Indian Space Program: News & Discussion

SSridhar · Post by **SSridhar** » 22 Jan 2025 06:40

Inia Demonstrates Space Docking - Ajay Lele, The Space Review

On December 30, the Indian Space Research Organisation (ISRO) successfully launched its PSLV-C60 mission. The primary objective of this launch was to test docking technology with two satellites, as part of the Space Docking Experiment (SpaDeX) mission. SpaDeX carried two satellites, each weighing 220 kilograms, into a circular low Earth orbit. One satellite, designated the Chaser (SDX01), and the other, the Target (SDX02), were involved in the docking experiment. On January 16, ISRO successfully achieved the docking, thus making India only the fourth country in the world after the United States, Soviet Union (Russia), and China to possess this capability.

ISRO appeared confident about the success of the mission and had originally planned a live broadcast of the docking experiment. However, they were required to make some last-minute adjustments to their plans for the execution of the experiment. ISRO maintained a highly professional approach, taking the necessary time and care without hurrying. There was a clear understanding that a collision between the satellites, instead of a successful docking, could lead to a significant risk of space debris. With this in mind, ISRO took extensive precautions, exercised patience, and ultimately achieved a successful outcome. It has been explained by the officials that the docking process was initiated with precision, resulting into successful spacecraft capture.

NASA defines docking as “mating operations where an active vehicle flies into the mating interface under its own power.” ISRO had done very systematic planning for the SpaDeX mission. Both satellites were into orbit at an altitude of 470 kilometers. The first step in this experiment was to ensure that as an initial condition, the satellites would stay apart at 20 kilometers. Gradually, from 20 kilometers, the inter-satellite distance was lowered to 5 kilometers, 1.5 kilometers, 500 meters, 225 meters, 15 meters, and 3 meters before finally the docking happened.

Initially, ISRO had announced that the docking would take place on January 7. However, the attempt was postponed. It was stated that the docking process required further validation through ground simulations based on an identified abort scenario, and as a result, the experimentation was rescheduled for January 9. Yet, ISRO was again required to postpone the process after discovering that during the maneuver to bring the satellites within 225 meters of each other, the drift was greater than expected.

There were indications that docking could occur on January 12, as ISRO had reduced the distance between the satellites to just three meters. However, ISRO exercised caution and refrained from attempting the docking immediately. It seems that ISRO took the opportunity to gather essential data while the satellites were three meters apart before increasing the inter-satellite distance once again. Throughout this period, ISRO dedicated considerable time to continuous data collection, assessment, and validation. Their approach appeared to be methodical, taking one step at a time to ensure that no potential glitches remained.

There are various types of docking mechanisms, and for this mission, ISRO employed an androgynous mechanism. In this system, the components on both the Chaser and Target satellites are identical. It is similar to the International Docking System Standard (IDSS), with the main difference being that IDSS uses 24 motors, while ISRO utilized only two motors. This is because ISRO’s mechanism is smaller (450 millimeters) with one degree of freedom for extension as compared to the IDSS (800 millimeters) on a hexapod. The process involved the Chaser satellite approaching the Target satellite. As the extended rings on both satellites made contact, they joined together, and eventually, the rings were retracted and locked in place. After the docking, ISRO also succeeded in controlling the joined satellites as a single unit. The mission will continue in the coming days with various planned maneuvers.

Now, the satellites are expected to share electrical power and function as a single unit for some time. According to the project design, ISRO also plans to perform an undocking, after which the satellites to drift apart and operate as independent systems once again. The expected lifetime of the satellites is around two years, and if all goes well, there could be additional docking and undocking attempts in the future.

According to the details provided by ISRO, SDX01, the Chaser, carries a High-Resolution Camera (HRC) with photo and video capabilities, while SDX02, the Target, carries a Multi-Spectral Payload (MMX) used for natural resource monitoring and vegetation studies. It also carries a Radiation Monitor, which will measure radiation doses encountered in space, which will help suitably plan and execute India’s proposed human mission Gaganyaan mission (expected to happen by 2026). In short, it could be said that one satellite is a scientific satellite and the other is a remote sensing satellite.

ISRO had been working on the concept of docking for many decades. However, it appears that the process of development was accelerated around 2016. There may have been a realization it is important to master this technology in view of some proposed projects like the establishment of a space station and crewed space missions. The Space Docking Experiment was approved by the government of India in 2017

ISRO is expected launch its next mission to the Moon, Chandrayaan-4, by 2027. Mastering the art of space docking is very crucial for this sample return mission. ISRO is planning to launch their fourth mission to Moon in two phases. According to the available information, the spacecraft will have five modules packed into two vehicles, which will be launched separately and the final spacecraft will get assembled into an integrated module by docking in Earth orbit before proceeding to the Moon.

