Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [antenna]

Questions about devices which collect and couple electromagnetic signals (communications, radar or other electromagnetic measurements) directly between free space, and conductors (e.g. waveguides or other transmission lines).

1
vote
0answers
16 views

Was there a prototype for Solar Probe's hybrid Heat Shield/Antenna?

An early concept of the Solar Probe (reborn as Solar Probe Plus then Parker Solar Probe) used parabolic antenna with a heat-resistant nadir facing side to double as a heat shield. While sourcing this ...
0
votes
0answers
17 views

Antenna FOV vs. beamwidth

What is the difference between the FOV of an antenna and its beam width? I know that from SMAD an antenna has a different beam width based on its geometry. But for some satellites, a FOV is mentioned ...
17
votes
1answer
2k views

Did NASA's Borg Collective-designed antennas work? Have similar designs ever been used in spacecraft beyond testing?

This interesting answer to the question Do antenna farms on spacecraft make any sense or are they purely aesthetic? in Worldbuilding SE links to the NASA Ames page 'Borg' Computer Collective Designs ...
2
votes
0answers
35 views

Did any of Voyagers' receivers' front ends take advantage of the “cold of space” to lower noise?

Most of the Voyagers' electronics are kept warm by electrical heaters powered by their RTG's, and presumably protected by some amount of insulation from the "cold of space" which means loss of heat ...
1
vote
0answers
66 views

How does this antenna work, with both a feed horn and hyperbolic secondary in front of the dish?

Scrolling through the Roscosmos twitter feed I saw this image of a dish antenna in a recent tweet. Google translate shows that the post says: Новый измерительный пункт будет построен на Сахалине ...
2
votes
1answer
61 views

Need help identifying this (likely to be) phased array antenna used to track launches

I need help identifying the (what I believe to be) flat (and possibly phased) array antenna shown next to the tracking telescope in this photo, which can be found both here and here where the ...
0
votes
1answer
91 views

What is this combination tracking telescope and helical antenna pair? was it really used, and who is/was FlightLine?

I spotted the image below here which I found here (also seen here). Zooming in on this combination pair of telescope trackers and pair of RHCP and LHCP (right- and left-handed circular polarization) ...
7
votes
2answers
458 views

What are these antenna-like structures seen in Oleg Artemyev twitter video?

Russian Cosmonaut Oleg Artemyev's Sept 3, 2018 tweet has a narrated video of Earth from the ISS, at the time over the Nile river. The video is also in YouTube (below). At the bottom of the screen, ...
1
vote
2answers
164 views

Why were the antennas on the spherical surface of some early satellites spiral-shaped?

In the question What's the spiral pattern on this satellite? I show this image of a spiral-shaped pattern on the spherical surface of a (presumably) vintage satellite or model thereof. @OrganicMarble'...
2
votes
1answer
54 views

What's the largest area dish antenna sent beyond the Earth-Moon system?

In the same vein as the question What's the largest aperture telescope sent beyond the Earth-Moon system?, I'd like to ask, what's the largest area antenna dish sent beyond the Earth-Moon system? If ...
3
votes
0answers
91 views

How would the antenna on a spacecraft in GEO be provided an electrical ground?

I would like to understand better what specifications or guidelines address the electrical grounding/Earthing a parabolic reflector Antenna in GEO to minimize the potential difference with respect to ...
12
votes
2answers
639 views

What is the large circular device with a dozen concentric circles on Sentinel 3B?

The Spaceflight Now article Photos: Sentinel 3B satellite prepared for launch from Plesetsk Cosmodrome has of course lots of photos. One of them shows a dish antenna covered with shiny, metallized ...
5
votes
1answer
223 views

How does Curiosity know how to point and move it's high gain antenna in real time?

The Curiosity rover has a compact X-band high-gain antenna (HGA) that allows for low data rate communication directly with Earth, but is used mostly for higher data rates to spacecraft orbiting Mars, ...
4
votes
1answer
150 views

The appearance of TESS' dish seems to be evolving, what will be the final configuration?

The question Why is TESS' high gain antenna made of undulating BLACK fabric rather than metal? has had three bounties, and is probably the recipient of this sites longest answer. My personal pet ...
2
votes
1answer
246 views

What is Canted Turnstile Antenna System? What it its Applications?

There are not many sources I can read to know about this kind of Antenna and its Applications
4
votes
1answer
699 views

How does SpaceX Falcon Heavy Starman live feed transmitter work?

I'm curious to find out answers to the following questions: Where is the antenna for the live feed transmitter of starman located in the payload? How is the transmitter being powered? Related to 2nd ...
3
votes
0answers
56 views

What is the Telescope Invariant Point?

