Monday, July 31, 2023
Sunday, July 30, 2023
Saturday, July 29, 2023
Friday, July 28, 2023
We Are Not Alone In The Universe!
The Cuomo family is political royalty in the state of New York. The family immigrated from Italy to New York. Mario Cuomo became a distinguished governor of the state of New York. He was a man of awesome intellect and humanity. His son Andrew Cuomo followed in his father's footsteps. He too became governor of New York. His younger brother followed in the family's footsteps. He graduated from law school and was admitted to the New York Bar. Then Chris Cuomo decided to take a different course in life. He went into television journalism. He has had a distinguished career lasting over two decades (so far!). He now hosts The Chris Cuomo Show on the News Nation Network.
Yesterday on his afternoon broadcast, he was talking about the congressional
hearings on UAPs (UFOs) held on Wednesday, July 26. His comment was "Mark
this date as a great moment in human history."
He was focused on the testimony of David Grusch. For those
curious, here are some fascinating details:
https://en.wikipedia.org/wiki/
I
carefully watched his testimony Wednesday during the congressional hearing. He
was under oath. If he lied, he could find himself serving years in prison
for lying to Congress. I watched David's body language. I carefully watched his
eyes. I am quite convinced that he told the truth about the US government
having crashed extraterrestrial spacecrafts and the remains of dead alien
crew members.
The US Senate was so impressed with the testimony that they put language into
the current Defense Authorization Act establishing a central office to collect
data on UAPs. David may have already gone into a SKIF and showed members of
Congress highly sensitive documents, etc.
Finally, we have verification of what I have known for many decades. We
are not alone. There are other intelligent civilizations out there in the
heavens. Some of these civilizations could be one million years in advance of
our technology. They could have hurt us badly or destroyed us long ago. They
haven't.
Wednesday, July 26, 2023
The Congressional Hearing On UAPs (UFOs) Dazzled Me ..It Exceeded All Expectations!!!
https://www.youtube.com/watch?v=TqVXSoIeCQM
Tuesday, July 25, 2023
Human Access To Venue
 Images of the surface of Venus taken from the Venera 13 mission. (credit: NASA) |
Access to Venus
by John Strickland
Monday, July 24, 2023
Venus is the opposite of Mars in regard to terraforming. In fact, you would practically have to terraform Venus before you could land humans on it. It has a planetary surface almost as large as the Earth’s. However, removing the 90 atmospheres of carbon dioxide, even at the very high volatile transfer rates proposed for terraforming Mars, would probably take many millennia and an enormous amount of energy. A low energy, faster alternative would be to build a 15,000-kilometer-wide sunshade for Venus which would cause the carbon dioxide atmosphere to collapse into a liquid carbon dioxide ocean or frozen dry ice layer, at Antarctic-like temperatures. After the collapse, enough sunlight would be allowed to keep the land surface from reaching low cryogenic temperatures and pressures, and provide good visibility. The remaining nitrogen and traces of argon would not be a problem. This would open most of the surface to scientific observation and potential mining operations for high-value materials. Insulated surface or below-ground settlements on such a partly sun-shaded Venus would also not be out of the question as there would be no GCR flux and almost a 1-G gravity environment.
Purpose
Note: This article is not about terraforming Venus, although the method described could eventually be used, as a first step, to start doing just that, given access to a staggeringly large amount of energy. Instead, here is a method to provide humans with permanent access to the surface of Venus, without requiring massive amounts of energy and thousands of years of time. Such a method can and would only be implemented when humanity has a space-based industrial civilization with the sufficient industrial strength, finances, technical knowhow, and energy output to support such an effort, and when we want access to the surface of Venus strongly enough to mount the effort. If such an effort were made, the level of effort would greatly decrease once the sunshade was built and the methods to keep it in position were verified. At that point, there would be a long wait, lasting over a century, for the cooldown to proceed. I should note that human efforts in the past which required a continuing large effort for over a century have occurred, including the building of huge gothic cathedrals.
| Lots of articles have been written about terraforming Venus, but most simply do not recognize the sheer scale of such a task. |
The basics of the method are reasonably well known to many space advocates—using a huge sunshade to block essentially all sunlight from reaching the surface of Venus—but differs in that we would be attempting only to provide relatively easy access to the surface, not supporting a full terraforming attempt following the sunshade step. The reason for the difference is that performing just the first step in what could be the start of a terraforming effort requires vastly less energy and effort.
Scale
Lots of articles have been written about terraforming Venus, but most simply do not recognize the sheer scale of such a task. In order to actually terraform Venus, the effort (step 2) would need to “deal with” the roughly 465 quadrillion metric tons of carbon dioxide, (that’s 465,000,000,000,000,000 tons) assuming that the 3.5 atmospheres (3.5 bar) of nitrogen have a mass of only about 15 quadrillion tons. This is also about 200 times more mass than the amount of gas needed to give Mars a full oxygen-nitrogen atmosphere: only about 2.8 quadrillion tons. The Venusian carbon dioxide is about one-third the mass of all of Earth’s ocean water. The carbon dioxide also contains several hundred septillion joules of heat. Any way you deal with it, such as physical removal or chemical interaction, though not impossible, would be incredibly energy intensive and probably take an extremely very long time to effect. By not attempting the terraforming step (at least for now), humanity could still get easy and rapid access to much of the surface of Venus.
There are clearly a lot of questions that need to be answered before such an effort could be attempted, primarily how to create a giant planetary sunshade and how to stably maintain its position at the Venus-Sun L1 point (VS-L1) for at least several centuries. While a similar sunshade proposed to reduce global warming for the Earth would be much smaller, I do not support using a sunshade for that purpose since it would still be a long time before we can build one. Instead, I support much nearer-term geoengineering methods whose effects end automatically when the method is suspended or stopped.
Why
Why should we want or need access to the surface of Venus? It is the closest planet we know to the Earth in terms of its size and probably its internal geology, so it would be the best planetary analog for the Earth. With the current hellish conditions on the surface (about 480 degrees Celsius), any scientific investigations of its internal geology will be massively hampered by the temperature, pressure, and acidic chemical environment. It is probable that there are active volcanoes on Venus, and geologists would love to know if there are any active plate tectonics or if the volcanoes are instead the result of multiple hot spots or mantle plumes. Radar maps from orbit do not tell us everything we need to know about geological activity on Venus. We know nothing about any seismic activity on Venus and, after probably a billion years of very high temperatures, the surface minerals must be very different from those on the Earth. There are thus multiple possible and practical reasons we would want such access, even including commercial mining and potential sub-surface human settlements. In addition, at least in the space community, there seems to be a strong desire to “do something” with and at Venus, when most of the realistic options seem currently impossible.
