Questions tagged [tracking]

Questions regarding systems used to continually locate objects, often radar.

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110 views

Exact speed/distance of JWST (& others in L1/L2 halo) from Earth; is it measured any differently than for more distant deep-space missions?

How is the exact speed and distance from Earth of the JWST or any spacecraft in a Sun-Earth L1/L2 halo orbit determined? While deep space missions require ranging at hundreds of millions of kilometers ...
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Track a satellite using python

I tried tracking a satellite - or rather confirming the data I got from the AMSAT pass prediction web page - using python, more precisly the sgp4 and navpy packages. Now I don't really now what I'm ...
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Suppose I wanted to compare TLEs to actual LEO satellite positions, what data is available? From which may it be easiest to extract X, Y, Z, T points?

Under @RyanC's answer to How can I plot satellite's trajectory from three different TLEs to detect any deviation on path with time? I wrote: I think that SGP4 + TLEs is so popular because the TLEs ...
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Was Chandrayaan-1 recovered (tracked) only that one time in 2016, or are folks still keeping an eye on it from time to time?

Has there ever been probability of conjunction between spacecrafts in Lunar orbit? describes a recent maneuver of two spacecraft in orbit around the moon to avoid a potential collision: Apparently ...
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801 views

Tracking of spacecrafts of the Mercury project

In the absence of any communication satellite in 1958, back in Mercury times, how did the tracking centers, which were spread world across, communicated with each other, passed on their data to the ...
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What are the differences (if any) between the techniques of range-rate and delay-doppler measurements?

This answer to How does an onboard atomic clock help interplanetary navigation? says: Range-Rate is the two-way measurement of signals broadcast from one location on Earth, received and retransmitted ...
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Would GRAIL be possible on more distant airless bodies such as Mercury and Callisto?

I was thinking for quite a while about sending this question to Maria Zuber's e-mail address (she was the principal investigator of the GRAIL mission to map the Moon's gravity field), but then I ...
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Is there a way (working or in development) to track satellites in lunar orbit like we track objects in Earth Orbit?

I understand that Earth orbiting satellites are tracked using technologies such as radar, but due to the distance between the Earth and the Moon, they aren't really useful for Moon sats. Is the ...
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What happened to Voyager 2's tracking loop capacitor? How did it get damaged? What is it for? What's a tracking loop anyway?

On 23-Aug-2021 Voyager 2 tweeted: DSN antenna DSS-43 at @CanberraDSN is starting a 300 min listen to hear the echo of a command tone sent up to me 35 hours ago. This will define the "Best Lock ...
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International SSA/STM 3-Layer Model

I'm working on a paper outlining an International SSA/STM1 approach for Civil SSA/STM and have read and referenced many publications. I believe it was an IDA documents such as https://www.ida.org/-/...
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How were Soviet/Russian aircraft used to track and/or communicate with spacecraft?

Russian Space Web's Russian ground control and tracking network mentions A Soviet Iluyshin-18 aircraft configured to maintain communications with spacecraft. in the sidebar and includes the small ...
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Vela 1A and IMAGE "once were lost, but now are found"; are there any more "lost" satellites thought to still be in Earth orbit?

@BillGray's answer to Where is Vela 1A? Is there any information what its orbit would be like now? says in part: This object was "lost" for some decades. In October 2014, the Palomar ...
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Does transmitting from a few dishes significantly improve the performance of radar surveillance from Earth at GEO and beyond? If so, how exactly?

The BBC's US wants giant radar in UK to track space objects says: Lt Col Jack Walker of the US Space Force told the BBC the US was "in discussion" with the UK about putting the radars "...
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Textbook or scholarly discussion of equations used by the SDP4 part of SGP4 TLE propagators beyond Space Track Report #1?

(the famous) Space Tract Report #3 discussed at length in Dr. T.S. Kelso's Revisiting Spacetrack Report #3, AIAA 2006-6753 Describes the "deep space" corrections to the original SGP4 known ...
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Did Tianzhou-2 have a TLE before docking with Tianhe 8 hours after launch? Which is the 2nd stage rocket body and roughly how soon will it reenter?

Clicking on https://celestrak.com/NORAD/elements/stations.txt I get ...
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Tradeoffs between using two 34 m and one 70 m Deep Space Network dish?

