Right around the time that SpaceX announced they were sidelining retro-repulsive landings I recall reading the main reason was difficulty in designing the retractable landing legs into the heat shield without risking compromise of the heat shield's function. Does anyone else remember this, and know if this was an officially stated reason?
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Ya lost me. This is for reentry, not launch.The fairing capture or abort from Kennedy/ Canaveral would only be in the Atlantic.
AHHHH They meant
Actually the other way around. Can’t make Gulf COMMA hop across peninsula to Atlantic.
I don't think reentry works that way though. Once committed to the de-orbit, there is no way to shift the landing zone by hundreds of miles (unless your vehicle is a good glider). They would know landing site conditions well ahead of time.
Correct, the cross range of capsules are not great, especially once it is part way through its re-entry process. The other thing to consider is that angle of entry is important for TPS effectiveness, so changing vehicle orientation to gain cross range could result in additional heating to the vehicle or sub-optimal utilization of TPS.
Elon needs to have some long talks with the President.
I can understand caution on NASA’s part.
1) Nobody wants to see anyone die.
2) The NASA swamp does not want to see SpaceX succeed where they have not only failed, but ran the Shuttle since 1981 with rising casts, not falling ones ( $450M/per mission). !!!
SpaceX can test roughly 300 missions for the price of one Shuttle mission. ($450M/$1.5M)=300
The President has very little to do with NASA. He can say whatever he wants. If Congress doesn't give the money to NASA to support his plans and ideas then what the President wants is ignored.
1. Losing astronauts and spacecraft look bad. NASA is funded by Congress and citizens. Bad publicity could mean that the NASA budget gets cut.
2. NASA loves SpaceX. There is little competition between the two. The fact that SpaceX can achieve what needs to be done for NASA for a much lower price is a huge win for NASA.
Congress controls NASA. Long ago the precedent was set that NASA money would be spread around the country. Congresspeople have adjusted that to having the NASA money spent in their districts and states. That has a much larger effect on why the cost of rockets in the USA are crazy high. Why else would rockets and engines be built in Alabama? Is Alabama some huge industrial state with lots of aerospace engineers that those smart individuals would want to live and work there? The Alabama politicians hate SpaceX because SpaceX makes their cash cow look silly. Those same politicians could care less whether the rockets do anything at all. That is the only explanation for SLS, Orion, and Constellation program before those.
Part of the reason the Space Shuttle system is so expensive is because of its original mission requirements to perform Air Force missions, which led to the vehicle design as we know it rather than something simple that can be operated less expensively. Also, the shuttle orbiter is huge compared to any other orbiting vehicle we have. I didn't realize how big that vehicle is until I stood next to the full mock up in the training facility in JSC. We also need to realize the vehicle was design and built in the 1970/80's with brand new TPS technologies, and those require a lot cares to make sure they are flight worthy for each flight. In hindsight, NASA likely could have gotten away with a simpler and cheaper system for majority of its missions, but we also would likely not have Hubble Telescope right now if we didn't have shuttle.
e-FTW
New electron smell
A lot (a LOT) of good info here. Great write up by Chris G: SpaceX makes progress toward Commercial Crew debut – NASASpaceFlight.com
Nikxice
Active Member
The promised followup story on Boeing's Starliner by Chris G. has been published.
Starliner gets potential mission duration increase for Crew Flight Test – NASASpaceFlight.com
It's also a good read. I was looking for hints as to whether Boeing or SpaceX will be the first to launch a commercial crew. Both companies are planning their first uncrewed orbital tests for this August. SpaceX will also be doing a voluntary in-flight abort test, while Boeing is only doing a pad abort test, which evidently still certifies and validates that a Starliner can pull away from an Atlas V during any stage of flight. Boeing and SpaceX are also looking at November and December respectively for their first crewed missions, but both are likely to slip into 2019.
My impression is that currently this race is a dead heat. Boeing might be slightly ahead with their development of a crew simulator, but this advantage might be offset by the need to prepare the first crewed Starliner for a potential long duration mission. Also, looking forward to finding out the crew assignments. The article mentions a "summer timeframe" and this news will likely make for some healthy competition among astronauts vying to be the first to fly for the company they represent.
e-FTW
New electron smell
For Boeing to do it would cost them a first and second stage. SpaceX can do for only the cost of a launch and second stage. I supposed they could even use a simulated second stage. Or they have a older scratch and dent unit they need to dispose of anyway...
Another way for SpaceX to demonstrate superior capability.
SpaceX has two Block 4 boosters without a payload named. I'm hoping they use one for the In Flight Abort and one for an extra heavy GTO satellite launch. The stress from the abort mid-flight could easily cause the loss of whatever booster they use. So using a booster they have no intention of recovering anyway would make the most sense. It could easily be this TESS booster launching Monday.
Wow, good point! The unshielded second stage is going to be even less aerodynamic than Watney's tarp based ascent vehicle. And at the worst possible time. Flight proven block 4 would be the way to go.
Will make for some great footage.
Good point, and one that went unmentioned in that article. Really quite embarrassing for Boeing. I think NASA is cutting them a lot of slack on that test, letting them do it without leaving the ground. But according to the article NASA does not specifically require a true in-flight abort test.
Quote: “While technically just a pad abort test, the certification objective will also validate Starliner’s ability to free itself from the Atlas V at any stage during flight should an abort be needed. However, Boeing will not perform an in-flight abort test as one was not mandated by NASA as part of the Commercial Crew Program.”
How exactly does a pad abort test “validate” that the capability will function properly “at any stage during flight”? That sounds like BS to me. I think NASA just says that because to do a real in-flight abort test is extremely expensive since the entire rocket is thrown away.
By doing the abort test during ascent SpaceX is really going above and beyond NASA’s requirements. I sure how that SpaceX can pull off a successful abort test during Max-Q! That sounds very challenging.
Excellent analysis!
That made me actually LOL.
"...Coming up to T+90 seconds, the point where the vessel reaches maximum Tarp Flap...."
That is not unprecedented, for interesting reads check out the Shuttle RTLS contingency plan, and the astronauts' thoughts on it.
Well, if you mock up the capsule attachment system, then show that the capsule's acceleration from the test maps to an acceleration higher than the first stage acceleration with adjustment for the increased drag produced by the rocket's speed through the atmosphere at all points in the flight profile.... then it demonstrates it.
or you could ... you know... go Nike
...and just do it.
Really, how do you test that engines light and you guidance system maneuvers properly when started trans-sonic? And can you imagine if it didn't work? Now you have a known problem and you need to trash a rocket everytime you want to test a fix. How many successes does it take to cancel the failure?
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