Mangalyaan-2

[Amber G.]

Mangalyaan thread is here

Starting a new thread Mangalyaan -2

Mangalyaan-2 unveiled: India poised be become third nation to land on Mars

India's renowned space agency, the Indian Space Research Organisation (Isro), is on the verge of a historic milestone: a mission to land a rover and helicopter on Mars. This ambitious endeavour, a feat so far accomplished only by the US and China, aims to firmly establish India's place as a significant player in the realm of space exploration.

The details about the upcoming ambitious project by Isro, named Mangalyaan-2, were made public during a presentation on National Technology Day at the Space Application Centre.

The groundbreaking mission will be blasted off from the surface using India's heaviest rocket developed by Isro yet – the Launch Vehicle Mark-III (LVM3).
Grand entrance on Mars

Bid farewell to conventional methods like airbags and ramps. Isro's rover is set to make its grand entrance on Mars with flair, courtesy of an advanced sky crane. Drawing inspiration from Nasa's triumphant Perseverance rover landing, this innovative system will delicately lower the rover onto the Martian terrain, ensuring a secure and precise touchdown even amidst challenging landscapes.
Additionally, to navigate the fiery descent through the Martian atmosphere, Isro is developing a supersonic parachute – a pivotal component for the success of this daring mission.

Taking flight on Mars with a special helicopter
The piece de resistance may very well be the helicopter engineered by Isro for this mission. Indian engineers are currently engrossed in crafting this rotorcraft specifically tailored to manoeuvre through the thin Martian atmosphere. This cutting-edge marvel will be equipped with a suite of scientific instruments, including the "MarBLE" (Martian Boundary Layer Explorer), which will conduct in-depth studies of the Martian atmosphere during its 100-metre flights.

Ensuring connectivity with a relay satellite
Isro plans to launch a relay communication satellite to ensure continuous communication with the rover and helicopter traversing Mars' surface, prior to the mission. Serving as a vital link between Mars and Earth, this relay satellite will ensure a steady flow of data and mission control.
With the formidable Launch Vehicle Mark-III (LVM3) propelling the mission towards Mars, Isro's second attempt promises to be a marvel of technological prowess. This ambitious undertaking not only showcases India's growing capabilities in space exploration but also lays the groundwork for further exploration of our celestial neighbour.
India was the first Asian nation to reach the Martian orbit – and in its first attempt. Recent ambitious missions to the moon and mars have propelled the country among the top spacefaring nations in the world.

[sanman]

This sounds a little ambitious to me. MOM-1 was barely able to get into a highly elliptical Mars orbit, but now we intend to go straight to the surface on MOM-2. And not only to roll across that surface with a rover, but also to fly across it with a helicopter. I personally wasn't happy with Chandrayaan-3's low-slung pizza-box lunar rover design, which kept its cameras very close to the ground and having very limited visual range. Nobody even thought to put a camera on the top edge of its upright solar panel.

But anyway, let's keep fingers crossed. If they can pull off such an ambitious mission, it would be a major feather in their cap. It would also again show that they have mastered the design-against-failure paradigm.

A mission like this would require them to make use of technologies developed across a variety of other programs. Supersonic parachute leverages parachute development work for Gaganyaan & SRE. SkyCrane lander would leverage the lander technology used for Chandrayaan-3. Hopefully the rover for MOM2 would be of better design than CY3, and would use a more conventional camera mast which US, Russian and Chinese rovers have long used. The aeroshell development would be completely new for ISRO, and so would the Mars copter. But NASA has shown that helicoptering around Mars to be very doable. Hopefully, ISRO would select a relatively area with suitable terrain to explore, since NASA found that line-of-sight between copter and rover is essential for communication.

[Amber G.]

India's ambitious 2nd Mars mission to include a rover, helicopter, sky crane and a supersonic parachute

India is preparing to launch a family of seemingly sci-fi robots to Mars, perhaps as soon as late 2024.

The Mars Orbiter Mission-2 (MOM-2), or Mangalyaan-2 (Hindi for "Mars Craft"), is set to include a rover and a helicopter, like a robotic NASA duo already on Mars — the Perseverance rover and now-grounded Ingenuity. A supersonic parachute and a sky crane that will lower the rover onto the Martian surface will also be part of Mangalyaan-2, Indian Space Research Organisation (ISRO) officials said last week during a presentation at the Space Applications Centre in Gujarat, India Today reported.

NASA pioneered the use of a Mars sky crane in 2012 with its Curiosity rover and employed it again in 2021 to get Perseverance down. The Ingenuity helicopter was attached to Perseverance's underbelly during the journey to Mars and later deployed onto the surface for its history-making mission.India is preparing to launch a family of seemingly sci-fi robots to Mars, perhaps as soon as late 2024.

The Mars Orbiter Mission-2 (MOM-2), or Mangalyaan-2 (Hindi for "Mars Craft"), is set to include a rover and a helicopter, like a robotic NASA duo already on Mars — the Perseverance rover and now-grounded Ingenuity. A supersonic parachute and a sky crane that will lower the rover onto the Martian surface will also be part of Mangalyaan-2, Indian Space Research Organisation (ISRO) officials said last week during a presentation at the Space Applications Centre in Gujarat, India Today reported.

