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# Tag Info

36

The Apollo Guidance Computer used a state vector either centered at the Earth or the Moon. The switchover point is the the lunar sphere of influence, defined in the AGC as 64,373,760 meters (https://www.ibiblio.org/apollo/NARA-SW/R-577-sec5-rev4-5.6-end.pdf PDF page 127). When in the idle program P00 the AGC will periodically check if it needs to update the ...

36

A caveat about this answer: it's not about SpaceX directly, more about the use of self-inspection cameras in general across space and launch vehicles. It is used for engineering and status information. "Selfie" footage has been standard (at least on launch vehicles) since Apollo. Telemetry offers a very limited view of things and is prone to ...

24

That claim is rather dubious. First, there is the claim of 320,000 channels of telemetry, while one paragraph earlier it lists 13,000 sensors on board. There will be setpoints in addition to sensor data, but 20x as many? The earlier 5L mission had 10,000 telemetry channels. I found these specifications for the S-530 computer: speed: 0.1 MIPS RAM: 256 ...

15

There is value added. I was an operator of a satellite that had a video of the satellite being deployed. We were able to see from the video that the deployment was clean. I assume if nothing goes wrong, the only value is PR, but if something does go wrong, video can help considerably. EDIT: This kind of thing is exactly what might be useful from the ZUMA ...

6

I suspect this confuses "bandwidth available" with "bandwidth that can be used concurrently at any one time". It certainly could not be processed at that rate by the ground based systems, let alone on-board.

5

It seems they have very small miniaturized tags on animals that do include GPS along with other sensors and they can transmit up to 800km. See the technical pdf at the end of this page Direct link to pdf: https://icarusinitiative.org/sites/default/files/MP_ICARUS_Flyer-EN-lowQ.pdf From the pdf, page 3: Animal Tag The main challenge of ICARUS is ...

5

Within the NASA firewall: yes, there is a service available to bring up recorded telemetry. I've not used it personally, but I know it's available. Publicly: The only archives I know of are where people personally recorded data from the ISS Live LightStreamer service, which is what all the various websites (telemetry.space included) use to stream their ...

5

This is actually pretty common in rocket launch profile design. For the Ariane rocket, we covered it in What is the reason for the Ariane 5 launcher with Intelsat 29e losing altitude?, but the same principal applies in general. When you have a low thrust high ISP upper stage, it is common for it to thrust more horizontally at a certain point than vertically, ...

4

Not much is known about Red Dragon yet. There will be a brief communications blackout. For Mars the blackout period is around 30 seconds. Detailed study of comms blackout for Mars. Blackout is related to electron density, which depends on the speed/altitude profile. This article discusses the analysis of the UHF communications blackout (and brownout) ...

4

About 29 au away. Speed * time = distance (since speed has units of distance/time). For this problem, the units are as follows: $$C \text{ meters}/\text{second} * 4 \text{ hours} * (60*60) \text{ seconds}/\text{hour} \approx 4*10^{12} \text{ meters} \approx 29 \text{ au}$$ I didn't know the conversion off the top of my head so I used trusty Wolfram Alpha.

4

I don't have any original sources, but I'd say: 9.6 GB/s are possible, albeit not an accurate description. It's very likely that the largest amount of data was not transported digitally but as raw analog signals. This has the advantage that you can take the raw output of the sensors and send them to ground where they can be recorded and/or digitized later on....

3

Elon Musk gave a press conference where he mentioned that it isn't returning any data. You can see the full press conference here, and the question where he answers what data the car is collecting occurs at around 15:00

3

It's a very large satellite, but some live ISS telemetry is available at https://isslive.com/displays/index.html (Theoretically anyway - it does not seem to be working at this writing) User uhoh offered a different link for ISS telemetry - a much nicer format, IMHO - but it also does not seem to be working at this time.

