Questions tagged [tracking]

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

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1answer
43 views

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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132 views

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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118 views

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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158 views

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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194 views

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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128 views

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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100 views

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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130 views

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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288 views

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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176 views

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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534 views

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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1answer
115 views

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 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 ...
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How does one use the Surveillance Fence feature in keeptrack.space?

keeptrack.space was mentioned in What would be a “big picture” understanding of how the orbits of Earth satellites are monitored? but I haven't visited the site since. Running across this again today ...
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Why is the NORAD Catalog number of SpaceX's Starlink's “Darksat” both 71130 and 44972?

@BowlOfRed's answer to Which of the recently launched Starlink satellites is the coated one? links to Celestrak's supplemental table for Starlink. https://celestrak.com/NORAD/elements/supplemental/...
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149 views

Real Real-Time tracking of satellites

I am looking for true real-time satellite tracking data. I know it can be calculated but that is not true real time tracking - or it does not seem to be when using TLEs. What I am looking for is the ...
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159 views

How exactly were the signals from quad dishes of Apollo Deep Space High-Gain Antenna or Russian B-529 processed for local control of tracking?

The images below (and their sources) show the quad dishes of the Apollo Deep Space High-Gain Antenna and the Russian B529 ground station tracking antenna. From NASA Technical Note TN D-6723 Apollo ...
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What will the US government start to label its GPS spacecraft after SVN 99

GPS spacecraft are currently identified by their “Space Vehicle Number” (SVN) which now number 01 through 75. What will happen after 99 GPS satellites are launched? Is there any plan currently in ...
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376 views

What (the heck) are “space-fixed coordinates” as described in Apollo mission trajectory analyses?

@Ludo's answer to If I wanted to reconstruct an entire Apollo mission's crewed spacecraft trajectories, what are the key sources of historical data I'd look for? shows the table and its source shown ...
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What do these Apollo era terms mean?

@Ludo's answer to If I wanted to reconstruct an entire Apollo mission's crewed spacecraft trajectories, what are the key sources of historical data I'd look for? links to Apollo Mission 11, ...
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How did the USSR track Gagarin's Vostok-1 orbital flight? Was tracking capability an issue in the choice of orbit?

For the USA's Mercury flights, a number of tracking stations were installed around the globe. John Glenn's first orbital flight was tracked with them, plus a number of ships. (Tracking stations used ...
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2answers
202 views

What caused so many objects in Earth orbit to “go NEA”? (no elements availabe)

T. S. Kelso tweeted the following, is this a case of lost and found? How can so many substantial objects become lost like this? The list of 23 objects "formerly known as Prince NEA" all seem ...
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1answer
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How will Starlink satellites be capable of tracking on-orbit debris and autonomously avoiding collision?

The press kit for the first Falcon 9 Starlink launch and deployment of the first 60 satllites scheduled for May 15, 2019 says: Starlink satellites are capable of tracking on-orbit debris and ...
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192 views

Why does 2018-099 (SpaceX, December 2018) still have a dozen unidentified payloads?

According to today's Raw SATCAT Data from Celestrak, the launch designated 2018-099 (SpaceX, December 2018) still has twelve unidentified payload objects! ...
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SpaceX Falcon 9 Heavy Launch 4/11/19

Will it be possible to see the launch from the Dominican Republic as to goes into space? Staying there the next few days/nights. What is the track out of Cape Canaveral?
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What is Space Policy Directive 3 and how does it relate to the Space Fence?

In response to a question about the recent ASAT test by India producing a new debris field in LEO, Patrick Murphy, Director of Strategy, Planning, & Integration for NASA Space Technology Mission ...