Discussion at this answer to Why does DSN sometimes uses two dishes at the same time to receive Voyager-1? include the possibility that in some cases it would be preferable to use two 34 meter DSN ...
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Tracking stations that could have been used in 1967 & 1971 for the launches of the WRESAT & Prospero, X3 satellites from Australia

In relation to the question, How many satellites were orbited from Australia in total? In November 1967 and October 1971 the WRESAT and Prospero, X3 satellites were launched from Woomera, South ...
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In a 3D space defined by semimajor axis, eccentricity and inclination, what would be the shape of the space where SDP4 works better than SGP4?

@BillGray's answer to Why can't custom-made TLEs for the DSCOVR launch booster in orbit around Earth work with SDP4? is quite interesting and informative; I fail to do it justice by summarizing it as ...
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Were photographs or optical measurements of orbital craft from the ground ever used during early crewed spaceflight missions?

The lengthy and interesting blogpost Baker-Nunn Camera, Island Lagoon on Colin Mackellar's Honeysuckle Creek website includes a photo of "Gemini 10 (with John Young and Mike Collins onboard) and ...
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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?

This answer to Is there independent evidence that China landed a robot on Mars in May 2021? and an extensive comment below it indicate that the Zhurong Mars lander had an X-band beacon, information ...
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Tracking de-orbiting debris

It appears that objects in orbit around Earth can be visualized in any of a number of websites. These sites use actual tracking data in order to depict the current position, velocity vector, and ...
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Which type of map projection is most commonly used in control rooms?

Mission control rooms often have a large map of the Earth (or other body being orbited) with a track of the orbit of the spacecraft. What type of map projection is commonly used for these displays?
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Does the Juno spacecraft have an "open signal, by design"?

The click-bate title'd Space News article China quietly used NASA’s Jupiter probe to test its deep space network contains the quoted material below. Everybody listens to everybody else's spacecraft's ...
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How is satellite's footprint/coverage calculated?

I was using Orbitron - Satellite Tracking software the other day and I saw that clicking on any of the satellites, you will see their footprint (they are usually not-ideal circles, usually ellipses), ...
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What ever happened to 6Q0B44E - potentially the "artificial satellite (with) the farthest orbit around the Earth"?

I just started flipping through Handbook of Space Engineering Archaeology, and Heritage Space Hardware Ann Darrin & Beth L. O'Leary, Eds. 2009, CRC Press, Boca Raton, 1035 pages It looks as though ...
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When are close approaches of Helios 1 and 2 to the Earth? Any historical tracking data? Any reports in sky surveys?

This answer to ** notes that it's hard to get current data on the orbits of Helios-1 and Helios-2 and I couldn't find any in JPL's Horizons. They are shiny and in nice elliptical orbits between ...
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I want to simulate the antenna pointing error when tracking LEO satellites

I am trying to simulate the antenna pointing error of our antenna when tracking LEO satellites using TLE data. I am using the Skyfield library in python. First I loaded the TLE data from the Celestrak ...
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Have lasers ever been used to track laser-reflective parachute cloth for spaceflight missions? And what is it by the way?

In the JAXA PDF Hayabusa2 Information Fact Sheet (Ver. 2. 3, 2018. 07. 05, found here) on slide/page number 53 there is a diagram labeled Re-entry sequence overview and in the top right corner is ...
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From interplanetary space to the Australian Outback, how will Hayabusa2's return capsule be tracked? Desert Fireball Network perhaps?

Wired.com's For the Second Time Ever, an Asteroid Sample Returns to Earth says that "the sample return capsule from Hayabusa2" will land "under parachute in the Australian outback" ...
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Why are objects in this highly elliptical orbit present in Vimpel but not USSpacecom

This is a screenshot from AstriaGraph. It mixes data sources for objects in orbit from Spacetrack/USSpacecom and JSC Vimpel. EDIT: I've created a separate question to split out the original two ...
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Is the United Nations Outer Space Objects Index anything more than a clone of the Celestrak's Satcat? Is it even that, or less?

This looks like this answer because that's where I found this. Ars Technica's SpaceX Starlink engineers take questions in Reddit AMA—here are highlights included a reader poll when I viewed it, screen ...
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Out of 47,108 lines in the Satcat why are there exactly two lines with launch of the year of 000?

This looks like this answer because that's where I found this. Celestrak offers a copy of a Satcat from which a tabulation of space objects can be gleaned: https://celestrak.com/satcat/search.php ...
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What radar-trackable steel ball was thrown from the ISS before October 2015? [duplicate]

The question What kinds of things have been tossed out of the ISS? contains a now-rotted link to a YouTube video of a steel ball being thrown from the ISS for radar tracking tests. I'd sourced it from ...
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Why aren't there any trajectories for the Viking missions in JPL Horizons' database?