3

Those people in the control room just see various things on their screens (see the attached image). It is quite evident that not all the monitors show the same data. NASA JPL Mission Control Room, shortly after a woman said "Touchdown confirmed." Watch this video, especially after minute 53. However, it is a bit baffling that immediately, seconds after the ...

3

I agree with Hobbes about TM being a subset of data, but from my experience I would define it differently: Spacecraft data: just all data that is inside the spacecraft at some time, no matter whether it is stored, transmitted or a transitional state information. Telemetry: data that is transmitted on a monitoring & control link in the "monitoring" ...

3

Telemetry is a subset of data. Telemetry: data related to the status of the spacecraft itself. Fuel level, temperature, engine speed, position information etc. This data is needed for the operation of the satellite. In addition to telemetry, the spacecraft's payload generates data. This is data that is useful for people other than the operator of the ...

3

Only Mars Polar Lander and Beagle 2 didn't. (Both when we would have wanted it the most, of course.) Mars Pathfinder's was limited to carrier, Doppler, and one subcarrier semaphore every 10 seconds on a direct-to-Earth link, since there were no relay orbiters there yet.

2

Yes, in fact, there have been several. It's not easy to figure out exactly which ones had such a system, but I'm sure Curiosity did. Usually what they have is a very low bandwidth signal or beacon. The signal changes to indicate key events have occurred, like parachute deployment. It's very hard to have meaningful telemetry during the decent, because the ...

2

In the SSME the "thrust control loop's" independent variable was chamber pressure. During the engine run phase, the MOV, MFV, and CCV are switched to run schedules, while the OPOV and FPOV are switched to closed-loop operations. The run schedules for the MOV and MFV cause them to simply remain fully open, whereas the run schedule ...

2

Here is one example (this is ESA actually), I am sure there will be others posted. This is a 2D histogram for the ExoMars Schiaparelli Lander, Schiaparelli’s UHF Signal captured by GMRT prior to Entry – Photo: ESA Data was received from the Giant Metre Wave Telescope in India. See Was the time of Schiaparelli's landing chosen specifically so the Giant Meter ...

2

I second most of what @mefitico said in his excellent answer. Most CubeSat operators even universities will not permit you to operate their satellite. It is a valuable asset, and they don't want anyone just playing with it. Not to mention, often their licenses (e.g. NOAA) has significant restrictions on how they must operate their satellite. You can ...

2

The short answer is: Unless you are really lucky, your request is unfeasible. The long answer is: If you goal is to get familiar with protocols and data flow, I'd suggest you start studying the CCSDS standards, as they're the usual starting point for telemetry and telecommand formatting. Then, I'd suggest you find some software that will help you get ...

2

It's the car's standard stereo system (colloquially called "radio" because it includes a radio receiver) playing a music track. It's neither receiving nor broadcasting anything. Portable/in-car sound systems are often called "radio" because the first such systems had only one source: a radio receiver. Later on, more functions were added, but the name stuck....

1

I think it's for monitoring the mission performance, given that the main mission is to deliver the payload into correct orbit. Recovering the first stage is always of lesser importance. Maybe you'll be wondering, why don't they just put both first and second stage parameters on screen? Well, I think, although it would be great for us space nerds, it would ...

1

It can be a replaceable feed for two ranges/bands. A horn (feed antenna) and a sub-reflector which are mechanically changed at dish's focus.

1

To answer one aspect of one the several questions, the telemetry data rate deemed necessary to establish and maintain spacecraft health drives the emergency data communication link. This is usually on low-gain antennas that require little to no pointing of the antennas, in case the spacecraft goes into a safe mode where the primary objective is to get the ...

1

There doesn't seem to be any glitch as far as I can tell. I watched the video. The altitude is expressed in integer kilometers. We don't know for sure if it's rounded or truncated, but a good guess would be truncated, so that 171000 and 171999.99 would both show up as 171 km, 'odometer style'. Every time I see the altitude change, I hit the spacebar (1/5 ...

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