Sunshade
We can assume that the sunshade would be made of solar sail-like material, as there would be a large amount of light pressure trying to move it from the desired position, and it would face the same type of problems that very large solar sails would face. The typical design has a polymer layer that supports a thinner layer of metal film that provides the reflectance and, in this case, primarily blocks the sunlight. I have seen numbers indicating that solar sails may eventually be able to be fabricated in space at thicknesses of between 0.2 and 5 microns, where a micron is one-thousandth of a millimeter. This thickness of just the metal layer is in the range of the size of bacteria and will require very advanced equipment to fabricate it in place. It could weigh as little as 0.1 gram per square meter, up to about 1.0 grams per square meter with the plastic support. All of these thin layers must be fully ultraviolet-resistant.
The material should probably be reinforced with heavier fibers at intervals to prevent tearing from meteoroid impacts, and possibly with heavier stiffening, open truss booms to keep the whole shade relatively flat and oriented correctly. Other options have the shade rotating to keep it relatively flat. The metal film layer needs to be thick enough to keep significant amounts of sunlight from penetrating through the ultra-thin foil. We do not yet have such technology but test solar sails with two layers have been successfully deployed in orbit.
Venus is about 108,000,000 kilometers from the Sun and the VS-L1 point is about 1.6 million kilometers sunward of Venus. The center of mass of the shade cannot stay exactly at the L1 point, since the orbit of Venus is not perfectly circular, so the shade might need to be oval in shape. However, Venus’s orbit is more circular than any other planet, so perturbations to the position of the sunshade might be affected more by the gravity of other planets. The need for the shade’s center of mass to “orbit” the L1 point makes its actual required size somewhat hard to estimate. Venus’s gravity pulls on any object at VS-L1 enough to balance the lesser solar orbital velocity, but this does not take into account the light pressure from the Sun, which is about 1.2 kilograms of pressure per square kilometer. Thus the actual position must balance gravity against light pressure. Estimating areas for the sunshade would give us both the total mass and the total light pressure. Note that the sunshade can have large, tilted segments which can slow or speed it up in its solar orbit, greatly reducing any need for station keeping propellants.
Venus has a diameter of about 12,100 kilometers. A full sunshade must be wider than the planet it is shading since the sun is about 1.4 million kilometers. A guestimate of a reasonable sunshade diameter would be about 15,000 kilometers wide, with close to 176,725,000 square kilometers of sunshade material needed. This would provide about 1,500 kilometers of shade margin for each side of the planet.
How heavy would such a sunshade be? Such a shade would be manufactured in place by in-space industry, probably using materials obtained from off-Earth sources. The point is to keep the energy requirements low. There are a range of thickness and mass estimates, ranging from about 0.1 gram per square meter up to about 10 grams. The thinner the material is, the harder it is to fabricate and deploy. Using the middle (logarithmic) value of 1 gram, the total sunshade mass would be 176,725,000 metric tons, while the lowest value would make it 17,672,500 tons, about the mass of 20 very large supertankers. Remember that this mass does not need to be launched from the ground since the sunshade would be made from in-space materials. Such a shade might have about 261,500 metric tons of light pressure against it, a tiny component compared to the gravitational forces.
Cooldown process
Let us assume that such a full sunshade can be built at a cost reasonable for the time it is built, and that it can also be relatively easily maintained at the Venus-Sun L1 point (VS-L1). Since Rome cannot be built in a day, the construction would probably start in the center and extend outwards in balanced segments or in a spiral. Thus there would be no sudden cutoff of light to Venus, but we could assume that it might be completed in about five years based on the total surface area of fabric able to be created and attached per month. As the amount of light reaching the cloud tops of Venus and the top air layers diminishes, the air there would cool off, eventually creating convection cells at random locations due to density differences. It is unclear how wide each convection cell would be, and whether the cells would extend all the way to the surface.
The physics of fluids, especially carbon dioxide, which has some remarkable properties, are crucial in this scenario. Since all of the carbon dioxide below a certain point in the atmosphere is a supercritical fluid, acting in some ways like a liquid, it may transfer heat faster than plain gases. In combination with the high wind speeds aloft and the thermally opaque sulfuric acid clouds, this keeps the temperature very similar all over the planet in spite of its slow rotation.
| If we remove part of the sunshade and keep the surface pressure just above five bars and at about –56 to –60 degrees Celsius, boat and ship traffic would be possible on the carbon dioxide ocean. |
Once the sunlight is fully cut off, the top air layers would start to strongly cool, as they radiate heat into space. The cloud tops radiate heat more strongly than the air itself, since it has no surface to radiate from. As the convection cells grow larger and stronger, they would start to interfere with the circum-Venus wind pattern, which moves the upper atmosphere around the planet in about four days at about 100 meters per second, a continuous blast of wind comparable to our strongest hurricane. The energy to sustain this massive movement ultimately comes from the solar heating, so at some point it would start to subside. Just like stirring a pot of boiling soup, the wind could temporarily disrupt the convection cells, more strongly towards the equator.
Eventually the convection cells would win out and surface heat would start to be rapidly moved to the top of the atmosphere. At altitudes above 120 kilometers, the thermosphere is the coldest place on Venus, cooling during the night due to radiation of infrared to as low as −173 degrees Celsius. This shows how strong the cooling effect is when there is no sunlight hitting the cloud tops. The convection cells would greatly enhance this effect if they extend down to the surface.
Assuming that the planetary wind pattern would be dispersed within about a year, the convection cells would then be the main factor in heat movement. Calculations in fluid dynamics or those who have planetary circulation models might be able to show how quickly the heat content of the atmosphere would be reduced. As temperature and pressure is reduced, the level where the carbon dioxide is supercritical would slowly fall towards the surface. At the point where about 17% of the carbon dioxide has been liquefied, the top of the supercritical layer would reach the surface and the remaining 83% would all be a regular gas.
Once the air temperature had been significantly reduced, the surface rock temperature would also start to slowly cool off. Heat moves through a solid more slowly since conduction is the only internal factor. There would be some radiation of heat from rock into the air right at the surface and some from conduction due to local circulation of the convection cells.
At some point, the air temperature at the surface would pass through the temperature range where humans could exist but the massive, crushing pressure would still be there. During this range of temperatures, the carbon dioxide would begin turning into actual liquid, since the high pressure would remain until a large portion of the carbon dioxide had condensed. As the temperature near the surface continued to fall, the liquid layer would start to accumulate, eventually reducing the pressure. The temperature would continue to drop below the freezing point of water, but the liquid carbon dioxide would probably boil continuously from the hot rock layers below it.
Cooldown time logic
This scenario is based on the simple fact that the same amount of heat as the daily heat input of the sunlight, in the form of Infrared radiation into the Venus atmosphere, leaves Venus every day, with the input and output of heat energy always in balance. If the solar input is removed, the entire surface of Venus will be left radiating the heat away from the top layer of the atmosphere.