NASA pioneered the use of a Mars sky crane in 2012 with its Curiosity rover and employed it again in 2021 to get Perseverance down. The Ingenuity helicopter was attached to Perseverance's underbelly during the journey to Mars and later deployed onto the surface for its history-making mission.
India aims to accomplish similar milestones, and if successful, would become the third country to land a spacecraft on Mars, after the United States and China. Media reports from late last year suggest that Mangalyaan-2 will have at least four science instruments designed to study the early history of Mars, analyze its leaking atmosphere, and look for a hypothesized dust ring around the planet generated by its two moons, Phobos and Deimos.

Local media reports suggest that Mangalyaan-2 could launch as soon as later this year, a timeline that seems a bit ambitious, given that few key components are still in development, including the multi-instrument helicopter, the sky crane and the supersonic parachute. ISRO has so far made no official announcements about the mission.

India's first Mars mission, MOM or Mangalyaan, was a homegrown technology-demonstrating orbiter put together in 18 months that reached Mars in September 2014. Mangalyaan's success made India the fourth entity to get an orbiter to Mars, after the United States, the European Space Agency and the Soviet Union — but India did so on its first try, and on a shoestring budget of $74 million. For comparison, NASA's most recent Mars orbiter, MAVEN, has a price tag of about $670 million.

Following the accomplishment, and to celebrate the country's first foray into interplanetary space, in 2016 the Reserve Bank of India (RBI) introduced an illustration of Mangalyaan on the back of the country's highest denomination currency note of ₹2,000 (approximately $24 US). (Last May, the RBI decided to withdraw that note from circulation, following what the organization said was a successful demonetization effort to curb black money.)

Mangalyaan also inspired multiple works in Indian cinema, including the 2019 popular Hindi movie "Mission Mangal," a fictional take on the lives of the project's scientists.

ISRO designed Mangalyaan to last just six to 10 months, but the orbiter far exceeded those expectations, operating for nearly eight years before ISRO lost contact with it in April 2022.

[Amber G.]

This sounds a little ambitious to me. MOM-1 was barely able to get into a highly elliptical Mars orbit, but now we intend to go straight to the surface on MOM-2. And not only to roll across that surface with a rover, but also to fly across it with a helicopter. I personally wasn't happy with Chandrayaan-3's low-slung pizza-box lunar rover design, which kept its cameras very close to the ground and having very limited visual range. Nobody even thought to put a camera on the top edge of its upright solar panel.

But anyway, let's keep fingers crossed. If they can pull off such an ambitious mission, it would be a major feather in their cap. It would also again show that they have mastered the design-against-failure paradigm.

A mission like this would require them to make use of technologies developed across a variety of other programs. Supersonic parachute leverages parachute development work for Gaganyaan & SRE. SkyCrane lander would leverage the lander technology used for Chandrayaan-3. Hopefully the rover for MOM2 would be of better design than CY3, and would use a more conventional camera mast which US, Russian and Chinese rovers have long used. The aeroshell development would be completely new for ISRO, and so would the Mars copter. But NASA has shown that helicoptering around Mars to be very doable. Hopefully, ISRO would select a relatively area with suitable terrain to explore, since NASA found that line-of-sight between copter and rover is essential for communication.

FWIW - From a physics's point of view - who taken up quite bit of interest and familiar with ISRO etc..

Here's a scientific and physicists -based response:

Addressing Concerns and Highlighting Feasibility

While the ambitious goals of MOM-2 may raise concerns, India's space program has demonstrated significant capabilities in recent years. The success of MOM-1 and CY2's and CY3's design and navigation achievements, as well as India's expertise in inertial guidance systems and controls, provide a solid foundation for this mission.

Building on Existing Technologies

The proposed mission will leverage technologies developed across various programs, including:

Supersonic parachute: Building on Gaganyaan and SRE parachute development work.

SkyCrane lander: Utilizing lander technology from Chandrayaan-3.

Rover design: Hopefully, incorporating conventional camera masts, like those used by US, Russian, and Chinese rovers.

Aeroshell development: A new challenge for ISRO, but one that can be overcome with careful design and testing.

Mars copter: Inspired by NASA's successful demonstration of Mars helicopter technology.


FWIW, From my point of view (from what I know) :Key Considerations
To ensure success, ISRO should:

Select suitable terrain: Choose a relatively flat area with minimal obstacles for the rover and copter to explore.
Ensure line-of-sight communication: Maintain a clear line of sight between the copter and rover for reliable communication, as demonstrated by NASA.

By addressing these concerns and building on existing technologies, India's space program can successfully execute the MOM-2 mission and demonstrate its mastery of complex space exploration.

In summary, the Mangalyaan-2 mission is an ambitious and exciting project that has the potential to make significant contributions to our understanding of Mars and the solar system. With its planned launch in late 2024, it will be an important milestone for India's space program and will demonstrate the country's capabilities in space exploration. As we continue to explore and learn more about our universe, missions like Mangalyaan-2 will play an important role in advancing our knowledge and understanding of the cosmos.

[SriKumar]

^^^ Is the launch date above correct? Launch to happen In 6-7 months?
Seems aggressive for all the new technologies that need to be developed and tested.

