What about a crew Dragon with 3x crew (2x experienced Shuttle-Hubble Astros) and CMG's in the trunk?! Two of the Astronauts could perform a pair of EVAs to install new gyros and batteries and the other Astro would be there to assist them in suiting up and 'flying' the Dragon.Can the Dragon be configured to do multiple EVAs? If the Falcon 9 is fully expended and launched to the 28.5 degree inclination orbit that Hubble is in: would the Dragon have enough delta-v to reach the telescope? Can a set of gyros and batteries fit in the Dragon's cargo trunk? I'd love to see someone do a feasibility study on a mission like this!! And could the Dragon dock with the docking unit that was left on the Hubble by the STS-125 crew? Could EVA's be done on the telescope without an RMS system? Or could the crew suffice with the pole system that was being looked at for the now abandoned Asteroid Rendezvous mission?Or would this be a mission better suited to an Orion, launched on a Delta IV-Heavy, now that the ICPS stage is going to be 'man rated'?Are there any Astronauts who repaired Hubble still on the active duty roster? How feasible would it be to reinstate 'Hubble Astronauts' who would still pass the physical or have only recently retired? Also: I know that it might be better to plow the mission's money into new space telescopes, or dock a 'stability' CMG control/command module to the base of Hubble......I'm only pondering this concept as a 'face saving' idea if - God fervently forbid - if the James Webb ends up in the drink after launch, or fails to deploy.
If, God forbid, JWST goes into the drink or fails to deploy, the astronomers will simply have to do without an orbiting telescope for the next decade (at least).
SpaceX, manufacturer of both the Dragon and the Falcon 9, did a very preliminary, informal study of using Crew Dragon with a robot arm to deorbit Hubble, or to repair and reboost the telescope. This was part of a wider SpaceX PowerPoint presentation on using Crew Dragon to service satellites, publicly released in March 2010 just before the first Falcon 9 launch.
Could you steer Hubble with external gyros attached to the LIDS mounted on it? You might not get very good slew rates but It's much easier that replacing the internal gyros.
Quote from: nacnud on 10/09/2018 08:26 amCould you steer Hubble with external gyros attached to the LIDS mounted on it? You might not get very good slew rates but It's much easier that replacing the internal gyros.How would they communicate with the internal computer? I seriously doubt that the Hubble has enough modularity to accomodate this external input. How would you power them?At best you would still need to connect multiple cables, which means opening it up, which would probably mean that a direct gyro replacement would be easier.
Quote from: IRobot on 10/09/2018 10:04 amQuote from: nacnud on 10/09/2018 08:26 amCould you steer Hubble with external gyros attached to the LIDS mounted on it? You might not get very good slew rates but It's much easier that replacing the internal gyros.How would they communicate with the internal computer? I seriously doubt that the Hubble has enough modularity to accomodate this external input. How would you power them?At best you would still need to connect multiple cables, which means opening it up, which would probably mean that a direct gyro replacement would be easier.In principle, solar, and reception of any of the existing antennas. While obviously not pointed at the LIDS mount, they can be received just fine at ~5m distance.(yes, solar adds additional observing constraints)
Really don't think a HST rescue mission with a single Dragon is that doable.But maybe adding a modified Cygnus with a 3 segment pressurized module to the mission might work. Using the Cygnus PM basically as an airlock with external racks for mounting manipulator arms, additional propellant storage and holding bins for the gyros along with external EVA helpful attachments. There is no cargo inside the Cygnus PM.The idea is to launched the Cygnus first then the Dragon later to docked with the Cygnus. The vehicle stack will then go to the HST using the Cygnus's propulsion with the additional propellants. Grapple the HST and replace the hardware. The Dragon then returns the crew back to Earth with almost a full propellant load remaining aboard.Of course it would take time to get the replacement hardware and training the service crew of maybe 3 astronauts.
I remember that there were two NRO 'Hubble class' telescopes that were 'gifted' to NASA. I've just Googled about them but only get articles with vague sets of details about them. Are one or both of these going to be recycled into space telescopes? Could one of them be a better platform for the WFIRST concept?
Love this idea. Big fan of Cygnus as a "truck" and combining it with Dragon 2 like this is a great idea.Quote from: Zed_Noir on 10/09/2018 10:14 amReally don't think a HST rescue mission with a single Dragon is that doable.But maybe adding a modified Cygnus with a 3 segment pressurized module to the mission might work. Using the Cygnus PM basically as an airlock with external racks for mounting manipulator arms, additional propellant storage and holding bins for the gyros along with external EVA helpful attachments. There is no cargo inside the Cygnus PM.The idea is to launched the Cygnus first then the Dragon later to docked with the Cygnus. The vehicle stack will then go to the HST using the Cygnus's propulsion with the additional propellants. Grapple the HST and replace the hardware. The Dragon then returns the crew back to Earth with almost a full propellant load remaining aboard.Of course it would take time to get the replacement hardware and training the service crew of maybe 3 astronauts.