I used a relatively simple calculation method to estimate the time it would take to collapse the atmosphere into a liquid state. I calculated the total global estimated heat flow, using both global heat flow, and that of single air columns: the roughly 1,000 tons of all the air directly above 1 square meter and the roughly 1 billion tons over each 1 square kilometer. The cross section area of sunlight in space that hits Venus is equivalent in area to the cross section area of Venus itself, or 115,066,000 square kilometers. Sunlight intensity in space is 2,603 watts/square meter near Venus. However, the clouds reflect away three quarters of the sun’s heat before it can be absorbed. So the total heat actually absorbed by the Venus atmosphere is one fourth of that, or only 651 watts/square meter from the cross-section “beam”. Even so, the total amount of energy absorbed is 76 quadrillion watts of heat per second.
Since the sunlit side of Venus is a hemisphere, twice the area of the cross section, the instantaneous absorption is spread (very unevenly) over an area twice the cross section size, and averages about 325 watts/square meter. Much of the heat is then distributed relatively evenly around the planet, to both hemispheres, so the resulting global infrared heat emission from Venus, which is continuous, is emitted over an area four times larger than the arrival cross section, averaging only 163 watts/square meter. If it did not radiate the heat away, Venus would continuously heat up until it glowed like a star. So the planet Venus simultaneously must radiate away heat at the same rate it arrives, or of about 76 quadrillion watts per second. If the sunlight is cut off, the heat will continue radiating away at the same high rate.
The part of the solar heat (sunlight) that hits Venus arrives in a “beam” with the cross section of Venus, while it actually hits the sunward hemisphere which has twice the area of the cross section, and departs from the whole globe with an area 4 times that of the cross section “beam”.
With a total mass of about 465–480 quadrillion metric tons, the atmospheric “surface” would have an area similar to the entire surface of Venus, (totaling 460,230,000 square kilometers), to cool the planet, not just the night side. Notice that this allocates roughly 1 square kilometer of surface (and slightly more for the atmosphere) to cool each billion tons of air, or 1 square meter for each 1,000 tons.
In summary, incoming sunlight in space is 2,603 watts per square meter. Three quarters of this, or 1,982 watts per square, is reflected away as light from the cloud tops, leaving 651 watts per square to be absorbed by the atmosphere. This adds up to the total of 76 quadrillion watts/second of heat. Divided by the area of Venus as a globe, each square meter must on average radiate away heat at a rate of about 163 watts/square meter. So each square meter of the atmosphere radiates away about one sixteenth of the energy per square meter that arrives from the sun in space. Since there are 31,557,600 seconds in a year, Venus should radiate away about 2.4 septillion watts in a year.
Cooldown time calculations
Several values are needed to determine the cooldown time:
- The specific heat for carbon dioxide gas. (This is the amount of heat needed to change the material’s temperature by 1 degree Celsius).
- The amount of material to be heated or cooled.
- The number of degrees of heating or cooling needed (and thus the amount of joules needed to be removed).
- The cooldown rates per second and per year.
Values 1, 2, and 4 have already been determined, while value 3 is determined by the intent of the operation (the desired target temperature). There are values for the specific heat of carbon dioxide on a number of websites, but they are inconsistent in how they are presented, and the values given vary a lot. I am using the value given by the Engineering Edge site, since they do specify a gas and give values for a range of temperatures. So this calculation would look like:
(1) Specific heat for carbon dioxide: 1,170 joules per kilogram (1,170,000 joules per ton) of carbon dioxide gas at about 800 kelvins. This number changes with the temperature of the carbon dioxide gas, which means the cooldown time result is approximate.
(2) Mass of all carbon dioxide: 480,148,000,000,000,000 tons or 480.15 quadrillion tons (using the larger number).
(4) Cooling rate: same as the solar input or 76 quadrillion watts per second or 2.4 septillion watts in a year.
The time question now shifts to how much heat is actually stored in all that hot carbon dioxide or rather how much heat we need to get rid of per ton of carbon dioxide. The two different values considered are:
(3a) The initial cooling target or milestone is –56 degrees Celsius, near the triple point for carbon dioxide. This initial temperature level might be used for a short time to allow runoff of condensing carbon dioxide liquid from areas above the new “ocean” level. The total temperature drop is determined by the Celsius temperature drop: adding the current temperature at the surface (where the gas is densest): 462 degrees Celsius plus the desired temperature (below zero): –56 degrees Celsius. So the temperature reduction (in absolute degrees) is: 462 °C + 56 °C = 518 °C.
1,170,000 J/ton times 480,148,000,000,000,000 tons times 518 °C = 290,998,496,880,000,000,000,000,000 total joules “in air” or 290 septillion, where the target temperature is –56 °C. Dividing the joules of heat to be removed by the amount of cooling per year gives the approximate cooling time:
290,998,496,880,000,000,000,000,000 joules/2,400,000.000,000,000,000,000,000 (2.4 septillion) watts in a year. Result: 121.28 years - time for global cooldown to reach a state at or just below the carbon dioxide triple point (assuming a steady cooling rate of air only). This may or may not allow the carbon dioxide to remain a liquid if the pressure drops below 5 bars.
(3b) The final target temperature should probably be about –80 degrees Celsius, which is where the carbon dioxide would stay frozen, except for over volcanic areas. This is a few degrees below the sublimation temperature, where with just 3.5 bars of nitrogen pressure left after condensation, (with essentially no carbon dioxide gas), the dry ice would be able to sublimate back into gas. Here the temperature reduction (again in absolute degrees) is: 462 °C + 80 °C = 542 °C:
1,170,000 J/ton times 480,148,000,000,000,000 tons times 542 °C = 304,481,052,720,000,000,000,000,000 total joules “in air” or 304.8 septillion where the target temp is –80 °C. Next, divide joules by heat removal per year:
304,481,052,720,000,000,000,000,000 (304 septillion) joules / 2,400,000,000,000,000,000,000,000 (2.4 septillion) watts in a year. Result: 126.9 years - time for global cooldown to reach a state at or just below the carbon dioxide sublimation point (assuming a steady cooling rate of air only).
The cooling times will be longer than the calculated values due to Newton’s law of cooling. However, since calculations using that law (which shows how cooling rates slow as temperature differences lessen), only apply accurately to relatively small masses and small temperature differences, it cannot be used to accurately calculate cooldown times for very large, very hot objects, like a planet’s entire atmosphere! So it is reasonable to expect that the time to effective full condensation would be more than 127 years and probably less than 200 years.
