Science writer passionate about space exploration and the Moon. Words at The Planetary Society, The Wire Science and more. All articles at

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Follow developments in lunar exploration and science every week!

Hi everyone, I’m excited to share with you my latest space project! 🚀

Launching Moon Monday, the only newsletter in the world dedicated to covering lunar exploration and science developments every week!

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Moon Monday

Moon Monday is inspired by Orbital Index and The Downlink, two terrific space newsletters. I started it because I didn’t see anyone putting out a dedicated Moon newsletter with global coverage of developments in the space (pun totally intended).

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Learn more about collecting samples from other worlds and what’s next.

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An artist’s impression of the OSIRIS-REx spacecraft descending on asteroid Bennu. Credit: NASA

NASA just had a truck-sized robot, OSIRIS-REx, autonomously sample an asteroidmillions of kilometers away under (literally) rocky circumstances. Is science cool or what! Here’s a bunch of curated links for you to learn more about collecting samples from other worlds.

Why do we even bother sending complex and expensive sample return missions to worlds when spacecraft can just study them using versatile instruments onboard? Jason Davis from The Planetary Society has written a great overview page to answer that.

Why sample return

As for why we study small worlds like asteroids at all, here’s my primer with an overview of learnings from all missions to asteroids, comets and small worlds till date and what’s next. …

The black hole’s spin rate also turned out to be close to the theoretical maximum. Beyond that limit, black holes lose their event horizons.

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An artist’s illustration of a black surrounded by an accretion disk, as in the discovery of 4U 1630–47. Credit: NASA/JPL-Caltech
This article was originally published for The Wire. This is a mirror of the same.

ISRO’s first space telescope, AstroSat, and NASA’s Chandra X-ray observatory, also space-based, have together found a black hole that spins at a rate close to the theoretical maximum. Designated 4U 1630–47, the black hole weighs about 10 solar masses — a stellar mass black hole, not one of the gigantic ones found at the centers of most galaxies.

Stellar mass black holes are formed when a giant star collapses under its own gravity, The entire mass is crushed to a single point called the singularity. As it happens, a singularity cannot be seen directly because not even light, the fastest thing in the universe, can escape from a region around it, known as a black hole. …

How the Apollo missions transformed our understanding of the Moon’s origin

This article was originally published on The Planetary Society as a contribution for the Apollo 11 landing anniversary. This is a mirror of the same.

Where did the Moon come from? The origin of our cosmic neighbor is a fundamental question in planetary science. From Galileo’s first telescopic observations of the Moon to humans walking on its surface, our understanding of its origins has come a long way. Yet it is far from complete.

There are multiple hypotheses that have attempted to explain how the Moon came to be. …

Designing lunar orbits to efficiently land on the Moon

The TeamIndus spacecraft will soft-land on the Moon in 2020. The landing site for this first mission (Z-01) is near Annegrit crater, in the vast lava plains of Mare Imbrium.

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TeamIndus Z-01 spacecraft landing site: Near Annegrit crater, in the vast lava plains of Mare Imbrium. Source: LROC Quickmap

The location of the landing site poses multiple constraints on how the spacecraft orbits are designed, including the launch/landing time and everything in between. Let’s take a look at the constraints imposed by the landing site first, followed by the nature of the lunar orbits.

Part A: Constraints on lunar orbits

1. Sun illumination

A lunar day is equivalent to 14 Earth days (between 70 N/S) and we want to maximize the surface operations time post-landing. Landing at local dawn would thus be ideal. However, at least two of the three solar panels need to be illuminated by sunlight for surface operations to begin. …

With great science comes great engineering

Gravity assists are a powerful technique which can help both extend the duration of a space mission and reduce its overall cost. This article will have a look at some of the most insane gravity assist techniques used in past space missions. If you’re not familiar with the concept of gravity assists, here is a simple explainer.

Studying the Sun from above

1990 saw the launch of joint NASA-ESA mission called Ulysses to study the poles of the Sun for the first time. …

A look at the propulsion system of the TeamIndus lunar lander

The TeamIndus spacecraft will soft-land on the Moon in 2020. We have designed a robust and unique propulsion system capable of landing a craft on the Moon and operate in different modes meeting the needs of each phase of the mission. Let’s have a look at some of the factors that go into designing the propulsion system of the spacecraft.

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Choosing a propulsion system for the journey

As discussed in our previous article on the variables governing rocket science, the destination decides the delta-v required which in effect determines the type of propulsion system that can be chosen.

The delta-v required to go from Low Earth Orbit (LEO) (at an altitude of 250 km) to the lunar surface is ~5.9 km/s. However, since the launch vehicle can put the spacecraft on a trajectory that intersects with the Moon’s orbit, the journey starts from a distance farther than LEO. The delta-v requirement is thus reduced to ~3 km/s. …

How the giant leap for mankind is not the first step on the Moon but attaining Earth orbit

The Universe is governed by the laws of physics that cannot be changed by us. As such, there are hard limits to what we can do with rockets and how we build them. The working of rockets is governed by the Tsiolkovsky rocket equation, named after the rocket scientist Konstantin Tsiolkovsky. This article is supposed to act as a basic introduction to variables governing rocket science and their implications. As such, some generalizations will be made.

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SpaceX’s Falcon 9. Source: John Kraus Photos

Knowing the players

Before we get to the rocket equation, let’s have a look at the governing players. …

An experiment to enable living habitats on the Moon

Going onboard the TeamIndus spacecraft in 2019 is the Lab2Moon experiment LunaDome. It aims to recreate the Earth’s atmosphere in a small inflatable dome on the lunar surface. In the absence of air on the Moon, any long term human presence on the surface would require some sort of a habitable dome to be setup. An enabling technology for that is what the LunaDome aims to test. This soda can sized experiment is being made by three students from University of Bath, UK.

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Left to right: Sam, Elliot and Nick of LunaDome. Source:LunaDome

The experiment setup

The soda can sized experiment contains a bottle of compressed air connected to an electronic ON/OFF valve. When on the Moon, this compressed air is used to inflate a flexible dome to atmospheric pressure (~1 bar). The outside of the inflatable dome is made up of a multi-layer insulating material (a.k.a MLI), which we extensively use on our spacecraft too. MLI provides thermal protection to the dome, in addition to protection from micrometeorites and radiation. …

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