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| Dr. Aldrin wants humans to explore Mars. | Dr. Aldrin wants humans to explore Mars. His approach is more rational than most, beginning with teleoperation of robots from Phobos. The mid-term goal still seems to be a permanent and self-sustaining human settlements (p181). Given that it took 4 billion years for evolution to produce our "better of most possible worlds", and a vast interconnected global economy to send a tiny amount of hardware into space (so far), it is difficult to conceive of how a second survivable world can be created on inhospitable Mars. |
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| His timeline for the buildup to this beginning when the book was written, soon after meeting with President Obama in 2010. Speech saying "by 2025, we expect new spacecraft designed for long journeys ...". In 2017, as I write this, the claims remain grandiose but the progress tiny. Such developments require far more time than a US presidential administration, and every new administration arrives with new speeches and new campaign contributors to fund. Reset the clock, make bigger claims than predecessors, pay a more, accomplish little. | His timeline for the buildup to this starts before the book was written, after a meeting with President Obama in 2010. Obama's speech saying "by 2025, we expect new spacecraft designed for long journeys ...". In 2017, as I write this, the claims remain grandiose but the progress tiny. Such developments require far more time than a US presidential administration, and every new administration arrives with new speeches and new campaign contributors to fund. Reset the clock, choose different goals, make bigger claims than predecessors, spend more, accomplish little. |
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| Aldrin is correct that a second manned race to the Moon is a waste of time and money. But the Moon is valuable for many kinds of research, and economic development. Throughout history, exploration was soon followed by economic exploitation; why not now? | Aldrin is correct that a second manned race to the Moon is a waste of time and money. But the Moon is valuable for many kinds of research, and economic development. Throughout history, exploration was soon followed by economic exploitation. If we skip the exploitation part, what justifies the continuing expenditure? The great explorations of the past were driven by profit and power. |
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| Aldrin hopes for cyclers in 2029, a Phobos visit in 2033 (last color plate) ... starting with a Constellation replacement in 2010. If we have any sort of orbital crew vehicle by the end of 2017, and the cadence of this illustration holds, we might reach the orbit of Mars in 2040, and travel to the surface and back years later, when Musk is in his 70s. Musk may make a attempt to Mars decades sooner, but unless there are miraculous biological advances soon, he will die in the attempt. | Aldrin hopes for cyclers in 2029, a Phobos visit in 2033 (last color plate) ... starting with a Constellation replacement in 2010. Didn't happen, restart the clock 7 years later. If we have any sort of orbital crew vehicle by the end of 2017, and the cadence of this illustration holds, we might reach the orbit of Mars in 2040, and travel to the surface and back years later, when Musk is in his 70s. Musk may make a attempt to Mars decades sooner, but unless there are miraculous biological advances soon, he will die in the attempt. |
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| The best idea in the book is the synchronous cyclers, space habitats with shielding and infrastructure to support astronauts between Earth and Mars orbit. The cyclers will still need to be supplied with consumables and propellant, ditto for the Mars outpost at the other end. They will also require "escape velocity plus" delta V to reach at both ends, plus additional thrust on the cycler itself to keep it in an orbit that synchonizes with both Earth and Mars. | The best idea in the book is synchronous cyclers, space habitats with shielding and infrastructure to support astronauts between Earth and Mars orbit. The cyclers will still need to be supplied with consumables and propellant, ditto for the Mars outpost at the other end. They will also require "escape velocity plus" delta V to reach at both ends, plus additional thrust on the cycler itself to keep it in an orbit that synchonizes with both Earth and Mars. |
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| I don't expect Dr. Aldrin to agree, but launch loops capable of putting megatons into high orbit would be a good way to assemble a cycler and launch it into its interplanetary cycle, and would have enough delta V to supply a cycler directly as it flies by near Earth. A 5 tonne launch loop would need to make many launches towards the steadily changing position and velocity of the cycler, with many chances for error. In time, experience and automation will reduce those errors. | I don't expect Dr. Aldrin to agree, but launch loops capable of putting megatons into high orbit would be a good way to assemble a cycler and launch it into its interplanetary cycle, and would have enough delta V to supply a cycler directly as it flies by near Earth. A 5 tonne launch loop could make many launches towards the steadily changing position and velocity of the cycler, with many chances for error ... or cumulative success, assembling kilotonnes of components for cyclers. In time, experience and automation will reduce those errors. ------ . How much? Gathering material to build a cycler will require many 5 tonne launches from multiple loops. If the sum of the launches are spaced 20 seconds apart, and leave Earth at 2.5 km/s, then the components are spaced 50 km apart. If the cycler assembles over 4 months (10 million seconds) on the way to Mars, and we allow up to 500 m/s delta V to advance or retard each component compared to the whole, AND (handwaving warning!) the 24 hour turn of the launch loop perigee can be accomodated somehow, then we can "close up" this constellation of components over a distance of 5 million kilometers to each side. That is 1e7/50 times 5 tonnes or 1 million tonnes. . This is probably WAY too optimistic - the Earth does indeed turn, and so the "launch window per day" may be 10% of the whole, and other problems may add another factor of 10; we might have only 10,000 tonnes to work with. Much of that will be propellant, which with proper design will double as shielding. So will food, and so will the excrement made from that food. --- |
Buzz Aldrin Books
Mission to Mars
MY VISION for SPACE EXPLORATION
With Leonard David, National Geographic Books, Multnomah County Central Library, 629.4553 A3658m 2013
Dr. Aldrin wants humans to explore Mars. His approach is more rational than most, beginning with teleoperation of robots from Phobos. The mid-term goal still seems to be a permanent and self-sustaining human settlements (p181). Given that it took 4 billion years for evolution to produce our "better of most possible worlds", and a vast interconnected global economy to send a tiny amount of hardware into space (so far), it is difficult to conceive of how a second survivable world can be created on inhospitable Mars.
