Indian Moon Rockets: First Look

The Preliminary Lunar Manned Mission Concept (Right) showing the launch vehicle architecture. Credit: ISRO

Back in December, Supernova posted the presentation by ISRO at the IAC 2009. A very less known and highly ambitious part of that presentation was the preliminary concept of an Indian Lunar manned mission. The concept in itself is not very detailed but gives us an insight into what ISRO has in store for the future. More importantly, the concept showcases the future UMLV family (Unified Modular Launch Vehicle) being used to loft the crew vehicle. This is the first time that we have had any insight into the possible architecture of the UMLV family, which will be powered by a Common Liquid Core stage in development.

The first thing that strikes when we look at the preliminary lunar concept are the 2 majestic launch vehicles. These launch vehicles, especially the one that launches the Earth Departure Stage (EDS), is a world beyond the capabilities that India possesses today.

ISRO plans to use two rockets for the manned lunar mission. The first will be a crew launch vehicle with the capability to launch 31 tons to Low Earth orbit. This vehicle with a liftoff weight of 1690 tons, would launch the crew module and the service module.

The second rocket will launch the Earth Departing Stage and the Lunar Descent module. This launch vehicle would be a true Super-heavy lifter with a capability to launch 84 tons into Low Earth orbit. The liftoff weight of this beast would 3075 tons.

ISRO has also given some of the technical details about the launch vehicles. The basis for these launch vehicles (as that of the UMLV family) is the new 2ooo kN Semi-cryogenic engine in development. The architecture of the two vehicles would be :

Crew Launch Vehicle
* Architecture - 4 S230 + SC500 + C60
* Capability - 31 tons to Low Earth Orbit
* Payload - Crew Module (6 tons) + Service Module (25 tons)

Carge Launch Vehicle
* Architecture - 8 S230 + SC800 + C60
* Capability - 84 tons to Low Earth Orbit
* Payload - Earth Departure Stage (67 tons) + Lunar Descent Module (17 tons)

The S230 would be solid boosters with 230 tons of propellants, future descendants of the S200 booster developed for the GSLV-Mk III. The SC500 and SC800 stages would be powered by the Semi-cryogenic engine and containing 500 and 800 tons of propellant respectively. The C60 would be the bleeder expander cycle upper cryogenic stage containing 60 tons of propellant.

The modular architecture of the launch vehicles and that of the whole UMLV family would help in reducing the cost of the rockets. The lunar architecture itself seems to be loosely based on the Constellation Program (which is supposed to be axed this year) architecture.

ISRO is pressing ahead with it's preliminary research on Lunar manned mission irrespective of prospective financial issues of such a high budget mission although the the program itself in full isn't expected to be started anytime before 2020.

Will be back with some analysis on the other part of mission ie beyond the launch vehicles.

Chandrayaan-2 Program updates

Soft-landing scenario on lunar surface. Copyright: ISRO

Rover deployment from the lander after landing on the lunar surface. Copyright: ISRO

Chandrayaan-2, India's next shot to the moon has come a long way since the project was first conceptualized back in first half of this decade. Although some payloads have already been finalized the process is expected to be fully completed in 2 months time. ISRO has had thousands of payload proposals from different countries on the table, from which it will have to finalize the payloads. Afterall the orbiter can accommodate only 50 kg of scientific payload.

The total weight of Chandrayaan-2 at launch will be 2457 kg, this including the lander and the orbiter. The orbiter and lander will be connected by an inter module adapter. The mass of the orbiter will be 1317 kg, of which 830 kg will be propellant for the orbiter and 487 kg will be the actual dry mass of the orbiter. Of 487 kg dry mass of the orbiter, the actual scientific payloads will weigh 50 kg. Only 10 kg of payload space will be open to international space agencies for their payloads.

Now, for the most exciting part. ISRO has gone ahead with the plant soft-land the rover on the lunar surface. The rover will be inside the rover-module of the lunar lander. As explained above the lander will be connected to the orbiter at launch. The total mass of the lander will be 1100 kg.

Out of the 1100 kg lander, 680 kg will be the propellant used for thrusters on the lunar-lander for soft landing. On the lunar surface the lander will weigh 420 kg including the rover and rover-module. Once the lander has landed on the lunar surface the 2 rovers, one Russian and another India will then emerge from the rover-module onto the surface of the moon.

Many of the scientific instruments on the lander/rover have already been finalized. The rover will drill into the lunar soil and obtain samples for analysis. The Regolith Evolved Gas Analyzer (REGA) and Mass Spectrometer will analyze the composition of Lunar soil. Two instruments, a Tunable Diode Laser and a Laser Induced ion Mass Spectrometer will look for the presence of water in the polar shadowed region of the moon.

Presently, ISRO is on-schedule for a 2013 launch of Chandrayaan-2. Chandrayaan-2 will be the stepping stone for a lots of things that in the future that ISRO already has planned for.