[Amber G.]

^^^ Is the launch date above correct? Launch to happen In 6-7 months?
Seems aggressive for all the new technologies that need to be developed and tested.

Few points and sources to draw your own conclusions: (with some interesting sources for record)

- The launch date mentioned in the article is late 2024, but IMHO it seems ambitious to me too, as key components like the multi-instrument helicopter, sky crane, and supersonic parachute are still in development: ( From what I know)

- OTOH ..India's first Mars mission, Mangalyaan 1 (See old dhaga) , was a homegrown technology-demonstrating orbiter put together in 18 months that reached Mars in September 2014. Mangalyaan's success made India the fourth entity to get an orbiter to Mars, after the United States, the European Space Agency and the Soviet Union — but India did so on its first try, and on a shoestring budget of $74 million. For comparison, NASA's most recent Mars orbiter, MAVEN, has a price tag of about $670 million.


India's ambitious 2nd Mars mission to include a rover, helicopter, sky crane and a supersonic parachute (linked above)

Also from space.com ..
India plans to include a helicopter on its next Mars mission
- By Andrew Jones published in February 24, 2024 -- saying India's first-ever Mars surface mission could lift off in the early 2030s.


Those who have more information please add:

Per ISRO (from what I know): " It has planned various space missions for 2024, including the Mangalyaan-2 mission.
It's reasonable to expect the launch to take place in the second half of 2024 ( as announced by ISRO - but the exact date is yet to be confirmed)
(https://economictimes.indiatimes.com/ne ... 641023.cms.

What we do know: MOM -2 things which many are progressing rather well like
- hyperspectral camera, a high-resolution panchromatic camera, a radar, MODEX, RO, EIS, and LPEX etc..
- The mission will be launched by LVM3 (Bahubali), which will enable the orbiter to carry a payload about 7 times more than Mangalyaan-1.
- The orbiter will use aerobraking to lower its initial apoapsis and enter into an orbit suitable for observations.

[sanman]

Amber ji, a quick google tells me that the upcoming launch window for Mars is only from Oct-Dec 2024 - so any overrun on readiness date for the mission would likely force postponement until the next synod-based launch window which is Nov-Dec 2026.

When ISRO already has major programs like Ganganyaan on the plate, as well as Chandrayaan-4, then does it really have the resources to spare for developing an aeroshell, a supersonic parachute, a SkyCrane, a lander, a helicopter, along with the assorted instruments - all in such a short period of time? And to make these robust enough that they can reliably work?

If they do, then my hat's off to them - but I can't see how it's possible.

[SriKumar]

If ISRO had it in their plan, then there is a possibility it gets launched this year. Interesting that they have a GSLV allocated for this as opposed to satellite launches. If they miss the 2024 chance, the next landing will be in 2027 ( ~1 year to get there). And all development gets delayed by 3 years. Modi and ISRO have to decide whether reliability or speed is the higher priority. I think if they are confident of the landing technologies (sky crane, supersonic parachute, deceleration protocol in Mars orbit, Martian atmosphere etc,) they'll go for the riskier option (ie 2024). I recall that ISRO had crashed an impactor on the lunar surface in CY1 (to measure local values of 'g' perhaps?, or to test lunar soil density/compaction) prior to CY2 landing attempt. I dont think any ISRO impactor has been crashed on Martian surface. Martian aerodynamics is the big difference from CY 3 moon landing, and a new unknown. All landing systems (chute, deployment pyrotecnics, sky crane, detachment etc.) have to work right, the first time, after staying dormant in cold space for ~ 9 months.

[sanman]

If ISRO had it in their plan, then there is a possibility it gets launched this year. Interesting that they have a GSLV allocated for this as opposed to satellite launches. If they miss the 2024 chance, the next landing will be in 2027 ( ~1 year to get there). And all development gets delayed by 3 years. Modi and ISRO have to decide whether reliability or speed is the higher priority. I think if they are confident of the landing technologies (sky crane, supersonic parachute, deceleration protocol in Mars orbit, Martian atmosphere etc,) they'll go for the riskier option (ie 2024). I recall that ISRO had crashed an impactor on the lunar surface in CY1 (to measure local values of 'g' perhaps?, or to test lunar soil density/compaction) prior to CY2 landing attempt. I dont think any ISRO impactor has been crashed on Martian surface. Martian aerodynamics is the big difference from CY 3 moon landing, and a new unknown. All landing systems (chute, deployment pyrotecnics, sky crane, detachment etc.) have to work right, the first time, after staying dormant in cold space for ~ 9 months.

There's Martian EDL (entry-descent-landing) through the atmosphere, as you say. There's the higher Martian gravity compared to lunar (Mars is 1/3 G compared to 1/6 G for Moon). The higher gravity will require stronger landing engines from this SkyCrane thing.

Haven't heard about any hardware tests so far for this Mangalyaan lander mission.

Let's review the NASA procedure for landing Perserverance rover on Mars:

https://www.youtube.com/watch?v=rzmd7RouGrM


Also, ISRO said there would have to be a relay satellite for transmitting signals back to Earth.
Is that supposed to go up in a separate launch (eg. PSLV) or will it all go up together in the LVM3 launch?

