13 votes
Accepted

How will the closure of the Arecibo dish impact deep space communications?

There is some indirect evidence that Arecibo's loss has already impacted communication with some of the deep space probes. NASA's official statement on Arecibo says this: NASA’s Goldstone Observatory ...
DrSheldon's user avatar
  • 47.9k
12 votes

Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?

Because the dish isn't a black body. At RF it has a very low emissivity, hence the name "reflector".
pericynthion's user avatar
  • 10.1k
12 votes

Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?

When discussing radio antennae, radio astronomers usually describe things in terms of temperatures. We can convert between power and temperature simply by multiplying (or dividing) by Boltzmann's ...
Phiteros's user avatar
  • 5,626
11 votes
Accepted

Embedding foundations from low lunar orbit?

Putting it bluntly, I don't like your idea. In addition to needing accuracy and precision from afar and all the problems associated with that, as mentioned in the answer by @Nuclear_Hogie, I get the ...
Fred's user avatar
  • 13.1k
9 votes

How far can SETI's ear listen?

Using current technology (and by that I mean experiments and telescopes that are available now) we would probably be unable to detect life on Earth even if observed from a distance of a few light ...
ProfRob's user avatar
  • 374
9 votes

Embedding foundations from low lunar orbit?

Accurately landing something on the moon is tricky business. Even performing a controlled landing within several hundred meters of your target is a noteworthy achievement. Dropping pylons from orbit ...
Nuclear Hoagie's user avatar
8 votes
Accepted

Was the time of Schiaparelli's landing chosen specifically so the Giant Meter Wave Radiotelescope could listen?

No. The landing time is determined by the interplanetary trajectory, largely fixed by launch energy constraints, and then by the landing site location, mainly the longitude. This paper identifies the ...
Mark Adler's user avatar
  • 58.1k
7 votes
Accepted

How does this strangely-shaped horn at Honeysuckle Creek Tracking Station work?

That antenna is a Cassegrain horn (or 'casshorn'). This is an evolution of the earlier horn-reflector antenna (paper that describes the design), where a horn radiates into a parabolic surface: The ...
Hobbes's user avatar
  • 127k
6 votes

How was radio telescope observation data transferred before wide availability of high-speed Internet?

Transportation of data between observatories was done via magnetic tape using a standard or common format. At least this was the case for the Westerbork Synthesis Radio Telescope and the observatories ...
called2voyage's user avatar
  • 23.7k
6 votes
Accepted

Why doesn't thermal radio emission from a DSN "hot dish" completely swamp the benefits of a cold LNA?

Planck → Rayleigh-Jeans: I'm not talking about the infrared radiation from the telescope. That is probably removed by managing line-of-sight within the cryogenic waveguide, or a low-temperature ...
uhoh's user avatar
  • 149k
5 votes
Accepted

Which map is right? Where exactly were the two Australian dish antennas used in the Apollo missions?

Supplemental answer: Three sites in Australia were used to communicate with Apollo. Tidbinbilla (now called Canberra DSCC) Designed and continues to be used for tracking and communications of deep-...
DrSheldon's user avatar
  • 47.9k
5 votes
Accepted

What's the status and timeline for Millimetron? (Russia's 10m Deployable Antenna cooled to 6 K Earth-Space VLBI)

Provisional launch date 2029 https://millimetron.ru/en/ This project is directly related to the P-2500 (RT-70) radiotelescope at the Suffa radioobservatory. This modification of the RT-70 radio ...
A. Rumlin's user avatar
  • 7,863
5 votes

What is the largest single project (in tonnage) in which an international space cooperative has launched and or constructed in space?

The International Space Station, by far. The mass of the station varies with time, but it's around 420 tons It was constructed over the course of about 13 years, although it is still being tweaked ...
PearsonArtPhoto's user avatar
  • 121k
5 votes
Accepted

If the largest spy satellites could take pictures, how detailed would they be?

The resolution of an optical telescope can be calculated using the Rayleigh criterion: this is the theoretical limit: an optical system cannot be better than this. $θ=1.22λ/D$ θ is the angular ...
Hobbes's user avatar
  • 127k
5 votes

Embedding foundations from low lunar orbit?

This is an idea that has had some investigation and could work, but probably not for a high-precision device like a telescope. See Weiss & Yung, 2010 for a feasibility study on deploying a (lunar) ...
Infinite_Maelstrom's user avatar
5 votes

Embedding foundations from low lunar orbit?

