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Questions tagged [jpl]

Jet Propulsion Laboratory(JPL), in Pasadena, California, is a joint venture between NASA and the California Institute of Technology(Caltech) to develop and operate robotic spacecraft missions (such as the Curiosity and Opportunity rovers on Mars). Use for questions specifically about JPL.

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9 votes
1 answer
454 views

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 ...
6 votes
4 answers
898 views

Access to Chebyshev coefficients from JPL ephemerides

I want to generate an ephemeris file containing the Chebyshev coefficients, similar to how we can generate ephemeris file of positions with Horizon tool (https://ssd.jpl.nasa.gov/horizons/app.html#/). ...
5 votes
1 answer
164 views

When NASA spacecraft arrive at Mars, is Mars always always above the horizon in the US?

Writing How long did the plasma blackouts of Perseverance's signals to MRO and direct-to-Earth last during its seven minutes of terror? I noticed that Mars was high in the sky over the Green Bank ...
0 votes
0 answers
45 views

Astroquery is returning very different semi major axis compared to one in https://ssd.jpl.nasa.gov/sats/elem/

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0 votes
2 answers
274 views

Why did Curiosity perform TCMs?

Why did Curiosity perform TCM (Trajectory Correction Maneuver)s 1 through 5? 6 makes sense since it needed to adjust course to actually once in the SOI, but the others don't. I understand that this ...
12 votes
1 answer
2k views

Why do we use Chebyshev polynomials to predict positions of solar system bodies?

I've seen information for how to use the Chebyshev coefficients that JPL publishes, but nothing that explains why. Why isn't a simpler mathematical model used? I'm also surprised that JPL uses a ...
7 votes
1 answer
1k views

How are the "lucky JPL peanuts" shared post-pandemic?

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. (Don't forget Part II as well!) A bit after 36:59 it discusses ...
23 votes
1 answer
3k views

Why are there four RTGs in a row sitting in this room? What are they waiting for? Were they built together and stored for separate launches?

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. At about 17:40 it discusses Cassini's RTG and at ...
2 votes
1 answer
355 views

When was the idea behind the DESCANSO Book Series first conceived, by whom, and what is its "mission"?

When was the idea behind the DESCANSO Book Series first conceived, by whom, and what is its "mission"? When I'm looking for information on deep space issues including communications and ...
6 votes
1 answer
461 views

Does NASA's Deep Space Network sometimes listen to other space agencies' spacecraft "just for the heck of it" or other non-mission related reasons?

This answer mentions: It's well known that other countries routinely spy on each other (i.e. the NSA tapping of Angela Merkel's phone). NASA's Deep Space Network's space-related activities (like ...
3 votes
1 answer
228 views

What JPL laboratory is this exactly, and what are the functions of these amazing-looking control panels?

The (somewhat strangely named) video clip How William Shatner Changed the World - Dr. Marc D. Rayman, Chief Propulsion Engineer, NASA, JPL contains several shots of what looks like an ion propulsion ...
3 votes
0 answers
76 views

Who said, "Take that, Jezero!" during the Perseverance landing?

During the Perseverance landing broadcast, many of us heard a voice call out, "Take that, Jezero!" Every article I can find simply identifies the speaker as "a controller" (or just ...
2 votes
1 answer
182 views

Are the Perseverance rover's "drivers" working on Martian sols or Earth days right now?

Business Insider's What is it like to drive the Perseverance rover remotely? A NASA engineer explains the challenges of piloting the vehicle's journey across Mars. includes the following discussion of ...
9 votes
1 answer
268 views

What are those plastic hoses on Perseverance used for?

I've been trying to find out what this plastic tube is for that got cut during descent. It's a single tube so as far as l can tell not a loop. It ends in the lower right corner of the body (in the ...
4 votes
2 answers
528 views

What time zone is used for JPL tests?

The JPL ASPIRE test video has a time code for the launch. Day Of Year:Hour:Minute:Second.Microsecond. What's the time zone?
1 vote
1 answer
263 views

Was the famous SPICE package of programs, utilities and data kernels named after "Melange" found on the planet Arrakis?

This question is NOT about a fictional planet: This question is about NASA JPL history and the naming of SPICE. It is not primarily about the fictional planet Arrakis nor the fictional drug Melange ...
8 votes
1 answer
306 views

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 ...
2 votes
0 answers
53 views

What's up with the peanut tradition? [duplicate]

I was reading up on Ranger 7 and at the very end a random bit of information is thrown in: The spacecraft performance was excellent and the success of the mission finally brought a turnaround in ...
1 vote
1 answer
112 views

Lunar landing module and orbiting space craft personnel transfer [duplicate]

How did the crew of Apollo get from the orbiting capsule into the Lunar lander, as the orbiter rocket engine was between the orbiter and Lunar lander?
5 votes
1 answer
576 views

What information was stolen from JPL during the Raspberry Pi hack?

The Engadget article A rogue Raspberry Pi helped hackers access NASA JPL systems highlights an incident where a networked Raspbery Pi at JPL was used to gain access to several other networks, ...
3 votes
1 answer
490 views

Why are JPL using this expression to emulate Schwarzschild orbits?

From the documentation ”Formulation for Observed and Computed Values of Deep Space Network Data Types for Navigation ” expression 4-61 on page 4-42 it can be seen that JPL uses the following ...
10 votes
2 answers
982 views

What is the numbering system used for the DSN dishes?

The title "What is the numbering system used for the DSN dishes?" pretty much sums it up. DSN dishes are referenced by seemingly arbitrary numbers: 14, 55, 36, etc... Do these numbers carry any ...
4 votes
2 answers
722 views

How to obtain Chebyshev coefficients directly from the JPL Horizon's interface?

I'm from Spain and I'm currently finishing my degree in Aerospace Engineering. I am starting with all of this. My objective is to obtain the Chebyshev coefficients for the major planets position, ...
4 votes
1 answer
647 views

What did JPL's 1939 lunar lander look like and what practical aspects of landing on the Moon did this engineering design address?

According to Wikipedia's Jet Propulsion Laboratory: During JPL's Army years, the laboratory developed two deployed weapon systems, the MGM-5 Corporal and MGM-29 Sergeant intermediate range ballistic ...
7 votes
1 answer
622 views

What is the history behind having peanuts in mission control during critical missions?

The InSight mission livestream showed a jar of peanuts with what appears to be the MarCO logo. Why is was this a significant shot in the livestream? Is there history behind this?