Spacecrafts for Celestia

[EarthMoon]

Very coincidentally I also was working on the THEMIS probes the whole morning.
It is really no copy of DaveBowman's addon (see page 94, bottom), it's coincident.
The funniest coincident I ever saw in the whole forum. :laugh:
How is that possible? Whatever:

This new addon adds all 5 THEMIS probes to Celestia.

Models, textures and THEMIS A, D, E originally by toutatis (https://celestia.space/forum/viewtopic.php?p=138926#p138926).

ALSO INCLUDES TRAJECTORY DATA FOR THEMIS B AND C.
Trajectory precision: time step = 3 or 6 minutes.



Download:

[DaveBowman2001]

Mine just got started yesterday. Also, made the orbital planes of A, D and E probes initially aligned with B and C to show that they originally came from a single launch, straight from the requested archive TLEs from CelesTrak.

[EarthMoon]

I began with my addon some months ago (first small ideas because toutatis' addon only contained THEMIS A, D and E), then it didn't work for some months (due to ssc syntax errors I didn't see), yesterday I got the idea again and today I converted the idea to .ssc/.xyz files. The syntax errors were just "Beginning" properties in 2nd and further timeline phases. After deleting them and adding "Ending" properties, it worked.

Let's say there are two 2022 versions: 2022.1 (DaveBowMan) and 2022.2 (EarthMoon), because yours was posted about 6 hours before mine, but I didn't want to kill my own addon because someone else made the same.
Other people may select one of them (or both at once, but that will cause duplication errors).

I mostly don't tell other people if I'm making an addon and I'm not very active on the Discord, so this coincident happened.

[gironde]

the 64th launch of STARLINK satellites by SpaceX took place on 24-09-2022 at 23:32 UTC
number of satellites: 52
international number: 2022-119
group 4-35
bus version: 1.5

SpaceX Launch Forecast:
03-10-2022 at 23:56 Gr4-29 52 sat.
oct-2022 to Gr4-36 54 sat.
oct-2022 to Gr4-31 53 sat.
oct-2022 to Gr4-37 54 sat.
(dec-2022 at OneWeb Flight 14 48 sat.)

Starlink 64.zip

(58.08 KiB) Downloaded 256 times

Added after 10 minutes 13 seconds:
DaveBowman2001 and EarthMoon

Cheers to both of you !

[EarthMoon]

Also cheers to gironde for the Starlink addons and always updates for the new launches!
I downloaded all of his Starlink addons and they flooded my Earth views.

Estimated 10000000 Starlink satellites

[DaveBowman2001]

I converted the idea to .ssc/.xyz files

I'd advise you to save your trajectory onto XYZV files rather than the older XYZ file format in your future spacecraft addons as the former is much easier to convert into simple Keplerian orbital parameters, which is really handy especially if the probe reaches its Ending date that would result in itself being stuck permanently in the same position in space. In addition, the XYZ file format is too messy to handle imho

See my other works and on Celestia Origin's spacecrafts (where the idea originally came from)

[gironde]

EarthMoon wrote

I downloaded all of his Starlink addons and they flooded my Earth views.

It is because there are many.
It is to avoid this that I use Vidiba from LUT5 to view the 'spacecraft' on demand

Starlink 64 only

All Starlink without orbit

[DaveBowman2001]

Approximate position of MOM on the day of contact loss, 2022-Sept-27

SSC Update to the Mangalyaan-1 addon. Added an Ending date for the spacecraft after it was announced that it recently ended its mission on Sept. 27th

NOTE: You could still view Mangalyaan-1 in the Present Day, only its name would not show up anymore after the Ending date

Mangalyaan (SSC Update).zip

(1.35 KiB) Downloaded 277 times

[DaveBowman2001]

INSAT-1B stowed on the payload bay of STS-8 (Challenger), 1983-Aug-30

The active (green) and derelict (red) satellites of INSAT-1 as of 1991-Oct-4

INSAT is an Indian multi-purpose satellite system that provides two high power TV broadcast and 12 telecommunications national coverage transponders, in addition to also providing meteorological services from GEO. The first generation fleet consists of four satellites launched between 1982 and 1990, one of which was launched on Space Shuttle Challenger during STS-8

