Suramya's Blog : Welcome to my crazy life…

January 23, 2024

New research shows that Neptune’s color is more of a greenish blue than the vivid blue we associate with it

Filed under: Astronomy / Space,My Thoughts — Suramya @ 5:15 PM

When we look at the photographs of the outer planets in our solar system, the planet Neptune stands out because of it’s striking blue color as shown in the photos taken by Voyager 2 back in 1989. (See below)

Photo of Neptune as taken by Voyager 2
Photo of Neptune as taken by Voyager 2

In a new study just published in the Monthly Notices of the Royal Astronomical Society, researchers found that the color balance in Voyager was a little skewed that led to the planet appearing more blue than it actually is. Basically due to the way the images from Voyager were contrast enhanced to accentuate fainter features and better illustrate the atmospheric features of the planet the image released was bluer than what the planet actually looked like. They used observations of the planet taken from 1950 to 2016 along with data from the Hubble Space Telescope and the Very Large Telescope to create a more accurate representation of the planet’s color which is closer Uranus’s color than the vivid blue we are used to seeing. (See below)

Panels a and b show early images of the visible appearance of Uranus and Neptune reconstructed from Voyager 2 ISS images in 1986 and 1989, respectively, showing Uranus to be pale blue-green, and Neptune dark blue (PIA18182 and PIA01492, credit: NASA/JPL-Caltech).
Panels c and d show more recent reconstructions of the true colours of these planets, showing them to be more similarly coloured (credit: NASA/JPL-Caltech/Björn Jónsson)

From the Paper:

We present a quantitative analysis of the seasonal record of Uranus’s disc-averaged colour and photometric magnitude in Strömgren b and y filters (centred at 467 and 551 nm, respectively), recorded at the Lowell Observatory from 1950 to 2016, and supplemented with HST/WFC3 observations from 2016 to 2022. We find that the seasonal variations of magnitude can be explained by the lower abundance of methane at polar latitudes combined with a time-dependent increase of the reflectivity of the aerosol particles in layer near the methane condensation level at 1 – 2 bar. This increase in reflectivity is consistent with the addition of conservatively scattering particles to this layer, for which the modelled background haze particles are strongly absorbing at both blue and red wavelengths. We suggest that this additional component may come from a higher proportion of methane ice particles. We suggest that the increase in reflectivity of Uranus in both filters between the equinoxes in 1966 and 2007, noted by previous authors, might be related to Uranus’s distance from the Sun and the production rate of dark photochemical haze products. Finally, we find that although the visible colour of Uranus is less blue than Neptune, due to the increased aerosol thickness on Uranus, and this difference is greatest at Uranus’s solstices, it is much less significant than is commonly believed due to a long-standing misperception of Neptune’s ‘true’ colour. We describe how filter-imaging observations, such as those from Voyager-2/ISS and HST/WFC3, should be processed to yield accurate true colour representations.

It is facinating how much more there is to learn in the cosmos even about our own stellar neighbors never mind the whole wide universe out there with its infinite mysteries and grandeur.

Source: Neptune is more of a greenish blue than is commonly depicted

– Suramya

December 6, 2023

ISRO Returns the Propulsion Module from Chandrayaan-3 mission to Earth orbit

Filed under: Astronomy / Space,My Thoughts — Suramya @ 10:55 AM

ISRO (Indian Space Research Organization) made a surprising announcement earlier this week about a new accomplishment by the Chandrayaan-3 Propulsion Module after the team managed to successfully return the propulsion module used by the spacecraft into a high orbit around Earth. This is a big deal and something only achieved by 3 countries before India (US, China and USSR).

This was not one of the planned missions for the module and was attempted when the team found that they still have over 100 kg of fuel in the PM available on the module for maneuvers. Its a credit to the precise planning and execution of the entire mission that the module still had extra fuel available for followup missions. So the orbit was modified over the course of a few months to move to an Earth orbit at about 1.54 lakhs kms (154,000 kms) allowing the module to complete an orbit every 13 days.

In order to continue SHAPE payload for Earth observation, it was decided to re-orbit the PM to a suitable Earth orbit.This mission plan was worked out considering the collision avoidance such as preventing the PM from crashing on to the Moon’s surface or entering into the Earth’s GEO belt at 36000 km and orbits below that. Considering the estimated fuel availability and the safety to GEO spacecrafts, the optimal Earth return trajectory was designed for October 2023 month.