Generally, docking processes are completed within a few hours after the spacecraft reaches the desired location. This is possible because spacecraft typically carry a significant amount of fuel, enabling them to fire their thrusters and maneuver to align with the target spacecraft. However, the SpaDeX mission involves both the chaser and target satellites weighing only 220 kilograms, limiting their fuel capacity. ISRO’s goal for the mission was to test indigenous docking technology, relying more on the natural drift of the two satellites and minimizing fuel usage.

For undertaking a space docking mission, ISRO followed the indigenous technologies development route and, along with the docking mechanism and a suite of rendezvous and docking sensors, it also had to develop various other technologies. That included inter-satellite communication links (ISL) for autonomous communication between spacecraft, a GNSS-based Novel Relative Orbit Determination and Propagation (RODP) processor to determine the relative position and velocity of the other spacecraft based on navigation satellite signals, and simulation testbeds for both hardware and software design validation and testing. ISRO patented its docking mechanism.

Space docking is crucial for various missions, such as on-orbit servicing, satellite refueling, debris removal, extravehicular activities, delivering supplies to space platforms, and deep space missions such as sample return missions. India recognizes that it is a latecomer in this field. The US demonstrated docking capability in 1966, the Soviets in 1967, and China in 2011. India needs to quickly master this robotic technology and progress toward human docking. With plans to undertake its human space mission by 2026, India is expected to include human space docking in subsequent missions.

There could be some strategic advantages, too, in possessing space docking technologies. India is also the fourth country to have an ASAT capability. While India identifies that concepts scuh as “space weaponization” and “space wars” have no place in the modern world, it understands the necessity of maintaining a comprehensive space deterrence architecture because of its unique security challenges. Technologies related to orbital rendezvous, docking, proximity operations, formation flying of spacecraft, and on-orbit satellite servicing can be considered dual-use technologies.

Amber G. · Post by **Amber G.** » 22 Jan 2025 10:15

^^^ Thanks.

RCase · Post by **RCase** » 23 Jan 2025 08:36

Nice explanation and simulation graphics of the docking process.

https://www.youtube.com/watch?v=O_HMyhDUi5s

bala · Post by **bala** » 24 Jan 2025 22:10

The Lt. Gen P R Shankar explains some nuances on India's Space Docking along with China's reaction.

https://www.youtube.com/watch?v=8MjbnMMTNQI

Apparently it is harder to control low mass satellites compared to the behemoths that the US, Russia and China have demonstrated in Geostatinary orbit. Controlling two small low kg satellites in non geostationary orbit is a tricky affair and small forces can put things into wierd positions. This docking experiment proves that India has capability of capturing satellites in space and neutering them. Full automation capability controlled by software algos is interesting especially when certain moves failed and in the end docking succeeded showing resilience of the software system.

Some of the chinese reaction is priceless and India needs to take note.

sanjaykumar · Post by **sanjaykumar** » 25 Jan 2025 04:55

India never reveals what it is really doing.

They had a robotic arm on perhaps the spent 4th stage.

This is wholly unnecessary for rendezvous or docking.

If such an arm is carried into orbit then it comes in handy when the intention is to deorbit another satellite. One such satellite can in theory roam its orbit and deorbit several enemy satellites as it does not entail destruction of own assets. More cost and resource effective than diabling by collision or explosives.

Amber G. · Post by **Amber G.** » 25 Jan 2025 11:39

ISRO is making its historic 100th launch from SDSC-SHAR spaceport in Sriharikota with the GSLV F15 mission on Jan 29.

drnayar · Post by **drnayar** » 25 Jan 2025 13:00

bala wrote: ↑24 Jan 2025 22:10 The Lt. Gen P R Shankar explains some nuances on India's Space Docking along with China's reaction.

https://www.youtube.com/watch?v=8MjbnMMTNQI

Apparently it is harder to control low mass satellites compared to the behemoths that the US, Russia and China have demonstrated in Geostatinary orbit. Controlling two small low kg satellites in non geostationary orbit is a tricky affair and small forces can put things into wierd positions. This docking experiment proves that India has capability of capturing satellites in space and neutering them. Full automation capability controlled by software algos is interesting especially when certain moves failed and in the end docking succeeded showing resilience of the software system.

