72 votes

How did NASA prevent third parties from spoofing Apollo communications?

The signal from the Moon was received using giant parabolic antennas, e.g. the 64-m dish at the Parkes observatory. These have very good sidelobe rejection so they won't pick up any Earthbound signals....
Hobbes's user avatar
  • 127k
48 votes

What is the feasibility of a rocket hobbyist achieving a LEO orbit with a microsat?

It isn't really feasible to launch your own rocket, unless you have a lot of money to spend. The required power is immense. Hitting sub-orbital might be possible, and has been done once by amateurs, ...
PearsonArtPhoto's user avatar
  • 121k
46 votes
Accepted

What would one need to do to get an amateur satellite into orbit?

Astronautical engineer here, welcome to the small satellite community! Firstly, it's important to recognize that the FCC tightly regulates the radio spectra available to satellites and amateur ...
MikeB's user avatar
  • 909
24 votes

How did NASA prevent third parties from spoofing Apollo communications?

The difference between 10 W at 350,000km, and 1,000 W at 1km is 131 dB. If the pranksters on Earth used a directional antenna like the Ham radio operators shown below, the ratio would be even higher ...
uhoh's user avatar
  • 149k
13 votes

What would one need to do to get an amateur satellite into orbit?

The Space Shuttle retired in 2011, and no amateur launch has ever reached orbit, but there are plenty of opportunities to piggyback on commercial and government launch services. Mostly this is ...
djr's user avatar
  • 1,705
12 votes

What would one need to do to get an amateur satellite into orbit?

A TV show addressed this some years ago. What appears to be the full video on You-tube: (Link gone--tv show "How Hard Can It Be", Episode 3 -- "Homemade Rocket".) Owner's website ...
Loren Pechtel's user avatar
6 votes
Accepted

First Ham Radio contact from space; what frequency, what kind of antenna, and how did they route the coax out the window?

This happened on the first Spacelab flight, STS-9. For the 1983 ham radio contact mentioned above, what wavelength... All ham radio operation for STS-9 will be in the Amateur Radio 2-meter band (144-...
Organic Marble's user avatar
5 votes

Have any satellites had lights visible from Earth besides FITSat-1?

Humanity Star According to Wikipedia: Humanity Star was a passive satellite designed to produce flares visible from Earth. Its shape was a geodesic sphere about 1 metre (3 ft) in diameter, ...
Skoddie's user avatar
  • 171
5 votes

What is the feasibility of a rocket hobbyist achieving a LEO orbit with a microsat?

It's probably good to bring up Copenhagen Suborbital up as a reference here. They're quite possibly the most competent amateur rocketeers, yet their name already points out that they're not aiming for ...
MSalters's user avatar
  • 1,644
5 votes
Accepted

After 21 years of silence how and by whom was OSCAR-7 first identified as functional?

Oscar-7's designed lifetime was three years. But it did work from 1974 to 1981 (in its first period), about the double designed lifetime. Oscar-7 was reliably used by the amateur radio community all ...
Uwe's user avatar
  • 48.9k
5 votes
Accepted

Are these really deep space amateur radio satellites?

They are in fact in deep space, but there were all carried there by some other mission already heading to deep space as a secondary payload. They were all university payloads, thus operating on the ...
PearsonArtPhoto's user avatar
  • 121k
5 votes

Are there cubesat fan clubs? Does anybody besides their owners pay attention to them, look for or listen for them via radio?

Checkout SatNOGS, an "Open Source Global Network of Satellite Ground Stations". These are individuals dedicated enough to set up ground stations to listen to random satellites, many of ...
Carlos N's user avatar
  • 4,444
4 votes

Cubesats in lunar orbit and beyond - how does communication work?

Yes, it's being researched. For instance, this JPL paper describes a design for a parabolic antenna with a diameter of 50 cm that can be folded and stowed in 1.5 U, and provides a gain of 42 dB. ...
Hobbes's user avatar
  • 127k
4 votes

Have amateur satellites ever experimented with optical communications?

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 ...
ErikK's user avatar
  • 316
4 votes

Have any satellites had lights visible from Earth besides FITSat-1?