The technique is popular for anchoring structures in deep water engineering. See for example torpedo pile, and similar. The problems I see are the hardness of lunar regolith compared to marine ...
user52543's user avatar
4 votes

Will there be joint observations from earth and the Juno spacecraft when it reaches Jupiter?

I've only been able to find one reference to joint observations thus far: Juno produces five pole-to-pole latitudinal maps of microwave opacity as a function of altitude to depths greater than ...
called2voyage's user avatar
  • 23.7k
4 votes

How far can SETI's ear listen?

A brief search led me to the conference proceedings for the "Life in the Universe" conference held at Ames Research Centre in 1979 (yes, this is old, but serves as a good baseline from which to begin)....
Brian Lynch's user avatar
  • 4,340
4 votes

Could a radio telescope orbit Earth-Moon L2 so that it is in the Moon's radio shadow?

The Earth-Moon L2 is located about 1.16 times as far from the Earth as the centre of the Moon (wikipedia, so the Earth is about 7 times as from L2 as the Moon is. Since the Earth is less than 7 times ...
Steve Linton's user avatar
  • 19.6k
4 votes
Accepted

How does a third DSN station serves as a “relay” to tie-together observations by two other stations doing VLBI?

Very-Long Baseline Interferometry is interferometry with telescopes that physically distant. The observation data is recorded locally, and post-observation the data is combined at a central location ...
Ludo's user avatar
  • 14.2k
4 votes
Accepted

At what wavelengths and for what particle types have astronomical objects been imaged or at least directionally resolved from Tiangong stations?

Only the first of these (Polar) has already happened, as specified in your question. I believe everything else is still to-occur. Gamma ray bursts Detailed polarization measurements of the prompt ...
Erin Anne's user avatar
  • 10.8k
4 votes
Accepted

Why are deep space "beacons" usually UHF, so low (in freq) that DSN can't hear them? And how unusual is it for a Mars lander to have an X-band beacon?

I don't think the UHF systems at Mars are intended to act as 'beacons', it's just a consequence of the existing UHF infrastructure at Mars and the operator's desire to squeeze more information out of ...
BrendanLuke15's user avatar
4 votes

Embedding foundations from low lunar orbit?

I see a critical problem here: Before you go embedding pylons in the ground you have a geologist check out what you're embedding them into. This is going to be an extra severe problem because you're ...
Loren Pechtel's user avatar
3 votes

Which map is right? Where exactly were the two Australian dish antennas used in the Apollo missions?

Naive maybe, but your Google Maps picture appears to be correct. This page goes into the history of the Parkes Telescope. It's clear that it has never been moved and is at the Visitor Center location ...
Organic Marble's user avatar
3 votes
Accepted

What kind of ground-based radio astronomy is NASA's DSN used for? Who are the PIs?

The basics: When they are not commu­nicating with spacecraft, the DSN antennas are used for radio astronomy. For more than 30 years, the Deep Space Network has played a significant role in radio ...
Hobbes's user avatar
  • 127k
3 votes
Accepted

At what wavelengths and for what particle types have astronomical objects been imaged or at least directionally resolved from the ISS?

Not claiming to be exhaustive, but there are/were: MAXI, is a soft X-ray all-sky monitor (0.7-20 keV) AMS, is a cosmic ray detector CALET, is again a cosmic ray detector working in synergy with AMS ...
SpaceBread's user avatar
3 votes

For how many total hours had Arecibo transmitted a signal?

The telescope had a very powerful (1 MW at 12.6 cm wavelength) radar that has been used to investigate surroundings. Radar images of asteroids and planets like Venus, Mars, Lunar poles have been ...
Nightrider's user avatar
  • 2,025
3 votes
Accepted

Specifications of a High Gain Antenna

So we are looking to specify an X-band high-gain antenna for the communication on a Entry-Descent-Landing vehicle at circa 10 AU, and want to determine the diameter of the antenna, power usage, ...
uhoh's user avatar
  • 149k
3 votes

Embedding foundations from low lunar orbit?

This is a largely impractical concept. As stated by Nuclear Hoagie, landing from orbit is difficult as-is. In regards to your idea, to use some of the orbital kinetic energy to plant the stakes is not ...
David S's user avatar
  • 131
2 votes
Accepted

Why will radioastronomy telescopes be used to listen to InSight's entry into Mars' atmosphere instead of DSN?

InSight used an UHF transmitter to transmit a tone beacon during EDL: At the top of each of InSight’s legs is a trigger sensor; when the surface pushes up the leg and hits the trigger, it shuts off ...
Hobbes's user avatar
  • 127k

Only top scored, non community-wiki answers of a minimum length are eligible