Presumably that relay satellite will have to be in a heliocentric orbit somewhere between Mars and Earth.
Should we assume the relay sat would be located closer to the Mars side, since the comms equipment on the Martian surface will be weakest and most in need of help?

[Amber G.]

Amber ji, a quick google tells me that the upcoming launch window for Mars is only from Oct-Dec 2024 - so any overrun on readiness date for the mission would likely force postponement until the next synod-based launch window which is Nov-Dec 2026.

When ISRO already has major programs like Ganganyaan on the plate, as well as Chandrayaan-4, then does it really have the resources to spare for developing an aeroshell, a supersonic parachute, a SkyCrane, a lander, a helicopter, along with the assorted instruments - all in such a short period of time? And to make these robust enough that they can reliably work?

If they do, then my hat's off to them - but I can't see how it's possible.

1. The upcoming launch window for Mars is, as you say, from Oct-Dec 2024, and the next synod-based launch window is from Nov-Dec 2026 seems to be right.
(Launch windows can be calculated using astronomical positions and orbital dynamics, taking into account the relative positions of Earth and Mars eg: see https://www.jpl.nasa.gov/edu/teach/acti ... h-windows/.)


In summary, launch windows are essential for a mission to Mars, and their calculation requires careful consideration of astronomical positions and orbital dynamics. Missing a launch window can result in significant delays, as seen in the case of the Indian mission, which would need to wait until the next synod-based launch window in Nov-Dec 2026 if there is an overrun on readiness.

----
FWIW, you raise some great points .. Here's an answer (IMO) that addresses the concerns about ISRO's resources and the feasibility of developing the necessary technologies for a Mars mission (we will wait for actual answers etc...they can surprise us)

While it's true that ISRO has major programs like Ganganyaan and Chandrayaan-4 ongoing, it's important to note that developing a Mars mission doesn't require starting from scratch. ISRO can leverage its existing expertise and technologies, adapting them for the Martian environment.

Landing on Mars is indeed easier than on the Moon due to its atmosphere, which provides some natural braking. Parachutes can be used to slow down the spacecraft, making the landing process less complex. Although Mars' gravity is slightly higher than the Moon's, the atmosphere helps reduce the landing velocity.

Also Sky Crane or helicopter components are not critical to the entire mission's success. ISRO can design the mission with redundancies and contingency plans to ensure that even if one component fails, the overall mission can still achieve its objectives. This risk management approach allows for some flexibility in case of unexpected setbacks. (ISRO has proven record for this kind of planning)

While developing the necessary technologies within a short timeframe is a challenge, ISRO can focus on incremental development and testing, building upon its existing capabilities. By prioritizing robustness and reliability, ISRO can ensure that the mission's critical components are thoroughly tested and validated before launch.

Overall, while ISRO faces significant challenges, its experience and expertise in space exploration can be leveraged to overcome these hurdles. With careful planning, risk management, and prioritization, ISRO can successfully execute its Mars mission despite the resource constraints.

(I will be impressed but not overly surprised if they can pull this... I will be impressed even if it delayed by many years..)

[Amber G.]

If ISRO had it in their plan, then there is a possibility it gets launched this year. Interesting that they have a GSLV allocated for this as opposed to satellite launches. If they miss the 2024 chance, the next landing will be in 2027 ( ~1 year to get there). And all development gets delayed by 3 years. Modi and ISRO have to decide whether reliability or speed is the higher priority. I think if they are confident of the landing technologies (sky crane, supersonic parachute, deceleration protocol in Mars orbit, Martian atmosphere etc,) they'll go for the riskier option (ie 2024). I recall that ISRO had crashed an impactor on the lunar surface in CY1 (to measure local values of 'g' perhaps?, or to test lunar soil density/compaction) prior to CY2 landing attempt. I dont think any ISRO impactor has been crashed on Martian surface. Martian aerodynamics is the big difference from CY 3 moon landing, and a new unknown.
--.

There's Martian EDL (entry-descent-landing) through the atmosphere, as you say. There's the higher Martian gravity compared to lunar (Mars is 1/3 G compared to 1/6 G for Moon). The higher gravity will require stronger landing engines from this SkyCrane thing.

As posted above Martian atmosphere (even it is quite thin compared to earth) makes the landing *much* less complex..

Martian aerodynamics is the big difference from CY 3 moon landing, and a new unknown. All landing systems (chute, deployment pyrotecnics, sky crane, detachment etc.) have to work right, the first time, after staying dormant in cold space for ~ 9 months.

[/quote]

All things considered, relatively speaking (IMO) - Martian Aerodynamics is not a challenge in contrast to airless moon landing..and we can have enough confidence.

As to make sure all components (electronics etc) working after remaining "dormant" for 9 months is not a challenge as we have dealt with it before without any problems ..

- the spacecraft will have access to sunlight during its journey, which can be used to power solar panels and keep electronics warm and functional.
- (Also possible - technically we are ready - ISRO can implement heating systems, like radioisotope thermoelectric generators (RTGs) or radioisotope thermoelectric units (RTUs), to maintain a stable temperature and prevent cold-induced failures.