First maneuver was performed on October 9, 2023 to raise apolune altitude to 5112 km from 150 km thus, increasing the period of orbit from 2.1 hrs to 7.2 hrs. Later, considering the estimate of available propellant, the second maneuver plan was revised to target an Earth orbit of 1.8 lakhs x 3.8 lakhs km. The Trans-Earthinjection (TEI)maneuver was performed on October 13, 2023. In thepost-TEI maneuver realized orbit, propulsion module made four Moon fly-bys before departing Moon SOI on November 10. Currently, propulsion module is orbiting Earth and crossedits first perigee on November 22nd with an altitude of 1.54 lakhs km. The orbit period is nearly 13 days with 27 deg inclination. The perigee and apogee altitude vary during its trajectory and the predicted minimum perigee altitude is 1.15 lakhs km. Hence as per current orbit prediction, there is no threats of close approach with any operational Earth orbiting satellites.

This test was a good way to prepare for future lunar missions where one of the mission parameters would be to bring back samples from the Moon to earth for study. The module’s expected lifetime was about 3 months and its already past that and still going on. Looking forward to finding out what other additional experiments we can run on it.

– Suramya

Source: India reveals that it has returned lunar spacecraft to Earth orbit

September 3, 2023

Aditya-L1 Mission is a successful launch

Filed under: Astronomy / Space,My Thoughts — Suramya @ 11:59 PM

The Aditya-L1 was launched successfully on Saturday and inserted into orbit as per the plan. This is India’s first mission to study the Sun, and is a natural next step (if you think about it) after a successful moon mission. The planned duration of the mission is 5.2 years.

Was talking to Jani yesterday and she asked what the L1 point was, and I had just assumed everyone knew what it was because I knew it. But then I realized that this is not common knowledge though more people are learning about it thanks to the coverage of the Aditya-L1 mission. Basically, the definition is as below:

Lagrange points are positions in space where objects sent there tend to stay put. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.

To put in a simpler way, this is a place between the Earth and Sun where the gravitational pull of the sun is cancelled by the gravitational pull of the Earth. There are multiple such points around the solar system. The L1 point is approximately 1.5 million km away from Earth (about 1% of the Earth-Sun distance)

Visual depiction of Lagrange Points
Visual depiction of Lagrange Points, curtsy of ISRO

The Indian space program is shining because of their two back to back missions where very few other countries have succeeded in the past, so obviously we have folks in the western media claiming that the Chandrayaan-3 mission was faked and lots of editorials where ‘experts’ talk about how India should focus on feeding its poor instead of the space program. These folks need to take a closer look at their own countries and the state of their poor & the state of their infra instead of lecturing India.

That being said, not everyone responded in a racist way, plenty of publications covered the mission and were complementary about how much India has achieved in the past few years. Ars Technica did a pretty indepth and balanced walk through of India’s space programs and how it ranks against the other global powers.

Also, to those who from the UK who are asking for their ‘aid money’ back (which was actually investment money being shown as aid money), you are more than welcome to ask for it back after you pay back all the money the British Raj looted from India, and have returned all the stolen treasures being showcased in the British museum. Actually, why don’t we do this: deduct the money you claim to have sent for aid and then return the rest and then we can talk. Till then we will keep ignoring you.

Jai Hind.

– Suramya

August 30, 2023

ISRO Aditya mission to the Sun is scheduled to Launch this Friday

Filed under: Astronomy / Space,My Thoughts — Suramya @ 12:39 AM

After successfully landing Chandrayaan-3 on the Moon, ISRO is not resting on its laurels. Their next mission (Aditya L1) is on schedule to launch on 1st Sept 2023 and this will be the first space based Indian mission to study the Sun. The craft, named after the Hindi word for the sun, will be launched from the spaceport in Sriharikota using India’s heavy-duty launch vehicle, the PSLV, which will travel about 1.5 million km (932,000 miles). The craft will be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, which gives it the advantage of continuously viewing the Sun without any eclipses or blockages. So far only 3 other countries/entities have successfully launched Solar probes: NASA (US), DFVLR (Germany), ESA (European Union). ISRO will be the 4th to do so.

Citizens are invited to witness the launch from the Launch View Gallery at Sriharikota by registering at their website. This is an awesome improvement in the process to visit the launch site. A few years ago when Surabhi and Vinit wanted to take the kids to watch the launch, they ended up having to reach out to an ISRO scientist and use a personal connection to get access. Now we can do it via a website. The advantage is that this is building up the hype for ISRO and getting more people interested in space.

The Science Objectives of the mission are as follows:

  • Study of Solar upper atmospheric (chromosphere and corona) dynamics.
  • Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares
  • Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the Sun.
  • Physics of solar corona and its heating mechanism.
  • Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density.
  • Development, dynamics and origin of CMEs.
  • Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
  • Magnetic field topology and magnetic field measurements in the solar corona .
  • Drivers for space weather (origin, composition and dynamics of solar wind .