Ginrei Yes! Ginrei is an LED satellite launched in 2014: Ginrei or ShindaiSat was a 400x400x450mm cube-like microsatellite intended to text experimental visible light communication. The satellite is ...
DialFrost's user avatar
  • 1,673
3 votes

What satellites can I receive Images from with a radio?

Here is a post on how to receive from geostationary orbit (GEO) weather satellites like GOES: https://www.rtl-sdr.com/setting-up-a-goes-weather-satellite-antenna-system/ You may also want to check ...
BlueCoder's user avatar
  • 2,113
3 votes
Accepted

Have amateur satellites ever experimented with optical communications?

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. ...
PearsonArtPhoto's user avatar
  • 121k
3 votes
Accepted

Why do these 'spy' satellites carry amateur radio packages?

There is an excellent article about Cosmos 2499 that explains some of the history of the satellite. One of the things in particular is the following: According to Ostapenko, the satellites were ...
PearsonArtPhoto's user avatar
  • 121k
3 votes

Would it be possible to receive the transmissions from JWST as an amateur?

Yes, it is possible to detect the S band telemetry from JWST as an amateur, and it has been done with a 6.1m dish. Hams have built dishes this big. The source you listed details this, and was written ...
John's user avatar
  • 31
2 votes

Are these really deep space amateur radio satellites?

The answer is no they are not Ham Radio Satellites, but they are amateur built satellites. These satellites are indeed in deep space, however I would like to point out that there is a difference ...
Andrew ZL3DW's user avatar
2 votes

Cubesats in lunar orbit and beyond - how does communication work?

I think that Earth - Moon communications with a CubeSat in lunar orbit are feasible, even though it would require a lot of effort. Closing the link is a trade off between operational frequency, the ...
Alessandro Cuttin's user avatar
2 votes

What is the feasibility of a rocket hobbyist achieving a LEO orbit with a microsat?

Since 1961, there have been a series of satellites called OSCAR, for Orbiting Satellite Carrying Amateur Radio. These have generally been launched when some other space mission has excess lifting ...
Mike Ciaraldi's user avatar
2 votes

What is the feasibility of a rocket hobbyist achieving a LEO orbit with a microsat?

G. Ericsson could potentially get a cube satellite into Low Earth Orbit for under $100,000.00. Vector is a nano-satellite launch company creating rockets targeted towards launching small payloads ...
gwally's user avatar
  • 1,064
2 votes

What would one need to do to get an amateur satellite into orbit?

Obligatory XKCD What If. Getting to orbit is not a a problem of just vertical distance. You also need to go really fast to stay in orbit (I assume you want your satellite to stay up there). First, ...
Nelson's user avatar
  • 139
2 votes

Data Rates and Radios with Satellites

A few issues here: You don't "pull" information with a radio. That just isn't a thing. When transmitting, radio waves follow an inverse square law: when you double the distance, you quarter the ...
Rory Alsop's user avatar
  • 13.6k
2 votes
Accepted

Is it allowed to interact with research satelites / rovers using the radio?

Receiving data from NASA spacecraft has happened several times, and seems to be fine. The problem is transmitting to said spacecraft where you can run in to legality issues.
PearsonArtPhoto's user avatar
  • 121k
2 votes

After 21 years of silence how and by whom was OSCAR-7 first identified as functional?

G4CUO re discovered Oscar seven just by accident... No! not by accident, far from it, Dave G4CUO had spent a lifetime tracking satellites he'd made observations worked times sure where it would be ...
John Nevin's user avatar
1 vote

Is it allowed to interact with research satelites / rovers using the radio?

Radio spectrum licensing prohibits sending transmissions on the same frequency and location as where licences are granted to protect licence holders from interference. So sending commands is not ...
Terrance Yee's user avatar
  • 2,264
1 vote

How can one know that Chang'e-4 was in "locked to the Queqiao" from this SDR spectrogram?

TL;DR: The plot shows that Chang'e 4 is not locked to any external source but uses its own on-board clock to send data. To answer this, we can ignore the Queqiao relay satellite and assume that we ...
asdfex's user avatar
  • 15k

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