Human communication

First Gaganyaan unmanned module to be injected into a 170×408 km orbit; indicates manned flight profile | India News

BENGALURU: In a likely indication of the eventual profile of the manned spaceflight mission (Gaganyaan), Isro has finalized several aspects of mission planning for the first uncrewed or G1 mission – scheduled for next year – which will see the launcher inject the orbital module into a 170x408km orbit.
The G1 mission will be followed by G2, the second uncrewed mission, both of which are precursors to the eventual human/crewed or H1 mission, as Isro named it. Like the H1, the G1 will also be launched by a GSLV-Mk3 or HRLV (human-rated launch vehicle).

According to Isro: “The injection parameter specification for HRLV during G1 has been revised from 170×395 to 170×408 kilometers to ensure adequate propellant margin in the service module propulsion system.”
Also, the circularization maneuver — to go from an inserted orbit to a more circular orbit — is planned in the third apogee of the orbit (the furthest point) instead of the fourth, in order to reduce the residence period of the perigee (nearest point) at a lower altitude of 170 km.
Isro said a Mission Interface Committee is formed to review and finalize all data flow interfaces between participating entities or teams in the ground segment and added that different types of SNAP scenarios (separation) – various conditions abort – overall (including manned) mission have been identified for which different sequences of operations are developed depending on the separation scenario.
“Mission plans for landing in nominal and emergency scenarios were developed. The availability of the communication network corresponding to the different options was also determined. Mission sequence documents for the descent phase of the mission G1 have been finalized for onboard implementation,” Isro said.
The mission sequence documents for the descent phase in G1 will be similar to those for TV-D1 – the first demonstration mission (D1) of the special test vehicle (TV). After TV-D1, which is expected later this year, Isro will also launch TV-D2, and G1 and G2 are only scheduled for 2023.
“Various touchdown locations for nominal descents, ascent phase aborts, and orbit phase aborts have been defined in accordance with the latest mission plan and presented to the Inter-Agency Committee for Recovery Operations (ICRO) Communication equipment requirements onboard recovery vessels to ensure real-time communication with the mission control center were also presented,” Isro added.
With the objectives and configuration of G1 having been defined and the design of the orbital module – composed of the crew module and the service module – with all the manufacturing drawings generated, Isro began the procurement of raw materials and the realization of subsets.
“The configuration of the propulsion system has been finalized and construction is underway. System demonstration tests for propulsion system qualification have been initiated and five ground tests have been completed for the module propulsion system,” Isro said.
In addition, the design of the HRLV has been completed and the hardware realization is at an advanced stage, both for the stage systems that some tests have been completed, while the raw materials have been purchased for the majority of the systems.
“The completion of three sets of hardware, namely for the qualification tests, the TV-D1 and G1 mission, is being undertaken in parallel,” Isro said, adding that the qualification tests for the solid engines of the evacuation system (CES) have been launched and the static tests of two engines have been completed.