I am working on an implementation of an SLR tool. At some points of the documentation of the CRD format the term telescope invariant point shows up. Apparently it's a point on an ILRS antenna system. ...
3
votes
2answers
454 views

How to design a ground antenna for sending & receiving from a satellite?

Let's suppose there is a wifi router or a cell phone or similar transmitter in an orbit of 3000 km. How could one make a dish antenna to connect and receive the signal from that wifi router or cell ...
3
votes
1answer
219 views

What were those motorized human-piloted platforms with helical antennas called (tracking launches)?

This interesting question got me started. I have these vignettes in my Apollo-era memory of antenna systems that tracked launches for telemetry. They had maybe four end-fire helical antennas pointing ...
7
votes
2answers
560 views

What is this spinning object seen on a spacecraft above the ISS?

In the YouTube Trailer for the PBS program A Year in Space at 00:56 a small spinning object can be seen, attached to a spacecraft well above the ISS. I think the ...
6
votes
2answers
923 views

How did this structure fit into the Shuttle and then expand to 28 meters?

In this answer I read about the Inflatable Antenna Experiment that flew with STS-77. According to this article: Packed into the Spartan, the IAE weighed only 132 pounds; on deployment (inflation), ...
1
vote
0answers
59 views

Calibration of Antennae in satellite and in ground station [closed]

How to orient the ground station antenna and that of the satellite just after the launch?
1
vote
2answers
785 views

Angular distance between two satellites given azimuth and elevation angles for each?

If the look angles for a pair of satellites are $Az_1, El_1$ and $Az_2, El_2$, what would be the angular separation between them? An associated problem is how do we determine whether and when the two ...
2
votes
1answer
201 views

Will there be “Near Space” Ka band allocations for TESS?

update: More information in Phys.org's news item TESS mission to discover new planets moves toward launch, including a video of the telescope array's final assembly. Also see GSFC's TESS page. The ...
7
votes
1answer
791 views

Why is TESS' high gain antenna made of undulating BLACK fabric rather than metal?

above: from Facebook, then annotated. There is an excellent review of the design of the TESS spacecraft in G. R. Richter et al. Journal of Astronomical Telescopes, ...
23
votes
2answers
3k views

What is the function of this (apparently) fixed dish on the ISS?

I saw this image in Popular Science, one of the example photos from the book by astronaut/photographer/astrophotographer(?) Donald Pettit. It's beautiful and impressive not only from a color/...
1
vote
1answer
174 views

What are these dishes looking at?

In this CSA video CSA Astronaut Chris Hadfield describes the attitude control of the ISS and its importance for things like communication with Earth. At 00:30 here ...
8
votes
1answer
234 views

How do commercial broadcast satellites in GEO produce such carefully shaped signal footprints?

SES-10 will be launched in a few days on Space-X's first commercial launch using a recycled rocket. Screenshots from the three links (Brazil, Central America, South America) on Satbeams page for SES-...
6
votes
1answer
321 views

How is GAIA's phased array configured, mechanically and electrically?

GAIA is an amazing pair of space telescopes that share a single Gigapixel CCD array, with a complex optical system capable of repeated, extremely precise position, brightness, parallax, proper motion, ...
17
votes
2answers
1k views

Why did Sputnik 1 have four antennas?

Sputnik was only launched a few hundred kilometers above Earth, and transmitted only a simple beeping signal. What was the purpose of having four antennas? Wouldn't one be powerful enough?
7
votes
1answer
238 views

Deep space craft antenna aiming

In order to aim an antenna at Earth, how do unmanned spacecraft find their own orientation (xyz position in space, what direction it is flying and which direction the antenna is pointing)? Are they ...
8
votes
1answer
659 views

When is a phased array antenna not a phased array?

This question is inspired by an answer to this question, where it is stated that: The real power of phased arrays is their ability to be steered electronically. This set me wondering about the ...
8
votes
1answer
624 views

Radiation pattern and signal strength of navigation satellite antennas

Where can I find the actual radiation pattern and signal strength of transmitting antennas used by GNSS navigation satellites/constellations (GPS, GLONASS, IRNSS, etc)?
6
votes
2answers
616 views

How are phased array antennas used in spaceflight? Benefits and limitations

It would seem to me that a phased array antenna would be great for spacecrafts since it removes the need to turn the entire spacecraft around in order to point the radio dish towards Earth. Many ...
3
votes
2answers
434 views

Can't we use laser transmitters instead of large radio dishes on deep space probes?

Isn't it possible to use a laser as an "antenna" that transmits data? This would save quite a lot of mass since you don't need a large dish. The only problem I can think of is how would you modulate ...
24
votes
2answers
5k views

What is the purpose of the rotating dish antenna on the ISS

I just saw some footage of the ISS in which a dish antenna could be seen, constantly rotating. The dish looked more-or-less parabolic, meaning that it is presumably sending/receiving along a fairly ...