but should steer clear of large planets, their systems and the gravitational consequences avoidance maneuvers would have on trajectory.
Given the times of such trips, even at modest fractions of 'c', there's sufficient time for identification of major planets to be sent to Earth and analysis of their orbits sent back before the probe enters the system proper. ... That allows the probe to be vastly dumber than would be required for true "fire-and-forget" autonomy.
too much reliance on desk jockeys [...] armies of desk jockeys [...] from desk jockeys
There won't be time to receive this from Earth.
Whether these calculations are done by the craft or on Earth - they're the same algorithms. The main difference is processing power. Using Earth's best supercomputers would still take seven years to retrieve while the craft could perform the task in at least 1-2yrs
There are thousands of astronomers and planetary scientists working on theories of stellar and planetary formation, using constantly improving data on a huge number of star systems, from hundreds of major observation facilities on Earth and in orbit. ...Even at unrealistic velocities, such as 10% of 'c', a trip to Proxima Centauri would take more than four decades. During which time, the entire theory of planetary formation will be revised and refined repeatedly. And during which, observers on Earth will be using vastly superior platforms to continue to observe the target system, and will thus have a vastly greater understanding of that system than when the probe was launched.
Quote from: Propylox on 07/21/2017 02:12 amWhether these calculations are done by the craft or on Earth - they're the same algorithms. The main difference is processing power. Using Earth's best supercomputers would still take seven years to retrieve while the craft could perform the task in at least 1-2yrsThe probe's computing power not be 1/7th or 2/7th of a super-computer. ... If anything like Moore's Law ... Dennard's Law ... Therefore there's no point even trying to give the probe that capacity, the probe's autonomy would be limited to making minor adjustments during the flyby to avoid hitting anything and to compensate for errors in trajectory (after the fact) due to errors in the gravitational-map. ...
Quote from: hop on 08/30/2016 08:45 pmQuote from: Robotbeat on 08/30/2016 07:42 pmAll the probe needs to do is collect data and relay it to Earth.Not if you want to collect useful data. It needs to autonomously identify and select targets, select appropriate observations, and execute the observations with incredible speed, precision and reliability.New Horizons, when it entered flyby phase, was entirely autonomous for the same reason as a probe to Proxima b would be. It was given all its instructions of where to look beforehand. ...
Quote from: Robotbeat on 08/30/2016 07:42 pmAll the probe needs to do is collect data and relay it to Earth.Not if you want to collect useful data. It needs to autonomously identify and select targets, select appropriate observations, and execute the observations with incredible speed, precision and reliability.
All the probe needs to do is collect data and relay it to Earth.
Deep Oberth burn right by the Sun, leave at ~100-120km/s (perhaps with help from RTG electric propulsion).
Quote from: Paul451 on 07/22/2017 02:20 amThere are thousands of astronomers and planetary scientists working on theories of stellar and planetary formation, using constantly improving data on a huge number of star systems, from hundreds of major observation facilities on Earth and in orbit. ...Even at unrealistic velocities, such as 10% of 'c', a trip to Proxima Centauri would take more than four decades. During which time, the entire theory of planetary formation will be revised and refined repeatedly. And during which, observers on Earth will be using vastly superior platforms to continue to observe the target system, and will thus have a vastly greater understanding of that system than when the probe was launched. And none of that is relevant to the mission. In several decades the probe will return facts confirming some theories and discrediting others. Until then these armies and their infrastructure can continue guessing.
This paper discusses the physics, engineering and mission architecture relating to a gram-sizedinterstellar probe propelled by a laser beam. The objectives are to design a fly-by mission to Alpha Centauri with a total mission duration of 50 years travelling at a cruise speed of 0.1c. Furthermore, optical data from the target star system is to be obtained and sent back to the Solar system.
If those ions impart 1N, deflecting the wire 10-degrees = Only 0.17N is applied to the z-axis and 0.98N laterally.
https://arxiv.org/ftp/arxiv/papers/1708/1708.03556.pdfThe Andromeda Study: A Femto-Spacecraft Mission to Alpha Centauri
Electric sail follow-up;I can't understand and/or disagree with the concept of rotating an electric sail to spread its wires as this cannot effectively translate force to the spacecraft. This is a basic applied physics problem which is why I'm struggling to understand how it could have been overlooked. Corrections? Facepalm and mockery of my obvious oversight?ie; A cable is extended laterally by centrifugal force, intending to catch ions and impart thrust along the z-axis. If those ions impart 1N, deflecting the wire 10-degrees = Only 0.17N is applied to the z-axis and 0.98N laterally. That's very inefficient use of already minimal force. If the ions wane, radial momentum will start to return the wires to their extended state, but require additional rotational force to fully extend them to their initial state. As such, this architecture is gaining little thrust while requiring constant rotational thrust, all while cranking out electrons. Seems like the centrifugal extension doesn't enable, but nullifies this design.
Quote from: savuporo on 08/18/2017 01:29 pmhttps://arxiv.org/ftp/arxiv/papers/1708/1708.03556.pdfThe Andromeda Study: A Femto-Spacecraft Mission to Alpha Centauri What would be the point of sending something to the stars that cannot gather, much less return information? Greeting cards too small to find? Space seeds?
The objectives are to design a fly-by mission to Alpha Centauri with a total mission duration of 50 years travelling at a cruise speed of 0.1c. Furthermore, optical data from the target star system is to be obtained and sent back to the Solar system.
Quote from: envy887 on 08/22/2017 12:40 pmIf you apply 1 N through the cg of a 1 kg spacecraft in space, it will accelerate at 1 m/s^2. It does not matter if it is rotating or a sail or anything else, this a basic application of Newton's 2nd law. Yes, but if you apply 1N through a structure held by centrifugal force, deflecting it by say - 1 degree, only 0.17N is applied to the spacecraft. That's why I question the electric sail's design. The electromagnetism is sound, but the architecture nullifies it rather than enables it. That constant rotational force would be required to maintain the structure is also an immense parasitic loss. May as well dump the electric sail and turn those thrusters rearward.
If you apply 1 N through the cg of a 1 kg spacecraft in space, it will accelerate at 1 m/s^2. It does not matter if it is rotating or a sail or anything else, this a basic application of Newton's 2nd law.
Quote from: Propylox on 09/13/2017 03:56 amYes, but if you apply 1N through a structure held by centrifugal force, deflecting it by say - 1 degree, only 0.17N is applied to the spacecraft. That's why I question the electric sail's design. The electromagnetism is sound, but the architecture nullifies it rather than enables it. That constant rotational force would be required to maintain the structure is also an immense parasitic loss. May as well dump the electric sail and turn those thrusters rearward.There is no such thing as a "parasitic loss" of angular momentum in a free-flying spacecraft. [...]You seem to be under the impression that it is possible to convert between angular and linear momentum in a closed system. It is not.
Yes, but if you apply 1N through a structure held by centrifugal force, deflecting it by say - 1 degree, only 0.17N is applied to the spacecraft. That's why I question the electric sail's design. The electromagnetism is sound, but the architecture nullifies it rather than enables it. That constant rotational force would be required to maintain the structure is also an immense parasitic loss. May as well dump the electric sail and turn those thrusters rearward.
That constant rotational force would be required to maintain the structure is also an immense parasitic loss. May as well dump the electric sail and turn those thrusters rearward.
You're not making any sense, can you please sketch out what you are trying to describe.