Full details of the mission are available at the ISRO: ADITYA-L1 Website. Will write more after the launch.

– Suramya

August 23, 2023

ISRO’s Chandrayaan-3 Successfully lands on the Moon!!!

Filed under: Astronomy / Space — Suramya @ 6:33 PM

We did it!!!! India made it all the way to the moon on its home grown Spacecraft and successfully achieved a soft landing on the Moon! This is a proud day for India and Indian’s world wide. We achieved something that only a few other countries have achieved so far and now India’s ambition to put up our own orbital station doesn’t seem that far fetched anymore…

The Indian Space Research Organisation’s (ISRO’s) Chandrayaan-3, which takes its name from the Sanskrit word for “mooncraft”, took off onboard a Launch Vehicle Mark-III rocket from the southern state of Andhra Pradesh on 14 July and has spent six weeks covering about 380,000 kilometres en route to the moon. It was a remarkably smooth landing process to the point that it wasn’t immediately apparent that it had touched down…

The news conference is ongoing: ISRO Live Telecast

Will post a more detailed post with my thoughts later on but for now: We are on the MOON!!!

Jai Hind!

– Suramya

August 16, 2023

ISRO’s Chandrayaan-3 successfully completed its Fifth and final orbit reduction maneuver

Filed under: Astronomy / Space — Suramya @ 6:57 PM

Chandrayaan-3 is the third spacecraft sent to the moon by the Indian Space Research Organisation (ISRO) and the second one to attempt a soft landing on the far side of the moon. The Chandrayaan-3 consists of a lander module (LM), a propulsion module (PM) and a rover. Earlier today the craft successfully completed its 5th firing that has put the Chandrayaan-3 into an orbit of 153 km x 163 km around the moon as intended bringing it another step closer to its moon landing attempt which is expected to happen at 5.47 p.m on August 23rd 2023.

Chandrayaan-3’s Moon-bound maneuvers

After the completion of the five orbit reduction maneuvers ISRO said that it is gearing up for the next most crucial operations which is scheduled on August 17.

“It’s time for preparations as the Propulsion Module and the Lander Module gear up for their separate journeys. Separation of the Lander Module from the Propulsion Module is planned for August 17, 2023,” the space agency said

The propulsion module will separate from the lander while in orbit.

Following that, a series of complex braking maneuvers will be executed to facilitate a soft landing in the South Polar region of the Moon on August 23. The lander is expected to touch down on the moon surface at 5.47 p.m.

I am eagerly waiting for this attempt with fingers crossed. Although I think that the mission would have been even better if it was landing on the moon on 15th Aug (India’s Independence Day). More details on the mission and the craft is available over at the IRSO’s Chandrayaan-3 site.

– Suramya

June 26, 2023

BepiColombo takes fabulous photos during its flyby of Mercury 236 km above the planet’s surface

Filed under: Astronomy / Space,Science Related — Suramya @ 9:10 PM

Mercury, the closest planet to the Sun has been a challenge to explore and examine because of its closeness to the Sun. This is the second craft to orbit the planet after NASA’s MESSENGER probe, which orbited the planet from 2011 to 2015. BepiColombo is a joint venture between European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). The latest flyby was 3rd of the 6 planned flybys of the planet. The team has released a short video composed of 217 images taken during the flyby.

Photo taken by BepiColombo during its 3rd flyby of Venus

Pic Credit: European Space Agency/ Japan Aerospace Exploration Agency

The closest approach took place at 19:34 UTC (21:34 CEST) on 19 June 2023, about 236 km above the planet’s surface, on the night side of the planet.

Approaching on the nightside of the planet, a few features started to appear out of the shadows about 12 minutes following the closest approach, when BepiColombo was already about 1800 km from the surface. The planet’s surface became more optimally illuminated for imaging from about 20 minutes after close approach and onwards, corresponding to a distance of about 3500 km and beyond. In these closer images, a bounty of geological features are visible, including a newly named crater.

While not apparent in these flyby images, the nature of the dark material associated with Manley Crater and elsewhere will be explored further by BepiColombo from orbit. It will seek to measure just how much carbon it contains and what minerals are associated with it, in order to learn more about Mercury’s geological history.

The next Mercury flyby will happen in September 2024 but the next next long solar electric propulsion ‘thruster arc’ is planned to start early August until mid-September which will help BepiColombo in Braking against the gravitational pull of the Sun. During the lifetime of the project, the module will have completed 15,000 hours of solar electric propulsion operations which will allow it to perform 9 planetary flybys in total — one at Earth, two at Venus, and six at Mercury.