Horizons has calculated trajectories for deep space spacecraft, including six objects related to Apollo 8 through 12. See an (old) list in the currently unanswered question What was Chang'e-2'...
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Does Jonathan McDowell access U.S. military tracking network data? If so, how? Is a security clearance involved? (Can I too?)

NPR's news item and audio podcast New Chinese Space Plane Landed At Mysterious Air Base, Evidence Suggests draws heavily from information and quotes from noted astronomer with the Harvard-Smithsonian ...
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Has Same Beam Interference (SBI) been used or at least tested at Mars? Are there plans to use it in the next few years?

Section 5.4 of Descanso I, Radiometric Tracking Techniques for Deep-Space Navigation by Catherine L. Thornton and James S. Border titled Future directions in Radiometric Tracking; Same Beam ...
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Why does OGO-1's trajectory and imminent reentry come from sky surveys and NEO tracking rather than normal satellite tracking?

Space.com's 56-year-old NASA satellite expected to fall to Earth this weekend says: "OGO-1 is predicted to re-enter on one of its next three perigees, the points in the spacecraft's orbit ...
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Difference between collecting satellite data and tracking its position

When people talk about "tracking" a satellite, do they generally mean receiving data / communication from it, or do they mean determining its position. When an organisation sends a satellite ...
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How is satellite position tracked in practice?

How do the increasing number of LEO satellites keep track of their position? I know they use ground stations, but do they employ private companies to keep track for them? It seems like there are way ...
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How to fit, into a cubesat, 29 trackable high drag subsatellites with well-defined aerodynamic profiles

Johnathan McDowell's recent tweet says: The @AerospaceCorp Aerocube-10a cubesat carries 29 small passive high-drag subsatellites used to probe the density of the upper atmosphere. 3 have been ejected ...
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How exactly does TDRSS provide tracking? (Tracking and Data Relay Satellite System)

This excellent answer to How does satellites know it is in apogee or perigee states: The NASA Tracking and Data Relay Satellite System (TDRSS) adds to this a constellation of satellites in such a ...
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Will the new "TLE format" be orbitally-mechanically better than traditional TLEs?

Celetrak's A New Way to Obtain GP Data (aka TLEs) by Dr. T.S. Kelso 2020 May 27 explains the arrival a new infoblob format that in several ways is "better" than the ancient TLE, and contains ...
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Where are post-2017 EPIC images of Earth and the DSCOVR spacecraft coordinates available for download?

I tried to download orbital positions for the DSCOVR spacecraft in its Lissajous orbit around Sun-Earth L1 from JPL's Horizons web page but I was surprised to see the following! No ephemeris for ...
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Why hasn't DSCOVR's trajectory determination been updated in JPL's Horizons after 2015-Aug-4?

I tried to download orbital positions for the DSCOVR spacecraft in its Lissajous orbit around Sun-Earth L1 from JPL's Horizons web page but I was surprised to see the following! No ephemeris for ...
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Do deployments of multiple cubesats generally obey proposed guidelines such as 20 seconds or more between deployments at 5 m/s or faster?

This answer to What can be done in future mass-cubesat deploys to make them “less irksome” to orbital space debris experts? links to Space Traffic Safety: A New Self-Governance Approach for the ...
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Do SpaceX and other US-based launch companies get "ITAR waivers" for live-broadcasting processed telemetry data?

The 17-Feb-2016 answer to Is the Falcon 9 launch/landing telemetry data available for visualisation purposes? explains that access to telemetry data is controlled by ITAR and/or other regulations, but ...
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When was the first successful photograph of an orbital spacecraft from Earth taken?

Early artificial satellites were tracked by radio and visually by amateurs, scientists and military personnel for various reasons including fun and improving the understanding of orbital dynamics ...
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How could RCA Satcom III have been completely lost? (Or was it?)

This answer to What “missing satellite” was part of the story of CNN's debut? quotes the 1981 UPI Article The RCA Satcom III-R commercial communications satellite, designed to... as follows: The ...
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Did Zuma complete at least one orbit? [duplicate]

Question: Did Zuma complete at least one orbit? CLOSE VOTERS, PLEASE NOTE: answers to What was the outcome of the launch of ZUMA by SpaceX, to the best of the public's knowledge? do not answer my ...
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What was so "Mini" about Minitrack?

In the US Naval Research Laboratory video Vanguard 60th Anniversary: A Look Back Roger L. Easton says: Now, how did Vanguard Start? I think it’s fair to say that Milt Rosen started the Vanguard ...