PSLV fourth stage (PS4)
Shape built from published dimensions and pictures; details simplified.
Turn it in 3D
Open the 3D viewer (www.spaceradar.ai).
The viewer loads when you ask: about 700 kB the first time (three.js and the model), much less after.
Pictures 4
Three-quarter view
From the side
From behind
From above
About this model
PSLV fourth stage (PS4) is one of the 203 3D models Space Radar made itself: a rocket stage, built in code from published dimensions and photographs, with no image-to-3D generator and no one else’s mesh.
Shape built from published dimensions and pictures; details simplified. It has 12,800 triangles in a 94 kB glTF file, and is 3.7 m across at full scale.
It is part of the map’s library; no object on the live map is drawn with it today.
Dimensions and their sources
| Measure | Value |
|---|---|
| Tank diameter | 1.34 m |
| Ring diameter | 2.8 m |
| Length | 3.74 m |
| Engines | 2 |
| Engine thrust | 7.4 kN |
| Propellant | 2500 kg |
Wikipedia, 'Polar Satellite Launch Vehicle', section 'Fourth stage (PS4)' (CC BY-SA 4.0; OPENED 2026-11-04): 'powered by regeneratively cooled twin engines, burning monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON). Each pressure fed engine generates 7.4 kN', 'The stage is pressurized by helium and carries 1,600 kg to 2,500 kg of propellant depending on the mission requirements. PS4 has three variants L1.6, L2.0 and L2.5'; the same article: the third stage has 'a Kevlar-polyamide fibre case', and during the combined coast 'burnt-out PS3 remains attached to PS4' (which is why the gold Kevlar case and the nozzle hang under the stage in ISRO's photographs). The 1.34 m tank and the 2.9 to 3.0 m length of the stage proper are the numbers the 1.4.0 build quoted from ISRO's PSLV-C55 mission brief (NOT opened again on 2026-11-04; they are consistent with 2 500 kg of MMH and MON-3 in a 1.34 m tank with a 1.3 m barrel, a cross-check that is ours). THE 2.8 m RING is the PSLV's standard 2.8 m core diameter (the same article, 'first stage': 'The 2.8 m diameter motor case') and agrees with the photographs, where the ring is 1.4 times the width of the 2.0 m third-stage case. NOT CITED, READ OFF THE PHOTOGRAPHS AND ESTIMATED against those two widths: the skirt's height (0.9 m) and its 2.0 m lower end, the ring (0.35 m), the struts (0.6 m), the platform, the heights of the barrel (1.3 m) and the dome (0.4 m), the helium spheres (0.46 m, four), the boxes, the harness, the adapter ring. NOT SEEN IN ANY PICTURE and drawn only because the stage has them: the two L-2-5 engines under the tank, inside the skirt (their size is ours). THE PICTURES DISAGREE about the skirt: the 2008 photograph stands the stage on a brown ribbed drum (a handling fixture, not drawn); the 2019 and 2023 photographs hang it from a black ribbed cone under the ring (drawn). Whether that cone stays with the stage in orbit no opened page says. The stage's tank is a 2 500 kg one (L2.5); the L1.6 and L2.0 stages have a shorter tank. (read 2026-11-04)
How it was made
Built in code from published dimensions and photographs, with no image-to-3D generator and no one else’s mesh. 3D model: built by Space Radar from published dimensions and ISRO's photographs of the stage (GODL-India), compared with them.
The full record
built by this project in code (tools/stage-builder/, stages.py `pslv_ps4`, rebuilt in release 1.8.0; first built and held in release 1.4.0); no image-to-3D model was used and no published mesh: none of NASA 3D Resources' paths is this stage and ISRO publishes none (read 2026-11-04)
Where the map uses it. catalogue name PSLV R/B (klass rocket), which also reaches PSLV R/B(1): the fourth stage (PS4) of ISRO's PSLV, the stage that stays in orbit after the burn; public #1171. NOT for PSLV DEB (debris) or for the PSLV-CA variant's other bodies (a different catalogue name)
Licence note. The shape is this project's, under this repository's licence, built from published numbers (facts). The ISRO photographs under references are GODL-India (Government Open Data Licence - India, as Commons records it): each was looked at, none was traced, copied or projected, and none is in the file. NO LOGO AND NO LETTERING is on the mesh.
References 5
What the shape was compared with. None of these pictures is in the file.
- PSLV-C11 Fourthstage.jpg (ISRO)Indian Space Research OrganisationGODL-India (Commons LicenseShortName, read 2026-11-04): looked at, nothing taken from it
- PSLV-C44 Third and Fourth stages at Stage Preparation Facility.jpg (ISRO)Indian Space Research OrganisationGODL-India (Commons LicenseShortName, read 2026-11-04): looked at, nothing taken from it
- PSLV-C55, TeLEOS-2 - Third and fourth stage combined stack being integrated with interstage.webp (ISRO)Indian Space Research OrganisationGODL-India (Commons LicenseShortName, read 2026-11-04): looked at, nothing taken from it
- PSLV-C52, EOS-04 (aka RISAT-1A) - Assembled third stage (PS3) and fourth stage (PS4) stack being hoisted.jpg (ISRO)Indian Space Research OrganisationGODL-India (Commons LicenseShortName, read 2026-11-04): looked at, nothing taken from it
- PSLV-C54, EOS-6 (aka Oceansat-3) - Oceansat-3 on PSLV fourth stage.webp (ISRO)Indian Space Research OrganisationGODL-India (Commons LicenseShortName, read 2026-11-04): looked at, nothing taken from it
_-_Assembled_third_stage_(PS3)_and_fourth_stage_(PS4)_stack_being_hoisted.jpg){kind=link}
_-_Oceansat-3_on_PSLV_fourth_stage.webp){kind=link}
Use it
The model is under the MIT licence: use it, change it and share it, in any project, also a paid one. Keep the credit:
PSLV fourth stage (PS4) 3D model by Space Radar (spaceradar.ai), MIT LicenseAny glTF 2.0 loader that reads meshopt compression (EXT_meshopt_compression) opens the file: three.js with its MeshoptDecoder, Babylon.js, model-viewer. Tools such as glTF-Transform can write an uncompressed copy.
Or embed the viewer in your page:
<iframe src="https://www.spaceradar.ai/model/?id=pslv-ps4" title="PSLV fourth stage (PS4), 3D model by Space Radar" width="600" height="450" loading="lazy" style="border:0;max-width:100%"></iframe>Related models
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