Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [doppler-ranging]

The tag has no usage guidance.

2
votes
0answers
29 views

Understanding shape of DSN's 'kinky uplink protocol' keeping frequency in coherent transponder's optimum bandpass?

This tweet by deep space SDR entheusiat Edgar Kaiser @df2mz shows a squiggly tone from MRO. Mars Reconnaiscance Orbiter (MRO) X-band downlink. The signal shows this kinky behavior due to a ...
3
votes
0answers
45 views

Was the Doppler shift of InSight's “tone” measured and plotted somewhere?

I watched a YouTube live broadcast from the InSight mission control area and saw lots of images of happy people cheering and jumping up and down, which is great! If it wasn't 4 AM where I was I might ...
3
votes
1answer
76 views

Help understanding BepiColombo's weak capture at Mercury's L1 and need for delta-differential one-way range measurements

This four-minute BBC podcast Mission to Mercury: BepiColombo spacecraft ready for launch highlights several challenges of the BepiColombo mission, including its orbital-mechanical aspects and is worth ...
2
votes
0answers
78 views

How many solar system bodies have had coherent radio transponders?

A transponder amplifies, (often) frequency-shifts, and rebroadcasts a received signal. Old-style telephone and TV distribution satellites in GEO used simple transponders to rebroadcast the uplinked ...
5
votes
1answer
482 views

Why such a large observed doppler shift from Apollo 17 orbiting the moon?

Following the links in this comment by @Uwe I've found some interesting sources of information on Ham (amateur) radio operators trying to listen in on Apollo transmissions. One of them is Sven Grahn's ...
2
votes
1answer
45 views

Have any deep-space spacecraft supported same-band turnaround of Earth-based doppler measurements?

Table 1 of this document gives Spacecraft Transponder Turnaround Ratios that are supported by the Deep Space Network. These are the PLL controlled divide-by ratios that a spacecraft uses when ...
5
votes
1answer
229 views

How does a three-way doppler shift measurement work?

I was looking at this document who's name I can only speculate. Its title and designation includes: 810-005, Rev. E, 201, Rev. B, DSN Telecommunications Link, Design Handbook, 201, Rev. B, ...
6
votes
0answers
151 views

What can be learned from NASA's choice of Didymos B for the Double Asteroid Redirection Test

The NASA News item NASA’S First Asteroid Deflection Mission Enters Next Design Phase describes a test the kinetic impactor technique that could someday be used to adjust the orbit of an asteroid in ...
2
votes
1answer
211 views

How have/how will Indian ground stations be used for comms or tracking of deep space spacecraft?

I have a few data points, but not the big picture. 19-10-2016, the Giant Metre Wave Telescope was used to monitor the doppler shift of a beacon signal from the Schiaparelli spacecraft as it descended ...
7
votes
3answers
276 views

Why was the 100m Green Bank dish needed together with DSN's 70m Goldstone dish to detect Chandrayaan-1 in lunar orbit?

The Phys.org article New NASA radar technique finds lost lunar spacecraft describes the use of radar to relocate two spacecraft that were in orbit around the moon but who's orbit had not been actively ...
9
votes
1answer
236 views

How are the Voyagers' thrusters configured in a novel way to minimize accelerations along Earth-spacecraft axis?

I've just read in Eshleman et al 1977 Radio Science Investigations with Voyager that the voyagers have: a novel attitude-control thruster configuration that minimizes accelerations along the Earth-...
1
vote
1answer
307 views

Why does DSN sometimes uses two dishes at the same time to receive Voyager-1?

I just looked at the Deep Space Network site DSN Now at https://eyes.nasa.gov/dsn/dsn.html and I saw that both dish numbers 25 and 26 are receiving a 8.42 GHz downlink signal from Voyager 1. Both ...
4
votes
1answer
228 views

How could tiny Hagoromo have been seen visually from earth confirming its lunar orbit?

I saw the following sentence in The Space Review, and became intrigued: Japan’s Hagoromo lunar orbiter, deployed in 1990, reached orbit but ceased transmitting enroute. If it ceasted transmitting ...
7
votes
1answer
1k views

What is the current record for the farthest detection of a “dead” spacecraft?

In order to better defend my position that trying to track Juno from Earth once it can no longer transmit would be Quixotic, I'd like to ask what the current record is for the farthest detection from ...