Some of the chinese reaction is priceless and India needs to take note.

Evil yindoos at it again...

Ashokk · Post by **Ashokk** » 25 Jan 2025 23:31

GSLV-F15/NVS-02 to launch on January 29: ISRO

BENGALURU: The Geosynchronous Satellite Launch Vehicle (GSLV)- F15/ Navigation with Indian Constellation-2 Satellite (NVS-2) Mission will launch from Satish Dhawan Space Centre, Sriharikota on January 29 at 6.23am.

Researchers from the Indian Space Research Organisation (ISRO) said that the satellite was flagged off to Sriharikota on January 5, 2025. This is the 17th flight of India’s GSLV and the 11th flight with indigenous cryostage. It is also the eighth operational flight of GSLV and with an indigenous Cryogenic stage and the 100th Launch from the India’s Spaceport Sriharikota. GSLV-F15 payload fairing is a metallic version with a diameter of 3.4 meters. ISRO also took to X- platform to announce the date announced that people can register through its online platform to view the launch from the Sriharikota centre.

The GSLV-F15 will place NVS-02 satellite into a Geosynchronous Transfer Orbit. The NavIC is an independent regional navigation satellite system designed to provide accurate Position, Velocity and Timing services.The NVS-02 uses a combination of indigenous and procured atomic clocks for precise time estimation.

ISRO shared, the NVS-02, is the second satellite in the NVS series and is configured with Navigation payload in L1, L5 and S bands in addition to ranging payload in C-band like its predecessor-NVS-01. It is configured on standard I-2K bus platform with a lift-off mass of 2250 kg.

bala · Post by **bala** » 26 Jan 2025 07:01

New ISRO Chief Dr. V. Narayanan interview discussing many things.

https://www.youtube.com/watch?v=VJ1KxXZj3Zk

Three uncrewed missions already underway at Sriharikota. Dr. V Narayanan described the Gaganyaan mission as a groundbreaking development, as it involves sending humans into space—a first for India. Highlighting the mission's complexity, he shared that significant progress has been made in human-rating the vehicle and developing the orbital module to safely transport astronauts. He also underscored the importance of the crew escape system, saying, "Safety is paramount, and we are learning from every global space mission". Extensive testing and qualifications are ongoing to ensure mission success.

Dr. V Narayanan has been involved in cryogenic propulsion systems since the 90's, he joined ISRO in 1984. His M. Tech from IIT Kharagpur was on cryogenic engineering. He has a Ph. D from IIT Kgp. Dr V. Narayanan's identification of errors made during Chandrayaan-2's landing attempt and fixing these in Chandrayaan-3's lander is a major contribution for his appointment as ISRO chairman.

Amber G. · Post by **Amber G.** » 26 Jan 2025 13:09

Congratulations IIT Kanpur alumnus Dr. Pawan Goenka Chairman, Indian National Space Promotion (IN-SPACe) for being conferred with the prestigious Padma Shri 2025.

Dr. Goenka’s recent contributions in uplifting the country’s space economy while also powering private entrepreneurs to drive this growth has created immense impact in the growth of the sector.

He is internationally recognized for his pioneering work in engine tribology. His methods for the analysis of engine bearing and engine friction still remain in use as a common reference in automotive engineering. He is an expert in vehicular emission control and alternative fuels.

rajkumar · Post by **rajkumar** » 26 Jan 2025 17:30

India's $460M Rocket Launchpad: Sriharikota's Giant Leap!

bala · Post by **bala** » 28 Jan 2025 23:19

ISRO 100 th rocket launch countdown of GSLV starts in Satish Dhawan lauch center, Sriharikota, AP. Launch will be on Wednesday 01/29/25. Navic satellites will be deployed.

youtube.com/watch?v=oqyI3GpNDvo

SSridhar · Post by **SSridhar** » 29 Jan 2025 06:45

Mission accomplished.

A milestone of 100th launch from SDSC, SHAR. Congratulations ISRO

Dispersion: 0.5 Km perigee, 72 Kms in apogee, 0.02 deg inclination. Excellent.

bala · Post by **bala** » 29 Jan 2025 07:40

Flawless launch and injection into orbit. The full launch Rocket has 4 solid stages, 1 liquid stage and 1 cryogenic stage. This is the first launch for Dr. V. Narayanan after taking over as ISRO chief. If you need to see the launch and ISRO's personnel involved, here is YT:

https://www.youtube.com/watch?v=LWzg5Z-bcLo

sanjaykumar · Post by **sanjaykumar** » 29 Jan 2025 07:59

Unfortunately, there is no report on the Spadex dedocking. Does not look good.