The convection cells should allow the cooldown of the atmosphere to occur at a rate not limited by conduction of heat. Since the top of the atmosphere will radiate heat as quickly as it is delivered by the convection cells, the cells themselves might be a somewhat limiting factor, since the supercritical fluid layer is probably more viscous than a true gas. Once the near surface layer of such gas disappears due to the lowering pressure, convection may speed up.
| For humans, the conditions would be similar to the Antarctic interior. They would need to wear insulated clothing similar to that worn outdoors at the South Pole Station, but would wear just a helmet supplied with an oxygen-helium mix. |
In addition to the joules of heat energy in the carbon dioxide gas, we would normally have to account for the heat released once the carbon dioxide gets cold enough to condense, but since the lowest layer of carbon dioxide is initially a supercritical fluid, there is probably no condensation point and thus no sudden release of extra heat at that point. Initially the weight of the carbon dioxide gas column would provide enough pressure to maintain supercriticality at and near the surface, but that should vanish after about one-fifth of the carbon dioxide mass condenses. After that point, some heat of condensation would be released.
As the last amounts of carbon dioxide condense, the remaining nitrogen would provide only about 3.5 atmospheres of pressure. This is below the 5 atmospheres needed to keep carbon dioxide as a liquid at room temperature, but the actual temperature at that point would be closer to the initially desired –56 degrees Celsius. It is not clear exactly what would happen during this phase, but conversion from what would then be just a gas to a liquid would probably occur gradually as the temperature drops closer to the desired temperature. Presumably the temperature would then stabilize at the triple point until all of the gas had condensed.
Hot rock heat conduction and carbon dioxide rivers
Heat from the hot surface rock would continue to flow by conduction into the layer of liquid carbon dioxide, and carbon dioxide that condensed at higher elevations might be flowing down into the new carbon dioxide global ocean in temporary streams and rivers. It may be desirable to maintain the temperature high enough to allow time for the carbon dioxide condensing over land areas to finish running off into the ocean, but pressure must be about five bars for the carbon dioxide to stay as a liquid. Some remaining carbon dioxide gas might keep it above that level for a while.
Any hot areas around active volcanic features would create constant boiling of the carbon dioxide ocean in those areas. Gas from these features would later probably fall as carbon dioxide rain nearby. This would provide a source of heat that would keep some small portion of the carbon dioxide as a gas. Like lava pillows that extrude into cold water, any fresh lava coming into contact with the –56 degree Celsius ocean would quickly freeze. The top several meters of rock would also cool to an intermediate temperature, since conduction of heat through rock is not fast.
Finally, if we let the planet cool down about another 25 degrees, the liquid carbon dioxide would begin freezing into dry ice. There is only a narrow zone of temperatures and pressures where carbon dioxide can be a liquid. This process would probably begin at the bottom, since dry ice would sink in the liquid. It is not clear how long it would take for the entire ocean to freeze all the way to the surface, but eventually this would provide access to the entire planet’s surface via drilling through up to about one kilometer of dry ice. This would allow access to much more of the planet even though three-fourths of it would then be covered by a layer of dry ice. This layer could probably be driven on. If we remove part of the sunshade and keep the surface pressure just above five bars and at about –56 to –60 degrees Celsius, boat and ship traffic would be possible on the carbon dioxide ocean.
The full sunshade status would nominally be maintained until the temperature near the surface reached about –80 degrees Celsius. At that point, most carbon dioxide boiling would have stopped except directly over volcanic vents, and enough sunlight would then be admitted to stabilize the temperature at about –80 degrees Celsius and to have enough sunlight to see with. The amount of sunlight let through would probably be comparable to about 10% of full sun at Venus, about half the sunlight received at Mars and similar to what is received by main belt asteroids. There would remain about 3.5 atmospheres of nitrogen and traces of argon, neither of which would liquefy at these temperatures.
Land areas above the new “sea level”, which would be about one kilometer above the average lowland level, would be at a lower pressure, and the temperature might also be lower, so some of the condensed carbon dioxide may freeze out on the land surface. Hopefully, most of the carbon dioxide as a liquid will have already drained off the higher areas before that happens. If some of these areas are covered with frozen white dry ice, the amount of sunlight let in can be increased, or if the dark rock absorbs too much sunlight, the level could be decreased.
Surface access for humans and robots
Once this stage is reached, humans and robots could land on at least 20-25% of the surface, and establish monitoring stations and even science bases. For humans, the conditions would be similar to the Antarctic interior. They would need to wear insulated clothing similar to that worn outdoors at the South Pole Station, but would wear just a helmet supplied with an oxygen-helium mix, and thus would not need to wear a pressure suit. Bases would probably be built underground, using standard Earth pressure, to take advantage of the planet’s massive internal heat.
While the surface materials seem to be primarily derived from volcanism, there are two or more continent-like areas. Of the largest two, one (Ishtar Terra) is closer to the North Pole and the other (Aphrodite Terra) is equatorial. Maxwell Montes, a volcanic massif about 11 kilometers high, is on Ishtar Terra. These do not seem to have been accreted by plate tectonics. There are also a number of large pancake “domes” that are really rather flat but very circular, as well as three other named highland regions. There are lots of landforms that seem to have no counterpart on Earth. Indications are that there are different rock types in some of the different areas, such as those that are highly radar-reflective, which could be extensive deposits of iron pyrite. There are also multiple indications that there are lot of active volcanoes on Venus, which do not show up as well on the topographic radar maps. One of the top geological mysteries is whether there are any areas of granitic (continent-like) rock, or even sedimentary rock from a possible ancient wet Venus.
Significantly lower air pressures than 3.5 bars could be found by focusing human landing sites on areas at higher elevations, but none of the locations would tax robotic landers. “Sea level” landings would be easier and takeoffs would be harder due to the thicker nitrogen atmosphere. Some of the surface mineralogy would be very different from the Earth, and there would be no limestone or marble, as all of the carbonates that might have existed would have been converted into carbon dioxide. Access to the surface would allow geological investigations to see if Venus had a moderate climate in the past, as well as direct investigations of its interior structure with seismograph networks.
| Once the stability of the sunshade and its temperature level had been proved, it would be possible to create human settlements on most of the parts of Venus above the “sea” level, whether liquid or solid. Such settlements would have the advantage of near 1G gravity and no galactic radiation. |
With solar input to the surface limited to an amount comparable to what asteroids get, the amount of wind and kind of weather patterns generated in the remaining nitrogen atmosphere could be difficult to predict. Due to the 25-fold reduction in atmospheric mass, the amount of heat transferred in the wind from the day to the night side, and the wind pattern that would carry it, would probably be very different. Heat might be carried by winds from the subsolar point to the center of the night hemisphere, with wind returning closer to the surface. This wind pattern would probably shift in time to match the slow Venus rotation rate. The amount of solar heat admitted to the day side might have to be adjusted in real time once we see what kind of temperature differences and wind patterns emerge. With 3.5 bars of air pressure, a gentle breeze could be the same as a strong wind.
