Ares 1 marches (or staggers) on:
Thrust Oscillation is specifically named in relation to end of the first stage burn of Ares I-X, which requires mitigation - proposed to be in the form of high strength fasteners.
"Preliminary results show lower axial loads and higher lateral loads during thrust oscillation at the end of the FS (First Stage) burn (T+120sec). Proposed mitigation (high strength fasteners in impacted hardware) in work, needs to be presented at ERB (Engineering Review Board).
Afraid it will shake apart? Use bigger screws!
I love this, too.
While beefing up the structure is a mitigation for the hardware, Ares I-X's components are also in the TO firing line, with the most concerning element referencing the Flight Termination System (FTS) - which may require a range waiver due to the potential TO could exceed the components certification, and the threat of vibrating them out of action.
"Requirement - Range Safety: multiple waivers. Lack of dual S&A device. Lack of initiation of LSC at both ends. Lack of "CRD Self-test" capability. Minimum separation of FTS components," added the presentation.
We may massage the thing so hard that we won't be able to blow up the vehicle if something goes wrong (e.g., it starts blasting toward the VAB). Can we have a waiver, please?
NASA's unending ability to waive itself from its own requirements is one of the reasons that the notion of "human rating" is nonsensical.
[Early evening update]
Link to NASA Space Flight was bad before. It's fixed now. I'm kind of surprised that it took all day for someone to point it out. Just more evidence that most people don't follow the links, at least if I post significant excerpts and/or commentary on them.
[Update a couple minutes later]
Rob Coppinger has Ares 1, then and now. That upper stage has really grown. I also hadn't realized that it had a common bulkhead for the tanks. Well, at least it's not hypergolic.
So there is now a danger that this will go "landshark" and take out Cocoa like that Chinese Long March that took out a nearby village.
Delta II has be using common bulkhead tanks for hypergolic propellants for decades.
"notion of "human rating" is nonsensical." Your dismissal of process is nonsensical. You don't have to go into the reliability rant, that is a given but it isn't everything. There are areas that play into "human rating". There are launch vehicle environments (thrust Oscillation/POGO) that are not conducive to human life, but most spacecraft can handle them. Additionally, adjusting trajectories to eliminate black zones is part of the process. Adding an LVHM system is applicable to the process.
"Human rating" is generic process that is also applicable to other vehicles. It has gone by other names, such as "commercialization" or conversion to civilian. The Boeing Stratocruiser is a good example.
EELV's and even the Ares FSB* weren't designed as human carriers and therefore need some mods. Whether you like it or not (you don't make the call) it is called human rating.
Your point that RLV's won't need to be "human rated" still has holes in it, since an unmanned one might impose environments on its passengers that may have to be changed.
"Human rating" is generic process that is also applicable to other vehicles. It has gone by other names, such as "commercialization" or conversion to civilian. The Boeing Stratocruiser is a good example.
No, it's not. It's unique to NASA. Those other things have other names, and other processes. There is no such thing as a "human-rated" aircraft.
Your point that RLV's won't need to be "human rated" still has holes in it, since an unmanned one might impose environments on its passengers that may have to be changed.
By definition, no one would put people in an "unmanned RLV." But I think that it's unlikely that such a thing will ever be built.
...adjusting trajectories to eliminate black zones is part of the process. Adding an LVHM system is applicable to the process.
Do you really imagine that I'm not aware of that? Despite the fact that I've pointed it out many times?
From what I have heard the common bulkhead is going to be the next ARES crisis.
From what I have heard the common bulkhead is going to be the next ARES crisis.
I'm not sure why it should be. Centaur has been flying that way for decades without a problem, as far as I know. Of course, Centaur never had to ride God's own paint shaker to orbit.
"to ride God's own paint shaker to orbit."
LOL! You should use this as a title for a book. I would definitely like an autographed first edition. I think the timing would be right.
rand, you need to link up nasaspaceflight.com where you took those comments from.
The entire Constellation program architecture is deeply flawed,
and highly unlikely to work.
Given the estimated first flight is now 2015, for Ares I,
that is just politically doomed. The next president will
not invest 90% of the capital needed so their successor can
take a victory lap.
The next administration will look at what is being proposed
and see that the odds of a slip into 2016 or 2017 are very
high and kill or seriously gut the program.
Shuttle slipped like crazy and it hurt Carter.
Station slipped like Crazy and it hurt Bush 1.
Clinton handed station, cut it's mission and roles and
forced NASA to just finish that.
Obama, is most likely to force NASA to work with Station
and stop the Ares V, Ares I and deep space effort.
If I was Obama, given his comments, I would dump Ares V, I, Constellation and make a competition to make capsules to resupply and man ISS launched with the EELVs. Demand the contractors to make test capsules and fly them before picking winners. Heck, the USAF did request test vehicles for ATF and JSF, so why not NASA?
It is just a capsule, not as expensive to design as an actual launch vehicle.