SSridhar · Post by **SSridhar** » 29 Jan 2025 09:12

The launch stream was much better with visuals this time. They are making improvements in visual presentation. However, the commentators keep talking too much, a long-standing complaint here, drowning out ISTRAC & Range communication callouts in the background which are interesting too.

drnayar · Post by **drnayar** » 29 Jan 2025 20:56

SSridhar wrote: ↑29 Jan 2025 09:12 The launch stream was much better with visuals this time. They are making improvements in visual presentation. However, the commentators keep talking too much, a long-standing complaint here, drowning out ISTRAC & Range communication callouts in the background which are interesting too.

i was looking at the live [ ! ] stream from Boom Supersonic's XB-1 demonstrator jet as it became the first U.S.-made civilian supersonic jet to break the sound barrier.

The live feed was throughput via Starlink satellite terminal [ broad band ]

neeraj · Post by **neeraj** » 03 Feb 2025 00:39

https://www.ndtv.com/india-news/isro-10 ... etopscroll

ISRO's Latest Mission Hits A Hurdle, Satellite Faces Technical Glitch. Orbit raising operations towards positioning the satellite to the designated orbital slot could not be carried out as the valves for admitting the oxidizer to fire the thrusters for orbit raising did not open.

Amber G. · Post by **Amber G.** » 03 Feb 2025 02:40

^^^^ Indian navigation satellite stuck in transfer orbit after propulsion failure
(
..NVS-02, is stuck in a transfer orbit due to a thruster failure, which might cause it to reenter the atmosphere soon. ISRO launched the satellite on January 28, but the onboard propulsion system failed, preventing it from reaching its intended geostationary orbit.

According to ISRO, the valves that admit oxidizer to fire the thrusters didn't open, causing the orbit-raising operations to fail. Although other systems on the spacecraft are functioning well, including the solar panels, ISRO seems to have given up on fixing the propulsion system.

The satellite's low perigee of 165 kilometers puts it at risk of reentering the atmosphere due to high atmospheric drag. ISRO is exploring alternative mission strategies to utilize the satellite for navigation in its current elliptical orbit. NVS-02 is part of India's Navigation with Indian Constellation (NavIC) program, which aims to provide positioning, navigation, and timing services in India and the surrounding region.)

SSridhar · Post by **SSridhar** » 03 Feb 2025 21:35

Very unfortunate and disappointing. LAM has always worked flawlessly.

bala · Post by **bala** » 04 Feb 2025 00:15

BTW sabotage cannot be ruled out. The folks who create satellites need to up their test regime suite, things as basic as thrust / correction should be triply checked prior to launch deployment. They should also have redundant systems, 1 fails the other works type design. Many things can go wrong, but the basic stuff should be rock solid, fool-proof, redundant design.

drnayar · Post by **drnayar** » 04 Feb 2025 00:41

bala wrote: ↑04 Feb 2025 00:15 BTW sabotage cannot be ruled out. The folks who create satellites need to up their test regime suite, things as basic as thrust / correction should be triply checked prior to launch deployment. They should also have redundant systems, 1 fails the other works type design. Many things can go wrong, but the basic stuff should be rock solid, fool-proof, redundant design.

have to agree.. its quite remarkable the NAVIC constellation has a string of failures compared to regular ISRO launches

https://en.wikipedia.org/wiki/Indian_Re ... ite_System

6 failures out of 9 IRNSS sats. !!

RCase · Post by **RCase** » 04 Feb 2025 05:40

Is it possible in the future to send a 'Repair' module craft to dock like SPADEX to either remotely repair the faulty satellite or dock and provide the necessary thrust to put it into the correct orbit? What are the drawbacks to such an idea?

SSridhar · Post by **SSridhar** » 05 Feb 2025 06:32

RCase, it is not possible. The NVS-02 is not equipped with a docking mechanism.
One possibility is if it can be grabbed with a robotic arm (which is being tested in the POEM experiments of the last PSLV) and then take it to the desired orbit. However, that is a long way away as our robotic arm technology and operation procedures have to mature.

SSridhar · Post by **SSridhar** » 06 Feb 2025 13:22

Chandrayaan-4 to launch in 2027, says Union Minister Jitendra Singh - ET

India will launch the Chandrayaan-4 mission to bring back samples of moon rocks to the Earth in 2027, Science and Technology Minister Jitendra Singh said. Chandrayaan-4 will involve at least two separate launches of the heavylift LVM-3 rocket that will carry five different components of the mission which will be assembled in orbit.