- ISRO can design redundant systems and backup plans to ensure that if one component fails, another can take over, minimizing the risk of mission failure.

- : ISRO as time to conduct rigorous testing and validation procedures to ensure the landing systems are reliable and functional before launch.

(As you said - ISRO has successfully demonstrated... with the Vikram lander during the Chandrayaan mission, which included a lunar impact probe ... While the mission didn't include a parachute or sky crane, it showed ISRO's expertise in designing and executing complex landing sequences. etc..)

[Amber G.]

Allow me to post this from basic physics and engineering principles
--Landing on the Moon is indeed more complex than landing on Mars -- because of its airless environment, which means:

No atmospheric braking: Spacecraft must rely solely on propulsion systems to slow down.
No parachutes: Can't be used to slow down the spacecraft.
Precise propulsion control: Required to ensure a soft landing.
Higher velocity: Spacecraft enter near the Moon's surface at higher velocities due to the lack of atmospheric drag.

In contrast, Mars' atmosphere, although thin, provides some natural braking, allowing for the use of parachutes and other aerodynamic techniques to slow down the spacecraft. This makes the landing process somewhat easier, despite the higher gravity.

So, considering all factors, landing on Mars is indeed easier than landing on the Moon, thanks to the presence of an atmosphere!

----
Thanks for providing NASA procedure for landing Perserverance rover on Mars .. to add:

(This image (see below linked) illustrates how spacecraft landings on Mars have become more and more precise over the years. Since NASA's first Mars landing of Viking in 1976, the targeted landing regions, or ellipses, have shrunk. Improvements in interplanetary navigation tightened the ellipses between the 1997 and 2008 landings of NASA's Pathfinder and Phoenix.)

NASA's Curiosity used those improvements, in addition to hypersonic guided entry similar to that used by astronauts returning to Earth during NASA's Apollo program, to further reduce the ellipse size and land just north of the slopes of Mount Sharp. The area of Curiosity's landing ellipse was just seven percent the size of the previous best landing ellipse for Phoenix. This guided entry technique also allowed a much heavier rover to land on Mars.

<picture>.)
Source > Link .https://science.nasa.gov/resource/landi ... rspective/

[SriKumar]

Allow me to post this from basic physics and engineering principles
--Landing on the Moon is indeed more complex than landing on Mars -- because of its airless environment, which means:

I think the presence of atmosphere, while it helps with braking/slowing down the lander, may create other complicating factors. The Soviets had failures of Martian missions after successful moon lander missions. Their Mars lander mission (Mars 2 lander, 1971) crashed, which was well after they soft landed on the moon prior to this (Luna 13, 1966), and returned a lunar sample in 1970 (Luna 16). Missions to Mars by USA, USSR, Russia and ESA are littered with failures including the recent Phobos-Grunt that never even left the earth orbit (IIRC).

Certainly true that the presence of (thin) atmosphere allows the craft to slow down (no question) but the presence of atmospheric forces has other effects. The control laws will have to change (I think) to account for forces from the supersonic parachute, reaction thrusters and aerodynamic forces. THen there is aerodynamic heating to contend with due to the atmosphere, which would mean development of a thermal protection system, adding to the need to model thermo-chemical degradation of the heat shield. Article below discusses complexities and unknowns in modeling this, including proving that the results are valid. I have no clue if and how ISRO has done all these simulations.

https://ntrs.nasa.gov/api/citations/201 ... 021401.pdf

[sanman]

My understanding is that Martian atmosphere makes EDL (entry-descent-landing) more complex than landing on the Moon.

That Martian atmosphere is too thin to sufficiently slow the vehicle, which ends up with a very high terminal velocity of up to 100m/s. The parachute has to be a supersonic parachute, because it needs to start its deceleration earlier at supersonic speeds to avoid crashing into the ground.
That same Martian atmosphere still however causes the frictional heating on entry, which necessitates a heat shield.

I want to say that I'm a fan of the Magnetoshell braking technology being developed by NASA. A magnet is used to generate a large magnetic field during entry into upper atmosphere. This magnetic field then captures some of the plasma being generated during the atmospheric entry, acting like a sort of parachute. The more plasma that enters into the magnetic bubble, the more its charge grows and the more its ability to capture more plasma to exchange momentum grows. This enables aerobraking to be done in the uppermost atmosphere instead of waiting until hitting thicker air down below, like for a regular parachute.

I'd really like for ISRO to develop this technology:

https://vimeo.com/229349348

https://www.nasa.gov/general/a-plasma-a ... -orbiters/

[Amber G.]

Allow me to post this from basic physics and engineering principles
--Landing on the Moon is indeed more complex than landing on Mars -- because of its airless environment, which means:

I think the presence of atmosphere, while it helps with braking/slowing down the lander, may create other complicating factors. The Soviets had failures of Martian missions after successful moon lander missions. Their Mars lander mission (Mars 2 lander, 1971) crashed, which was well after they soft landed on the moon prior to this (Luna 13, 1966), and returned a lunar sample in 1970 (Luna 16). Missions to Mars by USA, USSR, Russia and ESA are littered with failures including the recent Phobos-Grunt that never even left the earth orbit (IIRC).

