NASA Prepares for Flight Tests of Ares 1

NASA is beginning detailed planning for the first round of flight tests for the Ares I Crew Launch Vehicle (CLV), with documentation – acquired by this site – showing the full outlines of the test flight objectives.

The first flight, Ares I-1, will be a suborbital test of the booster with an inert fifth SRB segment and a dummy second stage with steel-filled propellant tanks and mock-up engines.

The test flight, originally called ADFT-0 (Ascent Development Flight Test-0), is currently scheduled to take place in April 2009 at a cost of about $300 million.

The flight will provide a simulation of the performance of the first stage of the Ares I and a test of the staging sequence. The flight is to be suborbital and will test the effect of the maximum dynamic pressure being exerted on the vehicle.

The booster which is slated to make this flight, called the Flight Test Vehicle (FTV), will be integrated at KSC shortly before launch, and will not have the capability to receive commands from the ground while in flight (though telemetry will be returned). The first stage of the vehicle will be recovered and returned after staging.

The only active part of the FTV will be the bottom four SRB segments on the launchers first stage. The fifth segment will be a real SRM, but empty of propellant. NASA refers to this configuration as ‘4-segment XL’. This stage is about 167 feet high and 12 feet across at the SRMs, widening to 18 feet in diameter at the frustum.

The first stage will include the recovery systems that might be present on the actual Ares I first stage. An interstage, frustum, and forward skirts will separate the 4-segment XL stage from the upper stage.

The upper stage simulator (USS) to be carried on this flight. will be completely inert but will have an outer mold line identical to that of the planned Ares I upper stage.

A decision has been made to replace originally planned water ballast on this stage with 20,000 lbs of steel ballast. However, it will still be the ‘Tuna Can’ design, allowing worker access into the upper stage during stacking, and whilst on the launch pad.

A simulator for the CEV and launch abort system (LAS) will also be carried on this flight, again with an identical outer mold line, and very similar mass, volume and center of gravity to the real vehicle. This boilerplate CEV and LAS will not be recovered.

The second stage will separate from the first near the flights apogee and will provide a simulation of the performance of the interstage. The entire time of powered flight for the vehicle will last for just over two minutes.

The flight will be launched from Launch Complex 39B at KSC and will also include a test of the vehicles RCS.

The CEV physical model is comprised of the following: mass and volume simulators of a Crew Module (CM), a Service Module (SM), a Spacecraft Adapter (SA) for mounting to the USS; and attachment mechanisms between the CM, SM, and SA. The combination CEV/LAS will have the same OML, weight, and CG as that of the actual CEV/LAS.

The flight vehicle will be shipped to KSC in segments, where it will be assembled. The Vehicle Assembly Building (VAB) will be used to stack the system prior to transporting it to launch complex 39B. Integration at KSC also includes installation, checkout ,and servicing of the Reaction Control System (RCS) and the avionics. Some segments of the vehicle have already been fabricated.

There are five primary objectives for this test flight. They encompass flight control, First Stage-USS separation, First Stage re-entry, launch processing, and First Stage roll torque. The success of this flight test will be determined by the degree these objectives are met.

Prototype CLV parachutes should be used to accomplish primary objective. These parachutes are already undergoing testing at the US Army range in Arizona. Tests have so far been successful.

Updated information points to the possibility that the LAS will indeed by tested – pending Lockheed Martin being able to support the test launch date. The dummy Orion on top of Ares I-1 won’t be recovered, with the test simulating a failed upper stage engine start – evaluating how the LAS performs in a live test.

Some of the biggest challenges for the vehicle will be on lift-off, with data showing how the TVC (Thrust Vector Control) handles the rise off the launch pad, plus the ride through Max Q, which some sources note concern over the structural integrity of the intertank section of the ‘stick’.

However, given the nature of the Ares I-1 vehicle, most of the systems that will undergo testing will be below the upper stage. Up to four test flights will be carried out in total, before the targeted 2014 debut manned mission.