Nov 2014 Nature: Thousands of shipping-container-sized and larger asteroids pass almost as close as the Moon each year. We need to find them far enough in advance, and abundant opportunities for crewed missions will open upARM is a multibillion-dollar stunt to retrieve part of an asteroid and bring it close to Earth where astronauts can reach it. It will require an ancillary spacecraft deploying either a huge capture bag or a Rube Goldberg contraption resembling a giant arcade-game claw. Neither technology is useful for getting humans to Mars.This gateway for human space exploration requires three things: 1- a thorough asteroid survey to find thousands of nearby bodies suitable for astronauts to visit; 2- extending flight duration and distance capability to ever-increasing ranges out to Mars; 3- developing better robotic vehicles and tools to enable astronauts to explore an asteroid regardless of its size, shape or spin.Nov 2014 Sci America A retrieval mission gets you one asteroid, but a survey gets you thousands that you could potentially visit. ARM doesn't advance anything and the hardware is short of delta-V and delta-P.
Quote from: muomega0 on 11/10/2014 07:27 pmNov 2014 Nature: Thousands of shipping-container-sized and larger asteroids pass almost as close as the Moon each year. We need to find them far enough in advance, and abundant opportunities for crewed missions will open upARM is a multibillion-dollar stunt to retrieve part of an asteroid and bring it close to Earth where astronauts can reach it. It will require an ancillary spacecraft deploying either a huge capture bag or a Rube Goldberg contraption resembling a giant arcade-game claw. Neither technology is useful for getting humans to Mars.This gateway for human space exploration requires three things: 1- a thorough asteroid survey to find thousands of nearby bodies suitable for astronauts to visit; 2- extending flight duration and distance capability to ever-increasing ranges out to Mars; 3- developing better robotic vehicles and tools to enable astronauts to explore an asteroid regardless of its size, shape or spin.Nov 2014 Sci America A retrieval mission gets you one asteroid, but a survey gets you thousands that you could potentially visit. ARM doesn't advance anything and the hardware is short of delta-V and delta-P.While more thorough surveys would be nice, I strongly disagree with the conclusion. The manned visit to the asteroid is the less important part, while the ARM is the really, really important part of the mission which enables practical asteroid ISRU or planetary protection. Using the figures from the Keck report, asteroid retrieval can net you over 50 times the IMLEO mass launched as asteroid rock in Lunar orbit, and for stony asteroids at least one third of that mass is Oxygen. With LOX ISRU, that is an insanely large mass multiplier. The LOX can be used for anything from extended lunar exploration to sending very large spacecraft to Mars.
Quote from: Nilof on 11/10/2014 09:19 pmQuote from: muomega0 on 11/10/2014 07:27 pmNov 2014 Nature: Thousands of shipping-container-sized and larger asteroids pass almost as close as the Moon each year. We need to find them far enough in advance, and abundant opportunities for crewed missions will open upARM is a multibillion-dollar stunt to retrieve part of an asteroid and bring it close to Earth where astronauts can reach it. It will require an ancillary spacecraft deploying either a huge capture bag or a Rube Goldberg contraption resembling a giant arcade-game claw. Neither technology is useful for getting humans to Mars.This gateway for human space exploration requires three things: 1- a thorough asteroid survey to find thousands of nearby bodies suitable for astronauts to visit; 2- extending flight duration and distance capability to ever-increasing ranges out to Mars; 3- developing better robotic vehicles and tools to enable astronauts to explore an asteroid regardless of its size, shape or spin.Nov 2014 Sci America A retrieval mission gets you one asteroid, but a survey gets you thousands that you could potentially visit. ARM doesn't advance anything and the hardware is short of delta-V and delta-P.While more thorough surveys would be nice, I strongly disagree with the conclusion. The manned visit to the asteroid is the less important part, while the ARM is the really, really important part of the mission which enables practical asteroid ISRU or planetary protection. Using the figures from the Keck report, asteroid retrieval can net you over 50 times the IMLEO mass launched as asteroid rock in Lunar orbit, and for stony asteroids at least one third of that mass is Oxygen. With LOX ISRU, that is an insanely large mass multiplier. The LOX can be used for anything from extended lunar exploration to sending very large spacecraft to Mars.Visit, Deflect, Retrieve—Least Energy/Cost to Most Required. The “ARM” is Retrieve. So the mission could be AVM, ADM, or APM for “Political”. Before visit, one needs to survey.No justification is given for "retrieve" because the costs of mission to retrieve one (very small, with little chance of resources ) asteroid are significantly higher than visiting and/or deflecting many asteroids. The figure from the Nature article (attached) by Binzel clearly identifies that moving the rock to L2 is the exact opposite of recommendation 2: extending flight duration and distance capability to ever-increasing ranges out *to* Mars. To head *TO* Mars, a LEO ZBO depot is THE number one priority--HLV not required. The re-usable deep space habitat, the L2 Based Gateway voyager--not stuck in one location, is key piece of hardware for crew missions. In-space propulsion, economic access to space, crew health, space power--the other space grand challenges, have equal or greater priority than ISRU. For example, and reusable EP and chemical tugs that travel to and from an asteroid from L2, which will eventually cycle to Mars. To pay for all this shift resources away from SLS/Orion.Spending a few *millions* on ISRU beginning with ground demonstrations in conjunction with the asteroid surveys is also required FIRST to justify the ISRU feasibility versus many other competing needs.For NASA, the direction continues to be *to* Mars with a new reuseable, launch vehicle independent architecture; and for the Country, consolidate the Atlas/Delta/SLS into a single common LV
I don't have a problem with the ARM mission in principle. But I would far rather see that Orion be docked with a Habitat Module - say an adapted ISS 'Zvezda' type module or similar - and have those craft link up with the S.E.P. module, augmented with a chemical stage(s) and go several million kms into deep space to a pretty large asteroid! Having a pair of Astronauts clambering over a huge 'flying mountain' while we watch on high-definition TV would give us this generation's Hillary & Tenzing moment. Or better yet; Phobos.But as we know; no bucks - no Buck Rogers...