Certainly true that the presence of (thin) atmosphere allows the craft to slow down (no question) but the presence of atmospheric forces has other effects. The control laws will have to change (I think) to account for forces from the supersonic parachute, reaction thrusters and aerodynamic forces. THen there is aerodynamic heating to contend with due to the atmosphere, which would mean development of a thermal protection system, adding to the need to model thermo-chemical degradation of the heat shield. Article below discusses complexities and unknowns in modeling this, including proving that the results are valid. I have no clue if and how ISRO has done all these simulations.

https://ntrs.nasa.gov/api/citations/201 ... 021401.pdf

SriKumar: Considering all things, at present, for ISRO: Landing part on Mars is *MUCH* less of a challenge than air-less Moon.

- compared to 1971 (or 1966) on-board computers are *much* faster, navigational systems are *much* better, inertial guidance systems are *much* (many orders of magnitude) better, and so are controls -- ISRO can do all that with less fuel and rocket power with much more confidence than they did..

- As I said *many* times in CY-2 and CY-3 threads, for me the *most* critical part was 'soft landing' on the airless moon.
- See the previous article from Nasa I linked - how the precise landing area on Mars has decreased in time.

Point is, even a very thin atmosphere (and use of parachutes can simplify last part) makes the critical landing part *much* less challenging --nothing new -- we always knew that.

Also - temperatures on Mars surface are not that extreme (again thin atmosphere) and near 24 hour - earth like vs 1 month day on the Moon) will provide solar power for batteries etc for rovers etc to work for longer time..

--- Good landings to compare and learn for ISRO's case (For Mars):
NASA's Perseverance rover successfully landed on Mars in 2021.
NASA's Curiosity rover has been operating on Mars since 2012.
NASA's InSight lander has been operating on Mars since 2018.

Moon:
NASA's Apollo missions successfully landed astronauts on the Moon between 1969 and 1972.
NASA's Lunar Reconnaissance Orbiter has been orbiting the Moon since 2009.
But .. along with CY-3 success , there has been lot of unsuccessful attempt by others even in recent times ..

[Amber G.]

My understanding is that Martian atmosphere makes EDL (entry-descent-landing) more complex than landing on the Moon.

<snip>

Thanks for all other info (which I snipped)-- But let me deal with one point only .. basically, point is: In soft-landing how much time (and capacity) to control and provide necessary delta-V to land at place we desire..*in timely manner**..Needs to do calculation using basic physics using *all* the factors -- answer, IMO, is simple.
(May be some other time I will dwell into this

Meanwhile for your reading pleasure ...
The best (and worst) Mars landings of all time

-- Just in recent times we had notable failures on Moon:
Peregrine: Launched by Astrobotic Technology, a private US company, on January 19, 2024. Due to a fuel leak, the lander was unable to land on the moon and eventually crashed into the Pacific Ocean.
Chandrayaan-2: Launched by the Indian Space Research Organisation (ISRO) in 2019. The Vikram lander lost contact with Earth just 2.1 kilometers above the moon's surface and crashed.
Russian Probes: In 2023, a Russian moon lander crashed on the moon's surface due to unknown reasons...

Soft landing on the moon is difficult due to the lack of atmosphere and the need for precise control over the spacecraft's descent..

Overall, both the Moon and Mars present challenges for soft landings, but the Moon's simpler environment makes it a more accessible target for spacecraft (Once you have overcome to reach it which is difficult than moon)

[Amber G.]

[...nd unknowns in modeling this, including proving that the results are valid. I have no clue if and how ISRO has done all these simulations.

https://ntrs.nasa.gov/api/citations/201 ... 021401.pdf

Thanks for the link .. was interesting read. This might of interest:

some of the Mangalayaan's Mission Objectives are:

To explore Mars' surface and atmosphere.

To conduct a high-resolution vertical profiling of critical atmospheric parameters and perform first-of-its-kind in-situ measurements in the near-surface boundary layers of Mars.

ISRO is Mars UAV, "Marble," a.k.a. the "Martian Boundary Layer Explorer," that will have a suite of payloads for aerial exploration of Mars.
The aerial vehicle will be designed to be capable of flying up to 100 meters in the thin Martian air to profile the Martian atmosphere.

(BTW: ISRO is depending of aerodynamic breaking for Mangayaan-2 planning -- Being launched by the LVM3 rocket and using Aerobraking the MOM-2 satellite can carry more than 7 times the payload for MOM-1 with a reduction in perigee to about 200 kms above the surface of Mars)

[Amber G.]

FWIW some of my post in CY2/CY3 ...s may be of interest -- as I posted several posts about landing on Airless moon wrt to CY2 and CY3..

For example in CY2 thread ..:

Indeed, the soft landing is the most difficult part as the moon has no atmosphere that you can't use parachutes or balloons to cushion a descent. Vikram's engines and thruster rockets to correct for yaw-pitch-roll all have to work in unison to get it right. On top of that, the moon's surface is rocky with lots of big and small craters. Hopefully the scanning goes well. Vikram has less than 2 minutes to make this decision. From ground control, sending messages back and forth to Vikram will take at least 3 seconds.

Though there are many critical challenges but for me, this will be the most critical. We and others have done other parts before but we are doing the soft landing on moon for the first time.. and many others who have tried failed in soft landing.

