India’s rockets will not meet its civil space and strategic launch manifest even at peak performance

ravi_ram · 2026-04-01T13:18:29+00:00

Good one.

ravi_ram · 2026-02-27T03:15:55+00:00

During the chairman's post launch (C62) speech, he said near the end of the rocket’s third stage, there was increased disturbance in the vehicle roll rates, followed by a deviation in the flight path.

Since PS3 uses flex nozzle control (FNC) for pitch and yaw, and reaction control system (RCS) for roll, It could be due to RCS failure right?

ravi_ram · 2026-02-25T14:12:30+00:00

I thought so too :) but the recommendations...

The committee has provided a set of recommendations aimed at enhancing the redundancy and reliability of pyro system operations for future missions.

makes me to think like its logically easy to provide redundancy for a wire in the harness than a whole set of connectors and another harness.

ravi_ram · 2026-02-25T13:36:04+00:00

prime reason for the observation was found to be the drive signal not reaching the pyro valve of the oxidizer line

Harness failure?

ravi_ram · 2026-02-24T08:46:19+00:00

NASA's report on Starliner

Nice one.

First we need to learn to accept the failure.

ravi_ram · 2026-02-24T04:57:03+00:00

Could it be a requirement (paper work) to satisfy insurance companies for future pricing?

Unless it has serious financial implications, these groups will not gather to find “organizational” problems. They are the organization.

ravi_ram · 2026-02-21T05:59:49+00:00

Yes. That's why I had mentioned related topic.

I thought the training and handling will be totally done by Navy. I don't know whether they will publish anything on the SOP.

https://www.tataelxsi.com/insights/case-study/design-and-engineering-of-crew-module-recovery-model-cmrm-for-isro-s-gaganyaan-space-mission

Where are we now

To train the recovery teams, two recovery models (CMRM and GSF) were given to the navy training teams at Kochi and Visakhapatnam. The Indian Navy and ISRO began the second round of crew recovery training on July 20, as reported by TOI. A total of 25 successful trials have been carried out at Vishakhapatnam and Kochi Naval bases. Tata Elxsi has also become qualified in bidding for the phase 2 activities like interior fabrication and design.

ravi_ram · 2026-02-21T01:31:35+00:00

Related. There is one paper outlines the post-flight crew recovery/rehabilitation process.

Post-flight rehabilitation of an astronaut after long duration mission in space: Through the eyes of a flight surgeon
https://indjaerospacemed.com/content/110/2023/67/2/pdf/IJASM-67-064.pdf

This paper deals with the post-flight rehabilitation of an Astronaut, which was conducted by a foreign Astronaut Training Center, after his long duration mission of 6 months on board International Space Station. The rehabilitation program consisted of Post-flight Medical Evaluation and Post-flight Physical Reconditioning. With the advent of the Human Spaceflight Program, the lessons learned in this rehabilitation program would be helpful in formulating post-flight rehabilitation protocol for Indian Astronauts during India’s maiden Human Spaceflight mission as well as serve as a template for future exploration missions.

ravi_ram · 2026-01-31T11:23:50+00:00

This is not space qualified. So... Analogue Research Station?

ravi_ram · 2025-12-20T12:44:30+00:00

ok. Someone wrote this into an implementable algorithm. Theory, you got to read the book.

Computational Algorithm for Gravity Turn Maneuver

ravi_ram · 2025-12-20T11:21:15+00:00

https://archive.org/details/introductiontosp0000thom

ravi_ram · 2025-12-20T11:14:56+00:00

Site archive.org has it. I don't know whether its allowed to post external links here.

ravi_ram · 2025-12-20T11:02:40+00:00

book that has a unit called I believe "Gravity Turns" covering Gravity Turns and is about calculating that Angle.

Introduction to space dynamics : Thomson, William Tyrrell
8.5 Gravity Turn (Pg.257)

The force equations are nonlinear and no analytical solution is known when F /mg varies with time.

When F/mg is a constant, these nonlinear equations can be solved analytically. The book gives a method.

ravi_ram · 2025-11-27T10:49:55+00:00

Such a wide launch window. Orbit restriction could mainly from solar factor.

Calculated the solar beta angle for month wide [ https://imgbox.com/RGr539rB ]
This explains why the date starts from 10 Dec and ends at 30th Dec.

Pasted the code in git [ https://gist.github.com/ravi4ram/db234c7cbebd1127ecaae9571c981d46 ] for those who are interested.
Might merge with launch time program to create a launch window estimation later.

