# Tag Info

24

No, quantum mechanics cannot be used to transmit information faster than light. This is a common misconception based on misunderstanding how quantum mechanics works. Go here to read more about it. Technologies like quantum communication are valuable for other reasons though, but they still end up transmitting information at the speed of light, but in a ...

21

Space Fence is what our current tracking system is called. This article claims that some companies and countries have an arrangement to receive tracking data, but few details. It appears that this in fact routine, but I don't know if companies have to pay in. To date, Strategic Command has announced data-sharing agreements with at least seven countries and ...

19

There's already two good answers that say a lot of what I wanted to say, and I will refrain from repeating any of their content here. I do think it is useful to add one more item of insight though. You say: "any quantum switch in this universe can be flipped instantaneously from elsewhere." When people talk about a "quantum switch flipping ...

15

Starlink and 5G don't have that much to do with each other--they compete for different customers. Starlink systems currently require a large receiver the size of a pizza box to uplink to satellites. It is unlikely that this will be miniaturized to fit into mobile devices within the next decade or so. 5G is a short-range, high-bandwidth technology designed ...

13

It's routine, and done as a service for the space community at large. Companies doing official business with the U.S. Government can get access to a variety of additional services, but the basic collision warnings to owners and operators of space vehicles are provided for the good of the world. You have to register for a free account on space-track.org to ...

7

Satcom 3 In fairly rapid succession, two Japanese communication satellites, Ayame I and II, and the RCA SATCOM III spacecraft failed during the firing sequence of the Apogee Kick Motor (AKM) in such a manner as to suggest a single common casual (sic) failure mode. Individual reviews of these three flights have all focused on the failure of the AKM ...

6

Or perhaps was it found again much later? It appears to have been found. According to Wikipedia, Satcom 3 is COSPAR ID 1979-101A; Celestrak has a current TLE for it. SATCOM 3 1 11635U 79101A 20165.54218687 -.00000091 00000-0 00000-0 0 9990 2 11635 9.1831 306.7881 4819048 43.5856 92.1293 1.82528373183904 That's an eccentricity of ...

6

Based on practically proven Quantum-Entanglement principle, any quantum switch in this universe can be flipped instantaneously from elsewhere. Indeed, quantum entanglement can connect (alias entangle) two particles in a way that the change in one particle results in an immediate change in state for the other one. Theories about transmitting information ...

5

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 over the world from just after launch until June 1981 when its batteries likely shorted. This in turn short-circuited the entire power system, just like ...

4

The cheapest communications satellite, at least in terms of the cost of the satellite itself, was almost certainly Echo 1. I don't have a dollar figure, but the sheer simplicity of the design is hard to beat: it was a 30-meter Mylar balloon that reflected high-frequency radio waves.

3

This is an interesting question and can be answered separately from the related questions. Given that the planets are in known orbits, their positions can be accurately predicted... and a given planet can be fairly close to or very distant from another... (t)hey can easily be on opposite sides of the sun, making direct communication impossible... Bottom ...

3

Yes. What would be stopping you besides cost and knowledge? You'd have to make sure the FAA is fine with your plans, so you'd have to demonstrate very well that you know what you're doing & you will do it safely. It's doubtful you'd ever have the time to manufacture your own engines & tanks & avionics & control systems & ground stations ...

3

Well I actually came here because I had a very similar question. But I have had a few thoughts about it and this is my answer to the question "What is the critical satellite density to cause a severe Kessler syndrome?". It is not complete, not the direct answer to your question and not necessarily correct. So if you want to determine the satellite ...

2

The Aireon Hosted Payload is a 1090ES ADS-B receiver that is attached to Iridium NEXT as a "Hosted Payload". The paper "Iridium NEXT SensorPODs: Global access for your scientific payloads" by Dr. Om P. Gupta of Iridium Communications Inc. describes in general how Iridium Next payloads communicate with the ground: Mission data and ...

2

A supplementary answer, in response to @JessRiedel's comment: this answer does not apply to communication from the satellite to Earth, for which it is reasonable to consider communication relay sats. (quoting because comments can vanish). There are two problems, broadly speaking: orbital dynamics and economics. Orbital dynamics means that you can't ...

2

One thing that many previous answers aren't taking into account are ways that a LEO satellite constellation could significantly enhance the internet for people who live in rural areas. Roughly 45% of the world is in a rural area (20% of the US), and for them internet currently kind of sucks. It would be prohibitively expensive to connect rural clients to ...

2

While the given answers are very complete, I feel like they are also very complex to understand. So here's my two cents: When two qubits are entangled, they have to be in a "superposition". Practically, this means that they both have a 50/50% chance of being either 1 or 0. The only things we can do with qubits is reset them to zero (which breaks ...

2

The Heavens-Above site can supply you with needed information. heavens-above.com -> Satellite database -> Select satellite whatever you want -> Orbit. Voila. And one more resource is Stuff in space, althouhg it shows only an inclination (from the needed parameters).

2

I don't think so. Delivering end user service is far more profitable than wholesale. And the full Starlink plan is having the satellites work as a global internet backbone, with the end users directly connected to the network. Think about it this way 10 million users @ US\$100/user = US$ 1 billion/month in gross revenue. The largest cost of a global ISP is ...

2

A Radioisotope Thermoelectric Generator (sometimes referred to as a nuclear battery) is probably your best best: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator Although it gets warm it doesn't need to be "kept warm" as it heats itself from nuclear processes within the radioactive materials sealed inside it and it produces ...

1

Why 53º orbits for Starlink? tl;dr: they need some cash ASAP, and to cover most paying customers in the medium term, and some polar inclinations will be added later. Why isn't it more more popular? Well right now the only example of real wholesale (okay sic, retail) dumping of spacecrafts into LEO for low-latency internet is Starlink. Until now it's been ...

1

This will almost certainly be the case for some 5G (and even 4G) cells. Starlink provides, at best, 20Gbps per satellite with the current fleet with real bandwidth likely to be 1/3 to 1/2 of this. This is nowhere near enough for a 4/5G cell with significant subscription, but in the cases where a carrier wants to extend coverage down an interstate or through ...

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

We don't know exactly how much krypton starlink satellites have, but some guesswork based on the orbital maneuvers performed says that they would need ~2.5 kg of fuel. See https://space.stackexchange.com/a/36471/40045 for more information.

1

Sorry for answering my own question, but I finally got some insights on the topic. 1) Where I can find those "released documents"? According to Marco Langbroek's (the same amateur satellite tracker that took the image in the OP) excellent review on the topic: On September 6, 2016, The Intercept published a number of new documents from the Snowden ...

1

The general strategy for this sort of situation is to construct a set of frames for the problem, then find rotation matrices for all of the frame transformations (possibly symbolically), then compute your output azimuth and elevation based on the matching rotation matrix. Frames at work in this problem: A: Earth-fixed (GEO sat is static) B: Aircraft ...

1

I think the term is used like it is with automobiles. According to Wikipedia's hybrid electric vehicle page they don't have to operate together to be a hybrid (at least for autos). I would think that keeping the trusty R-4D, see Wikipedia's "Used In", adds the some all important reliability to the system.

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