Quote from: MATTBLAK on 11/12/2014 05:11 amI don't have a problem with the ARM mission in principle. But I would far rather see that Orion be docked with a Habitat Module - say an adapted ISS 'Zvezda' type module or similar - and have those craft link up with the S.E.P. module, augmented with a chemical stage(s) and go several million kms into deep space to a pretty large asteroid! Having a pair of Astronauts clambering over a huge 'flying mountain' while we watch on high-definition TV would give us this generation's Hillary & Tenzing moment. Or better yet; Phobos.But as we know; no bucks - no Buck Rogers... Honestly, I'd rather have a testbed for ISRU available than a stunt flags and footprints mission.~Jon
And then again, any manned mission could be classified as a stunt mission, especially one that breaks new ground. Being first will always carry the "flags & footprints" persona and that's not all bad IMO. Combine the ISRU experiments with the manned mission.
Quote from: muomega0 on 11/11/2014 04:30 pmQuote from: Nilof on 11/10/2014 09:19 pmQuote from: muomega0 on 11/10/2014 07:27 pmNov 2014 Nature: Thousands of shipping-container-sized and larger asteroids pass almost as close as the Moon each year. We need to find them far enough in advance, and abundant opportunities for crewed missions will open upARM is a multibillion-dollar stunt to retrieve part of an asteroid and bring it close to Earth where astronauts can reach it. It will require an ancillary spacecraft deploying either a huge capture bag or a Rube Goldberg contraption resembling a giant arcade-game claw. Neither technology is useful for getting humans to Mars.This gateway for human space exploration requires three things: 1- a thorough asteroid survey to find thousands of nearby bodies suitable for astronauts to visit; 2- extending flight duration and distance capability to ever-increasing ranges out to Mars; 3- developing better robotic vehicles and tools to enable astronauts to explore an asteroid regardless of its size, shape or spin.Nov 2014 Sci America A retrieval mission gets you one asteroid, but a survey gets you thousands that you could potentially visit. ARM doesn't advance anything and the hardware is short of delta-V and delta-P.While more thorough surveys would be nice, I strongly disagree with the conclusion. The manned visit to the asteroid is the less important part, while the ARM is the really, really important part of the mission which enables practical asteroid ISRU or planetary protection. Using the figures from the Keck report, asteroid retrieval can net you over 50 times the IMLEO mass launched as asteroid rock in Lunar orbit, and for stony asteroids at least one third of that mass is Oxygen. With LOX ISRU, that is an insanely large mass multiplier. The LOX can be used for anything from extended lunar exploration to sending very large spacecraft to Mars.Visit, Deflect, Retrieve—Least Energy/Cost to Most Required. The “ARM” is Retrieve. So the mission could be AVM, ADM, or APM for “Political”. Before visit, one needs to survey.No justification is given for "retrieve" because the costs of mission to retrieve one (very small, with little chance of resources ) asteroid are significantly higher than visiting and/or deflecting many asteroids. The figure from the Nature article (attached) by Binzel clearly identifies that moving the rock to L2 is the exact opposite of recommendation 2: extending flight duration and distance capability to ever-increasing ranges out *to* Mars. To head *TO* Mars, a LEO ZBO depot is THE number one priority--HLV not required. The re-usable deep space habitat, the L2 Based Gateway voyager--not stuck in one location, is key piece of hardware for crew missions. In-space propulsion, economic access to space, crew health, space power--the other space grand challenges, have equal or greater priority than ISRU. For example, and reusable EP and chemical tugs that travel to and from an asteroid from L2, which will eventually cycle to Mars. To pay for all this shift resources away from SLS/Orion.Spending a few *millions* on ISRU beginning with ground demonstrations in conjunction with the asteroid surveys is also required FIRST to justify the ISRU feasibility versus many other competing needs.For NASA, the direction continues to be *to* Mars with a new reuseable, launch vehicle independent architecture; and for the Country, consolidate the Atlas/Delta/SLS into a single common LVI actually think getting a significant asteroid sample (we're talking 80-500mT here) back to a lunar orbit where you can develop ISRU capabilities is far more important than trying to expedite a NASA Mars mission that's never going to happen.I agree with you that depots are important, but NASA isn't going to fund them because they politically destroy the case for SLS, and so long as Senator Shelby is parked on the appropriation committee over NASA, that's going to be their focus. I'll take a consolation prize of having a second moon in cislunar space that is now easy to visit for any commercial or NASA entity that's interested.
Unlikely to be funded
Iron Duke Why not aim high and go for a Mars capture? It's way more exciting and equally likely to occur.