Once the stability of the sunshade and its temperature level had been proved, it would be possible to create human settlements on most of the parts of Venus above the “sea” level, whether liquid or solid. Such settlements would have the advantage of near 1G gravity and no galactic radiation. Settlements built in tunnels would be naturally warmer than the surface, while surface installations would need very efficient insulation from the cold. Habitation tunnels could be drilled at the most convenient temperature level. Most of these would probably exist to support scientific and commercial outposts. Mining could provide sources of materials for orbital installations. Boats could be used to move along coastlines at the higher of the two target temperatures, but swimming in the near-cryogenic carbon dioxide ocean would not be a good idea without a special insulated dry suit and sealed helmet.
Tourism could be expected to develop at some point once transport costs are reduced to affordable levels. Surface temperatures would be higher than on most asteroids, but with zero galactic radiation. Outdoor hiking trips on Venusian mountain terrain could be very interesting, as the sky would probably have few clouds and the sunlight admitted would illuminate the surface well. The temperature difference caused by the slow rotation rate could create high winds along the terminator line dividing the “day” side from the night side.
During the cooldown period, there would probably be an orbital monitoring station to keep track of this gigantic physics experiment, with a human crew and satellites in various orbits to observe both the changing dynamics of the atmosphere and the surface. It would be difficult to predict what will happen to the cloud layer for improved observation from orbit. If our technology has advanced far enough to have surface landers or active rovers that could survive the pre-condensation surface conditions for long periods, they could be positioned to capture the effects of the period of carbon dioxide condensation and runoff, which could be quite spectacular.
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The New Era Of Heavy Launch Vehicles
 SpaceX’s next Super Heavy booster on the pad last week for tests ahead of a launch later this year. Vehicles like Starship/Super Heavy have the potential to reshape the industry based on their price and performance. (credit: SpaceX) |
The new era of heavy launch
by Gary Oleson
Monday, July 24, 2023
Three new commercial heavy launch vehicles with test launches scheduled during the next year may usher in a new age of space, depending on which succeed. The new heavy launchers are the Vulcan by United Launch Alliance (ULA), New Glenn by Blue Origin, and Starship-Super Heavy by SpaceX. Should these launchers prove themselves, many of the historic barriers to orbital entry will go away, leaving room to think about space industry in bold new ways. (Starship-Super Heavy will be called Starship in this paper because the Starship second stage is always launched on the Super Heavy first stage.)
SpaceX conducted the first test launch of Starship-Super Heavy on April 20, 2023, and ULA is conducting tests in advance of the first launch of Vulcan in late 2023. All three new heavy launchers have launch contracts.
| If even one fully reusable launcher succeeds, it will provide opportunities for dramatic cost savings not only in launch, but also in spacecraft design, manufacture, and deployment. |
This new generation of heavy commercial launch vehicles could enable two distinct revolutions in space economics: increased mass and volume capability, and full reuse. Success of Starship or New Glenn would produce a revolutionary increase in payload mass and volume available per launch. Vulcan is an evolutionary improvement that can launch nearly as much mass as the Delta IV Heavy with 36% more volume, which may not be enough to produce revolutionary change. Starship, by comparison, will launch more than five times as much mass as the Delta IV Heavy with more than four times the volume.
Efficient reuse of both the first and second stages would, in addition, create a breakthrough in launch costs. Reuse of both stages is designed into Starship. New Glenn has a reusable first stage with an expendable second stage and Blue Origin plans to develop a reusable second stage. ULA may develop a first-stage engine module that could be detached, recovered, and reused, but that would not put the Vulcan on a path to full reuse.
If even one fully reusable launcher succeeds, it will provide opportunities for dramatic cost savings not only in launch, but also in spacecraft design, manufacture, and deployment. These cost savings would be great enough to enable new industries in space that launch costs otherwise prohibit.
Sometimes quantity has a quality all its own
These launchers offer dramatic increases in payload volume and mass to orbit at costs per launch no greater than today’s vehicles. They would thereby create new opportunities for the space industry even if none of them reduced launch costs.
High launch costs for larger rockets have created historical incentives for designers to launch spacecraft on the smallest possible launchers. Even as launch costs have declined, limitations on payload mass and volume have sustained the incentives. The universal practice has been to invest in designs, materials, processes, and technologies that are more expensive, but enable decreases in spacecraft mass and volume. Increases in launch performance allow spacecraft designers to forgo most, if not all, of these expensive investments. Many programs may be able to save money by purchasing commercial systems and instruments that would otherwise have required alteration or substitution due to mass limits.
Savings such as these may comprise a significant portion of total program costs. Forgoing mass reduction investments and using off-the-shelf systems could bring additional benefits, such as shortening project schedules for additional time-related savings and putting satellites into service earlier. The new vehicles would also enable projects requiring too much mass or volume for current vehicles.
Payload Mass. Figure 1 shows the maximum mass to standard LEO for the three new heavy launchers, as well as the current Atlas V, Delta IV, and Falcon launchers for comparison. For purposes of this paper, a heavy launcher is defined as a launcher with maximum payload mass to standard LEO greater than the Falcon 9 delivers, currently 22,800 kilograms. Maximum performance for the Vulcan is achieved by adding six solid rocket boosters (SRBs) to the first stage.
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The progression from Vulcan to Starship is clear. The high performance of Falcon Heavy is misleading because its relatively small payload fairing limits the payloads it can carry. The SpaceX estimate of the Starship mass performance to LEO was recently updated from 100+ to 150 metric tons (MT), revealing a wider gap with the others. SpaceX also estimates that Starship could launch 250 MT for an unspecified price if it expended both stages.
Launch performance to higher orbits is becoming more complex. The three new heavy launchers have different technical efficiencies in performing direct payload insertion into geosynchronous transfer orbit (GTO). Vulcan is the most efficient, placing 14.5 MT into GTO, 53% of its LEO performance. New Glenn places 13 MT into GTO, 29% of its LEO performance. Starship is least technically efficient at 14 percent of its LEO performance, but that places a best-in-class 21 MT into GTO. Furthermore, Starship could transport its entire LEO cargo to higher orbits by refueling in LEO. In addition, some spacecraft now provide their own propulsion beyond LEO and new orbital transfer vehicles are being developed to expand the range of choices.
Payload Volume. Figure 2 shows the maximum payload fairing volumes for the launchers.