To navigate and land softly ISRO and developed many sensors etc and we will see how good they are. All are developed by Indian sources over the years.
Specially -
- Very high resolution optical camera OHRC (Orbiter High-Resolution Camera" (OHRC).
- Ka-band Altimeter.
- Another optical devices LPDC ( Lander Position Detection Camera ) and LHDAC (Lander Hazard Detection and Avoidance Camera ).

Vikram will make vertical decent in the south pole region but before that ..
- Orbiter and Vikram Lander will enter the lunar orbit. The OHRC ( attached to the orbiter) that will image scan the landing site to find the exact descent point.
-Once landing site is finalized, Vikram will detach from the orbiter. After detaching, the lander will carry out manoeuvres (using the other sensors for feedback) and it will make use of rough braking.
- Then there will be a fine braking to stabilize and finally land softly at the descent point amid all the flying sharp moon dust.
- This will be a nail-biting 15 minutes even for cool/experienced operators.

****
Once successfully landed - Vikram Lander also has LRRA (Laser Retro-reflector Array'- given by NASA) - This instrument ( mirrors) will be used

Neil Armstrong said before the lunar module separated, there is only a 50% chance of landing on the moon, but 90% chance of safely returning.... something to that efffect..

I repeated this in many posts ... to me that part was most challenging for me the final 10-15 minutes of Vikram's soft landing..
(But now after CY3 may be now ISRO is now much better in that part too,,)

[SriKumar]

Doubtless, engineering and technology advancements have made things easier, but a Mars landing requires engineers to deal with an additional set of physics not existing on moon- aerodynamic forces and frictional heating. To be able to use aerodynamic forces to its benefit (i.e. slow down the lander), the big assumption is that parachute-air interactions are figured out, parachute design is mature and actual parachute deployment will work right. Perhaps this has been sorted out to a high degree of confidence by ISRO (and not mentioned publicly) . Below is a thesis on fluid dynamics simulation of, and challenges in simulation of, parachute deployment. There are several issues. Indeed, if these have been learnt out by ISRO, and tests performed, then Mars landings should be very much easier than moon landings.

https://thesis.unipd.it/retrieve/3a1c80 ... Giulio.pdf

[sanman]

Temperatures on Mars will still get quite cold, especially at night, where temperatures can drop to -128 C, nearly same as on the Moon.

We saw how CY-3 lander+rover didn't even survive one lunar night, even though that period is equivalent to 14 days on Earth or Mars.

Hardware on the surface of Mars would be facing similarly low temperature extremes, with temperature swings happening more frequently, albeit for shorter periods compared to the Moon.

So I'm wondering how ISRO intends to deal with this. They need to either improve the temperature tolerance of the electronics, or else they need to go for Radioisotope Heating Units (RHUs). Otherwise, you could try to store energy collected during the day in a battery or regenerative fuel cell (the battery idea would probably be too heavy)

[Amber G.]

Temperatures on Mars will still get quite cold, especially at night, where temperatures can drop to -128 C, nearly same as on the Moon.

We saw how CY-3 lander+rover didn't even survive one lunar night, even though that period is equivalent to 14 days on Earth or Mars.

Hardware on the surface of Mars would be facing similarly low temperature extremes, with temperature swings happening more frequently, albeit for shorter periods compared to the Moon.

To put the things in perspective:
Mars's atmosphere is about 100 times thinner than Earth's. Without a "thermal blanket," Mars can't retain any heat energy. On average, the temperature on Mars is about minus 60 degrees C) . In winter, near the poles, temperatures can get down to minus 125 degrees C . A summer day on Mars may get up to + 20 degrees C near the equator, but at night the temperature can plummet to about-73 degrees C .. but there are places - for NASA rovers where night time, (IIRC) temperature is close to -10-20 degree C (Again there is difference between surface temp and surface air temperature on mars ..MEDA instrument onboard Perseverance records the surface and atmospheric temperature in Mars...)

(Record according to some recent data lowest recorded -- a minus 128 degrees Celsius. As a point of comparison, the lowest recorded temperature on Earth is minus minus 88 degrees C in Antarctica
(On moon typical temps on equator Daytime temperature 122 degrees Celsius)
Nighttime temperature (-153 degrees Celsius)
(Poles it may go down to -238 C)

Night time (for CY3 near the pole) the temp is quite low, for 14 days to freeze the electronics and no sun ..on Mars, nights on equator is about 12 hours just like earth.. (And probes there have survived on solar power for *years*) In nutshell for ISRO (even if it does not use RHU/RTG) this is NOT a problem or show stopper..)

[Amber G.]

Doubtless, engineering and technology advancements have made things easier, but a Mars landing requires engineers to deal with an additional set of physics not existing on moon- aerodynamic forces and frictional heating. To be able to use aerodynamic forces to its benefit (i.e. slow down the lander), the big assumption is that parachute-air interactions are figured out, parachute design is mature and actual parachute deployment will work right. Perhaps this has been sorted out to a high degree of confidence by ISRO (and not mentioned publicly) . Below is a thesis on fluid dynamics simulation of, and challenges in simulation of, parachute deployment. There are several issues. Indeed, if these have been learnt out by ISRO, and tests performed, then Mars landings should be very much easier than moon landings.

https://thesis.unipd.it/retrieve/3a1c80 ... Giulio.pdf

From the data / link you gave (pp7) -- in last 20 years except for ExoMars all other landings using aerodynamic braking and use of parachutes were *successful*! ISRO should be able to do that.. (Viking 1 & 2 in 1976 also used them with success)

[Amber G.]

