Navigational warning for 2nd stage debrisvalid May 10 from 1449 to 1551UTCalternate May 11 from 1427 to 1529UTC
Are there any good radar tracking stations
As I remember NASA USED to maintain a fairly comprehensive tracking station that included a variety of Radar systems in Austrailia. But this was back during Apolloand as such, most of this equipment was likely rendered obsolite and dismantled.
Could the second stage eventually land in Australia? Would that be a problem from an ITAR perspective?
Quote from: yg1968 on 05/07/2014 06:52 pmCould the second stage eventually land in Australia? Would that be a problem from an ITAR perspective?That would be only applicable to ISS or Orbcomm type trajectories (inclinations in the 50's)
Due east, too. There is plenty of Australia north of 28.5 deg S. latitude. A couple of good RAAF bases in Western Australia, and Perth is close to the groundtrack at 31 deg S.
At some point, SpaceX will begin to do some controlled descent stage tests on the Falcon 9 second stage, on an otherwise used-up and economically worthless upper stage, after its productive use on a paid-for orbital mission.Analogous to the controlled descent flight tests and over-ocean simulated landings they began on the boosters with the CASSIOPE and CRS-3 missions, SpaceX can learn something from each part of the expansion of the descent flight envelope--at least until the no-Thermal-Protection-System (noTPS) upper stage begins to breakup--even as the used US ultimately breaks up, burns up, and craters into the surf, where it was headed anyway.My questions: 1 - How early can SpaceX begin to learn from any phase of that reentry to begin growing their own data bank for their reusable-team engineers? 2 - Might that time be now, in 2Q2014? SpaceX has been known to have many parts of various development and test programs well underway before they publicly announce that they are doing them. 3 - What sort of radar/tracking assets might exist that would make tracking the descent possible at various parts of it's reentry trajectory over the Indian Ocean, the path used to force deorbit both the CRS-3 US and the Orbcomm OG2 US in April/May 2014, where SpaceX could buy or lease such services to obtain the radar and telemetry data they want?4 - What sort of engineering things might be learned from a more-heavily-instrumented F9 US reentry with good US-to-ground telemetry and radar coverage?5 - Might it help to add Reaction Control System (RCS) thrusters to an early US, even before adding any TPS, in order to learn upper atmosphere stage dynamics prior to breakup? (analogous to what SpaceX learned on the first booster return: that their gaseous nitrogen RCS was apparently undersized, so they doubled it for CRS-3)6 - Does SpaceX have sufficient resources and capital to begin expending development/test expenses on the second stage aspects of their multi-phase reusable launch vehicle technology development program? And related, is it worth it, from a cost/benefit point of view? 7 - How might such data inform the design of the F9 reusable upper stage, the one that will ostensibly be designed to incorporate a TPS so it can make it through the atmospheric reentry and landing legs to, ultimately, land on terra firma?I look forward to your thoughts and analysis.Mods: I could not find another thread in this section that dealt with this topic. If such exists, feel free to move my post to that thread.
So plasma means not getting data back easily...Once the stage can reliably get through that part is there merit in making up something to record and retransmit telemetry? It sounds like it might be doable but is the window of usefulness too small? (it's not useful until you can get through the high plasma part of reentry repeatedly.... it's not useful after you are getting all the way back reliably)I think I just answered my own question.So then, how long does a trailing wire antenna need to be in order to transmit? And wouldn't it tend to get damaged close to the stage? How much mass would something like that add? what if it came unreeled too early? That could risk mission loss.
The shuttle could transmit to TDRS because there a hole in the back side plasma due to the large vehicle planform. The second stage is probably to small for this. Also, I don't think trailing wire would work for S-band/TDRS and would also likely burn off.
8. You're not listing safety here - its a major issue. Proving you won't mess things up or have it slam into someone is a major concern. What do you do when your experiment fails? Where does the debris go? You might bounce off track.
I thought it was a matter of frequency used? For example the latter Mars landers had telemetry received by orbiting assets with no blackout periods.