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As mass limits have relaxed over the last decade and small satellites have grown as a payload class, volume has emerged as a more important limit on spacecraft. Fitting spacecraft systems into a small volume is an increasingly frequent engineering challenge. Comparing Figure 1 with Figure 2 shows that launch companies have now designed payload fairing volumes for their new launchers that align much better with their mass performance. While the Delta IV Heavy has 8 cubic meters of volume per metric ton of mass to LEO and Falcon Heavy has only 2 cubic meters. Vulcan has 12 cubic meters, New Glenn has 10 cubic meters, and Starship has 7 cubic meters per ton.
| In this new era, the paradigm of gaining cost savings and additional performance from relaxed mass and volume limits is a matter of choice and opportunity, seeking to make best use of both higher-tech and lower-tech options. |
Payload fairing envelope diameter is an important limit for some payloads. While the diameter of all the current vehicles is about 4.6 meters, Vulcan’s diameter is 5 meters, New Glenn’s is 7 meters, and Starship’s is 8 meters. The larger diameters will open useful design options for some applications, such as space telescopes. For example, Starship could launch a space telescope with a monolithic mirror having two to almost three times the diameter of the Hubble Space Telescope’s 2.4-meter mirror.
Benefits of relaxed mass and volume limits. Designing large margins and devaluing optimization are two closely linked systems engineering approaches to reducing mission cost. Large margins reduce cost and the potential for cost and schedule overruns in many ways, including simplifying manufacturing processes, using more commercial and standardized components, and using heavier and cheaper materials.
Many of these cost-saving design changes could also produce spacecraft that are more robust and reliable, in turn reducing project risk. In addition to cost savings, budgets may also allow for relatively low-cost performance improvements, such as adding more fuel, larger solar arrays and batteries, or heavier radiation shielding.
These improvements could enable a cascade of additional savings. Increased fuel loads could increase lifecycle benefits by extending spacecraft lifetimes. Adding more power production could eliminate the need for some expensive investments to reduce power consumption. Broad relaxation of limits on power, in addition to mass, could further ease the challenge of inserting new technologies that have not yet been optimized to reduce their mass and power requirements.
The cost-saving benefits could cascade from mass to power and thermal control and then to mission systems. The cumulative effect is likely to improve the benefits and decrease the costs of using modularized or standardized systems. The design space for spacecraft will expand in many dimensions.
In this new era, the paradigm of gaining cost savings and additional performance from relaxed mass and volume limits is a matter of choice and opportunity, seeking to make best use of both higher-tech and lower-tech options. Expanded systems engineering frameworks and more flexible cost models could provide crucial assistance to these analyses.
Price versus cost
It’s useful to understand the dynamics of prices in the launch business before we discuss cost assessment. The price of a launch is the cost to the customer, but it is not necessarily an accurate reflection of the cost to the launch company. None of the companies have officially released launch prices for their new heavy launchers, but some of their senior executives have made comments. All three companies have stated that their prices will be competitive, which depends heavily on the behavior of their competitors and the market. Any estimated price must, therefore, be regarded as a starting point or perhaps a central tendency. When the distance between the starting points is great enough and backed by logic, however, we can begin to make comparisons between launchers.
To begin, there is always uncertainty in the original estimate. In addition, there may be discounts. SpaceX offered discounts for Falcon 9 launches prior to their first successful launch, offered discounts again to encourage the first customers for reused Falcon 9 first stages, and still offers modest discounts for multi-launch contracts. There are frequent surcharges as well for any special handling, paperwork, or engineering work required by a launch customer. Government launches frequently have surcharges in the $10–20 million range. Beyond all that, market conditions may allow higher prices or force lower ones.
ULA CEO Tory Bruno told a news conference at the 2015 Space Symposium in Colorado that Vulcan would cost about $100 million for a medium-lift booster and about $200 million for heavy-lift variants, assuming use of a reusable first-stage engine module that has not yet been developed. That was eight years ago and argues for a higher current estimate since costs for aerospace programs rarely decrease over time.
In August 2020, ULA won a $224.3 million Phase 2 National Security Space Launch (NSSL) Launch Service Procurement (LSP) contract for two Vulcan launches with four SRBs each, two SRBs fewer than the maximum of six. Allowing for special-service surcharges, this would argue for a much lower base-price estimate than Bruno’s 2015 estimate, except that ULA also won a $967 million Phase 1 NSSL Launch Service Agreements (LSA) contract in August 2018 to facilitate the development and certification of Vulcan as an NSSL vehicle. This Phase 1 LSA investment might have enabled ULA to discount the price of the Phase 2 LSP contract. While it is unlikely that Bruno’s eight-year-old estimate of $200 million is accurate, there is not yet sufficient evidence to estimate an alternative.
As a side note, an NSSL Phase 2 LSP also awarded a second pair of launches to the SpaceX Falcon 9 for $159.7 million. This contract is consistent with the Falcon 9 list price of $67 million per launch, leaving about $26 million for surcharges. SpaceX was not given an NSSL Phase 1 LSA contract but received other contracts to support Falcon 9 development a decade earlier.
| The new launchers display an unprecedented characteristic: the least capable is the most expensive and the most capable is least expensive. |
New Glenn presents a different challenge. There are no data available on its internal costs or pricing strategy, on any need to cover sunk costs, or on any possible discounts. This is a testament to the security of Blue Origin’s operations. In this data vacuum, we are left to form estimates by analogy. Arguing that the New Glenn configuration of a reusable first stage with an expendable second stage is similar to the Falcon 9 configuration suggests that a similar price would be appropriate. In the absence of any other information, there’s no reason not to use the Falcon 9 price of $67 million as New Glenn’s starting point.
On February 10, 2022, SpaceX CEO Elon Musk announced he was highly confident that Starship launch prices “would be less than $10 million all in, fast forward two or three years from now," including all SpaceX expenses. He also said a Starship flight could cost a few million dollars or “maybe even as low as a million dollars per flight” in the future. SpaceX has a history of hitting its launch prices, so these targets should be taken seriously as long-term possibilities if the flight rate gets high enough.
For the immediate term, SpaceX recently released some price information. Gary Henry, senior advisor for national security space solutions at SpaceX, told the Space Mobility conference on February 21, 2023, that SpaceX is forecasting a cost of $200 per kilogram. If that forecast is against the previous 100 MT payload estimate, it implies a price of $20 million per flight. If it is against the new 150 MT estimate, it implies $30 million per flight. Caution suggests that $30 million is a good starting point, but that number is still in advance of surcharges.
Figure 3 shows published or estimated costs per launch for the launchers. The New Glenn estimate is striped because it is based totally on analogy rather than data.
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We should have low confidence in the precision of any price estimates for the new launchers, but moderate confidence in their central tendencies. Vulcan is fully expendable, New Glenn is first-stage reusable, and Starship is fully reusable. These design differences drive cost differences that outweigh errors in price estimates that might otherwise be considered large.
SpaceX may initially have little incentive to price Starship launches much below New Glenn and Vulcan prices. In competitions for launch contracts, the cost per launch is often more important than the cost per kilogram because few payloads use the full capacity of the launcher. This will be especially true in the early years of Starship launches and continue until larger and heavier payloads are developed. If New Glenn is priced at $67 million per launch with an expendable second stage, for example, SpaceX may price Starship launches at just a little less until New Glenn has a reusable second stage and becomes fully price competitive.
