Mangalyaan-2/Mars Lander Mission: News and Updates

[Gautam]

Edit: (22-11-2024)
Changed the name of the thread in light of recent developments.

Things are heating up on this front with a recent prototype test. It is time to make a thread:

From Wiki, to be used as a primer :

Mangalyaan-2 ("Mars-craft", from Sanskrit: मंगल mangal, "Mars" and यान yān, "craft, vehicle"), is India's second interplanetary mission planned for launch to Mars by the Indian Space Research Organisation (ISRO). As per some reports emerged, the mission was to be an orbiter to Mars proposed for 2024. However, in a recorded interview in October 2019, VSSC director has indicated the inclusion of a lander and rover. The orbiter will use aero-braking to lower its initial apoapsis and enter into an orbit more suitable for observations.

In a podcast recording VSSC director Dr. S. Somanath in October 2019, it was reported the architecture for mission is yet to be finalised and may also have a lander and rover. There has been no timeline announced however.

ISRO's recently released Annual Report 2019-20 says :

RH300 MkII/IAD Technology Demonstration : Realisation of IAD system in Poly-chloroprene coated Kevlar fabric is in progress. Inflation system configuration has been carried out. The flight was targeted by the end of 2019.
​

IAD stands for Inflatable Aerodynamic Decelerator, otherwise known as Aerodynamic Decelerator Atmospheric-entry Module (ADAM). The system is being designed jointly by VSSC and IIST for deployment off of a Mars orbiter. More about ADAM :

1. ADAM is an atmospheric entry module that delivers safely micro/mini probes/payloads to Martian surface, weighing from minimum 5 kg to 15 kg net weight relevant for small scale researchers and explorers.
2. Conceptualized as a stretched sphere (tear drop shape during its atmospheric entry) and the rear cone separates out during the parachute deployment transforming the module to a sphere.
3. This sphere drops down decelerating, aided with three thrusters to bring down the velocity to near zero value for a safer touchdown.
4. Visco-elastic damping materials serves as shock absorbers to prevent impact load transfer to the payload inside.

Additional details :

1. Outer aeroshell in the shape of a stretched sphere (tear drop shape)
2. Multiple layer of Thermal Protection System (TPS)
3. Visco-elastic shock absorbing layer
4. Decelerator system consisting of parachute and thrusters
5. Concept is analogous to advent of mini-satellites when larger spacecrafts of agencies reign the space arena.
6. Small scale space enthusiasts can enter planetary exploration via such small payload delivery systems
7. Maximum deceleration: 11.5 m/s (3.28 ‘g’)
8. Altitude of maximum deceleration: 20.40 km from surface
9. Velocity at maximum deceleration: 491.93 m/s
10. Maximum dynamic pressure: 880 Pa
11. Drag force at maximum deceleration: 180 N
12. Altitude of maximum heating: 8.20 km from surface
13. Maximum heating rate: 3033 Watt/sqm (lesser than the space capsule recovery experiment heating rate as achieved by ISRO in earth atmosphere)

Here is what it looks like :

Pretty cool huh ?

 

[Gautam]

A lot our projects are drawing attention from Japan. Previously it was just the NASA and CNES. Another development that went unnoticed :

Now, a cooling system for shuttles entering the Martian atmosphere

Bangalore Mirror Bureau | Updated: Aug 31, 2016, 04:00 IST
By: Mihika Basu

Designed by scientists from IISc and NITK in Japan, it can prevent heat damage to aircraft

Mars has been a target for the space scientific community for the last four decades. The biggest challenge faced by a spacecraft on expeditions like the Indian Space Research Organisation or ISRO’s Mars Orbiter Mission (MOM) is the heat generated due to its speed. When a spacecraft starts to descend on the surface of a planet, a large amount of heat is generated due to the speed of descent. This heat could damage the spacecraft and hence the spacecraft requires an additional Thermal Protection System (TPS). Now, scientists from two institutions — Department of Civil Engineering and Department of Aerospace Engineering at the Indian Institute of Science (IISc), Bengaluru, and National Institute of Technology, Kisarazu College, Japan — have designed a cooling system for spacecraft entering the Martian atmosphere. “The exploration of planet Mars was started in the 17th century with the invention and development of telescopes. With the advancement in rocket technology in the late 20th century, several missions to explore mars were started. The first successful mission was Mariner 4. Since then, several spacecraft have been sent to the planet for its exploration, which includes orbiters, landers, and rovers, with the recent ones being NASA’s MAVEN and ISRO’s MOM,” said the authors in the paper, which has been published in the American Institute of Aeronautics and Astronautics Journal.

They further said, “For landers and rovers, the spacecraft have to pass through the atmosphere of the planet and reach its surface to start its mission. Martian atmosphere entry begins at an altitude of 125 km and typical entry velocities vary from four to nine km/s, depending on the entry trajectory.

At these entry speeds, the spacecraft are subjected to severe aerodynamic forces and aerodynamic heating, of which aerodynamic heating is a major aspect in the design of the spacecraft. Generally, largescale blunt cones are used as forebodies for the spacecraft to minimise the aerodynamic heating. These configurations also enhance the aerodynamic drag, assisting in reducing the speed of the spacecraft during entry.”