His timeline for the buildup to this starts before the book was written, after a meeting with President Obama in 2010. Obama's speech saying "by 2025, we expect new spacecraft designed for long journeys ...". In 2017, as I write this, the claims remain grandiose but the progress tiny. Such developments require far more time than a US presidential administration, and every new administration arrives with new speeches and new campaign contributors to fund. Reset the clock, choose different goals, make bigger claims than predecessors, spend more, accomplish little.
Aldrin is correct that a second manned race to the Moon is a waste of time and money. But the Moon is valuable for many kinds of research, and economic development. Throughout history, exploration was soon followed by economic exploitation. If we skip the exploitation part, what justifies the continuing expenditure? The great explorations of the past were driven by profit and power.
On page 20, Aldrin calls for a reusable booster - !SpaceX reused a booster early in 2017, and we will find out how that actually affects the bottom line when Elon Musk runs out of rich folks willing to invest without dividends. Musk seemingly claims he will go to Mars in his Dragon capsule, but even Aldrin's cyclers may be too cramped for this very long journey.
Aldrin hopes for cyclers in 2029, a Phobos visit in 2033 (last color plate) ... starting with a Constellation replacement in 2010. Didn't happen, restart the clock 7 years later. If we have any sort of orbital crew vehicle by the end of 2017, and the cadence of this illustration holds, we might reach the orbit of Mars in 2040, and travel to the surface and back years later, when Musk is in his 70s. Musk may make a attempt to Mars decades sooner, but unless there are miraculous biological advances soon, he will die in the attempt.
Aldrin's schedule is ambitious as well; Mars is 1000 times further away, and the journey will take 70 times as long as Apollo. We will need a lot of capability in place to support the eventual arrival of humans. Phobos is a good first goal; the delta V to Mars surface and back is around 9 km/s, a significant fraction of an Earth/Moon mission with no Mars-local infrastructure to support it.
The best idea in the book is synchronous cyclers, space habitats with shielding and infrastructure to support astronauts between Earth and Mars orbit. The cyclers will still need to be supplied with consumables and propellant, ditto for the Mars outpost at the other end. They will also require "escape velocity plus" delta V to reach at both ends, plus additional thrust on the cycler itself to keep it in an orbit that synchonizes with both Earth and Mars.
I don't expect Dr. Aldrin to agree, but launch loops capable of putting megatons into high orbit would be a good way to assemble a cycler and launch it into its interplanetary cycle, and would have enough delta V to supply a cycler directly as it flies by near Earth. A 5 tonne launch loop could make many launches towards the steadily changing position and velocity of the cycler, with many chances for error ... or cumulative success, assembling kilotonnes of components for cyclers. In time, experience and automation will reduce those errors.
- How much? Gathering material to build a cycler will require many 5 tonne launches from multiple loops. If the sum of the launches are spaced 20 seconds apart, and leave Earth at 2.5 km/s, then the components are spaced 50 km apart. If the cycler assembles over 4 months (10 million seconds) on the way to Mars, and we allow up to 500 m/s delta V to advance or retard each component compared to the whole, AND (handwaving warning!) the 24 hour turn of the launch loop perigee can be accomodated somehow, then we can "close up" this constellation of components over a distance of 5 million kilometers to each side. That is 1e7/50 times 5 tonnes or 1 million tonnes.
- This is probably WAY too optimistic - the Earth does indeed turn, and so the "launch window per day" may be 10% of the whole, and other problems may add another factor of 10; we might have only 10,000 tonnes to work with. Much of that will be propellant, which with proper design will double as shielding. So will food, and so will the excrement made from that food.
---
Page 154-157 of the book discusses telepresence in hopeful words. Me mentions UT Austin astronomer Dan Lester as a champion of exploration telepresence, and S. Fred Singer as an advocate of surface landers controlled from Phobos or Diemos via relay satellites. From Phobos, I figure that to be a 39000 km, 130 millisecond round trip, as opposed to a 0.7 hour round trip from Earth; an excellent opportunity for telepresence. If we develop 2.7 second predictive-adaptive telepresence from Earth to Moon, and 50 millisecond lunar orbit-to-surface telepresence, we will have excellent tools to do this.