The cost breakthrough
The new launchers display an unprecedented characteristic: the least capable is the most expensive and the most capable is least expensive. This is the effect of reusability. Figure 4 shows that full reusability in combination with capability increase moves us into a new and unprecedented economic domain. New Glenn is about twice as cost effective as the Falcon 9 due to its larger size, but Starship is about seven times as cost effective as New Glenn due to its still greater capability and lower cost.
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Reducing launch costs this much will remove launch as a prohibitive budgetary constraint for many projects. That will reinforce the cost of space systems as the dominant budgetary constraint. The next era of space engineering will explore how much the cost of space systems can be reduced with relaxed mass and volume constraints. New limiting factors are likely to be found in the base cost of systems and robotics needed for assembly and maintenance.
The Starship cost per kilogram is so low that it is likely to enable large-scale expansion of industries in space. For perspective, compare the cost of Starship launches to shipping with FedEx. If most of Starship’s huge capacity was used, costs to orbit that start around $200 per kilogram might trend toward $100 per kilogram and below. A recent price for shipping a 10-kilogram package from Washington, DC, to Sydney, Australia, was $69 per kilogram. The price for a 100-kilogram package was $122 per kilogram. It’s hard to imagine the impact of shipping to LEO for FedEx prices.
The full impact of such huge payloads being launched for such low costs will evolve from the interplay of innovation and market forces and are thus impossible to fully anticipate in advance. Industrialization of space is at a point similar to computing just before the introduction of the personal computer or telecommunications just before the introduction of the Internet.
Some broad developments can be anticipated even at this early stage. The following list captures some of them:
- Deploy large constellations of small satellites with a single launch
- Deploy space stations with much larger crews and laboratory space
- Support vastly expanded personal and corporate space travel
- Deploy larger space instruments and systems
- Support large-scale satellite refueling and orbital transportation services
- Support large-scale infrastructure assembly and maintenance
- Deploy space-based solar power stations
- Support space-based manufacturing and resource extraction
- Enable suborbital point-to-point intercontinental travel
NASA has contracted with SpaceX to provide lunar landers for Artemis using Starship’s ability to be refueled in orbit. This ability could enable Starship to deliver up to 150 MT to cislunar space and beyond. The mixed cargo/passenger design of the Starship lunar lander suggests possibilities for LEO transportation. Launch costs for a mixed cargo/passenger version of Starship might be fully paid by the cargo with passenger seats priced at the marginal cost of passenger service alone, reducing cost per seat by orders of magnitude from current prices.
The sheer size of the new launch vehicles may create demand for new services. It may be impractical for Starship and other large LEO transports to dock with many of the space stations and industrial facilities that they serve, creating demand for ship’s tenders to transfer cargo and passengers from the transports to nearby destinations. Other ships might take cargo from the LEO transports to farther destinations.
A few entrepreneurial space companies are already building space systems designed for the Starship era, including at least one commercial space station supplier that is using lower-cost terrestrial manufacturing techniques to produce large, heavy structures that only Starship can lift.
| The new heavy launchers will relax mass, volume, and launch cost as constraints for many projects. Everyone who is concerned with future space projects should begin asking what will be possible. |
Space-based solar power production could be enabled by Starship if the cost of in-space systems can be contained. One reference design for a two-gigawatt power station would weigh 7,500 MT. Earth to LEO transportation for such a station would take 50 Starship launches or more than 130 Falcon Heavy launches with reuse. Using Starship would cost about $0.5 billion since a two-gigawatt station probably won’t be built until long after Starship launch costs reach $10 million per launch. Using Falcon Heavy at today’s prices would cost over $12 billion. None of the current launchers could support price-competitive space-based solar power. Fully reusable launchers could. Recognizing this, Japan’s planning for space-based solar power is predicated on Starship launches.
What could you do with 150 metric tons in LEO for $10 million?
The new heavy launchers will relax mass, volume, and launch cost as constraints for many projects. Everyone who is concerned with future space projects should begin asking what will be possible. Given the time it will take to develop projects large enough to take advantage of the new capabilities, there could be huge first mover advantages. If you don’t seize the opportunity, your competitors or adversaries might. Space launch at FedEx prices will change the world.
References
Blue Origin. “New Glenn.”
Duffy, Kate. “Elon Musk Says SpaceX Starship Flights to Cost Under $10M in 2-3 Years.” Business Insider, February 11, 2022.
Foust, Jeff. “Inflation, high demand driving up launch prices.” SpaceNews, March 26, 2023.
Garretson, Peter. “The Starship Singularity.” American Foreign Policy Council, February 2023.
Shalal, Andrea and Irene Klotz. “'Vulcan' rocket launch in 2019 may end U.S. dependence on Russia.” Reuters, April 13, 2015.
SpaceX. “Starship.”
SpaceX. “Falcon User’s Guide.” September 2021.
SpaceX. “Capabilities & Services.”
United Launch Alliance. “Rockets.”
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A Meteor That Made A Round Trip From And To The Earth
DISCOVERIES
The Prodigal Stone
Scientists are working to confirm whether a small meteorite discovered in the Sahara Desert originated from Earth before being flung into space – and later returning to the planet, Science Alert reported.
First found in Morocco in 2018, the space rock – known as NWA 13188, NWA meaning “Northwest Africa” – could be the first known meteorite to have made such a cosmic roundtrip.
In their findings, a research team explained that the 23-ounce meteorite had a similar chemical makeup to the kind of rocks formed from the molten minerals produced by volcanoes near sinking oceanic plates.
What distinguishes NWA 13188 from Earth rocks is the small concentrations of Helium-3, Beryllium-10, and Neon-21, which means it was exposed to radiation from outer space.
The team noted that these concentrations are lower than those recorded on other meteorites, but higher than seen on other rocks from Earth. They added that the low amounts could be explained by the short period NWA 13188 spent in space – possibly in the low tens of thousands of years.
But the main question that researchers are asking is how did the rock leave the planet in the first place.
They suggest that it could have been ejected during a very powerful volcanic eruption or thrown into space when another meteorite smashed into Earth.
While other scientists are still skeptical of the findings, rocks leaving their home planets is not a new occurrence.
Meteorites originating from Mars have been discovered in the Sahara: One of them has been named “Black Beauty” and is estimated to be 4.4 billion years old.
It was later sold to a private collection in 2011 and the 320-gram (11.3 ounces) rock is now valued at over US$10,000 per gram.
Monday, July 24, 2023
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Thursday, July 20, 2023
Tuesday, July 18, 2023
The Chandrayaan-3 Mission To The Moon Is On Its Way!
