However -- and someone please correct me if I'm wrong -- doesn't it take more energy to get onto a trajectory that takes you closer to the sun than it does to go farther out from the sun? ISTR this was one of those counter-intuitive things I've run across in re interplanetary trajectories.
Should you do the transposition and dock, make sure you have a good hard dock, check out the hab, and after making sure all is well, then do the departure burn? Then dispose of the EDS.
Quote from: jtrame on 12/15/2014 03:40 pmShould you do the transposition and dock, make sure you have a good hard dock, check out the hab, and after making sure all is well, then do the departure burn? Then dispose of the EDS.BEAM has insufficient internal structure to support itself during the burn.
Edited to add: also not sure of what the flight times would be from Earth to Venus and back again. I know Venus is closer to Earth than Mars is.
As for near future missions for Orion....I had a thought for a mission that wouldn't involve any new costly deep space habitats, landers, etc. and that uses only existing equipment/equipment already funded and in development. What about an Orion/SLS launch to Venus with a crew of two (maybe 3?), as well as a Bigelow BEAM module stuffed with supplies and extra oxygen/life support systems, food, water, treadmill, etc. (Use the transposition method to dock BEAM with Orion after trans-Venus injection). Launch the mission during a good conjunction of Venus with Earth, and use the mission to test Orion's systems as well as astronauts' medical and psychological responses during a 6-12 month trip (or 18 month?) through deep space. Bonus points: become the first people to fly to and past another planet. Possible problems: besides the ever present issues of budget, politics, and desire, Venus is closer to the Sun than the Earth and the higher solar radiation would need to be taken into account. Also I don't imagine it would be a good mission for the first crewed flight of Orion only because it would be a long flight, a shorter flight to the Moon would be a better "shakedown" cruise for the first crewed flight. Also would a BEAM module be enough storage capacity for all the crew would need in addition to the Orion's interior space?How feasible would this type of mission be as an early EM mission while asteroid and Mars missions are fleshed out?Edited to add: also not sure of what the flight times would be from Earth to Venus and back again. I know Venus is closer to Earth than Mars is.
*snip*EDIT: The Block I (70 tonne-to-LEO) SLS can put, by my math, 30.323 metric tons through TVI. Since mission delta-v after that point is only 60 m/s, we can probably de-tank Orion to only 300 m/s of delta-v with plenty of margin, so we have more payload. But even if Orion needs to be fully-tanked for some or other abort scenario, that still leaves 9.073 metric tons for a hab module. The MPLMs mass 4 metric tons each, leaving five tonnes for supplies and scientific payload (and also extra radiation shielding). Alternatively, one can use a Cygnus-derived Mission Module.How much would 4 people need for 400 days?
It's always a theological/scientific puzzle to me that the two closest terrestrial planets lack a true magnetosphere, yet it's "middle cousin" between the two has one that's as well-shielding as Uranus and Neptune's. How did we get to be so special?
Quote from: clongton on 12/15/2014 04:01 pmQuote from: jtrame on 12/15/2014 03:40 pmShould you do the transposition and dock, make sure you have a good hard dock, check out the hab, and after making sure all is well, then do the departure burn? Then dispose of the EDS.BEAM has insufficient internal structure to support itself during the burn.Not hard to modify it in order to have a mountable/dismountable column.
We cannot in good faith take what we have without modification and fly this mission. But we could fly it with a stretched Cygnus, and I think the original poster mentioned Cygnus, but not with Cygnus as it presently exists. I get it, it's a "just for fun" thread. But can't we inject a little reality?
A BA-330, on the other hand, is a full-fledged miniature space station, and probably represents about the minimum scale of _habitat_ necessary for a planetary flyby mission with 3-5 people aboard, assuming half a dozen other smaller-volume modules are attached. It is *much* lighter weight and easier to launch than 330m^3 of hab volume would otherwise be.
Quote from: MattMason on 12/15/2014 06:33 pmIt's always a theological/scientific puzzle to me that the two closest terrestrial planets lack a true magnetosphere, yet it's "middle cousin" between the two has one that's as well-shielding as Uranus and Neptune's. How did we get to be so special? That is a rather larger question, deserving at least its own thread ... perhaps on another site (there are many that are more oriented toward this type of inquiry).
...no way we could land a sample return or Human on the planet, given the surface conditions.