Talk:Lucy (spacecraft)

Lucy's propulsion system
This article does not mention anything about Lucy's propulsion system. The only thing here is a difference between dry and wet mass.

I do not claim that I did a through research, but I found only little paragraph in the press-release (reference 25) stating that: ''On Sept. 18, propulsion engineers finished filling Lucy’s fuel tanks with approximately 1,600 pounds (725 kilograms) of liquid hydrazine and liquid oxygen, which make up 40% of the mass of the spacecraft. The fuel will be used for precise maneuvers that will propel Lucy to its asteroid destinations on schedule, while the solar arrays – each the width of a school bus – will recharge the batteries that will power spacecraft instruments.'' — Preceding unsigned comment added by 173.34.55.155 (talk) 22:15, 18 October 2021 (UTC)


 * Why does this article still say nothing about Lucy's propulsion system (or its power system in general)? That's simply unencyclopedic. 204.11.189.94 (talk) 13:31, 23 January 2023 (UTC)

Lucy - how many diamonds are in the sky with her? Just one, or more than one?
In short, is Lucy carrying more than one diamond, or just one?

Having looked fairly deeply into this, I've found that all the official sources (from NASA and the associated labs) all state that the L'TES instrument has a single, large, artificial diamond that's used as a beamsplitter.

Unfortunately, the only citations I can find that support the idea that there are more than one diamond on board, such as the citation used to back up the idea that it has multiple diamonds, are like this article (currently used to support the idea that there are more than one in the article): by the LA Times which doesn't have any sources, and is more of a pop science article than anything.

So, I would like to know if anyone has a reliable source that demonstrates that Lucy has more than one diamond on board, perhaps another in the L'TES instrument, one in another instrument, or perhaps one someone sneakily added to ensure Lucy would be in the sky with *diamonds.*

If not, I think it should probably be changed to reflect the more authoritative sources that it only has one diamond, as sad as that may make me and many others.

Sources: Lucy's LCTES

This entire PDF press kit from NASA for this one short line "Lucy’s L’TES instrument has a diamond beamsplitter, so the Lucy will be carrying a diamond into the sky."

Further muddying the waters is the PI of the L'TES instrument saying: "We are indeed taking diamonds into the sky," said Phil Christensen, principal investigation for the L'TES instrument at Arizona State University, referring to the song "Lucy in the Sky with Diamonds" by The Beatles."[The diamond] is a part of the instrument that breaks the light and sends it in two different directions." according to CollectSpace which both suggests one diamond, and multiple.

The closest thing I can find is that the L'Ralph instrument's mirrors are made of aluminum, and diamonds were used during manufacture to polish them down to the degree necessary. I guess a small diamond fragment (still a diamond) could be embedded in the mirror, but it's extremely unlikely.

I'd love for there to be more than one, but all I can find is evidence for one. Lucy in the sky with a big diamond just doesn't fit. I suppose the "large diamond" beamsplitter was created in such a way that it could be considered more than one, but that's iffy.

Apologies if I butchered the links or anything else format related, attempting this on the Wikipedia android app, which is... difficult.

Chemputer (talk) 05:56, 19 October 2021 (UTC)

Excellent source on the entire context & history of Lucy
The space journalist team at NasaSpaceflight have put together a marvelous and well-researched 10-minute video on the entire history and context of Lucy: including NASA's meta-objectives with the "low cost" Discovery-class missions, the solicitation and proposal process of 2014, Lucy's selection, spacecraft development including each of the four science instruments, preparations for launch through October 2021, and then a well-done video walkthrough of the eight-asteroid primary mission from 2025 (flyby of a mainbelt asteroid), to 2027-2028 (when it flies through Sun-Jupiter L4 Trojan group to gather close-up data at four asteroids) through 2031 (the L5 Trojan group and the amazing binary asteroids that are possibly primordial survivors of the early formation of the Solar system), and possibly beyond if the spacecraft remains healthy.

Really a quite complete overview for those who like video rather than written summaries: Asteroid Hunter: Lucy's Journey to the Trojan Asteroids, October 2021, NASASpaceFlight.com, Haygen Warren, Chris Gebhardt, Stephen Marr, and Derek 'DK' Knabenbauer. Is awesome to have a bit of journalism that is researched/written by people with both science and engineering backgrounds.

Definitely something that can improve the article as a source. N2e (talk) 11:41, 25 October 2021 (UTC)

Description of launch in target table
In the targets table, for the launch date the comment section says gravity assist - Why ? or is this a mistake ? - Rod57 (talk) 13:40, 22 December 2022 (UTC)