Scott Manley mentioned an interesting idea, send up a rocket and change the orbit. After that the astronauts on ISS could service the telescope.
Quote from: Swedish chef on 10/09/2018 03:07 pmScott Manley mentioned an interesting idea, send up a rocket and change the orbit. After that the astronauts on ISS could service the telescope. he also stated that you would need an enormous upper stage to push it. Noting it's about a 30 degree plane change.
(fan) Also, Rocket parts are not LEGO elements, to be put together in whatever way one can imagine. Doesn't work that way. A D2 mission would take a lot of engineering and be diversionary. When the last HST science (positioning and desaturating) gyro gives out, safe HST and build a fixture to stow it inside a BFS and bring it home. The safe mode gyros should have some considerable life remaining presumably.
Both the rate sensors and the reaction wheels can be changed out. The RSUs are inside the aft shroud, and one of the hardest tasks for Hubble servicing is getting the access doors open and closed (they tend to flex/jam).
This is an interesting topic, but there is a paucity of information here.Can Falcon V send Crew Dragon to the required 600 km circular orbit? And with how much payload?Can the Dragon hatch be opened briefly to allow EVA? Can Dragon boost HST to a higher orbit? Apart from mission specific ops costs, what would be the cost of such a mission?Please do not answer with discussion about procurement of a new telescope, or about robotic servicing.
Could Dragon be used without airlock? Have a few bottles of pressurized air to refill after EVA? Some extra bottles could be stored in the trunk.
Dragon cannot support an EVA. It would require an external airlock module.Orion can, but that's because it is designed to be able to do it, which means that the internals are fully vacuum rated (electronics) and that the entire cabin can be depressurized and pressurized again (and again?). This requires a lot of consumables. The Orion spacesuits are also designed to support it, unlike the Dragon IVA suits.
Orion would have to be redesigned. It is not designed for long stay in the LEO environment.I would suggest an architecture with a regular Crew Dragon plus an « Airlock Dragon ». Could be a two dragon mission : the « Airlock Dragon », a Cargo Dragon derived spacecraft with an airlock as pressurised module launched from SLC-40, and then a Crew Dragon which would launch and dock to the Airlock Dragon. In the trunk of the Airlock Dragon there would be a mechanical interface with the HST and the new ORUs for the maintenance.The beauty of it is that the « Airlock Dragon » could reenter and be reused.
Quote from: Lars-J on 10/09/2018 06:21 amDragon cannot support an EVA. It would require an external airlock module.Orion can, but that's because it is designed to be able to do it, which means that the internals are fully vacuum rated (electronics) and that the entire cabin can be depressurized and pressurized again (and again?). This requires a lot of consumables. The Orion spacesuits are also designed to support it, unlike the Dragon IVA suits.Atmosphere lost due to depressurization would be some 10 kg, so not a big deal.Cannot see US EVA suits fitting through the top hatch.
What if a module was built that had a docking adapter and support for 2 Z-2 suits and would fit in dragon's trunk? It could separate and dragon could dock with it LEM style. All systems would be tested before the dragon hatch was opened. The Z-2 suits have a built in airlock called a suit port, so they would be attached to the module the whole time with the astronauts entering from the support module. Then two astronauts would enter the Z-2 suits with the help of a third who stays with the capsule. The dragon hatch could be closed when the suits are pressurized for some extra protection from failures of the suit airlocks (though the astros in the suits obviously would be relying on success of that suit airlock). Any large components needed would either be attached to the outside of the Z-2 support module, or pre positioned by a previous flight.This would all be purpose built hardware and none of it could return, so definitely not an inexpensive or quick undertaking. I don't know if Z-2 would be up to the task. Astronaut positioning and locomotion would have to be resolved since a canada arm is not a given; though perhaps a smaller version could also be part of the Z-2 support module.