"The Chandrayaan-4 mission aims to collect samples from the moon's surface and bring them back to the Earth," Singh told PTI Videos in an interview.

The minister said the Gaganyaan mission, which involves sending Indian astronauts in a specially designed spacecraft to low-earth orbit and bringing them back safely, will be launched next year.

The first uncrewed mission of the Gaganyaan project carrying a robot, 'Vyommitra', will also take place this year.

The minister said that India's space economy, currently valued at USD 8 billion, is projected to reach USD 44 billion in the next decade, further cementing India's role as a global space powerhouse.

rajkumar · Post by **rajkumar** » 06 Feb 2025 15:47

𝑀𝑂𝑀 : 𝐌𝐢𝐬𝐬𝐢𝐨𝐧 𝐎𝐯𝐞𝐫 𝐌𝐚𝐫𝐬

Much better than regular Bollywood Masala...

SSridhar · Post by **SSridhar** » 08 Feb 2025 22:33

drnayar wrote: ↑29 Jan 2025 20:56i was looking at the live [ ! ] stream from Boom Supersonic's XB-1 demonstrator jet as it became the first U.S.-made civilian supersonic jet to break the sound barrier.

The live feed was throughput via Starlink satellite terminal [ broad band ]

Today, even TT&C functions (tracking, telemetry & command) functions are done through satellites.

Ashokk · Post by **Ashokk** » 18 Feb 2025 17:16

SSridhar · Post by **SSridhar** » 11 Mar 2025 06:33

How difficult moon landing has been proven by the second successive failure of a NASA-backed Intuitive Machine lander.

Sagrawal · Post by **Sagrawal** » 13 Mar 2025 13:56

Spadex dedocking successful.

https://x.com/isro/status/1900100280345321521

Cyrano · Post by **Cyrano** » 13 Mar 2025 15:53

Awesome ISRO!

sanjaykumar · Post by **sanjaykumar** » 13 Mar 2025 20:43

I had written it off as a failure. Pleasant surprise.

Does the lower inertia of the target satellite, compared to a space station or manned capsule make the docking aspect more difficult?

bala · Post by **bala** » 13 Mar 2025 22:04

sanjaykumar wrote: ↑13 Mar 2025 20:43
Does the lower inertia of the target satellite, compared to a space station or manned capsule make the docking aspect more difficult?

Yes, the movements are not geo-stationary wrt to the earth. The reference point for geo-stationary is quite simple not so for other orbits and hence quite tricky, since you are dealing with high orbital velocities and a small small error can be off by miles/kms.

Amber G. · Post by **Amber G.** » 13 Mar 2025 23:53

bala wrote: ↑13 Mar 2025 22:04
sanjaykumar wrote: ↑13 Mar 2025 20:43
Does the lower inertia of the target satellite, compared to a space station or manned capsule make the docking aspect more difficult?

Yes, the movements are not geo-stationary wrt to the earth. The reference point for geo-stationary is quite simple not so for other orbits and hence quite tricky, since you are dealing with high orbital velocities and a small small error can be off by miles/kms.

Disclaimer: < From a physics professor's perspective - for those who are not interested in physics/math can ignore the post>

The provided answer attempts to highlight the challenges of docking with a lower-inertia target satellite but fails to provide a clear and physically accurate explanation. A more precise answer would focus on the specific dynamics and control challenges associated with docking in space, rather than relying on unclear statements about "geo-stationary reference" points and error accumulation.

The answer mentions that "movements are not geo-stationary wrt to the earth." This statement is unclear and physically inaccurate (or does not make sense):.

Geo-stationary refers specifically to an orbit where a satellite remains stationary relative to a fixed point on the Earth's equator. This is achieved by orbiting the Earth at an altitude of approximately 35,786 km.
The statement seems to imply that non-geo-stationary orbits are inherently more challenging due to their reference point. However, this is misleading, as the reference point for any orbit can be well-defined and tracked.

The answer also mentions "high orbital velocities and a small error can be off by miles/kms." While it is true that orbital velocities are high, the statement about error accumulation is oversimplified ..
Orbital mechanics involve complex calculations, but modern navigation systems and control algorithms can accurately account for these factors...
The impact of small errors on orbital trajectories depends on various factors, including the specific orbit, the spacecraft's mass and maneuvering capabilities, and the control strategy employed.