The more we explore our celestial neighbors, the more information we will have before we start working towards space colonization and building settlements. Although, I don’t think that Mercury will be a contender in the near future for a settlement, unless we find a rare mineral or something over there.

Source: Slashdot: New Video Shows a Flyby of the Planet Mercury – with AI-Assisted Music

– Suramya

June 21, 2023

India launches 2nd Gen satellite for the NavIC Navigation System

Filed under: Astronomy / Space,Science Related — Suramya @ 1:07 PM

GPS has become so ingrained in our life that it is hard to imagine a world before GPS. I remember having to use paper maps and asking folks for directions during our road trips and now I don’t need to worry about anything, just follow the map and you can find anything. Even during my mountaineering course back in 1999 we learnt how to navigate and how to figure out where you were using landmarks. Towards the end of the course the instructor showed us a GPS receiver (which was ridiculously expensive at that time) as something that was available but couldn’t be relied upon because it was too expensive and might not be available. Now we have watches with built in GPS so the technology has come a long way since then.

However, since GPS is a US controlled system they have the ability to disable it for any area if they want and that creates a major risk. In the Kargil war, US disabled GPS for the entire region making it difficult for them to figure out where they were and perform the attacks more safely. This highlighted the risk and strategic importance of the functionality for India and they started working on an indigenous replacement.

Other countries have also realized the same and implemented their own version of GPS, these include Russian GLONASS, European Galileo, Japanese QZSS (Covers Japan and surrounding areas), and Chinese BeiDou. India’s replacement is called NavIC, which means sailor in Hindi. It is an regional satellite navigation system that provides accurate real-time positioning and timing services and currently covers India and a region extending 1,500 km (930 mi) around it. The system went live in 2018 via seven satellites. These satellites only operated in the L-5 band and S-band frequencies which are not supported in civilian equipment so wasn’t available for civilian use. After the Galileo constellation was granted approval to use the L1 band India also requested access and was granted permission by the International Telecommunication Union to use the L1 and L2 frequency bands.

On 29th May 2023, ISRO successfully placed the NVS-01 navigation satellite into orbit. This second generation satellite supports the L1 band which means the device manufacturers such as GPS receivers and smartphones just need a software update to support navigation using NavIC instead of needed extra hardware which was the case with the previous generation of the system. ISRO is planning on launching a satellite every six months over the next few years to put 11 new satellites in orbit so that the system has redundancy.

NVS-01 is the first of the second-generation satellites envisaged for the Navigation with Indian Constellation (NavIC) services. NVS series of satellites will sustain and augment the NavIC with enhanced features. This series incorporates L1 band signals additionally to widen the services. For the first time, an indigenous atomic clock will be flown in NVS-01.

For now the system is concentrating on the Indian subcontinent and the area around it but as more satellites are launched they are planning on covering the entire globe and provide users with an alternative to GPS.

Source: EurAsian Times: Backstabbed During Pakistan War, India ‘Ditches’ US GPS For ‘Much More Accurate’ NavIC Navigation System

– Suramya

June 7, 2023

Proof of Concept setup demoing technology to beam solar power down to Earth successfully demoed

Filed under: Astronomy / Space,Emerging Tech,Science Related — Suramya @ 4:20 PM

The ability to beam power from space to earth has long been a staple of Science Fiction books and movies. On the surface it makes sense, space is huge and if we can setup solar panels in space to collect energy and get it to earth in a usable format then it is a win-win. No more having to deal with fossil fuels/nuclear reactors etc. Folks have been working on this for over 5 decades now and progress was slow as most people focused their efforts on other options such as improving land based solar panels, geothermal etc etc.

Now researchers from California Institute of Technology (Caltech) have successfully demonstrated MAPLE (Microwave Array for Power-transfer Low-orbit Experiment) which is an array of 32 flat antennas packed onto a surface slightly larger than a dinner plate. During the experiment the energy was transmitted to earth and successfully received by a receiver on the roof of the Gordon and Betty Moore Laboratory of Engineering and they were able to successfully target receivers about a foot away alternatively and transmit ~200 milliwatts of power to the receiver that powered a LED light.

Using constructive and destructive interference between individual transmitters, a bank of power transmitters is able to shift the focus and direction of the energy it beams out—without any moving parts. The transmitter array uses precise timing-control elements to dynamically focus the power selectively on the desired location using the coherent addition of electromagnetic waves. This enables the majority of the energy to be transmitted to the desired location and nowhere else.