NOTES:
- Orbits are based on the TLEs obtained from CelesTrak
- Requires the STS-2022 addon installed first in order for one satellite (INSAT-1B) to be viewed on Celestia
- Shuttle missions modified by this addon: STS-8

INSAT-1.zip

(747.83 KiB) Downloaded 231 times

[DaveBowman2001]

The active (green) and derelict (red) Himawari/GMS satellites as of 1995-Aug-10

The first-generation Himawari satellites, also known as the Geostationary Meteorological Satellite (GMS) were a series of five Japanese weather satellites placed in GEO that provided accurate weather forecasts and climate models in the Pacific. They were launched between 1977 and 1995

All GMS satellites are no longer operational (as of 2022), and were replaced by the second (MTSAT) and third generations of Himawari satellites. Orbital data are obtained from CelesTrak

Himawari 1 to 5.zip

(936.58 KiB) Downloaded 236 times

[EarthMoon]

SPICE UPDATE FOR THEMIS/ARTEMIS (2022, EarthMoon's version):

Replaced all .xyz files with more accurate (and heavy) spice kernels.

IMPORTANT: READ THE INCLUDED TXT FILE BEFORE INSTALLATION! WITHOUT DOING THOSE STEPS THE ADDON WILL NOT WORK!

---

I'd advise you to save your trajectory onto XYZV files rather than the older XYZ file format ...

I prefer the .xyz file format because the file format is smaller:
.xyzv stores 7 data points: JD, X, Y, Z, VX, VY, VZ
.xyz stores 4 data points: JD, X, Y, Z

I can also use spice orbits like the THEMIS v1.1 SPICE orbit update (see above).

... easier to convert into simple Keplerian orbital parameters ...

I don't convert .xyzv with huge calculations to keplerian orbital elements.
I generate them with JPL Horizons' "Osculating orbital elements" (not the "Vector table") ephemeris type.

[DaveBowman2001]

I prefer the .xyz file format because the file format is smaller:
.xyzv stores 7 data points: JD, X, Y, Z, VX, VY, VZ
.xyz stores 4 data points: JD, X, Y, Z

Yes, I know their differences and sizes, but XYZ files are much difficult to work with if you're planning to create historical spacecrafts of your own (that has no data from HORIZONS or CelesTrak) or entirely fictional ones.

[DaveBowman2001]

DongFangHong 1 (DFH-1) was the first artificial satellite of the People's Republic of China, which was launched successfully on 1970-Apr-24. A 173-kg polyhedron measuring 1 m in diameter, it carried a radio transmitter that broadcasted the revolutionary song of the same name around the world. Its mission lasted for 28 days, when it lost contact on 1970-May-22 due to battery failure. It is still in orbit as a derelict object to this day


Orbital data retrieved from CelesTrak

DongFangHong-1.zip

(289.36 KiB) Downloaded 227 times

[EarthMoon]

A new update for THEMIS (compatible with DaveBowman's and my THEMIS/ARTEMIS addon because we use the same model).

Just copy the models and textures folder in the specific addon and confirm file replacement.

For more info about this update see Readme.txt.

[DaveBowman2001]

Inside the payload bay of STS-30 (Atlantis), May 1989

Cruise to Venus, 1989-1990

Venus Orbital Insertion, 1990-Aug-10

Mapping Phase (Cycles 1-3), 1990-1993

Aerobraking Phase (Cycle 4), 1993

Final Low Venusian Orbit (Cycles 5-6), 1993-1994

Magellan, formerly known as the Venus Radar Mapper (VRM), was a NASA spacecraft that was designed to map the entire unseen surface of Venus via synthetic aperture radar. Launched from Space Shuttle Atlantis in May 1989, it reached Venus more than a year later and mapped about 98% of the entire Venusian surface until 1992. It then performed the first-ever aerobraking maneuvers in history in 1993-1994. With all of its mission objectives been accomplished successfully, the spacecraft was decommissioned by being destroyed in the atmosphere on October 1994