------ (IMO how I will answer this Q):

The inertia of the target satellite indeed plays a crucial role in the docking process. In technical terms:

- When two spacecraft dock, their relative motion must be carefully controlled to ensure a safe and successful mating. The inertia of the target spacecraft affects the docking dynamics in several ways:
- A lower-inertia target satellite (i.e., smaller mass) results in a higher mass ratio between the chaser spacecraft (e.g., SDX-1) and the target. This increased mass ratio can lead to a more complex control problem, as the chaser must adapt to the target's smaller inertia.
- The lower inertia of the target satellite means it will be more susceptible to changes in its motion due to the chaser's approach. This can result in a more dynamic and unpredictable relative motion between the two spacecraft, making the docking process more challenging.
- To compensate for the target's lower inertia, the chaser spacecraft may require more control authority (e.g., higher thrust levels or more precise control) to maintain a stable and controlled approach. This can be particularly demanding for the chaser's propulsion and control systems.

----
To overcome the challenges posed by a lower-inertia target satellite, docking systems employs: various strategies:
Advanced Sensors and Navigation,
Robust Control Algorithms
Target Stabilization
.. ityadi mitigation strategies and designers and operators can ensure a successful docking operation.

Amber G. · Post by **Amber G.** » 14 Mar 2025 00:02

Sagrawal wrote: ↑13 Mar 2025 13:56 Spadex dedocking successful.

https://x.com/isro/status/1900100280345321521

Awesome!
My take on why it's impressive:

- ISRO has demonstrated its capability to bring two satellites together in orbit and then separate them, a complex task requiring high precision and control.

- The SDX-1 and SDX-2 satellites were able to perform the docking and undocking maneuvers autonomously, without real-time human intervention.

- The development of SDX-1 and SDX-2 has pushed the boundaries of Indian spacecraft design and propulsion systems.

Amber G. · Post by **Amber G.** » 14 Mar 2025 00:45

ISRO:SPADEX UNDOCKING SUCCESSFUL

March 13, 2025

The SPADEX satellites were successfully docked on January, 16 2025. ISRO has now accomplished the pivotal operation of undocking of SPADEX satellites in the very first attempt on 13th March, 2025 at ~09:20 Hrs. The undocking of the satellites took place in 460 km circular orbit with 45-degree inclination. The satellites are now orbiting independently and their health is normal. With this, ISRO has now successfully demonstrated all the capabilities required for rendezvous, docking and undocking operations in a circular orbit.

The in-orbit performance of the docked satellites was extensively analysed and an immediate opportunity was found to be feasible from March 10, 2025 till March 25, 2025. The entire operations were monitored through ground stations located at Bengaluru, Lucknow and Mauritius.

Having accomplished this major mile stone of undocking, further experiments with satellites are planned in the coming days.

Exhaustive ground simulations and analysis were the cornerstone of achieving the undocking in the first attempt itself. Various tests replicating on-orbit conditions were meticulously planned and carried out in preparation for the earliest opportunity for undocking operations.

ISRO has now successfully demonstrated space docking technology using two small satellites. It is a cost-effective experiment through which, India has achieved space rendezvous, docking and post docking control technologies.

bala · Post by **bala** » 14 Mar 2025 01:06

From an engineering perspective to rely entirely on physics is foolish. We know that sensors/advanced sensors, etc are prone to failure, wrong values and moreover the sensor requires proper calibration. When all moving you have to have a reference point to know wrt situation besides relative position/velocity and the controllers guys happen to be on earth systems monitoring the docking/undocking process. Redundant information and other systems are used for actual engineering solutions. One key algo used is voting between 3 sensor values to see where the actual truth (byzantine general's algorithm is used) lies and such systems are routine in space based rockets and systems.

sanjaykumar · Post by **sanjaykumar** » 14 Mar 2025 03:18

My question actually queried the influence of mass/inertia of the target. That is the error values in approaching a massive body wrt velocity of approach may be more forgiving. Orbital/positional perturbation would be greater for a less massive target if the kinetic energy of the chaser happens to be fractionally higher.

Further the target may be displaced by the chaser if it is less massive, making latching problematic.

Amber G. · Post by **Amber G.** » 14 Mar 2025 05:29

^^^ Read what I wrote, carefully, it explains it.

sanjaykumar · Post by **sanjaykumar** » 14 Mar 2025 07:45

My exposition was for Bala. Ideas of reference?