MAPLE features two separate receiver arrays located about a foot away from the transmitter to receive the energy, convert it to direct current (DC) electricity, and use it to light up a pair of LEDs to demonstrate the full sequence of wireless energy transmission at a distance in space. MAPLE tested this in space by lighting up each LED individually and shifting back and forth between them. The experiment is not sealed, so it is subject to the harsh environment of space, including the wide temperature swings and solar radiation that will be faced one day by large-scale SSPP units.
MAPLE also includes a small window through which the array can beam the energy. This transmitted energy was detected by a receiver on the roof of the Gordon and Betty Moore Laboratory of Engineering on Caltech’s campus in Pasadena. The received signal appeared at the expected time and frequency, and had the right frequency shift as predicted based on its travel from orbit.

This is a big step forward, but I still have major doubts about the feasibility of the project, at least in the current form. Here we are using microwaves to transmit the energy from space to earth, at the level of power we need to transmit the microwave beam will cook anything that crosses it, for example if a plane flies through the beam you can say goodbye to the passengers. Even if we decide that we will establish a no-fly zone around the area what is to stop birds etc from flying into the beam and getting fried. Another problem is that microwave beams generate heat as a side-effect and that can cause a major heating of the atmosphere and change the air-currents which can cause a massive environmental impact.

We also need to consider that in order to collect the solar energy at a scale where it would be useful and make financial sense we would need to setup massive solar-panels in space. This will case a huge problem for astronomers. We already have issues being caused by the Starlink Satellites, this will be the same but at a much larger scale.

However, that being said I see the potential and if we can ever get quantum entanglement or spooky action at a distance as Einstein called it working reliably and consistently then that could potentially be used to transmit the power to earth without frying everyone in the path.

Lets see what else the researchers come up with…

Source: In a First, Caltech’s Space Solar Power Demonstrator Wirelessly Transmits Power in Space Satellite beams solar power down to Earth, in first-of-a-kind demonstration

– Suramya

April 3, 2023

ISRO successfully completes the landing experiment of the Reusable Launch Vehicle-Technology Demonstration

Filed under: Astronomy / Space — Suramya @ 2:07 PM

ISRO (Indian Space Research Organisation) has been quite active in the past few years and has been making significant progress in its mandate to power the next generation of Indian Space capabilities. On Sunday ISRO successfully completed the landing experiment of the Reusable Launch Vehicle-Technology Demonstration (RLV-TD) which is a key part of ISRO’s goal to create a reusable low cost two-stage orbital launch vehicle.

“The RLV took off at 7:10 a.m. by a Chinook helicopter of the IAF as an underslung load and flew at a height of 4.5 km. Once the predetermined pillbox parameters were attained, based on the RLV’s Mission Management and Computer command, the RLV has released mid-air, at a down range of 4.6 km,” ISRO said.

The autonomous landing was carried out under the exact conditions of a Space Re-entry vehicle’s landing —high speed, unmanned, precise landing from the same return path— as if the vehicle arrives from space. Landing parameters such as Ground relative velocity, the sink rate of Landing Gears, and precise body rates, as might be experienced by an orbital re-entry space vehicle in its return path, were achieved. The RLV LEX demanded several state-of-the-art technologies including accurate Navigation hardware and software, Pseudolite system, Ka-band Radar Altimeter, NavIC receiver, indigenous Landing Gear, Aerofoil honey-comb fins and brake parachute system.

In a first in the world, a winged body has been carried to an altitude of 4.5 km by a helicopter and released for carrying out an autonomous landing on a runway. RLV is essentially a space plane with a low lift to drag ratio requiring an approach at high glide angles that necessitated a landing at high velocities of 350 kmph. LEX utilized several indigenous systems. Localized Navigation systems based on pseudolite systems, instrumentation, and sensor systems, etc. were developed by ISRO. Digital Elevation Model (DEM) of the landing site with a Ka-band Radar Altimeter provided accurate altitude information. Extensive wind tunnel tests and CFD simulations enabled aerodynamic characterization of RLV prior to the flight. Adaptation of contemporary technologies developed for RLV LEX turns other operational launch vehicles of ISRO more cost-effective.

Keep in mind that this was a Technology Demonstration test, or what we call Proof of Concept (PoC) in Software Development. Now that we have successfully shown that the technology works as expected, they can start scaling it up, add more functionality/redundancy etc to productionalize it and make it ready for the live test a couple of years down the line.

Looking forward to more such positive news from ISRO going forward.

Source: ISRO successfully conducts the Reusable Launch Vehicle Autonomous Landing Mission

– Suramya

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