For those who want more detail or are interested ..

Things to study are recent Tianwen-1 and InSight landings (2021 and 2018 - see Sri Kumar's link)

Both used a parachute to slow down during descent
Both used a heat shield to protect the spacecraft during entry into the Martian atmosphere
Both used a radar system to sense velocity and distance to the ground
Both used a robotic arm to deploy scientific instruments

Some Differences:

Tianwen-1 landed in the Utopia Planitia region, while InSight landed in the Elysium Planitia region
Tianwen-1 landed in 2021, while InSight landed in 2018
Tianwen-1 has a more complex design, with a rover and an orbiter, etc..
Scientific objectives: Tianwen-1's primary objective is to search for signs of water ice and study the Martian geology, while InSight's primary objective is to study the Martian interior and subsurface

Both Tianwen-1 and InSight successfully landed on Mars ..

[sanman]

So is Mangalyaan-2 going to have both a rover and a lander, or will it just have a lander and no rover?

Also, I wonder how the helicopter will be attached, and what kind of instruments it would be expected to carry.

NASA's brilliant Ingenuity helicopter had cameras, inertial sensor (IMU) and laser altimeter as its instruments.

https://en.wikipedia.org/wiki/Ingenuity_(helicopter)



However, NASA does have possible future plans for more advanced helicopters that can do more science:



I think ISRO's helicopter should directly try to include useful science instruments on it that will enable it to take useful measurements out in the field.

But what science instruments should it include?

[Amber G.]

So is Mangalyaan-2 going to have both a rover and a lander, or will it just have a lander and no rover?
....
But what science instruments should it include?

Above NASA plans we have much more information but we are also looking at China plans to launch an ambitious Mars sample-return mission in 2028, which will involve landing on Mars, collecting samples, and returning them to Earth. Tianwen-1 used a parachute to slow down during its descent, which was deployed after the heat shield protected the spacecraft during the fiery descent. Landing site is Utopia Planitia region, a plain inside an enormous impact basin in the planet's northern hemisphere. The Zhurong rover was deployed from the lander and began its exploration of the Martian surface.
The Tianwen-1 mission was successful in achieving its objectives, including taking images of the entire Martian surface and exploring the planet's composition and searching for signs of water ice.. etc.. lot of learnings there too.

For Mangalyaan 2 Mission plans are - in general way - (either in 2024 or 2026) --upgraded orbiter ( launched aboard the heavy-lift Launch Vehicle Mark-III (LVM3)..ISRO's engineers must be actively engaged in designing and developing specialized instruments .. will be able to take about 100 Kgs of scientific instruments.

- A rover and helicopter combination akin to NASA's Perseverance rover.
(SRO is currently working on a supersonic parachute and sky crane system, - lot of inputs from NASA's deployment techniques.
tailored to the Indian rover's unique requirements)

-- Instruments to conduct a high-resolution vertical profiling of critical atmospheric parameters and perform first-of-its-kind in-situ measurements in the near-surface boundary layers of Mars.
-- Mars UAV, "Marble," a.k.a. the "Martian Boundary Layer Explorer," that will have a suite of payloads for aerial exploration of Mars.
The aerial vehicle will be designed to be capable of flying up to 100 meters in the thin Martian air to profile the Martian atmosphere.

- ISRO plans to deploy a dedicated relay communication satellite before the mission launch.

(From published reports etc .. Payloads are in various stags are Mars Orbit dust Exp, Radio Occulation (RO), Energetic Ion Spectrometer & Langmuir Probe & electric field experiment (LPEX)


Let us wait for further details..

[Amber G.]

SriKumar, Sanman --

Here is landing sequence of chinese Tianwen-1 landing ..



And Perseverance Landing on Mars:

[sanman]

So far it sounds like ISRO will do a lander without a rover, and just have the helicopter as the mobile piece coptering around the landscape.

It should be noted that NASA's Ingenuity copter stopped functioning due to a landing where it toppled and shredded one of its rotor tips, thus grounding it forever.
How can we avoid suffering the same fate? What can we learn from Ingenuity's mishap to be able to avoid a similarly bad fate?

The only thing I can think of so far, is having a wider landing leg stance.




Or is it possible to do something like this to guard the rotor tips?

[vera_k]

Using a drone with propeller guards should be studied.

[Amber G.]

Let me mention: 'Yaanam', the world's first science documentary in Sanskrit, based on our BoG Chairman & ISRO's former Chairman Dr. Radhakrishnan K. Koppillil's book 'My Odyssey: Memoirs of the Man Behind the Mangalyaan Mission' was released not that long ago.. worth watching..

[Amber G.]

Three recently discovered craters on the surface of Mars have been named for renowned cosmic ray physicist late Devendra Lal and the towns of Mursan and Hilsa in northern India.