LIVE BLOGGING: AIAA SPACE 2008 ARES I-X session

The "XL" dummy 'fifth' segment includes avionics

its one big massive laboratory we're flying

launch out of 39B

2min into flight have separartion,m srbburn out and separate

whole mission takes 4min, burn 2min

LAS hardware being built right now at Langley Research Center

For LAS, I would expect sometimin nOvemebr arriev at Cape, assesing them now, fine tuning of dates, it will not drive the launch date

will have LOX tank ballast and have to be careful due to crane limitatons at KSC so some ballast will be added during stacking

35,000lb of ballast at top of upper stage siulator
15,000lb at bottom of upper stage simulator

The entire interior structure of the upper stage is fitted out with ladders etc to access vehicle at various levels for sensors and fittings are permanent, they have been factored into the vibration analysis of the vehicle - and can sign their names in it

This is necessary as the Shuttle launch pad is not tall enough for the Ares I-X vehicle

$12 million saved by using RCS from a Peacekeeper missile, only cost was shipping

Will show cold flow test of RCS in due course

Aft skirt already being worked on

Avionics in 'fifth' segment, dampens out a lot of vibration, includes guidance and control and ground command control comms

instrumented for 924 measurements, thermal, structures, etc

cameras strategically located, data fmor telemetry and data recorder box in first stage

Hardware arrives in November, RCS, LAS upper stage

start stackng some upper stage elements soon after

early spring stakciong actual vehicle

only out at the pad for four or five days

CM/LAS and upper stage segments stored in high bay four

at the pad, extended ligtning mast

rolled out only with pins to hold it to the gruond, one final check in wind tunnel

so far everything looks good and looking at fatigue analysis and pivot points within vehicle

we are putting in some strain gauges at top of dome of first stage to validate the science to understand thurst oscillation

we recenty did a test on first stage being this old (five years old) and done a analysis and it was fine

1030h

Steve Derry
Langley Research Center
stability and control flight test, analysis and plans

slenderness ratio and significnt aerodynamic instability of concern

elastic structure: bending mode less than 1Hz at launch
- ensure adequate strutural damping
- avoid avderse flight control-structural interaction
- correct placement of sensors for effective control

Will place sensors along stack length to measure bending modes

CM sees +/-2g bending mode due to acceleration

have ballast for thrust to weight ratio accurately reflected at lift off but the thrust, weight ratio can't be altered later

very good match up to M4
separation velocity low compared to Ares I
separation dynamic pressure is high compared to Ares I

RRGU instruments at top of upper stage
FTINU toward lower end of upper stage

if we add extra manouveres we cover much more of the dynamic conditions
will add pre-programmed inputs into TVC to minimise impact of loads and trajectory

frequency sweps done on pitch and yaw axes, to get data on flight vcontrol system reposne and aerodynamics
will have brief tvc pulse late in fligt to get strutural reposne
will disable RCS for 1s every 10s

38-44s pitch and yaw frequency sweeps on TVC during transonic
48-58s pitch and yaw frequency sweeps on TVC during maxq

flying with the manouveres takes some energy out of the trajectory "but very little"

substantial deflection on LAS/CM from about 80s

will have tumble motion to reduce the energy for descent for recovery

1100h

Paul Bartolotta

integrated design and analysis for Ares I-X

CG extremely important for potential amount of roll that could be seen

this is the first time we have ever simulated the roll out of a fully fuelled vehicle, neither Saturn V or Shuttle rolled out fuelled

CM/LAS mass 18,000lb on Ares I-X

44,000lb upper stage simulator mass

doing fundamental checks with model, because it controls flight control, joint stiffness between segments and mass distribution is very important to flight

coupled load analysis
induced turbulence and shocks due to atmosphere
static-aerolastic (wind only) due to relative wind and local angle of attack

we do lots of monte carlo analysis, including ignition overpressure, wind and wind induced oscillation

looking for forcing functions; gust, change in local aoa due to bending and airloads; thrust oscillation; roll control system;buffet

Frustrum is the place we're most concerned about in the modal sense, its a plastic hinge

Had to find right shade of white paint to help with thermal issues

5% of components will require waivers for shock environments and 10% of components will require waivers for vibroacoustics

Sonic boom map for Ares I-X is very similar to Shuttle

1% scale separation test , completed 550 wind tunnel runs