NOTES:
- All XYZV files here are semifictional. This is due to the real SPICE trajectory data for Magellan being largely incomplete (according to pedro_jg). That being said, they roughly follow the two trajectory maps from NASA (cruise phase and the mapping phases)
- There is a state vector bug in the earliest timesteps of the Aerobraking Phase. Hopefully will be fixed in the next update
- The CMOD model is heavily modified to allow suntracking and fitting to its custom IUS booster during its launch configuration
- The HGA will only point towards Venus only during VOI and the Mapping Phases, 1990-1992. Outside this timeframe, it is always pointed towards Earth
- Requires the STS-2022 addon installed first in order for the entire mission to be viewed on Celestia
- Shuttle missions modified by this addon: STS-30

CREDITS:
- Original addon by toutatis

Magellan.zip

(2.63 MiB) Downloaded 316 times

[DaveBowman2001]

The Wilkinson Microwave Anisotropy Probe (WMAP) was a NASA spacecraft that measured the Cosmic Microwave Background radiation from 2001 to 2010. It was placed in a halo orbit around the Sun-Earth Lagrange-2 point, and its findings helped advance our knowledge of the universe itself.

Trajectory data is retrieved from HORIZONS

WMAP.zip

(2.71 MiB) Downloaded 235 times

[EarthMoon]

A small problem in WMAP's EllipticalOrbit: The EllipticalOrbit in this section

Code: Select all

#Derelict remains
Add "WMAP:Wilkinson Microwave Anisotropy Probe:Explorer 80" "Sol"
{
   Class    "diffuse"
   Mesh      "wmap.cmod"
   Radius      0.00255
   Clickable true

   Beginning   "2010 08 19 12:00:00"

   EllipticalOrbit
   {
      Epoch         2454928.500000000
      Period            1.00001742096 ########## PROBLEM
      SemiMajorAxis         1.043339859475788
      Eccentricity         0.03540264638640796
      Inclination         0.1344292944198843
      AscendingNode       228.3397538019993
      ArgOfPericenter       299.6368490974306
      MeanAnomaly        27.27146732404754
   }
   FixedRotation   { }
...
}

and in WMAP's last timeline phase has period 1.000017, but the semi-major axis is bigger than Earth's SMA. Arccording to Kepler's third law WMAP's orbit must have a period >1.00001742096

SemiMajorAxis (AU)1.5 = Period (years) (this fast way works only for bodies around our sun!)

1.0433398594757881.5 = 1.06570916099, so the period must be 1.06570916099

Also see https://en.wikibooks.org/wiki/Celestia/SSC_File#Period_f and https://en.wikibooks.org/wiki/Celestia/Trajectories#Period

[DaveBowman2001]

All the elements on WMAP's SSC-orbit are converted correctly from its last state vector, except for the Period because the calculation that Celestia uses internally assumes a normal Keplerian orbit and NOT a halo orbit around L2.

I am aware of this, but if I follow the Period defined (1.065 something), the spacecraft will slowly move away from Earth and the Lagrange points, which is not my intention as the last state vector defined before conversion is a year before it was sent even in heliocentric graveyard orbit. The current Period used is the closest one that I could find that the spacecraft maintains relative "close proximity" to Earth at all times.

Also I patterned that after the code used on Celestia Origin's DSCOVR, Gaia, JWST and SOHO spacecraft

[EarthMoon]

... spacecraft will slowly move away from Earth and the Lagrange points ...

After mission's end the spacecraft will leave L2 (or L1 for other spacecrafts with this period error) due to

1. the instability of L1 and L2 or
2. an engine burning to push the probe in a graveyard orbit around the sun

With the old period (1.000017...) it will stay near L2 for 50+ years.

[DaveBowman2001]

With the old period (1.000017...) it will stay near L2 for 50+ years.

Like I said, Celestia's orbital calculations cannot handle halo orbits quite well because it assumes a normal elliptical orbit around its parent body. And that value is the closest one I found to make it stay relatively close to L2 for a long period.