SCAN. LCRD’s dual optical link system will allow it to serve as the first step in demonstrating optical communications for use in a next-generation space-based relay system and potentially provide early operational support ...

2

A bit of sparse data are available for the EDRS system from ESA: EDRS And a bit from Airbus EDRS At least some basic data rates and distances.

2

What's on the flatbed trailer? If you're referring to slide 4, that's a FRAM (Flight Releasable Attachment Mechanism) - it's a standardized roughly 4x4 foot pallet like thing that the SCaN Testbed is bolted to that has the mechanical and electrical connections to hook it to ISS. Slide 5 shows it being moved by the Canadarm to it's final position on ELC-3. ...

2

Unfortunately, those slides don't provide much information on what they mean by "relay pathfinder" but the concept of using optical communication in space has been tested and is planned for several missions. NASA has previously tested optical communications during a lunar mission. This was used as a demonstration of the concept for the (now not-so-)...

1

They haven't publicly laid out detailed plans, but they have or are actively working on all the pieces such a system would require, and have mentioned it a couple times. Shotwell discussed it in an interview for TIME magazine: The second reason was once we take people to Mars, they're gonna need a capability to communicate. In fact, I think it will be even ...

1

One report of a study on the topic funded by NASA JPL in 2005 is "Deep-space to ground laser communications in a cloudy world". Based on global cloud statistics, they worked out the probability of success as a function of number of receiving stations and optimized their location, and found that the number needed to achieve the desired availability ...

1

No, the COLKa (Columbus Ka-band antenna) provides only Ka-band communications. This paper, while focused on the thermal design, provides the best overview of the system I have found: Columbus Ka-band Terminal thermal control - a compact design for varying conditions It is made up of a steerable antenna, RF signal processing assemblies (...

1

See https://eoportal.org/web/eoportal/satellite-missions/content/-/article/pixl-1 for more details on the mission Launched beginning of 2021! Launch: PIXL-1, a 3U CubeSat mission of DLR, was launched as one of many payloads (total of 143 satellites) on the Transporter-1 mission of SpaceX from the Cape Canaveral Space Force Station (SLC-40) in Florida on 24 ...

1

As of October 2018, the programme is in Qualification. Launch is scheduled for Q1/2019 with a Rocketlabs Electron on a Gomspace 3U platform. Optical communication is for downlinks. Gomspace/DLR eoPortal GOMX-3 (GomSpace Express-3)

1

The re-entry blackout problem was resolved for the Space Shuttle with the implementation of the TDRSS system. It consists of (currently) 7 satellites in geostationary orbit. During re-entry, the shuttle was able to communicate with a satellite "through a "hole" in the ionized air envelope at the tail end of the craft, created by the Shuttle's shape".

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