The telescope (T-170M) is composed by the optical system, a structural module and a service complex. The primary mirror unit (PMU) is the main structural element of the telescope.

There are three attachment points between the telescope and the spacecraft service module in the bottom frame part. The optical bench with the scientific instrumentation devices, and the primary mirror baffle are mounted on the PMU frame. The secondary mirror unit (SMU), the light protective cover with the deployment mechanism, and the rotary external baffle with its fixing unit are located in the top part of telescope tube. The external rotary baffle has an oblique cut for light exposures prevention of the telescope internal cavity. It can be put in two positions: transport and operational. The translation of the external baffle from the transport position to the operational one is carried out after spacecraft insertion onto the low Earth orbit (LEO) by turning it by 180 deg. The turning is performed by the actuators located on the top frame parts of the telescope. The T-170M telescope is based on the classic Ritchey-Chretien scheme.

1.Primary Mirror
2.Mechanical frame
3.Primary Mirror Unit basic frame
4.Radiator with heating elements
6.Secondary Mirror Unit
7.External Baffle
8.Telescope Light Protective Cover
9.Primary Mirror Baffle
10.Secondary Mirror Baffle
11.Ring knifes
12.Optical Bench
13.Focal Camera Unit
15.External Electronic box
16.Scientific instruments protective cover

The telescope is under development by Lavochkin Association (Russia). Optical elements are being manufactured by the Lytkarino Optical Glass Factory (Russia). Space qualification is under resposibility of the Institute of Astronomy RAS (Russia). The primary mirror and other optical elements are being manufactured by the Lytkarino Optical Glass Factory.

In the images below the process of installation of the mirror is shown in the container for trasportation. The primary mirror of T170M telescope was moved from Lytkarino Optical Plant to SIA "LUCH" for applying of the coating.

T170M Telescope (NPO Lavochkin).
Optical System Ritchey-Chrétien
Aperture diameter 1.7 m
Focal length 17 m (primary mirror)
f/# 10.0
Field of View (FoV) 30 arcmin (150 mm in diameter)
Wavelength range 102-320 nm
Primary Wavelength 200 nm
Optical quality Diffraction limited at FoV center
Angular resolution on focal plane 12.13 arcsec/mm
Mass 1570 kg (1600 kg with adapter truss)
Size 5.67 x 2.30 m (transport)8.43 x 2.3 m (operational)
The primary mirror without coating.
Preparation of the mirror for coating.
The mirror in the vacuum chamber after applying of the coating.
Secondary mirror of the T170M Telescope with A1+MgF2 coating in vacuum chamber.
Additional tests samples were used to study the quality of the coating process.