 An LVM3 rocket successfully launched India’s Chandrayaan-3 lunar lander mission July 14. (credit: ISRO) |
The Chandrayaan-3 mission to the Moon is underway
by Ajey Lele
Monday, July 17, 2023
On July 14, the Indian Space Research Organisation (ISRO) started its latest mission to the Moon. For India, this is an important mission because an earlier mission Chandrayaan-2, launched four years earlier, was only a partial success. That mission had two elements: an orbiter and a lander and rover system. ISRO was successful with the orbiter, but the lander crashed attemping a soft landing in September 2019.
| Normally, ISRO makes public their investigation reports for failures during space missions. However, in the case of the Chandrayaan-2 disappointment, no failure assessment report has been made public. |
In that 2019 mission, ISRO’s craft took 30 days after launch to achieve lunar orbit insertion, and subsequently two more weeks for separation of the lander. Finally, the landing was attempted on the 48th day, which resulted in a failure. For the Chandrayaan-3 mission it is expected that the Moon landing will happen around August 23, a little more than a month after launch. It’s worth noting that this time ISRO has not launched any orbiter with this mission. The orbiter launched in 2019 is in good health and is expected to remain operational until 2026. Hence, all necessary support for this mission, like finalizing the exact landing location and supporting communications, would be provided by this orbiter.
Chandrayaan-3 mission has two main components: a Propulsion Module and a lander & rover unit (lunar module). ISRO identifies three main phases of this mission. The first phase is the Earth-centric phase and could be said to have begun with this successful launch. Some 16 minutes into the flight the spacecraft separation happened at a perigee of 180 km. ISRO wil undertake around five Earth orbit raising maneuvers, two of which have been completed as of July 17. Phase 2 is a lunar transfer phase as the spacecraft leaves Earth orbit to go to the Moon. The last phase will have different sub-phases, which mainly includes lunar orbit insertion, propulsion module and lunar module separation, and the landing attempt itself.
The structure of lunar module is nearly the same as the one flown on the Chandrayaan-2 mission. The earlier mission’s total mass was 3,877 kilograms, which includes the orbiter and lunar module. The Chandrayaan-3 mission weighs approximately 18 kilograms more. Since this mission doesn’t have an orbiter, ISRO had an opportunity to make the lander more robust. The Chandrayaan-3 lunar thus weighs 252 kilograms more.
ISRO has announced the details of the payloads that this mission is carrying. The propulsion module has single sensor for studying the spectro-polarimetric signatures of the Earth in near-infrared wavelengths. The lander has three payloads, while the rover has two. There is not much change in the nature of the payloads from what was carried on Chandrayaan-2. The instruments on the lander will carry out measurements for understanding the thermal properties of the lunar surface at its location. Also, there is a sensor to measure seismicity around the landing site and delineate the structure of the lunar crust and mantle below the surface. The Langmuir Probe will measure the near surface plasma density and its changes with time.
 The Chandrayaan-3 spacecraft, consisting of the lander (top) and propulsion module, during pre-launch preparations. (credit: ISRO) |
The rover payloads include an Alpha Particle X-Ray Spectrometer and Laser Induced Breakdown Spectroscope. Here the basic aim is to understand the chemical composition and elemental composition of lunar soil and rocks around the lunar landing site. There is also a plan to pierce a sensor into the surface of the Moon (to a depth of around ten centimeters) and measure the thermophysical characteristics of the lunar regolith.
This mission was undertaken by the LVM3 heavy-lift launch vehicle of ISRO. This was only the fourth mission for this rocket and hence it could be considered a new rocket. This is a three-stage launch vehicle consisting of two solid-propellant strap-ons, a liquid-propellant core stage, and a cryogenic upper stage. The previous two launches for this rocket were commercial launches carrying 36 satellites each for OneWeb, a UK-based company offering broadband satellite Internet services.
This mission is expected to land near the south pole region, at about 70 degrees south latitude. Until now most missions have landed around the Moon’s equatorial region. Technically, it is more challenging to land close to the south pole since the area has big craters and some completely shadowed areas. Hence, there are limited choices for a landing site. ISRO has designed the spacecraft keeping those aspects in mind. ISRO is keen to land close to the south pole because it would allow them to do more science. The cold traps around the south polar region could harbor deposits of water ice and other volatiles of great interest to science and human exploration.
In 2008, during the Chandrayaan-1 orbiter mission, ISRO released its Moon Impact Probe (MIP) from the orbiter close the Shackleton Crater at the lunar south pole. Some observations were picked up during this intentional hard-landing there, and MIP is the first human-made object to reach that area.
| So far only the US, the former Soviet Union, and China had succeeded with Moon landing missions. By the last week of August, we should know if India will join that coveted club. |
Normally, ISRO makes public their investigation reports for failures during space missions. However, in the case of the Chandrayaan-2 disappointment, no failure assessment report has been made public. There have been some official indications that one of the main reasons for the failure was a software glitch. It is known that the lander followed a normal path until reaching an altitude of 2.2 kilometers above the landing zone. Subsequently, communication with the lunar module was lost. There is a possibility that the trajectory deviation could have arisen between 2.1 and 0.2 kilometers above the landing zone. The lander had five engines for velocity reduction, and here higher thrust than required could have been generated, causing a loss in stability. The system witnessed an accumulation of errors and the software was not trained to handle several parameter dispersions.
This time ISRO has taken numerous precautions to ensure that no glitches take place. Some software and hardware changes have been made and a lot of testing and simulations have been carried out. Various scenarios have been generated to understand wider dispersions that may happen. Algorithms are built based on diverse possibilities leading to problems in the mission, and various alternative solutions have been worked out and incorporated into the system. Since the lunar module for this mission is heavier than the earlier mission, the landing system has one additional engine. Also, more fuel has been carried for any last-minute challenges.
Much of groundwork has already happened to select the landing location based on the data received by the Chandrayaan-2 orbiter. As the mission approaches the Moon, fresh images will be provided by the orbiter. There is software available to compare the earlier imagery and the recent imagery. Finally, the system will make the decision for the landing area. As such, a landing zone with a bigger area has been already identified, providing more options for the lander to land than for Chandrayaan-2’s lander.
Two private missions have attempted soft landings on the lunar surface. Unfortunately, both these missions were unsuccessful. Israel’s SpaceIL crashed while landing in April 2019 while Japanese company ispace also crashed during a landing attempt this past April. The Japanese company had carried two rovers, of which one was for the United Arab Emirates (UAE). The Israeli agency has decided to continue with their Beresheet program and is planning for its second mission as soon as 2025.
Reaching the Moon is not an easy proposition. So far only the US, the former Soviet Union, and China had succeeded with Moon landing missions. By the last week of August, we should know if India will join that coveted club.