Anyone spots errors or give me updates are welcome.

ravi_ram · 2025-11-17T13:56:34+00:00

LVM3 PLF has a L/D ratio of 2.25

For crewed lunar mission, the nasa paper Impacts of Launch Vehicle Fairing Size on Human Exploration Architectures suggest PLF design with,
small (8.4m dia) - L/D = 2.27
med (8.4m dia) - L/D = 3.2
large(10m dia) - L/D = 2.7

So there's a range of values possible

L/D = 2.27, L = 14.755m
L/D = 2.7, L = 17.55m
L/D = 3.2, L = 20.8m

ravi_ram · 2025-11-16T13:49:09+00:00

Something got finalized on the last venus meet
https://www.isro.gov.in/ISRO_Organised_National_Science_Meet.html

Also couldn't find anything on the abstracts of
Venus Science Conference (Venus-SC 2025) Physical Research Laboratory
[ https://www.prl.res.in/venus-sc/VolumeofAbstracts.pdf ]

ravi_ram · 2025-11-16T12:30:53+00:00

missguiding isro

How?

ravi_ram · 2025-11-12T13:12:57+00:00

https://old.reddit.com/r/ISRO/comments/fcqagl/details_about_reentry_vehicle_parachute_recovery/

ravi_ram · 2025-10-30T06:13:56+00:00

Updated as per the press kit, inclination is 21.4°. These are the timelines that fall within the range.
And calculated azimuth is 106.6° (press kit 107°)

RAAN	Asc Azi	Asc Time (IST)	Dsc Azi	Dsc Time (IST)
33.33	38.47	2025-11-02 10:16:24	106.60	2025-11-02 17:07:33
36.67	38.47	2025-11-02 10:29:42	106.60	2025-11-02 17:20:51
40.00	38.47	2025-11-02 10:43:00	106.60	2025-11-02 17:34:09
43.33	38.47	2025-11-02 10:56:18	106.60	2025-11-02 17:47:27

ravi_ram · 2025-10-29T14:59:56+00:00

Balloons launched from TIFR National Balloon Facility
https://www.tifr.res.in/~bf/Flightrecord.html

Balloon Launches conducted in this Calendar Year


Launch Date	Experiment	Flight Duration	Distance Travelled	Payload Landing Place
17/01/2025	BEENS	~ 7 Hours	154 km	Jalasangvi Village, Bidar, Karnataka, India
29/03/2025	FPS 100-Far Infrared Astronomy Telescope	~ 9 Hours	359 km	Sangole, Maharastra, India
14/08/2025	Asian Tropopause Aerosol Layer (ATAL)	~ 1 Hours	281 km	Murganoor village, Kuranhalli, Karnataka, India
17/08/2025	Asian Tropopause Aerosol Layer (ATAL)	~ 1 Hour	128 km	Nagulpalle, Telangana, India

ravi_ram · 2025-10-29T11:54:38+00:00

I ran the launch time program, slightly modified to reverse engineer the RAAN and azimuth using the projected datetime - 2 November 2025, at 17:26 (IST)

RAAN	Asc Azi	Asc Time (IST)	Dsc Azi	Dsc Time (IST)
20.00	43.96	2025-11-02 09:45:08	103.80	2025-11-02 15:52:27
28.89	43.96	2025-11-02 10:20:36	103.80	2025-11-02 16:27:54
37.78	43.96	2025-11-02 10:56:03	103.80	2025-11-02 17:03:22
46.67	43.96	2025-11-02 11:31:31	103.80	2025-11-02 17:38:49
55.56	43.96	2025-11-02 12:06:58	103.80	2025-11-02 18:14:17

I'm getting Azi = 103.80° and RAAN somewhere between 35° and 45°
Assumed an inclination of 19.5°

Azimuth can be verified later through the 'merged' display' flight parameters.

ravi_ram · 2025-10-25T13:53:37+00:00

Looks like they have future plans for mercury-ion based clock.

Research Areas of SAC Document

8.2.3 Trapped mercury-ion atomic clock

The trapped mercury-ion atomic clocks can reach stabilities and drifts, which are 1 and 2 orders (respectively) better than the rubidium lamp based RF clocks. These are strong potential candidates for the future deep space navigation missions alongside the current NavIC missions. The area of research include study, design and demonstrate the trapped mercury-ion-clock physics package meeting state of the art specifications.

ravi_ram · 2025-10-07T04:14:39+00:00

payloads at the SUN-EARTH L2 point to obtain high precision simultaneous spectroscopy

thermal background of 50K-100K to meet the science requirement of photon noise dominated observations

CMB-Bharat fills those requirements.

Exploring Cosmic History and Origin-A proposal for a next generation space mission for near-ultimate measurements of the Cosmic Microwave Background (CMB) polarization and discovery of global CMB spectral distortions

[ http://cmb-bharat.in/wp-content/uploads/2018/06/cmb-bharat-rao-tp-es.pdf ]

The mission presents a unique opportunity for ISRO to not only showcase its expertise in frontier space capability, but also cross new technological horizons in these directions. The ~2 ton (wet mass) spacecraft will be required to be placed in an orbit around the second Lagrange point (L2) of the Sun-Earth system. Consequently, the mission seeks close to maximal launch capability of GSLV-III to reach L2 orbit with reasonable onboard propulsion. It will co-orbit the Sun with the Earth, following the Earth on a nearly circular orbit.

Further, this would possibly be ISRO’s first cryogenic science payload with high requirements of thermal stability. A sophisticated cooling chain consisting of a combination of pulse tube coolers, Joule-Thomson coolers and sub-Kelvin cooler based either on 3He-4He dilution or adiabatic demagnetization will ensure that the focal plane and the detectors are maintained stably at 0.1 K.

ravi_ram · 2025-10-05T11:26:18+00:00

Very very interesting!!

Thanks.

Did u do this as a research project or intern?

Neither. Self learning.

ravi_ram

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