Spacecraft for Celestia: Thread 2

[DaveBowman2001]

Spacecraft add-on projects planned for April-May 2025 release:

BepiColombo
European-Japanese mission to Mercury. Original add-on by John van Vliet

GLONASS-M
A series of 45/51 Russian navigation satellites launched between 2003 and 2022

Lunar Gateway
New version of the space station based on NASA's 2024 redesign

Lunar Trailblazer
A failed small lunar orbiter that launched alongside IM-2 (Athena) and Odin

SPHEREx
NASA infrared telescope, intended to survey 450 million galaxies. Also known as Explorer 98
Released: 2025-Apr-12, 04:56

Spitzer Space Telescope
A NASA infrared telescope that observed the cosmos from 2003 to 2020. Original add-on by Jack Higgins
Released: 2025-Apr-12, 12:58

Upper Atmosphere Research Satellite
A NASA Earth observations satellite deployed from STS-48 (Discovery)

XMM-Newton
A European x-ray observatory in operation since December 1999
Released: 2025-Apr-11, 05:36

[Art Blos]

Is it possible to improve model for the "XMM-Newton" and "Kepler"? There are the same problems with visible polygons.

[DaveBowman2001]

Is it possible to improve model for the "XMM-Newton" and "Kepler"? There are the same problems with visible polygons.

Theoretically, yes. I'll take a look on them to see what's the problem later.

[Art Blos]

Anyone planning on making nine "Rangers"? These spacecrafts are historically important. I will definitely add such a collection to "Celestia Origin". If not in April, then in October for sure.

[DaveBowman2001]

I had a model for Ranger 7–9 two years ago but unfortunately lost it in a previous computer reformat alongside their trajectories (there's no surviving actual data for these anywhere so I had to make it on scratch through GMAT and Orbiter2016)

Maybe I'll revisit another attempt in making one in another time, but it's kinda low priority for me at the moment.

[DaveBowman2001]

XMM-Newton in orbit around Earth

XMM-Newton is a European space telescope designed to observe objects in both x-ray and visible light simultaneously. It was launched in December 1999, about two months after NASA's Chandra X-ray Observatory. Newton is still operational as of 2025, and will continue to observe the universe until 2026 or 2029.

This add-on presents a new and improved CMOD model for the observatory, by Art Blos's request. This is based on ESA's own 3D model from SciFleet.

XMM-Newton.zip

(2.95 MiB) Downloaded 40 times

[Art Blos]

This add-on presents a new and improved CMOD model for the observatory, by Art Blos's request.

Cool! I didn't know it was so dark. Even darker than "Galileo". But before, on the contrary, it was snow-white.

I will mention a few more spacecrafts with simple models that are worth improving in the future: "Mariner 2", "IRIS", "Spitzer Space Telescope", "Nozomi" and "Genesis".

[John Van Vliet]

the obj file in the Cosmographica folder
https://spiftp.esac.esa.int/data/SPICE/XMM/misc/cosmo/
is rather dark

[DaveBowman2001]

SPHEREx, also known as Explorer 98, is a small space observatory that conducts an all-sky survey to measure the near-infrared spectra of approximately 450 million galaxies in the universe. It was launched on March 2025 alongside the PUNCH microsatellites into a polar orbit around Earth.

Orbital data from CelesTrak. CMOD model is derived from NASA's Eyes of the Solar System website

SPHEREx.zip

(4.41 MiB) Downloaded 35 times

[DaveBowman2001]

The Spitzer Space Telescope, also known as the Space Infrared Telescope Facility (SIRTF) is the fourth of five NASA's Great Observatories. Launched in 2003, it is primarily designed to observe the universe primarily in infrared light, the third spacecraft to do so after IRAS (1983) and ISO (1995-1998). The observatory was eventually decommissioned in 2020, a year before its direct successor, the James Webb Space Telescope, became operational

This serves as an update/replacement to the 2007 add-on of the same name by Jack Higgins. The more detailed CMOD model is derived from NASA's Eyes of the Solar System website

Spitzer.zip

(2.68 MiB) Downloaded 30 times

[Art Blos]

Can anyone tell me?
Is there a way to use the "Two Vectors" construction for interplanetary spacecraft, but in such a way as to avoid spontaneous rotations around the axis? This happens all the time, whether it is an "Earth"-"Earth" combination or an "Earth"-"Sun". "FixedRotation" it doesn't help either.

[DaveBowman2001]

I think the spontaneous rotations happen when they "react" in regards to changing orbital inclinations during close flyby approaches to any planet they come into.

The most stable one is the Sun-Sun vector combination, but rarely use it especially those with large HGAs, which I'd like to always point at Earth (to simulate it getting in regular contact with mission control)

[Art Blos]

I think the spontaneous rotations happen when they "react" in regards to changing orbital inclinations during close flyby approaches to any planet they come into.

It turns out that I correctly understood the main reason. But how to deal with it?

The most stable one is the Sun-Sun vector combination, but rarely use it especially those with large HGAs, which I'd like to always point at Earth (to simulate it getting in regular contact with mission control)

I'm facing the same dilemma now. In the CO I most often used "Sun"-"Sun", but now I want to orient the antennas to the Earth. And here the problems begin.

[DaveBowman2001]

But how to deal with it?

To me, I just leave it as it is. Think of it as the spacecraft are either maneuvering itself with RCS thrusters/gyroscopes or gravity gradients gently tugging them along