SYSTEM HAS MULTIPLE DRAWBACKS

The additional Thermal Protection System acts as a barrier between the high-temperature gas in shock layer (which is layer of molecules formed between the outer blunt portion of the spacecraft i.e. forebody and the atmosphere like a cushion) and the spacecraft, during planetary entry. “For any successful planetary entry, there is a need for an efficient thermal protection system,” said the paper.

The team says the TPS used so far on all spacecraft entering the Martian atmosphere is “ablation” cooling, where the “TPS material chars, melts and undergoes pyrolysis, and the hot gas formed gets blown away, blocking the heat transfer to the surface.” The ablation cooling, according to the research team, has several drawbacks. Ablation cooling is also very expensive when reusability of the spacecraft is concerned.

“During ablation, complex hydrocarbon products are formed, and their presence in the boundary layer of the spacecraft leads to a chemically reacting boundary layer, which can have an influence on aerodynamic forces and moments. The shape change occurring during ablation can affect the aerodynamics of the spacecraft, resulting in change in the flight path. Further, if the spacecraft experiences insufficient heat flux to cause pyrolysis, then the TPS will serve as a thermal insulator rather than an ablator,” said the findings.

NEW TECHNIQUE TESTED

The drawbacks of the current thermal protection system led the research team to investigate the feasibility of using an alternate system. The team led by Dr KPJ Reddy, a professor at IISc’s Department of Aerospace Engineering, conducted an experimental study to investigate the effectiveness of the “transpiration” cooling technique, an alternative to the conventional “ablation” cooling.

This technique involves passing of a coolant gas through a porous wall that absorbs the heat and gets blown away. The coolant gas forms a film on the outer surface of the spacecraft, absorbing heat from the molecules that it comes in contact with, via convection. The heated coolant gas is then flushed downstream by the continuous supply of gas from the spacecraft. “In this way, the heat transferred to a vehicle traveling at hyper-velocities can be greatly reduced,” said the paper.

ALTERNATIVE IS CHEAPER

They tested the transpiration cooling ability of two gases, nitrogen and helium. According to the research team, nitrogen and helium were chosen because of their inert nature, which would not react with the environment and result in high heat transfer rates. These experiments were carried out in conditions similar to the Martian atmosphere and the team tested the transpiration cooling under different internal energy levels, pressure conditions and volume.

The team concludes that both gases can be used as coolants in the transpiration cooling process with different efficiencies. While one gas is a better coolant at lower atmospheric energy levels, another is better at higher atmospheric internal energy levels.

The paper states that “with the development of ceramic matrix composites like Carbon/Carbon ceramic,” which can withstand very high temperatures and has natural porosity, transpiration cooling seems to be a promising technique.

“Transpiration cooling is relatively cheaper when reusability of the spacecraft is concerned. With the recent flight test of ISRO on reusable vehicle and with the development of C\C composites within the country, we feel that transpiration cooling technique will be incorporated within next 10 years. Research is currently underway in our laboratory to generate mist using water, and use it as coolant,” said Dr Reddy.

THE ANALYSIS

A reduction in the heat transfer rate was observed using both the coolants. At low levels of internal energy, pressure and volume, helium resulted in a better heat transfer rate reduction than nitrogen. The team explained that this is because nitrogen molecules absorb more heat for the corresponding increase in temperature as compared to helium due to its higher volume flow rate.


At high levels of internal energy, pressure and volume, said the researchers, nitrogen performed better than helium “due to the diatomic nature of nitrogen molecules.” “As nitrogen is always present as a dimer along with one other nitrogen atom, it is able to store more energy, undergoes excitation and dissociation at higher temperatures. Greater reduction in heat transfer rate was observed when more coolant gas was pumped downstream,” said the findings of the research team.

Now, a cooling system for shuttles entering the Martian atmosphere

 

[Gautam]

Manglayaan-2 mission profile has changed significantly in the past 4 years. Now the mission will feature a rover & a rotorcraft.

The mission is tentatively named Mars Lander Mission (MLM). Prior to this MLM taking off ISRO will launch a data/communication relay satellite and place it in orbit around Mars. This relay satellite will be launched by a PSLV launcher, probably PSLV-XL. Launch of MLM will possibly be in the 2031 window.

The MLM will carry the following sensors:

This rover that will land with the help of a sky crane that would look something like this:

ISRO has been building prototypes for the Mars rotorcraft for around 4-5 years

Initial prototypes:

Recent prototype:

This rotorcraft is now named Martian Boundary Layer Explorer (MarBLE).

 

[Gautam]

Slide from a recent conference:

PSLV's TMI payload capacity is around 1350 kg. By extrapolation, LVM3's TMI payload capacity should be ~3500 Kg. Here the Mars entry mass is shown as 1750 kg. This would probably be the combined weight of the depleted propulsion module, descent module, rover & sky crane. So, we can expect a 500+ kg rover. This mission will also have a co-axial roto UAV.

The mission is very much modelled after NASA's Perseverance mission. Except it will be lighter owing to launch vehicle payload restrictions. The Perseverance rover has a 110W RETG. ISRO & BARC are also developing a 100W RTEG. They have flight tested a 1W RHU with the CY-3 mission. BARC is currently testing a 5W RTEG which will eventually get scaled up to a 100W unit.